JPH10319342A - Eye ball projection type video display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light video display device capable of reproducing a high definition video by projecting a resolution video on the retina without being eclipsed. SOLUTION: Relating to an eye ball projection type video display device provided with a video display device 3 containing two-dimensionally arranged pixels and an observation optical system 1 containing a microlens array 2 having an action adding positive power to luminous flux emitted from respective pixels of the video display device 3, the microlens array 2 is provided with the action increasing the resolution of the pixels and leading to an observer eye ball E, and is provided with a movable part 6 moving the microlens array 2 or the video display device 3 so that an exit pupil formed by the observation optical system 1 answering to the movement of the pupil follows so as to be made the luminous flux outgoing from the observation optical system 1 incident on the observer pupil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eyeball projection type image display device, and more particularly, to an image display device using a short focal length optical element for forming an image of one pixel of an image display means on a retina of an observer. By tracking the exit pupil of the optical system in the apparatus to the position of the observer's pupil and allowing the luminous flux containing image information to always pass through the pupil, a thin, high-resolution eyeball projection type that enables good image observation The present invention relates to a video display device.

[0002]

2. Description of the Related Art Recently, in the field of virtual reality, an image is projected on a retina of an eyeball by projecting a virtual image of a small display also located in front of the observer's eye by an optical system arranged in front of the observer's eye. Head-mounted display device (HMD: Head Mo)
unted Display. Hereinafter, it is called an HMD. )
Has been proposed. In this type of device, a user wears such a display device on his / her head,
It is expected to be used for various purposes such as enjoying a large screen video, image, and sound of a TR or the like by one person.

On the other hand, in order to present a high-quality image, a retinal direct display device has been proposed in which an image can be observed by deflecting visible light or a beam in the infrared region where output is weak and scanning directly on the retina. Have been.

JP-A-5-328261, JP-A-6-433
No. 91, 7-31361, 8-213125
No. 7,135,623, and 8-205052 are techniques for displaying an image by any of the above-described methods. Hereinafter, these conventional techniques will be individually described.

JP-A-5-328261, JP-A-6-4
No. 3391 is a method of projecting a virtual image of a video display element onto the retina via an observation optical system, but since the observation optical system includes a microlens array corresponding to the pixels of the display element, High resolution is achieved by the conjugate relationship between the retina and each pixel of the display element, and thinning is achieved by the short focal length of the microlens array.

However, in this technique, the size of the exit pupil of this optical system is very small, about the diameter of each minute lens of the lens array. Therefore, when observing an image, the luminous flux is vignetted by the observer's eyeball. A state in which image observation becomes impossible occurs.

The present invention, as will be described later, discloses a configuration for improving vignetting in the observer's eyeball caused by a small exit pupil diameter, and is basically an improvement of the prior art.

Japanese Unexamined Patent Publication No. Hei 7-31361 discloses a technique for detecting a shift in the positional relationship between an apparatus and an eyeball and performing mechanically optimal position adjustment. This technique does not use an optical element with a very short focal length, such as the above-mentioned microlens array, in the observation optical system, so the distance from the image display element to the eyeball-side final surface of the observation optical system is the above-mentioned microlens. Greater than with arrays. Therefore, the mechanical movable range required for the adjustment increases. For this reason, the stroke amount of the actuator or the minute motor for realizing the mechanical movability is increased, and the size of the entire apparatus is increased.

In addition, a technique is described in which an illumination light source is used as a point light source for miniaturization, and the point light source is moved by a small actuator or the like so that the point light source is located at a position conjugate with the eyeball. Has the following technical difficulties.
In the point light source illumination configuration, the image display element is not in a conjugate relationship with the retina, so in order to obtain a high-definition image, it is necessary to reduce the diameter of the pinhole formed on the pupil when considering geometrically. Must. However, if this is made too small, the blur due to the diffraction effect of light becomes large, and as a result, a high-definition image cannot be obtained with point light source illumination.

The illumination by the point light source is N
Since A (numerical aperture) is extremely small, the luminous flux forming a virtual image reproduced on the retina has an extremely deep depth of focus. The human pupil is composed of countless fibrous bodies, but is not perfect, and some fibrous bodies have missing parts. For this reason, if the depth of focus of the light beam is deep, this lack of the pupil is also projected on the retina, and the resolution of the image is reduced. As described above, it is desirable to achieve both miniaturization and high resolution, but this conventional example does not take this into account.

Japanese Unexamined Patent Publication No. Hei 8-213325 discloses a method in which a plurality of point light source arrays are arranged as illumination light sources in order to prevent vignetting of a light beam due to movement or movement of an eyeball, and the array is conjugate with a detected pupil position. This is a technology that is supported by selectively lighting only a point light source corresponding to a position. According to this conventional example, the mechanical movement is not required, and the movement of the eyeball can be followed only by switching the point light source. Therefore, there is an advantage that the configuration is simple and the response is fast.

However, as described above, there is a problem of the resolution in the point light source illumination, and the consideration is lacking. Furthermore, since no short-focus optical element is used in the optical system,
The distance to the eyeball-side final surface of the observation optical system is large.

JP-A-7-135623, JP-A-8-2
05052 is a technology that makes it possible to observe a high-resolution image by deflecting just before the observer's eyeball and scanning directly on the retina using visible light or a beam in the infrared region with weak output. is there. In this conventional example, since a laser or a beam having a high directivity similar to the laser is used, the generator is expensive, and it is easy to increase the size and complexity. There are also concerns about the effects on the eyes.

[0014]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to project a high-resolution image onto the retina without vignetting. It is an object of the present invention to provide an image display device capable of reproducing a fine image in a form in which the weight is reduced. It should be noted that the video display device in the present invention is not particularly limited, and means all known applicable devices.

[0015]

According to the present invention, there is provided an eyeball projection type image display apparatus for achieving the above object, comprising: an image display means including two-dimensionally arranged pixels for displaying an image; An observation optical system including an optical member having a two-dimensionally arrayed micro optical element having a function of adding a positive power to a light beam emitted from each pixel of the eyeball projection type image display apparatus. The member has an effect of increasing the resolution of the pixel and guiding it to the observer's eyeball,
An exit pupil formed by the observation optical system is configured to move in accordance with the movement of the pupil so that a light beam emitted from the observation optical system can be made to enter an observer pupil. Is what you do.

According to another aspect of the present invention, there is provided an eyeball projection type image display device, comprising: an image display means including pixels arranged two-dimensionally for displaying an image; and two pixels corresponding to each pixel of the image display means. An observation optical system that is arranged in a three-dimensional manner and includes a micro optical element that guides an emitted light beam from each pixel of the image display unit to an observer's eyeball, a pupil position detection unit that detects an observer pupil position, and the observation optical system And an exit pupil position moving means for changing the position of the exit pupil. In these, the image display means can be of a self-luminous type.

Still another aspect of the present invention is a transmissive image display device having two-dimensionally arranged pixels for displaying an image, and an illumination for illuminating the transmissive image display device. Means, an observation optical system including a micro optical element for guiding an emitted light beam from each pixel of the transmission type image display means to an observer's eyeball, a pupil position detection means for detecting an observer pupil position, and An exit pupil position moving means for changing the position of the exit pupil.

In the present invention, since the observation optical system has the micro optical element having a short focus, the size of the eyeball projection type image display device can be reduced, and in addition, each pixel of the image display means and the viewer's By providing a conjugate relationship between the retina, a high-definition image can be provided.Furthermore, by detecting the pupil position of the observer and tracking the exit pupil of the observation optical system at the pupil position, this high-definition image is obtained. Images can be observed without vignetting. In addition, if a self-luminous type is used as the image display means, no illuminating means is required, so that the configuration is simplified.

Further, when the transmissive image display means is used, the NA can be controlled on the illuminating means side, so that light enters a small optical element other than a regular small optical element which also causes a deterioration in resolution. This can prevent a phenomenon called so-called crosstalk, which causes ghosts and flares.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an eyeball projection type image display device according to the present invention will be described based on several embodiments. Embodiment 1 Embodiment 1 of the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of the first embodiment. The configuration includes, in order from the right side of the figure, an eyeball E of an observer including a pupil, a crystalline lens, a retina, and the like, a field lens 1, a microlens array 2 behind the eyeball E, A self-luminous display device 3 such as an LED array, for example, is arranged as image display means for displaying an image behind, and a pupil position detector 4 for detecting the position of the pupil of the observer, based on the detection result. The arithmetic and control unit 5 for calculating and controlling the amount of movement of the microlens array 2 by driving the microlens array 2 on a plane perpendicular to the optical axis (hereinafter referred to as moving the microlens array 2 on two axes). A part 6 is provided. Eyeball E
Are arranged such that the pupil is located at a position substantially away from the focal point of the field lens 1.

The pupil position detection unit 4 captures and captures the vicinity of the pupil position of the observer with a charge-coupled device such as a CCD, and performs image processing or the like to determine the pupil position. The scleral reflection method that focuses on the difference in the rate, the corneal reflection image called the Purkinje image and the reflection image of the fundus, or the method of determining the gaze direction from the position of the edge of the glow, There are methods to use, etc., but the most appropriate method is used according to the situation.

In this embodiment, the observation optical system is formed by the field lens 1 and the microlens array 2. However, the display field angle may be changed by disposing an eyepiece immediately before the eyeball E. Since the eye relief becomes shorter, it may be incorporated if necessary.

The field lens 1 may be constituted by an aspherical lens or the like since the peripheral aberration and the like become remarkable when the display angle of view is increased. FIG. 2 shows FIG.
1 shows a state in which a small glasses-type HMD 10 enabled by incorporating the device having the configuration according to the present invention shown in FIG.

Next, referring to the block diagram of FIG.
The operation principle when the device having the schematic configuration described above is built in the HMD 10 will be described. A video display unit 3 which is a display device such as an LED array in response to a video signal from a video control unit 7 comprising a circuit group such as a display device driving circuit and an image generation circuit (not shown) for outputting and displaying a video on the video display device 3. To display the video. At this time, the pupil position of the observer is C
Pupil position detector 4 for detecting by an area sensor such as a CD
The pupil position of the optical system that projects an image as shown in FIG. 1 onto the eyeball of the observer is moved to the pupil position according to the movement of the pupil of the observer based on the pupil position information detected by For this purpose, the microlens array 2 is shifted by the microlens array movable section 6. The movable amount of the microlens array 2 is calculated and controlled by the movable amount calculation and control unit 5. In the case of a display system form called an HMD, as shown in FIG. 3, a video control unit 7, a movable amount calculation and control unit 5, and a power source (not shown) are built in the controller 11, and the video display unit 3, The line-of-sight detection unit 4 and the microlens array movable unit 6 are built in the HMD 10.

Next, the principle of moving the exit pupil of the observation optical system by moving the microlens array 2 will be described. In FIG. 4, the distance between each pixel 13 of the video display device 3 and the main plane of each lens of the micro lens array 2 is a, and the distance from the object side main plane of the micro lens array 2 to the main plane of the field lens 1 is b. Hereinafter, in the present invention, the principal planes of the micro lens array 2 and the field lens 1 are assumed to be substantially equal on the object side and the image side, and are simply referred to as principal planes. In FIG. 4, the image display device 3 illustrates only the pixels 13 for convenience. Focal length of the microlens array 2, the focal length of the field lens 1 respectively f _m, if the f _o, from imaging relationship, and ^{_{a = f m -f m 2 /}} (f o + f m -b). Here, if b ≒ 0, because it is f _m «f _o, the above equation becomes ^{_{a = f m -f m 2 /}} (f o + f m) ≒ f m. Here, in FIG. 4, when the microlens array 2 is shifted S in the left direction in the figure (the moved microlens 2 is indicated by a dotted line), the moving amount of the exit pupil of this optical system is denoted by D. if, because the shaded triangle OPQ and triangle O'P'Q 'have the relationship of similarity, the relationship _{S = aD / f o ≒ f} m D / f o is derived. Thus, since the relationship between the moving amount of the exit pupil and the shift amount of the microlens array 2 will approximately equal relation to the ratio between the focal length f _m of the focal point of the field lens 1 distance f _o and the microlens array 2, both Is large, the exit pupil position can be largely moved even if the shift amount of the microlens array 2 is small.

Here, assuming that the distance between the principal point on the eye side of the observation optical system including the micro optical element and the exit pupil is R, and the variation of the inclination of the principal ray exiting the observation optical system is Δ, the exit pupil shift Quantity D
Is, D = RΔ ··· (1) Further, if the variation of the principal ray inclination at the time of injecting the microlens array 2 and delta ', the movement amount S of the microlens array 2, S = f _m Δ '··· (2) ∴Δ' = a S / f _m.

The ray tilt angle can be generally expressed by the following equation, where h is the image height. 'Here _{= θ-h / f o,} θ is the incident angle of the principal rays entering at a height h to a lens of focal length f _o, θ' θ is the exit angle.

When the tilt angle of the chief ray incident on the field lens 1 from the microlens array 2 changes from θ ₁ to θ ₂ , the tilt angle of the chief ray emerging from the field lens 1 becomes θ ₁ ′.
To θ ₂ ′, thereby increasing the image height from h ₁ to h ₂
If the changes to a _{θ 1 '= θ 1 -h 1} / f o θ 2' = θ 2 -h 2 / f o.

Δ ′ = θ ₂ ′ −θ ₁ ′, Δ = θ ₂ −θ ₁ ,
Also, the change amount h ₂ −h of the image height h due to the change of the chief ray inclination angle.
If the ₁ and xi], taking the difference between the two equations, equation of Δ'-Δ = ξ / f _o is derived. Here, since the principal point on the object side of the microlens array 2 and the subsequent principal point on the eye side of the field lens 1 are approximately close to each other, ξ≪f _o and Δ ′ = Δ. ) And (2), the following relational expression is derived.

[0030] D / S = R / f _m above is a method of moving the exit pupil of the optical system by moving the microlens array 2, the microlens array 2 without moving, illustrated in FIG. 5 like,
The exit pupil can be moved even when the image display device 3 is moved. Note that in FIG. 5 as well, the image display device only illustrates the pixels 13 for convenience.

FIG. 5 shows how the exit pupil of the optical system moves by moving the image display device. The distance between each pixel 13 of the video display device and the main plane of each lens of the micro lens array 2 is defined as a, and the distance from the main plane of the micro lens array 2 to the main plane of the field lens 1 is defined as b.

[0032] Also in this case, the focal length of the microlens array 2, if the focal length of the field lens 1 f _m, respectively, and _{f o, a = f m -f} m 2 / (f o + f m) ≒ f _The relationship _m holds, and in FIG. 5, when each pixel 13 is shifted S in the right direction in the drawing (each pixel 13 after the movement is hatched), the movement amount of the exit pupil of this optical system is If D, triangle OPQ and triangle O'P'Q '
There the relation that similar relationship _{S = aD / f o ≒ f} m D / f o is derived.

Next, each lens of the micro lens array 2 corresponds to each pixel 13 of the video display device 3,
The pitch of the microlenses 2, that is, the pixel pitch of the video display device 3 will be described. Each pixel 13
When the light emitted from the microlens array 2 reaches the microlens array 2, if the pitch is small, a so-called crosstalk phenomenon in which the light enters a lens other than one regular microlens corresponding to one pixel 13 easily occurs. Become. This depends on the distribution of light emitted from each pixel 13 of the image display device 3. However, since the distribution of light emitted from the image display device 3 is usually sufficiently larger than the NA (numerical aperture) of each microlens, crosstalk always occurs. It is thought that there is. At this time, the crosstalked light is unnecessary light that degrades a normal image.
That is, it causes ghost and flare. for that reason,
In order to obtain a good image display state, it is necessary to configure the optical system so that a light beam due to crosstalk does not enter the eyes E of the observer.

As shown in FIG. 6, light (hereinafter referred to as first-order crosstalk light) entering a lens adjacent to a corresponding normal microlens from a certain pixel 13 is applied to each pixel 13.
, The light beams also form a pupil next to the regular exit pupil. If the distance from the regular pupil to the pupil by this primary crosstalk light is sufficiently large compared to the pupil diameter,
Since not only the pupil due to the second-order or higher crosstalk light generated by entering the lens adjacent to the adjacent lens but also the crosstalk light flux which is unnecessary light does not enter the eyes, good observation can be performed. Now, as shown in FIG. 7, a half angle of view of the display angle of view is θ, a distance from the center of rotation of the eyeball E to the pupil is e, Assuming that the distance to the center of the pupil when watching, that is, the maximum pupil movement distance is D, D = e · sin θ. As shown in FIG. 8, assuming that the angle at which the primary crosstalk occurs is θ _c and the pitch of the microlens array 2 is p, the exit pupil position d due to the primary crosstalk is indicated by oblique lines. Triangle OST and triangle O'S '
T 'is because it is substantially similar relationship is _{d = f o p / a ≒} f o p / f m. If this d is larger than the pupil maximum movement distance D,
Crosstalk light, which is unnecessary light, does not enter the eyes of the observer.
Therefore, such a limiting condition of the pitch is given by the following equation.

[0035] _{p> aD / f o ≒ f} m e · sinθ / f o Also, when to track the exit pupil in the pupil by moving the microlens array 2 or the display device 3 as described above, it is noted is there. That is, when the microlens array 2 or the display device 3 is moved, the displayed image is shifted. FIG. 9A shows a state before the microlens array 2 or the display device 3 is moved. The left side shows the state of the light beam entering the eyeball E, and the right side picture is projected on the retina at that time, that is, a recognizable display image. When the user moves his / her line of sight to look in the direction indicated by Y from the center of the screen indicated by X in this image, the microlens array 2 or the display device 3 is moved accordingly, and the exit pupil is shifted to track the pupil. At this time, the state of the light beam incident on the eyeball E and the state of the display image are as shown in FIG. 9B, and the image on the retina moves. That is, it slightly deviates from the direction of the point to be viewed.

In order to avoid this inconvenience, a shift of the display image accompanying the movement of the microlens array 2 or the display device 3 may be anticipated, and the shift may be made to the opposite side on the image side to be displayed so as to correct the shift.

Regardless of whether the display device 3 is moved or the microlens array 2 is moved, the relationship between the shift amount and the movement amount of the exit pupil due to the shift amount is approximately as follows.

[0038] Here _{S ≒ f m D / f o} , In any case, FIG. 4, 'apex angle ∠P'O'Q in' triangular O'P'Q in FIG 5 are equal, the angle δ If so, the shift amount of the displayed image is this δ minute. Therefore, it is only necessary to display an image shifted in the reverse direction by an amount corresponding to this angle for correction. Here, δ = tan ⁻¹ (D / f _o ) = tan ⁻¹ (S / f _m ). If only the horizontal direction is mentioned, assuming that the pixel 13 is in the direction of Θ from the center in the direct viewing state, the following relationship is established if the number of pixels from the center of the device 3 to the direction is N / 2.

[0039] N = however _{(2f o tanΘ / P m)} , the pitch of the display device 3 (microlens array 2) and P _m.

[0040] Thus, only the _{N d = (2f o tanδ /} P m) number of pixels N _d equivalent to, if a shift in the opposite side of the display image in real time towards video control means (not shown), without image shift , You can see the image of the viewing direction itself.

Hereinafter, an example using actual numerical values will be described. FIG.
In the display optical system as shown in FIG. 2, the element size of the image display device 3 such as an LED array is 30 mm × 22.
The element lenses of the microlens array 2 having a focal length of 1 mm are arranged at the same pitch and the same arrangement as the pixel pitch of the display device 3. Immediately on the observer side is a field lens 1 with a focal length of 30 mm, and the eye relief up to the exit pupil is 30 mm. In this display system, the horizontal angle of view is about 53 °. Pixel pitch,
The lens pitch is set to 150 μm. Incidentally, if the distance from the center of rotation of the eyeball to the pupil is 9 mm under the condition that the pupil due to the crosstalk light does not enter the eye E, the lens pitch becomes 134 μm or more. The number of pixels is 200 × 150
Is 30,000.

In this display system, when the pupil moves to the maximum, the horizontal angle on the paper is a half angle of view of ± 26.6 °.
Is 9 × sin 26.6 ° = 4.03 mm. In order to track the movement of the pupil by moving the video display device 3 of this system, the display device 3 is set to a maximum of 134 μm from the relational expression between the pupil movement amount and the device movement amount.
It is only necessary to be able to shift m.

When viewing 10 ° in the horizontal direction, the amount of movement of the pupil is 9 × sin10 ° = 1.56 mm. In order to move the exit pupil by this amount, the image display device 3 may be shifted by 52 μm from the relational expression of the shift amount. At this time, the image shift amount is about 3 degrees in angle. In order to correct this, the image can be observed without unnecessary image shift by shifting the pixel by about 3 pixels in the reverse direction from the above equation.

The size of the display system of this embodiment is as follows. The thickness of the field lens 1 is a condition satisfying the display angle of view and the eye relief. In the case of a glass material having a refractive index of about 1.5, the thickness is about 8 mm. Is 1 mm
In this case, the display system of this embodiment has an extremely thin, wide angle of view, high-definition eyeball in which the thickness in the optical axis direction from the display device 3 to the final surface of the field lens 1 on the observer side is about 13 mm. A projection display can be provided.

[Embodiment 2] FIG. 10 is a schematic structural diagram of Embodiment 2 of the present invention. FIG. 10 shows an example in which there is no field lens in the first embodiment (FIG. 1). The self-luminous display device 3 is also used as the image display means. The display angle of view depends on the focal length of the microlens array 2 and the size of the display device 3. As shown in FIG. 11, the size of the display device 3 is L, the pixel pitch is p _d , and the lens pitch is p.
_m, also, the focal length of the microlens array 2 and f _m, the distance from the microlens array 2 to the exit pupil R
And Image display device 3 and micro lens array 2
By arranging the microlens array 2 separated by the focal length, the luminous flux emitted from each pixel 13 becomes a parallel luminous flux and can be guided to the eye E. Since the number of pixels on the paper surface, that is, the number of pixels in the horizontal direction of the display device 3 corresponds to each minute lens, it is equal to the number of minute lenses. If the display half angle and theta, 11, from the geometrical _{relationship, Np d / Np m = (} R + f m) / R ∴p m = Rp d / (R + f m) However, R + f _m = L / (2 tan θ).

Next, the principle of moving the exit pupil of the observation optical system by moving the display device 3 will be described. In FIG. 12, each pixel 13 of the video display device 3
And the distance between the main plane of each lens of the microlens array 2 and the focal length f _m of the microlens array 2. For convenience, the image display device 3 shows only the pixels 13.

Here, in FIG. 12, when the pixel (display device) 13 is shifted S in the right direction in the figure (each pixel 13 after the movement is hatched), the exit pupil of this optical system is changed. If the moving amount is D, the triangle OPQ and the triangle O
Since P'Q 'have the relationship of _{similarity, S = f m D / R} = 2f m Dtanθ / (L-2f m ta
nθ) is derived.

Here, in the relational expressions (1) and (2) described in the first embodiment, when the observation optical system is composed of only the microlens array 2, Δ = Δ ′. R / f _m is derived. This satisfies the above equation.

The above is a method of moving the exit pupil of the optical system by moving the display device 3, but without moving the display device 3, the micro lens array 2 is moved as shown in FIG. However, the exit pupil can be moved.

FIG. 14 shows how the exit pupil of the optical system is moved by moving the microlens array 2. The distance between the main plane of the lens of each pixel 13 and the microlens array 2 of the image display device 3 and the focal length f _m of the microlens array 2. For convenience, the image display device 3 shows only the pixels 13. Also in this case, when the microlens array 2 is shifted S to the left in the drawing (the moved microlens array is drawn by a dotted line), the movement amount of the exit pupil of this optical system is D. , from the geometrical _{relationship, S = f m D / (} R + D) = 2f m Dtanθ / L the relationship is derived. However, it is R»f _m.

Next, the pitch of the microlens array 2 and the pixel pitch of the video display device 3 mentioned in the first embodiment will be described. Also in this embodiment, since it is considered that crosstalk always occurs, it is necessary to make the pitch configuration such that the light beam due to the crosstalk does not enter the eyes of the observer in order to obtain a good image display state.

As shown in FIG. 15, this 1
If the distance to the pupil by the next crosstalk light is sufficiently large compared to the pupil diameter, the crosstalk light flux, which is unnecessary light, does not enter the eyes, so that a favorable observation state can be provided. As shown in FIG. 7, the half angle of view of the display angle of view is θ, the distance from the center of rotation of the eyeball E to the pupil is e, and the observer looks at the center from the center of the pupil when viewing the outermost periphery of the image. Assuming that the distance to the center of the pupil when the pupil is present, that is, the maximum pupil movement distance, is D, then D = e · sin θ. As shown in FIG. 15, the angle at which the first-order crosstalk occurs and theta _c, if the pitch of the microlens array 2 and p _m, the exit pupil position d by the primary crosstalk, geometric relationships more, if _{tanθ c = d / R = p} m / f m the d is greater than the pupil maximum movement distance D, the crosstalk light is unnecessary light does not enter the eyes of the observer. Therefore, such a limiting condition of the pitch is given by the following equation. The size of the display device 3 is L.

P _m > f _m D / R R + f _m = L / (2 tan θ) ∴p _m > 2 ef _m sin θ tan θ / (L−2 f _m ta
nθ) With such a pitch configuration, a crosstalk light beam, which is unnecessary light, does not enter the eyes, so that a favorable observation state can be provided.

An example of a display device using a monochrome EL (electroluminescent) display will be shown by giving actual numerical values. Since the EL display is an all-solid display, it is a self-luminous display that is highly suitable for use such as an HMD because it is resistant to vibration, has low power consumption, is thin, and is lightweight.

The pupil position detector 4 for detecting the position of the pupil of the observer uses, for example, the scleral reflection method. The scleral reflection method
The direction of the line of sight is obtained by irradiating the observer's eyeball E with infrared light, receiving the reflected light by a light receiving element, and converting the intensity of the reflected light into current to reflect the difference between the black eye and white eye reflectance. Is a method for detecting In order to detect the signal of the iris part by using an infrared light emitting diode etc. as a light source and sensing with an area sensor such as a CCD as a light receiving element,
A combination of a low-pass filter, a binarization circuit, a gain circuit, and the like is used. An advantage is that the configuration is simple.

The eye relief up to the observer's pupil is about 30 m
If m, the horizontal display angle of view is about 30 °. The element size is 16 mm × 12 mm, and the pixel pitch (2 μm for both the horizontal and vertical directions) of the display device 3 is approximately the same (2 μm).
9.7 μm), and the element lenses are arranged in the microlens array 2 having the same arrangement and a focal length of 0.3 mm. Incidentally, the limit condition of the pitch at which the pupil cannot enter the eyes due to the crosstalk light is 23 μm or more if the distance from the center of rotation of the observer's eyeball to the pupil is 9 mm. The micro lens array 2 is arranged at a focal distance of 0.3 mm from the display device 3. The number of pixels is 533 × 400 and the total number of pixels is 21
3,200, which makes it possible to present a very high-definition monochrome image.

In this display system, when the pupil moves at the maximum, the angle of view which is a half angle of view in the horizontal direction on the paper (FIG. 12) is ±.
When looking at 15 °, 9 × sin15 ° = 2.33 mm
It is. In order to track the movement of the pupil by moving the microlens array 2 of this system, the microlens array 2 may be shifted up to 97 μm from the relational expression of the pupil movement amount and the movable amount of the microlens array 2.

FIG. 16 shows the range in which the pupil moves when viewing an image having a horizontal angle of view of 30 ° with an aspect ratio of 4: 3. The hatched circle is the pupil. In FIG. 16, the center circle is the pupil when viewing the center of the screen, and the upper right, lower right, upper left, and lower left circles represent the upper right, lower right, upper left, and lower left, respectively, of the video screen. Shows the pupil position when the pupil is turned on. If the exit pupil can be shifted to nine small circle positions shown in the figure according to the position of the pupil within the pupil movement range, the image can be observed without vignetting. A small circle indicates the exit pupil position. Nine places are defined as 0 to 8 as shown in FIG. (Angle in the horizontal direction, angle in the vertical direction), the point 0 is (0
°, 0 °) shows the center position of the pupil when viewing the image,
Points from 1 to 8 below are (-6 °, 4.5 °), (0
°, 9 °), (6 °, 4.5 °), (-9 °, 0 °),
(9 °, 0 °), (−6 °, -4.5 °), (0 °, 9
°) and (6 °, -4.5 °). Depending on the state of the pupil position, the exit pupil is moved to any suitable position from 0 to 8. Assuming that the angle in the horizontal direction is x and the angle in the vertical direction is y, the exit pupil may be moved from the detected pupil position to a position suitable for that position by the control system shown in FIG.

In this case, the means for moving the microlens array 2 may be any as long as it can cover the maximum stroke amount of about 100 μm, and includes a solenoid, a very small step motor having a small torque, a piezoelectric element, and
What is necessary is just to move using an optimal thing according to a situation, such as a combination with an elastic member used as needed. Horizontal,
Since there are three vertical points each, using a precision ball screw for the feed mechanism and a relay type using a digitally controlled servomotor will allow for a highly responsive operation.

When the thickness of the display device 3 is 3 mm and the thickness of the microlens array 2 is 1 mm, the display system of this embodiment has a very thin thickness of about 4 mm in the optical axis direction. The HMD as a device can also be a very thin glasses type.

Third Embodiment A third embodiment of the present invention will be described with reference to FIG. The schematic configuration of this embodiment is shown in FIG.
In order from the right side of the figure, an observer's eyeball E composed of a pupil, a crystalline lens, a retina, and the like, a field lens 1, and an exit pupil side micro lens array (hereinafter, exit pupil side MLA) 2 behind it.
1. A transmissive display device 3 such as an LCD (Liquid Crystal Display) as an image display means for displaying an image behind it, and an illumination-side microlens array (hereinafter, referred to as an LCD) that condenses illumination light on each pixel of the device 3. , Illumination side MLA) 22,
A plate-shaped parallel illumination unit 14 in which a planar light source that supplies parallel illumination light and a unit that limits NA are arranged, and a pupil position detection unit 4 that detects the position of a pupil of an observer, A calculation control unit 5 that calculates and controls the movement amount of the exit pupil side MLA 21 based on the detection result,
There is provided a driving unit 6 for moving the two axes. Eyeball E
Are arranged such that the pupil is located at a position substantially apart from the focal length of the field lens 1.

An image is displayed by control means of the display device 3 (not shown). At this time, the pupil position of the observer is detected based on the pupil position information by the pupil position detector 4 for detecting the pupil position of the observer. By shifting the exit pupil side MLA 21 by the drive unit 6 so that the exit pupil tracks the movement, a favorable observation state can be always provided.

The principle of moving the exit pupil of the observation optical system by moving the exit pupil side MLA 21 is described in the first embodiment.
What has been described in the above can be applied as it is. The distance between the main plane of the lens exit pupil side MLA21 and each pixel of the image display device 3 and the focal length of approximately the exit pupil side MLA21, the focal length of the exit pupil side MLA21, the focal length of the field lens 1 respectively f _m , F _o . Exit pupil side MLA21
When was allowed to S shift, the amount of movement of the exit pupil of the optical system D is _{S ≒ f m D / f o} . Therefore, the relationship between the shift amount of the exit pupil side MLA 21 and the movement amount of the exit pupil is that if the ratio of the focal length between the exit pupil side MLA 21 and the field lens 1 is large,
Even if the shift amount of the LA 12 is small, the position of the exit pupil can be largely moved.

In this embodiment, since the transmission type display device 3 is used, an illumination system is included as a configuration. The lighting system
The light from the parallel illumination unit 14 that supplies the parallel light described above is
In order to obtain a bright image with increased light amount efficiency, the light is condensed on each pixel by the illumination side MLA 22 corresponding to the pixel. At this time, each pixel of the display device 3 and the illumination side MLA
22 has a value equal to the focal length of the illumination side MLA 22.

The above is a method of moving the exit pupil of the optical system by moving the exit pupil side MLA 21. As shown in FIG. 18, the video display device 3 is moved without moving the exit pupil side MLA 21. The exit pupil can be moved.

Here, the description given in the first embodiment can be applied. Each pixel of the image display device 3 and the exit pupil side M
The distance between the main plane of each lens of LA21 and the exit pupil side ML
The focal length of the exit pupil side MLA 21 and the focal length of the field lens 1 are f _m and f _m , respectively.
_o . When the image display device 3 is shifted S,
The moving amount of the exit pupil of the optical system D, the relationship of S ≒ f _m D / f _o is derived.

In the case where the exit pupil side MLA 21 is moved, the illumination system is not particularly moved.
In the case where the display device 3 is moved, the pixel cannot be illuminated if the light-collecting point by the illumination side MLA 22 deviates from the pixel due to the movement of the display device 3,
Since the image becomes dark, it is necessary to move the illumination side MLA 22 in conjunction with the display device 3. That is, the movable unit 6 is configured to move the display device 3 and the illumination-side MLA 22 integrally so that the light-collecting point of the illumination-side MLA 22 always coincides with the pixel of the display device 3.

Next, the exit pupil side MLA 21 and the illumination side MLA
Each lens of the two microlens arrays 22 corresponds to each pixel of the video display device 3, but the pitch of this microlens array, that is, each pixel pitch of the video display device 3, and the microlens arrays 21, 22 Will be described.

As mentioned in the first and second embodiments, as a countermeasure against the crosstalk phenomenon, the MLA 21 on the exit pupil side is used.
, Ie, the pixel pitch, can be dealt with by configuring the pupil by the primary crosstalk light so as not to enter the observer pupil.

In this embodiment, it is the NA of the illumination side MLA 22 that determines the emission light distribution at the pixel. Lighting side MLA
The distance between the main plane of the MLA 22 and each pixel is equal to the focal length of the MLA 22 on the illumination side, but the distance between the main plane of the MLA 21 on the exit pupil side and each pixel is not exactly equal to the focal length of the MLA 21 on the exit pupil side. . However, if the focal length of the field lens 1 is sufficiently longer than the focal length of the exit pupil side MLA 21 and the distance between the exit pupil side MLA 21 and the field lens 1 is sufficiently small, the distance between the exit pupil side MLA 21 and each pixel is substantially equal. It is equal to the focal length of the MLA 21 on the exit pupil side. Therefore, when the illumination side MLA 22 and the exit pupil side MLA 21 have the same specifications, the relative relationship between the display device 3 and the exit pupil side MLA 21 is changed by moving the video display device 3 or the exit pupil side MLA 21 as shown in FIG. Thus, the amount of light that forms the normal exit pupil in the light emitted from the pixel 13 is reduced. The NA of the illumination side MLA 22 is set to be larger than the NA of the exit pupil side MLA 21 in order to prevent the light amount from dropping when the exit pupil side MLA 21 or the display device 3 is moved to track the pupil. At this time, since the lens pitches of the two are equal, a material having a high refractive index is used, the R (curvature radius) of the lens is changed, a refractive index distribution type is used, and the NA of the illumination side MLA 22 is changed.
20 is larger than the NA of the exit pupil side MLA 21, and as shown in FIG. 20, the crosstalk light enters the pupil in a state where about 1.5 to two microlenses of the exit pupil side MLA 21 are irradiated. It is desirable not to do so.

As described above, the exit pupil can be tracked at the observer's pupil position even with the transmission type image display device 3, but the NA of the illumination side MLA22 is made larger than the NA of the exit pupil side MLA21. By setting the pitch so that the pupil due to the primary crosstalk light does not enter the observer's pupil, a good image can be displayed.

An example of an HMD using an LCD will be described. LCD
Is a mainstay of flat panel displays because it is relatively inexpensive, has low power consumption, is thin and lightweight, and is a representative display that is very often used in HMDs.

The eye relief up to the exit pupil of the optical system is about 2
3 mm, and the horizontal display angle of view is about 60 °. The element size is 1.3 inches diagonally 26.4 mm × 19.8 mm, and the pixel pitch of the display device 3 is 15
9 μm. With the same pitch and the same arrangement, the focal length is 0.
The exit pupil-side microlens array 21 in which 8 mm element lenses are arranged is arranged at a distance of about 1 mm from the pixels of the LCD. Immediately thereafter, the field lens 1 having a focal length of about 23 mm is arranged on the observer side, and the eye relief up to the exit pupil is about 23 mm. Incidentally, the limiting condition of the pitch of the microlens array or the pixel where the pupil due to the crosstalk light does not enter the eye is 9 points from the center of rotation of the eyeball of the observer to the pupil.
mm, it is 156 μm or more from the above conditional expression.
The number of pixels is 166 × 125, and the total number of pixels is 20,750.

Here, RGB (red,
In order to make three pixels (green, blue) correspond to one microlens as one dot, a microprism array 15 as shown in a perspective view of FIG.
Combine with 21. FIG. 21 shows the horizontal optical path.
As shown in (a), three RGB pixels correspond to one microprism and one microlens. As for the orientation of the surface of the microprism array 15, the plane side faces the microlens 21 side and the prism surface faces the observer side in FIG. 21A, but the reverse is also possible.

Thus, the micro lens array 21
The lens pitch does not need to match the pitch of the RGB pixels, and is relatively larger than the pixel pitch, so that the lens manufacturing accuracy is improved. As a result, the total number of RGB pixels becomes 20,750 × 3 = 62,250.

As an illumination system for illuminating the LCD, a plane backlight used as a rear light source of the LCD and a means for limiting NA is used as a parallel light supply source. An illumination-side microlens array 22 in which element lenses are arranged at the same pitch and condensed on LCD pixels is used. LCD pixel and illumination side micro lens array 22
Is the length of the focal length of the illumination-side microlens array 22 of 0.5 mm.

The pupil position is detected by a pupil position detection unit 4 attached to the HMD having this display system, and the LCD is driven by the drive unit 6 in accordance with the detected position information to move the exit pupil. The pupil is tracked (FIG. 18).

In this display system, when the pupil moves to the maximum, 9 × sin 30 ° = 4.5 mm when viewing ± 30 ° which is a half angle of view in the horizontal direction. FIG. 22 shows the pupil movement range when the pupil diameter is 4 mm when viewing a screen having an aspect ratio of 4: 3 including the vertical direction. In the figure, a hatched circle is a pupil, and a small circle is an exit pupil. In the figure, the center circle is the pupil when looking at the center of the screen, and the upper right, lower right, upper left, and lower left circles are the upper right of the video screen,
It shows the pupil position when looking at the lower right, upper left, and lower left.

To cover this pupil movement range,
This range is divided into 23 regions, the destination of the exit pupil is arranged in each of the 23 regions, and the region where the pupil center is located is detected, and is indicated by a small circle in the figure in that region. The pupil is tracked by moving the exit pupil to such a predetermined position. Therefore, the required pupil position detection accuracy requires a resolution of about 2 mm, whereby it is possible to determine which of the 23 regions has the pupil center. If the exit pupil can be shifted to the small circle position shown in the figure according to the detected area, the image can be observed without vignetting.

In order to track the movement of the pupil by moving the LCD of this system, it is sufficient that the LCD can be shifted by a maximum of 196 μm from the relational expression between the pupil movement amount and the LCD drive amount. Furthermore, if the illumination-side microlens array 22 is not moved by the same amount as the LCD, the image will be dark. Therefore, the illumination-side microlens array 22 and the display device 3 will have a spacer corresponding to the focal length of the illumination-side microlens array 22. The illumination-side microlens array 22 and the display device 3 are integrally moved as a unit integrated with each other (FIG. 18). A small and light micro motor is used as the driving mechanism. The maximum stroke amount may be an amount by which the exit pupil is moved by the maximum movement amount. Since there are nine moving points in the horizontal direction and seven points in the vertical direction, it is configured to move stepwise according to the current value.

The illumination-side microlens array 22 increases the NA by increasing the refractive index while maintaining the same pitch as the exit pupil-side microlens array 21 in order to prevent the light amount from dropping due to the movement of the display device 3 as described above. I have. The illumination side microlens array 22 uses a refractive index distribution type microlens, the focal length is 2/1 of the exit pupil side microlens array 21, and the NA is 2
It is twice. As a result, the light emitted from the pixel is applied to the exit lens on the exit pupil side microlens array 21 about half of the regular lens and the lens on both sides of the regular lens, and it is possible to prevent the light quantity from dropping due to the movement of the LCD.

In this embodiment, an example of a transmissive LCD has been described as the image display means, but it can be changed to another transmissive image display element. However, it is preferable to use an LCD because it can be displayed in color with small size, light weight and low power consumption.

The thickness in the optical axis direction of the display system of this embodiment is about 11 mm when the thickness of the field lens 1 is a glass material having a refractive index of about 1.5, and the thickness of the parallel illumination section 14 is 8 mm. When the display device 3 is 3 mm and the thickness of both micro lens arrays 21 and 22 is 1 mm, about 24 mm is required from the display device 3 to the final surface on the observer side of the observation optical system.
It is possible to provide a very thin and lightweight HMD having a wide angle of view such as mm.

[Embodiment 4] FIG. 23 is a schematic structural view of Embodiment 4 of the present invention. FIG. 23 shows an example in which there is no field lens in the third embodiment (FIG. 17). A transmissive display device 3 such as an LCD is used as an image display means.
The display angle of view depends on the focal length of the exit pupil side MLA 21 and the size of the display device 3 as described in the second embodiment. As shown in FIG. 11, the size of the display device 3 is L, the pixel pitch is p _d , the lens pitch of the exit pupil side MLA 21 is p _m , and the focal length of the exit pupil side MLA 21 is f.
_m, and the distance from the exit pupil side MLA 21 to the exit pupil is R
And If the distance between the image display device 3 and the exit pupil side MLA 21 is the focal length of the exit pupil side MLA 21, the light flux emitted from each pixel 13 becomes a parallel light flux and can be guided to the eye E. If the display half angle and _{θ, p m = Rp d /} (R + f m) , however, the relationship between _{R + f m = L / (} 2tanθ) is derived.

Also in this embodiment, since the transmissive display device 3 is used, the parallel illumination section 14 is used as an illumination system.
Is collected on each pixel by the illumination side MLA 22 corresponding to the pixel. At that time, the display device 3
Is a value equal to the focal length of the illumination side MLA 22.

In order to move the exit pupil of the observation optical system, as shown in FIG. 23, the exit pupil side MLA 21 is moved by a predetermined amount. Each pixel of the image display device 3 and the exit pupil side MLA2
1 of the distance between the main plane of the lens and the focal length f _m of the exit pupil side MLA21. When the exit pupil side MLA21 was S shift, if the amount of movement of the exit pupil of the optical system _{D, S = f m D /} R = 2f m Dtanθ / (L-2f m ta
nθ) is derived.

In the above description, the exit pupil of the optical system is moved by moving the exit pupil MLA 21, but the display device 3 is moved without moving the exit pupil MLA 21 as shown in FIG. The exit pupil can be moved.

Each pixel of the image display device 3 and the exit pupil side M
The distance of each lens of LA21 from the principal plane is defined as the MLA on the exit pupil side.
The focal length f _m of 21. When the display device 3 is S shift, if the amount of movement of the exit pupil of the optical system _{D, S = f m D /} (R + f m) = 2f m Dtanθ / L the relationship is derived. However, it is R»f _m.

In the case where the display device 3 is moved as described above, the illumination side MLA 22 is also driven integrally with the display device 3 in order to make the converging point of the illumination side MLA 22 coincide with the pixel.

In either case where the exit pupil is moved by moving the MLA 21 on the exit pupil side in this embodiment, or where the exit pupil is moved by moving the display device 3, as described in the third embodiment. In addition, the NA of the illumination side MLA22 is changed to the N of the exit pupil side MLA21.
It is important to display a good image by setting the pitch to be larger than A and to make the pitch configuration such that the pupil due to the primary crosstalk light does not enter the observer pupil.

Next, as shown in FIG. 25, an example of a stationary viewer 20 using an LCD as a display element will be described.
In the vicinity of the viewing window of the viewer 20, a pupil position detection sensor 23 captures an image of an observer's eye and detects an pupil position by an infrared light emitting element and a CCD as a light receiving element.
Is attached. The pupil position is detected by image processing from the captured image of the observer's eye. A computer used for detection is built in a housing below the viewer 20.

The eye relief up to the observer's pupil is about 35 m
m, and the horizontal display angle of view is about 80 °. The element size is 3 inches diagonally, 61 mm × 45.7 mm, and the pixel pitch of the display device 3 is 160 μm both horizontally and vertically. An exit pupil-side microlens array 21 having the same array but having a pitch of 155.6 μm and having an element lens with a focal length of 1 mm is arranged at a distance of 1 mm from the LCD.

By the way, the limiting condition of the pitch of the lens or the pixel where the pupil due to the crosstalk light does not enter the eye is 155 μm or more from the above-mentioned conditional expression if the distance from the center of rotation of the observer's eyeball to the pupil is 9 mm. The number of pixels is 381 × 28
5, the total number of pixels is 108,585.

As an illumination system for illuminating the LCD, light from a halogen-based high-intensity light source is guided by an optical fiber, and light emitted from the end of the optical fiber is collimated by a collimator lens. LC on the illumination side to collect light
A micro lens array 22 having element lenses having the same arrangement and the same pitch as the pixels of D is arranged apart from the LCD by a focal length of 0.5 mm of the lens array 22.

The illumination system, the display system, and the observation optical system are built in the viewer 20. Further, the microlens array on the exit pupil side based on the position information detected by the pupil position detection sensor 23 attached to the viewer 20. 21
, The exit pupil tracks the observer's pupil, and a good image can always be provided.

In this display system, when the pupil moves to the maximum, 9 × sin 40 ° = 5.8 mm when viewing ± 40 ° which is a half angle of view in the horizontal direction. In order to track the movement of the pupil by moving the microlens array 21 on the exit pupil side of this system, the microlens array 21 on the exit pupil side can be moved up to a maximum from the above-mentioned relational expression between the pupil movement amount and the driving amount of the microlens array. What is necessary is just to be able to shift by 159 μm. If the moving position is continuously moved in real time so that the exit pupil is always located at the center of the detected pupil, a bright image can always be observed.

To drive the micro lens array,
A device with a high response that can vary the amount of driving by a voltage applied by an actuator using a piezo element or the like is used. The illumination-side microlens array 22 has a performance in which the NA is 1.5 to 2 times larger than that of the exit pupil-side microlens array 21 in order to prevent a drop in the amount of light when tracking the line of sight.

The viewer of this embodiment is a relatively small-sized and inexpensive wide-field-of-view image display device using an LCD, which is made possible by tracking a line of sight using a microlens array as an observation optical system.

Fifth Embodiment A fifth embodiment of the present invention will be described with reference to FIG. The schematic structure of this embodiment is shown in FIG.
In order from the right side of the figure, the observer's eyeball E, the field lens 1, and the exit pupil side microlens array (hereinafter, referred to as
An exit pupil side MLA) 21, a transmissive display device 3 such as an LCD as an image display means for displaying an image behind the pupil side MLA), and an illumination side micro lens array (hereinafter, referred to as an LCD) for condensing illumination light on each pixel of the device , Illumination side MLA) 2
2. A point light source array 16 in which a plurality of point light sources are arranged is arranged, and further, a pupil position detector 4 for detecting the position of the pupil of the observer, based on the detection result, the exit pupil side MLA2.
1. An arithmetic control unit 5 for calculating and controlling the moving amount of the point light source array 16 and the illumination side MLA 22 and a drive unit 6 for moving the exit pupil side MLA 21, the point light source array 16, and the illumination side MLA 22 in two axes are provided. . The eyeball E is arranged so that the pupil is located at a position substantially apart from the focal length of the field lens 1.

When an image is displayed by the control means of the display device 3 (not shown), a good observation state is always provided without the image becoming unobservable. The MLA 21 on the exit pupil side is shifted by the microlens array drive unit of the drive unit 6 based on the pupil position information of the observer detected by the unit 4 so that the exit pupil tracks the movement of the pupil of the observer. .

When the exit pupil side MLA 21 is shifted by S, the movement amount of the exit pupil of this optical system is D, and the distance between each pixel of the video display device 3 and the principal plane of each lens of the exit pupil side MLA 21 is approximately the focal length of the pupil side MLA21, the focal length of the exit pupil side MLA21, f _m the focal length of the field lens 1 respectively, when the f _o, a relationship of _{S ≒ f m D / f o} . Therefore, the relationship between the shift amount of the exit pupil side MLA21 and the movement amount of the exit pupil is that if the ratio of the focal lengths of both is large, the exit pupil position can be largely moved even if the shift amount of the exit pupil side MLA21 is small. Can be.

Since a transmissive display device is used as the image display device 3, a plurality of point light sources are used as illumination light sources.
A point light source array 16 arranged in a dimension is used. Each point light source of the point light source array 21 corresponds to a pixel of the display device 3, and light emitted from each point light source is also condensed on each pixel by the illumination side MLA 22 corresponding to the pixel. To display bright images efficiently. At this time, each point light source and each pixel are arranged at conjugate positions with respect to the illumination side MLA 22.

Accordingly, the plurality of point light sources and the pixels have a conjugate relationship, and the pixels and the retina have a conjugate relationship. When the exit pupil side MLA 21 is moved in order to track the pupil, the illumination side MLA 22 and the point light source array 16 are also independently and independently moved in order to increase illumination efficiency and prevent generation of unnecessary light due to crosstalk. On the extension of the object-side principal point of each micro lens of the exit pupil side MLA 21 and the center of each corresponding pixel, the image-side principal point of each corresponding micro lens of the illumination side MLA 22 and each point light source are located. As described above, the point light source array 16 and the illumination side MLA 22 are moved by the drive unit 6.

As a result, a clear image can be observed even when viewing the periphery. The above is the exit pupil side MLA
This is a method of moving the exit pupil of the optical system by following the movement of the pupil by moving the image pupil 21. As shown in FIG. 27, the image display device 3 is moved without moving the exit pupil side MLA 21. However, the exit pupil can be moved.

As described in the first and third embodiments, the distance between each pixel of the video display device 3 and the main plane of each lens of the exit pupil MLA 21 is substantially set as the focal length of the exit pupil MLA 21, focal length of MLA21, when the focal length of the field lens 1 f _m, respectively, and f _o, when the image display device 3 was S shift, the movement amount D of the exit pupil of the optical system, S ≒ f _m D / are in a relationship of f _o.

Also in this case, the point light source array 16 and the illumination side MLA 22 are independently moved to increase the illumination efficiency and prevent the generation of unnecessary light due to crosstalk. At this time, the image-side principal points of the corresponding microlenses on the illumination side MLA22 and the points on the extension of the object-side principal points of the microlenses on the exit pupil side MLA21 and the centers of the corresponding pixels on the object side. The point light source array 16 and the illumination side MLA 22 are moved so that the light source is located.

In the present embodiment, the exit pupil side MLA 21 or the display device 3 is moved in order to track the observer's pupil.
By moving the illumination system A22 along with the movement of the exit pupil side MLA 21 or the display device 3, it is possible to provide a clear image without causing a drop in peripheral light amount or image deterioration due to crosstalk. It is an example.

Next, FIG. 28A shows an example in which the present optical system is attached to an observer, and FIG. 28B shows an example in which the optical system is used for a handy type monocular viewer 24 whose front view is shown. As the image display device 3, an LCD having a diagonal of 0.55 inches is used. The eye relief up to the exit pupil is about 26 mm,
The horizontal display angle of view is about 24 °. Element size is 11.1
It is 8 mm × 8.38 mm, and the pixel pitch of the display device 3 is 50 μm both horizontally and vertically. The number of pixels is 224 ×
The total number of pixels of 168 dots is 37,632.

An exit pupil-side microlens array 21 and a field lens 1 for collimating and guiding light from each pixel of the LCD are arranged on the viewer side of the LCD. The exit pupil-side microlenses 21 have the same pitch and the same arrangement as the LCD, and element lenses having a focal length of 0.7 mm are arranged. The microlens array 21 on the exit pupil side is arranged with its main plane being about 0.7 mm away from the pixels of the LCD. Immediately thereafter, the field lens 1 having a focal length of about 26 mm is arranged on the observer side, and the eye relief up to the exit pupil is about 26 mm.

The LCD is illuminated as follows. A light guide plate of a straight tube type backlight in which a cold cathode tube is provided on the side of a light guide plate of a transparent member used as a back light source of an LCD is provided with a plurality of light leak ports as pseudo point light sources. The leak openings are two-dimensionally arranged corresponding to the pixels of the LCD. The leak port is used as a point light source, and each point light source is condensed and illuminated on the pixel by the illumination-side microlens array 22 having the same arrangement and pitch. The above-described configuration of the illumination system including the backlight and the illumination-side microlens array 22 enables thin and highly efficient illumination.

Portable viewer 2 incorporating this display system
The pupil position is detected by a pupil position detection sensor 23 attached to the LCD 4, and the LCD is moved by the LCD movable unit according to the detected position information to move the exit pupil and follow the pupil. The detection sensor 23 is a method called a limbus tracker, and two light receiving elements are arranged near a viewer's eyeball with a light emitting element interposed therebetween. The sum of the analog signals of the light receiving elements is information in the horizontal direction and the difference is information in the vertical direction. Therefore, the pupil position can be detected from the signal.
Although the accuracy is not high, since the mechanism is simple and the cost is low, this detection method is suitable for an example in which the display angle of view is narrow and the cost is suppressed as in the present embodiment.

In this display system, when the pupil moves to the maximum, 9 × sin12 ° = 1.87 mm when viewing ± 12 ° which is a half angle of view in the horizontal direction. In order to track the movement of the pupil by moving the LCD of this display system, it is sufficient that the LCD can be shifted by a maximum of 50 μm from the above relational expression between the pupil movement amount and the LCD movable amount. As the movable mechanism, an inexpensive micro actuator having a small torque and a small stroke is used.

Further, in order to prevent generation of unnecessary light and decrease in light amount due to crosstalk due to the movement of the LCD, a backlight as a multi-point light source and each point corresponding to each pixel of the illumination side micro lens array 22 are used. The center of the light source and lens is each pixel of the LCD and the exit pupil side micro lens 21
Are moved independently by the illumination-side microlens array movable section and the point light source array movable section so as to be arranged on an extension line connecting the centers of the lenses.

That is, as the actuator, as in the present embodiment, three piezo elements capable of independently moving the backlight, the illumination-side microlens array 22, and the LCD with the movable portion 6 are used. A new driving mechanism is required.

The thickness of the display system of this embodiment in the optical axis direction is about 2 to 3 mm when the field lens is made of a glass material having a refractive index of about 1.5. Is 3 mm, and the thickness of both microlens arrays is 1 mm. In the display system of the present embodiment, the thickness in the optical axis direction is about 12 mm from the display device 3 to the final surface on the observer side of the observation optical system. And a thin portable display.

[Embodiment 6] FIG. 29 is a schematic structural diagram of Embodiment 6 of the present invention. This embodiment is an example in which there is no field lens in the fifth embodiment (FIG. 26). A transmissive display device 3 such as an LCD is used as an image display means. FIG. 30 is a diagram showing the illumination and observation system in FIG. 29. From the left, the point light source array 16 and the illumination side MLA2 are shown.
2, a transmission type display device 3, an exit pupil side MLA 21, and an observer's eyeball E. The pitch p _i of the point light sources of the point light source array 16, the lens pitch p _n of illumination side MLA22, the focal length f _n of the illumination-side MLA22, the size of the display device 3 L, the pixel pitch p _d, exit pupil Side MLA
The lens pitch of 21 p _m, the focal length of the exit pupil side MLA21 and f _m, the distance from the exit pupil side MLA21 to the exit pupil and R. Point light source array 1 in any one direction
The number of point light sources, the number of lenses on the illumination side MLA 22, the number of pixels on the display device 3, and the number of lenses on the exit pupil side MLA 21 are the same because they correspond to each other, and are N. Distance between the exit pupil side MLA21 an image display device 3 if the focal length f _m of the exit pupil side MLA21, the light flux emitted from each pixel can be guided to become th E parallel beams. The distance between the point light source array 16 and the illumination side MLA 22 is x, and the illumination side M
Assuming that the distance between the LA 22 and the display device 3 is y and the display half angle of view is θ, the following relationship is derived from the imaging formula and the geometric relationship.

[0117] _{tanθ = Np m / (2R)} = Np d / {2 (R + f m)} = Np n / {2 (R + f m + y)} = Np i / {2 (R + f m + x + y)} θ = tan - ^{1 [L / {2 (R} + f m)}] (x-f n) (y-f n) = source and each pixel point of each relative to f _n ² illumination side MLA22 is placed in a conjugate position. Therefore, the plurality of point light sources and the pixels have a conjugate relationship, and the pixels and the retina have a conjugate relationship. When the exit pupil side MLA 21 is moved in order to track the pupil, the illumination side MLA 22 and the point light source array 16 are also independently moved in conjunction therewith in order to increase illumination efficiency and prevent generation of unnecessary light due to crosstalk. Exit pupil side MLA
The image-side principal point of each corresponding microlens of the illumination side MLA 22 and the point light sources are located on an extension of the object-side principal point of each microlens 21 and the center of each pixel corresponding thereto. The point light source array 16 and the illumination side MLA 22 are moved.

To move the exit pupil of the observation optical system, the exit pupil side MLA 21 is moved by a predetermined amount. If the distance between each pixel of the image display device 3 and the main plane of each lens in the exit pupil side MLA21 the focal length f _m of the exit pupil side MLA21, when the exit pupil side MLA21 was S shift of the optical system movement amount D of the exit pupil, a relationship of _{S = f m D / (R} + f m) = 2f m Dtanθ / L.

The above is a method of moving the exit pupil of the optical system by moving the exit pupil side MLA 21. As shown in FIG. 31, the image display device 3 is moved without moving the exit pupil side MLA 21. Even if it is moved, the exit pupil can be moved.

Each pixel of the image display device 3 and the exit pupil side M
The distance of each lens of LA21 from the principal plane is defined as the MLA on the exit pupil side.
If the focal length f _m of, when the display device 3 was S shift, the movement amount D of the exit pupil of the optical system, as if moving the exit pupil side MLA21, S = f _m D _{/ R = 2f m Dtanθ / (} L-2f m ta
nθ) is derived. However, it is R»f _m.

In the case where the display device 3 is moved as described above, the illumination side MLA 22 and the point light source array 16 are also moved independently of each other in order to increase illumination efficiency and prevent generation of unnecessary light due to crosstalk. On the extension line between the principal point on the object side of each microlens on the exit pupil side MLA 21 and the center of each pixel corresponding thereto, the illumination side MLA
The point light source array 16 and the illuminating side ML are located such that the corresponding image-side principal points of each of the microlenses 22 and the point light sources are located.
A22 is moved. As a result, it is possible to provide a clear image without causing a decrease in the amount of light in the periphery or image deterioration due to crosstalk.

Next, an example in which numerical values are actually used will be described. The eye relief up to the exit pupil is 22.5 mm, the horizontal display angle of view is about 30 °, and the vertical display angle of view is about 23 °. A 0.7 ″ LCD having an element size of 14.2 mm × 10.7 mm is used. The LCD has a pixel pitch of 28 μm horizontally.
The vertical direction is 36 μm, and the number of pixels is 507 × 297 dots, and the total number of pixels is 150,579. An exit pupil-side microlens array 21 for collimating and guiding light from each pixel of the LCD is provided on the viewer side of the LCD, and the focal length of the microlens from the main plane to the pixels of the LCD is 1 mm. They are placed apart. The pitch of the exit pupil-side microlens array 21 is 26.9 μm in the horizontal direction and 34.6 μm in the vertical direction according to the above relational expression of the pitch.
m pitch.

The LCD is illuminated by the following illumination system. The LED element having a very small light emitting area is set to 30.1 μm in the horizontal direction and 3 in the vertical direction calculated by the above-described relational expression of the pitch.
Using an LED array two-dimensionally arranged at a pitch of 8.7 μm as a pseudo point light source, a horizontal direction of 29 μm and a vertical direction of 37.4 μm also derived from the above-described pitch relational expression.
This illumination system has a configuration in which light from each micro LED is condensed on each pixel of the LCD by an illumination-side microlens array 22 having a focal length of 0.5 mm arranged two-dimensionally at a pitch. The distance between the illumination side micro lens array 22 and each pixel of the LED array and the LCD is 1 mm. The small LED array produces a color image by arranging three colors of RGB in a stripe shape.

Further, according to the pupil position information detected by the pupil position detection sensor for detecting the pupil position of the observer.
The drive unit 6 moves the exit pupil side micro lens array 21, the micro LED array, and the illumination side micro lens array 22 so as to track the exit pupil to the pupil.

In this display system, the maximum movement of the pupil is when the viewer views ± 15 ° which is a half angle of view in the horizontal direction, and the distance from the center of rotation of the eyeball of the observer to the pupil is 9 m.
If m, 9 × sin15 ° = 2.33 mm.

In order to track the movement of the pupil by moving the microlens array 21 on the exit pupil side of the display system, the relationship between the amount of pupil movement and the drive amount of the microlens array on the exit pupil side is obtained from the above-mentioned relational expression. In order to prevent the generation of unnecessary light due to crosstalk and the decrease in the amount of light due to the movement of the micro lens array 21, the micro LED array and the micro lens array 22 on the illumination side correspond to the respective pixels, The illumination-side microlens array movable unit and the micro LED array movable unit are independently moved so as to be aligned on an extension line connecting each pixel of the LCD and the center of each lens of the exit pupil-side microlens 21.

With this configuration, it is possible to provide a very thin display with full-color resolution and good resolution.
As described above, the eyeball projection type image display device of the present invention has been described based on some embodiments, but the present invention is not limited to these embodiments, and various modifications, as appropriate, within the spirit of the present invention.
Combinations and the like are possible.

The above-mentioned eyeball projection type image display apparatus of the present invention can be constituted, for example, as follows. [1] Image display means including two-dimensionally arranged pixels for displaying an image, and a micro-optical element having an action of adding a positive power to a light beam emitted from each pixel of the image display means In an eyeball projection type image display device comprising an observation optical system including an optical member arranged two-dimensionally, the optical member has an action of increasing the resolution of the pixel and guiding the pixel to the observer's eyeball, An exit pupil formed by the observation optical system is configured to move in response to the movement of the pupil so that a light beam emitted from the observation optical system can be made incident on an observer pupil. Eyeball projection type image display device.

[2] Image display means including pixels arranged two-dimensionally for displaying an image, and two-dimensionally arranged corresponding to each pixel of the image display means. An observation optical system including a micro-optical element for guiding an emitted light beam from each pixel to an observer's eyeball, a pupil position detecting means for detecting an observer pupil position, and an exit pupil position for changing a position of the exit pupil of the observation optical system An eyeball projection type image display device comprising: a moving unit.

[3] In the above [1] or [2],
The image display means is a self-luminous type, and is an eyeball projection type image display device.

[4] In the above-mentioned [3], the exit pupil position moving means has a drive mechanism for moving the micro optical element, and is an eyeball projection type image display apparatus.

In this case, by using the micro optical element for the optical system and moving it, the exit pupil position can be largely displaced with a small moving amount, and the stroke amount of an actuator or the like for moving the micro optical element can be changed. The pupil can be tracked with good response by simple moving means. The fact that the stroke amount is small has the advantage that the actuator and, consequently, the entire device can be miniaturized. In addition, since the emission light distribution of each pixel of the image display means, which is an object point, is usually sufficiently large as compared with the NA of the micro optical element,
Even if the micro optical element is moved, the amount of luminous flux does not decrease, and a bright image can be provided.

[5] In the above [3], the exit pupil position moving means has a drive mechanism for moving the video display means, wherein the eyeball projection type video display apparatus is provided.

In this case, by moving the image display means in which pixels are arranged corresponding to each micro optical element, the exit pupil position can be largely displaced with a small amount of movement, and the image display means is moved. Therefore, the stroke amount of the actuator or the like can be small, and the pupil can be tracked with good response by a simple moving means. The fact that the stroke amount is small has the advantage that the actuator and, consequently, the entire device can be miniaturized. Also, since the emission light distribution of each pixel of the image display means, which is an object point, is usually sufficiently large compared to the NA of the micro optical element, even if the image display means is moved, the amount of luminous flux does not decrease and a bright image is provided. Can be.

[6] Transmission image display means having pixels arranged two-dimensionally to display an image, illumination means for illuminating the transmission image display means, and each pixel of the transmission image display means Optical system including a micro-optical element for guiding the emitted light beam from the camera to the observer's eyeball, pupil position detecting means for detecting the observer's pupil position, and exit pupil position moving means for changing the position of the exit pupil of the observation optical system An eyeball projection type image display device comprising:

In this case, a transmission type image display means requiring illumination means is used, and the observation optical system has a short-focus minute optical element. In addition, since each pixel of the image display means and the retina of the observer have a conjugate relationship, a high-definition image can be provided. Further, the pupil position of the observer is detected, and the pupil is detected. By tracking the exit pupil of the observation optical system at the position, this high-definition image can be observed without vignetting.

Also, since the NA can be controlled on the illuminating means side, so-called crosstalk which causes ghost or flare, in which light enters a small optical element other than a regular small optical element, which is a cause of degradation of resolution, is also caused. Can be prevented.

[7] In the above [6], the illuminating means is a two-dimensional array corresponding to each pixel of the transmissive image display means, and a parallel illuminating means for supplying substantially parallel light, A microscopic light condensing element for condensing light from the parallel illumination means on each pixel of the transmission type image display means.

In this case, by including parallel illumination means for supplying substantially parallel light to the illumination means, the light passing through each pixel of the image display means is condensed by the minute optical element in the observation optical system. In addition, it becomes easy to perform control so that a crosstalk phenomenon that light from a pixel other than the normal pixel corresponding to the micro optical element corresponding to each pixel of the image display means enters the micro optical element does not occur. Further, by condensing the light supplied from the parallel illuminating means on each pixel by the minute condensing means, the illumination efficiency is improved and a bright image can be provided.

[8] In the above-mentioned [7], the exit pupil position moving means has a drive mechanism for moving the micro optical element, and is an eyeball projection type image display apparatus.

In this case, by using the micro optical element for the optical system and moving it, the exit pupil position can be largely displaced with a small moving amount, and the stroke amount of the actuator or the like for moving the micro optical element can be changed. The pupil can be tracked with good response by simple moving means. The fact that the stroke amount is small has the advantage that the actuator and, consequently, the entire device can be miniaturized.

[0142]

[9] In the above [7], the exit pupil position moving means has a drive mechanism for moving the image display means and the minute light condensing element.

In this case, by moving the image display means in which the pixels are arranged corresponding to the respective micro optical elements, the exit pupil position can be largely displaced with a small amount of movement, and the image display means is moved. Therefore, the stroke amount of the actuator or the like can be small, and the pupil can be tracked with good response by a simple moving means. The fact that the stroke amount is small has the advantage that the actuator and, consequently, the entire device can be miniaturized.

In addition, by moving the minute light condensing element by the same amount of movement in conjunction with moving the image display means, light from the parallel illumination means can always be condensed on the pixel, and a bright image can be provided.

[10] The above [8] or

[9] The eyeball projection type image display device according to [9], wherein a numerical aperture of the minute light condensing element is larger than a numerical aperture of the minute optical element.

In this case, the light emitted from the parallel illuminating means passes through the pixels of the image display means. In the micro optical element, the light is applied to each of the regular micro light condensing elements corresponding to each pixel. When moving the exit pupil position, the amount of incident light flux decreases as the image display means or the minute optical means moves. As a countermeasure against this, by making the focal length of the micro-focusing element on the illumination side across the pixel smaller than the focal length of the micro-optical element on the exit pupil side, the luminous flux emitted from a certain pixel is Not only the corresponding micro-optical element but also the adjacent micro-optical element etc., even if the micro-optical element or the image display means is moved, the luminous flux including the information from the regular pixels will not be reduced, and will be emitted to the pupil. Even if the eyes are tracked, the brightness does not decrease.

[11] The eyeball projection type image display device according to the above [10], wherein 1.5 <NA of the small light condensing element / NA <2 of the small optical element is satisfied.

In this case, in order to obtain the operational effect when the numerical aperture of the above-mentioned minute light-collecting element is made larger than the numerical aperture of the minute optical element, it is desirable that the material of the minute light-collecting element and the minute optical element be used. By controlling the refractive index difference of the micro lens and the radius of curvature of the surface of the micro lens, or by using a refractive index distribution type or the like, the focal length of both is controlled, and the NA of the micro light condensing element is NA
It is preferable to have a value 1.5 to 2 times as large as. At this time, when the light beam condensed on the pixel by the micro light condensing element is incident on the micro optical element, it is incident on approximately 1.5 to 2 of the micro optical element elements, and the pupil of the observer In order to move the exit pupil in accordance with the movement of the image, it is possible to prevent a decrease in the amount of light accompanying the movement of the micro optical element or the image display means.

[12] In the above item [6], the illumination means illuminates each pixel of the transmission type video display means.
An eyeball comprising: a plurality of small light emitting points arranged in a dimension; and at least one light collecting element for collecting light from the small light emitting points to each pixel of the transmission type image display means. Projection type video display device.

In this case, a plurality of light emitting point light sources are formed in some form as an illumination system, and a short focal point minute light condensing element is made to correspond to the plurality of light emitting points, so that light emitted from the light emitting points is displayed on an image. Light is condensed for each pixel of the means. As a result, the optical path length from the light emitting point through the pixel to the point where the light and dark color information is collected and collected is shortened. That is, the lighting unit becomes thin. Therefore, in a video display device of a type worn on the head or face, the projection amount is small, which is very suitable.

When light is condensed on each pixel, each pixel is arranged such that a pixel and a light emitting point corresponding to the micro light condensing element have a conjugate positional relationship.
The crosstalk phenomenon that light from a pixel other than the regular pixel enters is unlikely to occur, and the generation of unnecessary light that causes deterioration of a displayed image can be prevented. Further, the lighting efficiency is improved, and a bright image can be provided.

[13] In the above item [12], the exit pupil position moving means includes a driving mechanism for moving the micro optical element, and the plurality of micro light emitting points and the image display with respect to the micro light condensing element. An eyeball projection type image display device, comprising: a driving mechanism for moving the plurality of minute light emitting points and the minute light condensing element so that each pixel of the means has a substantially conjugate relationship.

In this case, by using a micro optical element for the observation optical system and moving it, the exit pupil position can be largely displaced by a small amount of movement, and a stroke of an actuator or the like for moving the micro optical element can be obtained. The pupil can be tracked with good response by a simple moving means with a small amount. The fact that the stroke amount is small has the advantage that the actuator and, consequently, the entire device can be miniaturized. Further, by moving the minute light emitting point and the minute light condensing means so that the minute light emitting point and each pixel of the image display means are substantially conjugate to the corresponding minute light condensing element, unnecessary light flux is always obtained. This makes it possible to illuminate the pixel without causing the occurrence of light, thereby providing a bright image with high light quantity efficiency.

[14] In the above item [12], the exit pupil position moving means includes a drive mechanism for moving the image display means, and the plurality of minute light emitting points and the image display means with respect to the minute light condensing element. An eyeball projection type image display device, comprising: a driving mechanism for moving the plurality of minute light emitting points and the minute light condensing element so that each pixel of the means has a substantially conjugate relationship.

In this case, by using a micro optical element for the observation optical system and moving the image display means, the exit pupil position can be largely displaced with a small amount of movement, and an actuator or the like for moving the image display means can be used. Is small, and the pupil can be tracked with good response by simple moving means. The fact that the stroke amount is small has the advantage that the actuator and, consequently, the entire device can be miniaturized. Further, by moving the minute light emitting point and the minute light condensing means so that the minute light emitting point and each pixel of the image display means are substantially conjugate to the corresponding minute light condensing element, unnecessary light flux is always obtained. This makes it possible to illuminate the pixel without causing the occurrence of light, thereby providing a bright image with high light quantity efficiency.

[15] The above [4], [5], [8],

[9] The eyeball projection type video display according to [13] or [14], wherein the observation optical system includes only the micro optical element.

In this case, since the observation optical system is constituted only by the minute optical elements, it is very simple and thin.

[16] In the above-mentioned [15], the pitch of the micro optical elements is smaller than the pixel pitch of the video display means, and further satisfies the following expression. _{18f m sinθtanθ / (L-2f} m tanθ) <
p _m <1 (mm) where p _m is the pitch of the micro-optical element, f _m is the focal length of the micro-optical element, L is the length of any one side of the image display means, θ is the above-mentioned arbitrary Is the maximum viewing half angle of view in one side direction.

In this case, if light emitted from a pixel of the image display means enters a small optical element other than the regular small optical element corresponding to the pixel, an unnecessary pupil is formed around the regular pupil. However, if the configuration is such that it is not visible, the resolution can be prevented from deteriorating. Specifically, if the pixel pitch or the pitch of the micro-optical elements increases, the angle of the light beam that crosstalks increases. As a result, the angle of incidence on the observer's pupil differs from the angle of incidence of normal light, and At the pupil position, an unnecessary pupil position is separated from a normal pupil position, and it is difficult for the observer to enter the eyes. Also, as described in [21] below, the pitch is 1 mm
It is reasonable that: Accordingly, it is preferable that the pitch of the micro optical elements be in the above range.

[17] The above [4], [5], [8],

In [9], [13], [14] or [15], the distance from the principal point in front of the observation optical system to the exit pupil is R,
When the focal length of the micro-optical element and f _m, the ratio f
_m / R is 0.0001 <before eyes projection type image display device which is a f _m /R<0.03.

In this case, the pupil position moving amount which is moved by moving the micro optical element or the image display means by the moving amount S is defined as D, and from the principal point on the eye side of the observation optical system including the micro optical element to the exit pupil. if the distance R, the focal length of the micro-optical element and f _m, as described in examples 1 and 2, the ratio S / D is equal to f _m / R.

When the observation optical system includes a field lens and an eyepiece lens if necessary in addition to the micro optical element, the distance between the principal points between the micro optical element and the other field lens or eyepiece can be reduced by reducing the distance between the principal points. S / D is approximately equal to the ratio of the focal length of the micro optical element to the focal length of the field lens or eyepiece, which serves to focus the light beam substantially parallelized by the micro optical element on the eye. Thus, the amount of movement of the micro optical element or the image display means for moving the pupil is obtained.

At this time, it is preferable that the moving amount of the micro optical element or the image display means is small in order to reduce the size of the device itself to be moved for quick response. That is, it is preferable that the focal length of the micro optical element is short. However, there is a gap between the surface of the display device and the pixels because there is glass as the substrate, as in the case of an LCD, which is a typical example of a transmissive display device. Therefore, there is a limit in shortening the focal length of the micro optical element. Also, due to the problem of manufacturing micro-optical elements, the focal length greatly depends on the pitch of each lens of the micro-optical elements, and if it is made too small, crosstalk is likely to occur, and in terms of brightness, Not preferred. Therefore, the focal length of the micro optical element can be limited.

At this time, since the distance from the final surface of the field lens or the eyepiece to the exit pupil, that is, a reasonable value of the so-called eye relief is about 10 to 50 mm, f _m / R relating to the focal length of the micro optical element is required. Has an appropriate range.

The amount D of moving the exit pupil needs to be larger as the display angle of view is larger. However, considering the aberration of the observation optical system, the viewable angle of view is limited. If it is too small, the displayed image is too small, which is not preferable. Thus, an appropriate range for D is approximately determined.

Further, there is an appropriate range for the movement amount S of the micro optical element or the image display means. If the amount of movement of the micro optical element or the image display means by an actuator or the like is too small, accuracy cannot be obtained, and If it is too long, the range will be determined due to poor response.

As described above, S / D, that is, f
There is a suitable range for _m / R. To obtain the operation and effect of the above, reasonable values 0.0001 <f _m /R<0.0
3. f _m / R is the lower limit of 0.00 in this range.
When the value is less than 01, the accuracy becomes poor as described above, and when the value exceeds the upper limit of 0.03, the response becomes poor.

[0168] The same applies to the case where the observation optical system is composed of only micro-optical elements. There are valid values for the focal length of the micro-optical elements and the distance from the micro-optical elements to the eyeball. Range.

[18] In the above item [17], the distance R from the principal point on the eye side of the observation optical system to the exit pupil is 10 to 10.
An eyeball projection type image display device characterized by being in a range of 50 mm.

In this case, if the eye relief is too close as the eyeball projection type image display device, the final surface of the observation optical system will touch the eyelashes of the observer, or the person wearing the glasses will wear the glasses. If it is too long, it will not be possible to increase the amount of light, it will be dark, and the device itself will be large,
The above ranges are suitable for overcoming those problems.

[19] In the above item [17], the distance R from the principal point on the eye side of the observation optical system to the exit pupil is 20 to
An eyeball projection type video display device characterized by being within a range of 30 mm.

In this case, while taking into account the effects and effects of the above item [18], the observer's face may move, the final surface of the observation optical system may touch the observer's eyelashes, or wear eyeglasses. In the sense that it does not hit the eyeglasses of the person, in the sense of brightening the image while further miniaturizing the device,
It is preferable that R satisfies the condition of 20 to 30 mm.

[0173] [20] In the above [17], 0.001 <before eyes projection type image display device which is a f _m /R<0.01.

In this case, considering the operation and effect of the above item [17], f _m / _{m is used in} order to match the actual display device and further to improve the manufacturing accuracy of the micro optical element. R is preferably, 0.001 <f _m /
It is preferable to satisfy the condition of R <0.01.

[21] The above [4], [5], [8],

In any one of [9], [13] and [14], the pitch of the micro optical elements is equal to the pixel pitch of the image display means, and further satisfies the following expression. _{9f m sinθ / f o <p} <1 (mm) Here, p is the pixel pitch, f _m is the focal length of the micro-optical element, f _o is the composite focal length of the observation optical system other than the micro-optical element, theta Is the maximum viewing half angle of view.

In this case, if light emitted from a pixel of the image display means enters a minute optical element other than the regular minute optical element corresponding to the pixel, an unnecessary pupil is formed around the regular pupil. However, if the configuration is such that it is invisible to the eyes, the resolution can be prevented from deteriorating.

Specifically, if the pixel pitch or the pitch of the micro optical element is increased, the angle of the light beam that cross-talks is increased. As a result, the angle of incidence on the observer pupil is different from the angle of incidence of the normal light. At the exit pupil position, an unnecessary pupil position is separated from a normal pupil position, making it difficult to enter the observer's eyes. In the above equation, the length from the center of rotation of the eyeball of the observer to the pupil was 9 mm.

Further, when considering the manufacture of a micro optical element, if the pitch is small, etching or the like by photolithography may be used, and if the pitch is large, cutting or molding may be considered. In addition, it is difficult to obtain the accuracy of the surface shape, and as a frequently used method, there is a case where a curvature is given by annealing by heat. In this case, if the pitch is too large, the balance between the surface tension and the pitch is lost, and the surface shape cannot be conveniently formed.

In the case of a display device that projects onto the retina, a small display element is used to avoid an increase in the size of the device.
The upper limit of the pixel pitch which is assumed to be equal to the pitch of the micro optical element is naturally determined. As described above, it is desirable that the pixel pitch or the pitch of the micro optical element be in the appropriate range described above.

[22] The above [4], [5], [8],

[9] The eyeball projection image display device according to [13] or [14], further comprising an image shift function of shifting an image displayed on the image display means.

In this case, the image shift caused by tracking the exit pupil of the observation optical system to the observer's pupil is eliminated by displaying the image shifted to the opposite side on the display side, and a good image is obtained. Becomes observable.

[23] In the above item [22], when the shift amount in an arbitrary observation direction by the video shift function is δ °, δ is 30% of the maximum observation field angle.
An eyeball projection type image display device characterized by the following.

In this case, if the shift amount is large, the screen display area in the shifted direction becomes narrow when the shift is performed. If this is too large, it is unnatural, and it is preferable to shift within the above range to supply a good image.

[24] The eyeball projection image display device according to [3] or [6], further comprising a prism array in which minute prisms are arranged corresponding to the minute optical elements.

In this case, if each micro optical element is made to correspond to each RGB pixel, the pitch between each micro optical element becomes small and the size of the micro optical element becomes small. as a result,
Although the NA of the micro optical element is reduced, one micro optical element can be made to correspond to each of the three RGB pixels by using the micro prism, and the micro optical element pitch can be made larger than the pixel pitch. , N
A can also be increased. This is preferable in terms of manufacturing accuracy of a lens which is a micro optical element.

[25] The eyeball projection type video display device according to any one of the above [1] to [24], wherein the device is configured to be mounted on a head or a face.

In this case, the observation optical system has a short-focus micro-optical element, and further, each pixel of the image display means and the retina of the observer maintain the conjugate relationship, and the observation optical system exits to the pupil position of the observer. By tracking the pupil, a compact display system capable of reproducing a high-resolution image without vignetting can be provided. This is very suitable for an image display device of a type that is mounted on the head or the face, because the amount of protrusion is small and an image with high resolution can be supplied.

[26] The eyeball projection type video display according to any one of the above [1] to [24], which is configured to be a head or face mounted type capable of performing left and right stereo display. apparatus.

In this case, an optical system for displaying an image independently for each eye is required for stereoscopic display in an image display device for projecting an image to an observer's eyeball. By using a compact, high-resolution optical system, the entire apparatus can be made lighter, more compact, and have a higher resolution.

[27] The above [4], [5], [8],

[9] In [13] or [14], the driving mechanism may be configured to drive the pixels of the image display means so as to exert a moving action in substantially the same direction as the two-dimensionally arranged direction. An eyeball projection type image display device.

[0191]

As is apparent from the above description, according to the present invention, since the observation optical system has the short focus micro optical element, the eyeball projection type image display device can be reduced in size and weight. By providing a conjugate relationship between each pixel of the image display means and the retina of the observer, it is possible to provide a high-definition image, and further, the pupil position of the observer is detected,
By tracking the exit pupil of the observation optical system at the position of the pupil, this high-definition image can be observed without vignetting.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an eyeball projection type image display device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a state in which the glasses-type head-mounted display device according to the present invention is mounted on an observer's head.

FIG. 3 is a block diagram for explaining the operation of the device having the schematic configuration of FIG. 1;

FIG. 4 is a diagram for explaining the principle of moving the exit pupil of the observation optical system according to the first embodiment.

FIG. 5 is a diagram for explaining a principle of moving an image display device to move an exit pupil.

FIG. 6 is a diagram for explaining how a pupil other than a normal pupil is formed by crosstalk light.

FIG. 7 is a diagram for explaining the relationship between the display half angle of view, the distance from the center of rotation of the eyeball to the pupil, and the maximum pupil movement distance.

FIG. 8 is a diagram for explaining a position of a pupil formed by crosstalk light.

FIG. 9 is a diagram for explaining how a display image shifts when an exit pupil is tracked by a pupil.

FIG. 10 is a schematic configuration diagram of an eyeball projection image display device according to a second embodiment.

FIG. 11 is a diagram for explaining a display half angle of view in the second embodiment.

FIG. 12 is a diagram for explaining the principle of moving the exit pupil in the second embodiment.

FIG. 13 is a schematic configuration diagram of a modification of the second embodiment.

FIG. 14 is a diagram illustrating a principle of moving an exit pupil according to a modification of the second embodiment.

FIG. 15 is a diagram for explaining a position of a pupil formed by crosstalk light according to the second embodiment.

FIG. 16 is a diagram illustrating a range in which a pupil moves in the second embodiment.

FIG. 17 is a schematic configuration diagram of an eyeball projection image display device according to a third embodiment.

FIG. 18 is a schematic configuration diagram of a modification of the third embodiment.

FIG. 19 is a diagram illustrating a state in which a light amount drop occurs due to pupil tracking in the third embodiment.

FIG. 20 is a diagram for explaining an arrangement for preventing a light quantity drop in the third embodiment.

FIG. 21 is an optical path diagram and a perspective view of a microprism of a modification in which microprisms are combined to make three RGB pixels correspond to one microlens.

FIG. 22 is a diagram illustrating a range in which a pupil moves in a third embodiment.

FIG. 23 is a schematic configuration diagram of an eyeball projection type image display device according to a fourth embodiment.

FIG. 24 is a schematic configuration diagram of a modification of the fourth embodiment.

FIG. 25 is a perspective view showing an example of a stationary viewer.

FIG. 26 is a schematic configuration diagram of an eyeball projection type image display device according to a fifth embodiment.

FIG. 27 is a schematic configuration diagram of a modification of the fifth embodiment.

28A and 28B are a perspective view and a front view showing a state in which a handy type monocular viewer is attached to an observer.

FIG. 29 is a schematic configuration diagram of an eyeball projection type image display device according to a sixth embodiment.

FIG. 30 is a diagram for explaining a relationship among various parameters according to the sixth embodiment.

FIG. 31 is a schematic configuration diagram of a modification of the sixth embodiment.

[Explanation of symbols]

 E ... eyeball 1 ... field lens 2 ... micro lens array 3 ... video display device 4 ... pupil position detection unit 5 ... arithmetic control unit 6 ... drive unit 7 ... video control unit 10 ... HMD 11 ... controller 13 ... pixel 14 ... parallel illumination Unit 15: Micro prism array 16: Point light source array 20: Stationary viewer 21 ... Exit pupil side micro lens array 22 ... Illumination side micro lens array 23 ... Pupillary position detection sensor 24 ... Monocular viewer

Claims (3)

[Claims] An image display means including two-dimensionally arranged pixels for displaying an image, and a microscopic element having an action of adding a positive power to a light beam emitted from each pixel of the image display means. An eyeball projection type image display device comprising: an observation optical system including an optical member in which optical elements are two-dimensionally arranged. An exit pupil formed by the observation optical system moves in accordance with the movement of the pupil so that a light beam emitted from the observation optical system can be made incident on an observer pupil. Eye projection type image display device. 2. An image display means including two-dimensionally arranged pixels for displaying an image, and two-dimensionally arranged corresponding to each pixel of the image display means, An observation optical system including a micro-optical element for guiding an emitted light beam from a pixel to an observer's eyeball; a pupil position detecting means for detecting an observer's pupil position; And an eyeball projection type image display device. 3. An eyeball projection type image display apparatus according to claim 1, wherein said image display means is of a self-luminous type.