JP4103319B2 - projector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a projector (projection display device) that projects a color image.
[0002]
[Prior art]
As a display device having a large screen, a projector that displays an enlarged image on a screen is often used. As a projector for projecting a color image, three electro-optical devices such as a liquid crystal panel are used as light valves to form three color component images constituting the color image, and a cross dichroic prism is used as a color composition unit. A type of projector that forms a color image by combining three color component images is known. Such a projector may be referred to as a “three-plate projector”.
[0003]
In such a three-plate projector, the three electro-optical devices are arranged in a substantially rectangular image for the purpose of reducing the size of the device by reducing the size of the cross dichroic prism, reducing the price, and suppressing color unevenness. In some cases, the long side direction of the formation region is arranged so as to coincide with the direction of the line of intersection of the two types of dichroic surfaces of the cross dichroic prism. Examples include those described in JP-A-11-249070 and JP-A-2000-122174.
[0004]
[Problems to be solved by the invention]
However, in the projector in which the three electro-optical devices are arranged as described above, in order to make a projected and displayed image a general horizontally long image, three projectors are arranged in a plane including the direction of the short side of the image forming area. The electro-optical device, the cross dichroic prism, and other optical elements must be arranged three-dimensionally. For this reason, the projector has an overall tall and long appearance. In addition, there is a demerit that it is difficult to manufacture an optical system. There is also a demerit that it is difficult to efficiently cool the electro-optical device.
[0005]
The present invention has been made to solve the above-described problems in the prior art, and the electro-optical device and the color light combining means are along a plane substantially perpendicular to the direction of the short side of the projected image displayed on the projection plane. It is an object of the present invention to provide a technology capable of projecting and displaying a general horizontally long image while being arranged on the screen.
[0006]
[Means for solving the problems and their functions and effects]
In order to solve at least a part of the problems described above, an apparatus according to the present invention is a projector that displays a substantially rectangular image on a projection surface as a projection image,
Three electro-optic devices for forming three color component images;
A color synthesizing unit having two types of dichroic surfaces arranged in a substantially X shape, and synthesizing the three color component images to form a color image;
A projection lens for projecting a color image formed by the color synthesizing means,
The color synthesizing means is arranged so that the direction of the line of intersection by the two types of dichroic surfaces is substantially parallel to the direction of the short side of the projected image,
Each of the electro-optical devices has a substantially rectangular image forming area, and is parallel to the intersecting line of the color synthesizing unit so that the direction of the long side of the image forming area coincides with the direction of the intersecting line. Of the three entrance surfaces of the color composition means, the respective entrance surfaces are arranged to face each other,
The three electro-optical devices and the color synthesizing means are arranged along a plane substantially perpendicular to the direction of the short side of the projected image,
The projector further includes:
A plurality of mirrors for reflecting the color image formed by the color synthesizing unit so that the direction of the long side of the color image formed by the color synthesizing unit faces the direction of the long side of the projected image; It is characterized by that.
[0007]
The plurality of mirrors may reflect the color image formed by the color synthesizing unit such that the direction of the long side of the color image formed by the color synthesizing unit faces the direction of the long side of the projection image. Therefore, a vertically long image (landscape image) synthesized by the color synthesizing means can be made a general horizontally long image. For this reason, the color synthesizing means can be arranged such that the direction of the intersecting line is substantially parallel to the direction of the short side of the projected image. In addition, among the three incident side surfaces parallel to the intersecting line of the color synthesizing unit so that each of the three electro-optical devices has the direction of the long side of the image forming area coincident with the direction of the intersecting line of the color synthesizing unit. , And can be arranged to face the incident side surface corresponding to each. As a result, a general horizontally long image can be projected and displayed while the electro-optical device and the color light combining means are arranged along a direction substantially perpendicular to the direction of the short side of the projected image.
[0008]
In addition, since the color image formed by the color synthesizing means is reflected by a plurality of mirrors, the same optical path length can be ensured in a small space as compared with the case of reflecting by one mirror. Thereby, the apparatus can be miniaturized.
[0009]
The plurality of mirrors are rotated at a predetermined angle so that the direction of the long side in the screen of the color image formed by the color composition unit is the direction of the long side in the screen of the projected image. Having at least two mirrors,
The at least two mirrors can be configured by arranging so that normals passing through the centers of the respective reflecting surfaces do not cross each other.
[0010]
In the projector, the predetermined angle is preferably 90 degrees.
[0011]
In this way, the projection unit and the plurality of mirrors can be easily arranged.
[0012]
In the above projector,
It is preferable that at least one of the plurality of mirrors is disposed integrally with the projection lens.
[0013]
By doing so, the arrangement space of at least one mirror can be reduced, and the apparatus can be downsized. Note that “integrated arrangement” includes not only the case where the projection lens is disposed in an integrated manner in the vicinity of the incident surface or the exit surface of the projection lens but also the case where the projection lens is disposed inside the projection lens.
[0014]
Here, it is preferable that at least one mirror arranged integrally with the projection lens is constituted by a total reflection prism.
[0015]
In this way, it is possible to easily realize a reflective surface having a high reflectivity, and to realize high alignment accuracy between adjacent lens bodies.
[0016]
In the above projector,
Preferably, each of the three electro-optical devices has a signal input terminal on the side having the long side of the image forming area.
[0017]
A signal input terminal of an electro-optical device conventionally used in a projector is provided on the side having the long side of the image forming area. Therefore, according to the projector, a conventional electro-optical device can be used.
[0018]
Here, the signal input terminal has a signal line formed so as to extend from the side having the long side of the image forming region to the side having the short side,
It is preferable that the signal line along the long side direction has a shape bent three-dimensionally so that the width of the signal line becomes narrow.
[0019]
In this way, the arrangement space required for the signal input terminal can be reduced.
[0020]
The electro-optical device disposed on the first incident surface side parallel to the emission surface of the color synthesizing unit is a first electro-optical device, and is on the second incident surface side perpendicular to the first incident surface. When the electro-optical device disposed is a second electro-optical device, and the electro-optical device disposed on the third incident surface side parallel to the second incident surface is a third electro-optical device,
Either one of the first and second electro-optical devices has a signal input terminal formed by a component of a relay optical system disposed in an optical path of light that illuminates the second electro-optical device and the color synthesizing unit. It is preferably arranged in the enclosed space area.
[0021]
By doing this, it is possible to arrange the signal input terminals of the first and second electro-optical devices by utilizing the spatial region surrounded by the components of the relay optical system and the color synthesizing means.
[0022]
The three electro-optical devices include an electro-optical device arranged on a first incident surface side parallel to an emission surface of the color synthesizing unit, and second and third perpendicular to the first incident surface. The electro-optical device disposed on the incident surface side is preferably configured by two types of electro-optical devices in which the driving directions with respect to the long side direction of the respective image forming regions are opposite to each other.
[0023]
In this way, since the three electro-optical devices can be constituted by two types of electro-optical devices, it is easy to optimize the electro-optical device.
[0024]
Further, in the three electro-optical devices, the electro-optical device disposed on the first incident surface side parallel to the emission surface of the color synthesizing unit is a first electro-optical device, and is perpendicular to the first incident surface. The electro-optical device arranged on the second incident surface side is a second electro-optical device, and the electro-optical device arranged on the third incident surface side parallel to the second incident surface is a third electric optical device. When the optical device is used, the driving direction with respect to the long side direction of the image forming region of the second electro-optical device is opposite to the first electro-optical device, and the image forming region of the third electro-optical device. It is preferable that the driving direction with respect to the short side direction is constituted by three types of electro-optical devices that are opposite to the first electro-optical device.
[0025]
By doing so, the signal input terminals of the three electro-optical devices can be arranged in different spatial regions, so that the configuration of the device is easy.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
A. First embodiment:
Next, embodiments of the present invention will be described based on examples. FIG. 1 is an explanatory diagram showing a schematic configuration of a rear projector (a rear projection display device) as a first embodiment of the invention. As shown in the perspective view of FIG. 1A, the rear projector 10 includes a projection unit PJ, two projection light reflecting mirrors MR1 and MR2, and a rear screen SCR.
[0027]
In the following, the optical axis direction of the projection light from the projection unit PJ is the y direction, the 3 o'clock direction is the x direction and the 12 o'clock direction is the z direction when viewing the + y direction. Let the xy plane be a horizontal plane. In order to facilitate the description of the direction of light, the direction of the central axis of light will be described as the direction of light.
[0028]
A1. Projection Department PJ:
FIG. 2 is a schematic plan view showing the main part of the optical system of the projection unit PJ. The projection unit PJ includes an illumination optical system 100, a color light separation optical system 200, a relay optical system 300, three light valves 400R, 400G, and 400B, a cross dichroic prism 500, and a projection lens 600. Each component is arranged along a substantially horizontal plane (that is, an xy plane) around the cross dichroic prism 500. For this reason, as shown in FIG. 1A, the projection part PJ has a horizontally long and low profile as a whole.
[0029]
The illumination optical system 100 includes a light source 110, an integrator optical system 120, and an illumination light reflecting mirror 130. The light emitted from the light source 110 uniformly illuminates the light valves 400R, 400G, and 400B that are illumination targets via the integrator optical system 120. The illumination light reflecting mirror 130 has a function of reflecting the illumination light emitted from the integrator optical system 120 in the direction of the color light separation optical system 200. The illumination light reflecting mirror 130 may be disposed in the optical path in the integrator optical system 120. The illumination light reflecting mirror 130 can be omitted depending on the arrangement of the light source 110 and the integrator optical system 120. The polarization conversion optical system 140 has a function of aligning non-polarized light with polarized light having a polarization direction that can be used by the light valves 400R, 400G, and 400B.
[0030]
The color light separation optical system 200 includes two dichroic mirrors 210 and 220 and a reflection mirror 230, and has a function of separating the illumination light emitted from the illumination optical system 100 into three color lights having different wavelength ranges. ing.
[0031]
The first dichroic mirror 210 transmits red (R) light and reflects color light (substantially green (G) light and blue (B) light) shorter in wavelength than the transmitted color light. The R light that has passed through the first dichroic mirror 210 is reflected by the reflection mirror 230, passes through the field lens 240, and enters the R light valve 400R.
[0032]
Of the G light and B light reflected by the first dichroic mirror 210, the G light is reflected by the second dichroic mirror 220, passes through the field lens 250, and enters the G light valve 400G. On the other hand, the B light is transmitted through the second dichroic mirror 220, and the relay optical system 300, that is, the incident side lens 310, the first relay reflection mirror 320, the relay lens 330, the second relay reflection mirror 340, and the emission. The light enters the B light valve 400 </ b> B through the side lens 350. Here, the reason why the relay optical system 300 is used for the B light is that the length of the optical path of the B light is longer than the length of the optical path of the other color lights, and therefore the light use efficiency is reduced due to light diffusion or the like. This is to prevent it.
[0033]
Each color light valve 400R, 400G, 400B modulates the incident color light according to the corresponding color signal (image information) and emits the modulated light as transmitted light. As such a transmissive light valve, a transmissive liquid crystal panel is used. Note that these light valves 400R, 400G, and 400B correspond to the electro-optical device of the present invention, and the image represented by the modulated light of each color corresponds to the color component image of each color constituting the color image.
[0034]
FIG. 3 is a schematic perspective view showing the cross dichroic prism 500 and the light valves 400R, 400G, and 400B for the respective colors. The cross dichroic prism 500 is arranged such that an intersection line 530 where the first dichroic surface 510 and the second dichroic surface 520 intersect is perpendicular to the xy plane, that is, the horizontal plane. Of the four side surfaces 550, 560, 570, and 580, the first side surface, that is, the exit surface 550 and the second side surface 560 are parallel to the xz plane, and the third and fourth side surfaces 570 and 580 are yz. It arrange | positions so that it may become parallel to a plane. Corresponding color light valves 400G, 400B, and 400R are arranged on the second to fourth side surfaces 560, 570, and 580, respectively. In these light valves 400R, 400G, and 400B, the long side direction (long side direction) ls of the substantially rectangular image forming region (light irradiation surface) is the direction of the intersection line 530 (intersection line direction), that is, the z direction. It is arranged vertically so as to match. Hereinafter, such an arrangement may be referred to as a “longitudinal arrangement”.
[0035]
The second side surface 560 corresponds to the first incident surface of the present invention. The third side surface 570 corresponds to the second incident surface of the present invention, and the fourth side surface 580 corresponds to the third side surface.
[0036]
The R light emitted from the R light valve 400R is reflected by the first dichroic surface and emitted from the emission surface 550. The B light emitted from the B light valve 400B is reflected by the second dichroic surface and emitted from the emission surface 550. Further, the G light emitted from the G light valve 400G passes through the first dichroic surface 510 and the second dichroic surface 520 and is emitted from the emission surface 550. As a result, the three colors of modulated light modulated by the light valves 400R, 400G, and 400B for the respective colors are combined by the cross dichroic prism 500. A color image represented by the combined modulated light is projected by the projection lens 600. However, the color image synthesized by the cross dichroic prism 500 becomes a vertically long image with the long side facing the z direction corresponding to the vertically long arrangement of the light valves 400R, 400G, and 400B, and after being projected by the projection lens 600. The image displayed on the screen SCR is a horizontally long image with the long side facing the y direction. Note that light representing a color image is emitted in the + y direction.
[0037]
The configuration and function of each part of the projector as shown in FIG. 2 are described in detail in, for example, Japanese Patent Application Laid-Open Nos. 10-177151 and 10-186548 disclosed by the applicant of the present application. Detailed description is omitted in the book.
[0038]
A2. Arrangement of the projection light reflecting mirrors MR1, MR2:
As shown in FIG. 1C, the second projection light reflecting mirror MR2 is disposed so as to reflect the projection light from the projection unit PJ traveling in the + y direction in the + z direction. Specifically, the normal line n2 on the reflecting surface of the second projection light reflecting mirror MR2 is arranged so as to be parallel to the yz plane and inclined 45 degrees clockwise with respect to the y axis. ing. Further, as shown in FIG. 1B, the first projection light reflection mirror MR1 is disposed so as to reflect the projection light from the second projection light reflection mirror MR2 traveling in the + z direction in the + x direction. . Specifically, the normal line n1 on the reflecting surface of the first projection light reflecting mirror MR1 is arranged so as to be parallel to the xz plane and inclined 45 degrees counterclockwise with respect to the z axis. Has been. That is, the first and second projection light reflecting mirrors MR1 and MR2 are arranged at twist positions where the normals n1 and n2 on the respective reflecting surfaces do not intersect each other. The rear screen SCR is disposed in parallel to the yz plane.
[0039]
By the projection unit PJ and the two projection light reflection mirrors MR1 and MR2 arranged as described above, the projection light from the projection unit PJ is transmitted by the second projection light reflection mirror MR2 and the first projection light reflection mirror MR1. Reflected and incident on the rear screen SCR.
[0040]
Here, the two projection light reflecting mirrors MR1 and MR2 set the direction of the long side in the screen of the image projected from the projection unit PJ as the direction of the long side in the screen of the image projected on the rear screen SCR. Rotate 90 degrees. As a result, as shown in FIG. 1A, the horizontal arrow image projected from the projection unit PJ becomes an upward arrow figure by the two projection light reflecting mirrors MR1 and MR2 arranged at the twisted positions. And is projected onto the rear screen SCR.
[0041]
As described above, in the rear projector 10 of the present embodiment, the long side direction of the image forming areas of the three light valves 400R, 400G, and 400B in the projection unit PJ coincides with the direction of the intersection line 530 of the cross dichroic prism 500. With the configuration as described above, each component of the optical system constituting the projection unit PJ is a plane perpendicular to the direction of the short side of the image projected on the screen SCR (z direction in FIG. 1A) (FIG. 1). In (A), a general landscape image can be projected and displayed while being arranged along the xy plane).
[0042]
Further, in the rear projector 10 of the present embodiment, since the two projection light reflecting mirrors MR1 and MR2 are arranged at twisted positions, the projection unit PJ is arranged in a state substantially parallel to the screen SCR. For this reason, the depth and height of the rear projector 10 (x direction and z direction in FIG. 1A) can be shortened, and the size of the entire apparatus can be reduced.
[0043]
By the way, the second projection light reflecting mirror can be arranged as follows. FIG. 4 is an explanatory diagram showing an example in which the second projection light reflecting mirror MR2 is arranged in the projection lens of the projection unit PJ. As shown in FIG. 4A, the projection lens 600 is a compound lens composed of a plurality of lenses (FIG. 4 shows an example in which three partial lenses are composed of five lenses). Therefore, as shown in FIG. 4B, a projection lens 600 ′ in which the second projection light reflecting mirror MR2 is disposed in the optical path of the compound lens may be used as the projection lens of the projection unit PJ. If such a projection lens 600 ′ is used, the arrangement space of the second projection light reflecting mirror MR2 in FIG. 1 can be reduced, and thus the rear projector can be further miniaturized. In the case where the second projection light reflecting mirror MR2 is disposed in the projection lens, it is preferable that the projection light reflecting mirror is constituted by a total reflection prism. According to the total reflection prism, a mirror having a high reflectance can be easily configured in the projection lens.
[0044]
Further, the projection light reflecting mirror MR2 is not limited to being arranged in the middle of the plurality of lenses as shown in FIG. 4B, but may be arranged integrally on the incident surface or exit surface side of the projection lens.
[0045]
A3. Arrangement of light valves 400R, 400G, 400B:
FIG. 5 is a schematic plan view showing the periphery of the cross dichroic prism 500 in an enlarged manner. The signal input terminal of the light valve is generally provided on the side having the long side of the image forming area (hereinafter, sometimes simply referred to as “long side”). Therefore, in arranging the light valves 400R, 400G, and 400B in the projection unit PJ, it is necessary to consider the arrangement space for each signal input terminal provided on the long side. Specifically, the signal input terminals 410G and 410B of the G light valve 400G and the B light valve 400B are respectively connected to the incident side lens 310, the relay lens 330, the emission side lens 350, and the field lens of the relay optical system 300. 250 and the cross dichroic prism 500 are arranged so as to be in a spatial region SP1 (region indicated by a broken-line circle in the drawing). Further, the signal input terminal 410R of the R light valve 400R is arranged in the space region SP3 on the projection lens 600 side.
[0046]
FIG. 6 is a schematic front view of the light valves 400R, 400G, and 400B for each color in the arrangement shown in FIG. 5 as viewed from the light incident surface side (light irradiation surface side). The solid line arrows in the figure indicate the driving direction in the long side direction and the driving direction in the short side direction of the image forming area. A broken line arrow indicates a clear vision direction. In the arrangement shown in FIG. 5, with reference to the G light valve shown in FIG. 6B, as shown in FIGS. 6A and 6C, the R light valve 400R and the B light valve are used. As the valve 400B, a light valve of a type in which the driving direction with respect to the long side direction is opposite and the clear vision direction is symmetric with respect to the short side direction is used. That is, the three light valves can be composed of two types of light valves.
[0047]
As shown in FIG. 5, there is an arrangement space for the signal input terminal in the space region SP2 surrounded by the two field lenses 240 and 250, the cross dichroic prism 500, and the first dichroic mirror 210. In this case, the signal input terminal 410R of the R light valve 400R and the signal input terminal 410G of the G light valve 400B may be arranged in the space region SP2. However, the size of the light beam incident on the first dichroic mirror 210 from the illumination optical system 100 is larger than the size of the light beam incident on the light valves 400R, 400G, and 400B for each color, and the first dichroic mirror. The 210 color light separation surface (dichroic surface) needs to be considerably large. For this reason, the space region SP2 often has little arrangement space for arranging the signal input terminals. On the other hand, the light beam passing through the relay optical system 300 is considerably condensed, and its size is considerably smaller than the size of the light beam incident on the first dichroic mirror 210. Therefore, it is possible to secure a space in the space region SP1 in which the signal input terminal 410G of the G light valve 400G and the signal input terminal 410B of the B light valve 400B are arranged.
[0048]
FIG. 7 is an explanatory diagram showing the signal input terminal 410G of the G light valve 400G. As shown in FIG. 7A, the signal input terminal 410G of the light valve 400G is formed to extend from the side surface on the long side to the top surface on the short side. A plurality of signal lines are formed in a plane on the signal input terminal 410G using an FPC (flexible printed circuit), and the cross-sectional shape along the line AB is flat as shown in FIG. Is. However, the cross-sectional shape in the middle part of the FPC is not planar. For example, the cross-sectional shape along the line CD is folded in three as shown in FIG. 7C, or FIG. As shown in FIG. 3, it has a three-dimensional shape such as a shape bent in a U shape. If the signal input terminal 410G has a structure in which a plurality of signal lines are gathered in a three-dimensional manner as described above, the arrangement space required in one direction (the x direction in FIG. 5) of the signal input terminal 410G is reduced. be able to. In addition, by extending the signal input terminal 410G from the long side to the short side, a flow path in the vertical direction (z direction in FIG. 5) of the cooling air can be secured, so that the cooling efficiency can be improved.
[0049]
Since the light valves 400R and 400B for other colors are the same, the description thereof is omitted.
[0050]
FIG. 8 is another schematic plan view showing the periphery of the cross dichroic prism 500 in an enlarged manner. In this example, only the signal input terminal 410G of the G light valve 400G is arranged in the space region SP1. The signal input terminal 410R of the R light valve 400R is arranged in the space region SP3 on the projection lens 600 side, and the signal input terminal 410B of the B light valve 400B is in the space region SP4 on the projection lens 600 side. Arranged to be.
[0051]
FIG. 9 is a schematic front view of the light valves 400R, 400G, and 400B in the arrangement shown in FIG. 8 as viewed from the light incident surface side. The solid line arrows in the figure indicate the driving direction in the long side direction and the driving direction in the short side direction of the image forming area. A broken line arrow indicates a clear vision direction. In the arrangement shown in FIG. 8, as shown in FIGS. 9A, 9B, and 9C, different types of light valves are used for the three light valves 400R, 400G, and 400B. Specifically, if the G light valve 400B in FIG. 9B is used as a reference, the R light valve 400R has a driving direction in the long side direction opposite to that shown in FIG. 9A. A light valve with the opposite direction of clear vision is used. As shown in FIG. 9C, the light valve 400B for B uses a light valve whose driving direction in the short side direction is opposite and whose clear vision direction is symmetric with respect to the long side direction.
[0052]
In the case of the arrangement shown in FIG. 8, the input terminals 410R, 410G, and 410B of the light valves 400R, 400G, and 400B for the respective colors may be arranged in different space regions SP1, SP3, and SP4, respectively. . However, it is necessary to use three types of light valves as shown in FIG. In this regard, the arrangement shown in FIG. 5 is advantageous because two types of light valves may be used.
[0053]
B. Second embodiment:
FIG. 10 is an explanatory diagram showing the rear projector 20 of the second embodiment in comparison with the rear projector 10 of the first embodiment. The rear projector 20 of the second embodiment is denoted by the same reference numerals with respect to the same configuration as that of the first embodiment, and description thereof will be omitted below. In the rear projector 10 of the first embodiment, the projection light from the projection unit PJ traveling in the + y direction is reflected by the second projection light reflecting mirror MR2 and travels in the + z direction as shown in FIG. The light is reflected by the first projection light reflecting mirror MR1, travels in the + x direction, and enters the rear screen SCR. For this reason, the second projection light reflecting mirror MR2 is arranged such that the normal line n2 on the reflecting surface thereof is parallel to the yz plane and has an inclination of 45 degrees in the clockwise direction with respect to the y axis. (FIG. 1C). Further, the first projection light reflecting mirror MR1 has a normal line n1 on the reflecting surface thereof inclined in the direction of θ1 (= 45 degrees) parallel to the xz plane and counterclockwise with respect to the z axis. It is arranged to have.
[0054]
On the other hand, as shown in FIG. 10B, the projection light from the projection unit PJ traveling in the + y direction in the rear projector 20 of the second embodiment is reflected by the second projection light reflecting mirror MR2, and is directed in the + z direction. On the other hand, the light travels counterclockwise in the direction inclined by α degrees, further reflects by the first projection light reflecting mirror MR1, travels in the + x direction, and enters the rear screen SCR. Therefore, the second projection light reflecting mirror MR2 in the second embodiment rotates the second projection light reflecting mirror MR2 in the first embodiment counterclockwise by an angle α about the central axis parallel to the y axis. Are arranged. Further, in the first projection light reflecting mirror MR1, the normal line n1 on the reflecting surface is parallel to the xz plane and counterclockwise θ2 (= (45 + α / 2)) degrees with respect to the z axis. It is arrange | positioned so that it may have inclination of. That is, as in the first embodiment, the first and second projection light reflecting mirrors MR1 and MR2 are arranged at twisted positions where the normal lines n1 and n2 on the respective reflecting surfaces do not intersect each other.
[0055]
However, θ2> θ1 (0 <α <90). Therefore, the inclination of the first projection light reflection mirror MR1 in the second embodiment with respect to the yz plane can be made smaller than the inclination of the first projection light reflection mirror MR1 in the first embodiment. As a result, the rear projector 20 of the second embodiment can be configured thinner than the rear projector 10 of the first embodiment.
[0056]
The rear projector 10 of the first embodiment is equivalent to the case where α = 0 in the rear projector 20 of the second embodiment.
[0057]
However, in the rear projector 20, it is preferable that the projection unit PJ is arranged to be rotated α degrees counterclockwise around a central axis parallel to the y axis with respect to the horizontal plane (xy plane).
[0058]
Therefore, “the three electro-optical devices and the color synthesizing means are arranged along a plane substantially perpendicular to the direction of the short side of the projected image” of the present invention means that the projected image is as in the first embodiment. In addition to the case where the optical system including the light valve (electro-optical device) and the color synthesizing means (cross dichroic prism) is disposed along a plane perpendicular to the direction of the short side (that is, the xy plane), Thus, the case where the optical system is tilted by tilting the projection part PJ by α degrees is also included.
[0059]
C. Third embodiment:
FIG. 11 is an explanatory diagram showing a schematic configuration of a rear projector as a third embodiment. In the rear projector 30, the rear projector 10 (FIG. 1A) of the first embodiment reflects the projection light from the projection unit PJ by the two projection light reflecting mirrors MR1 and MR2, whereas FIG. As shown in the perspective view of A), another projection light reflection mirror MR3 is added to the two projection light reflection mirrors MR1 and MR2, and the projection light from the projection unit PJ is reflected by the three projection light reflection mirrors. Is different. Note that in the rear projector 30 of the third embodiment, the same reference numerals are given to the same configurations as those of the rear projector 10 of the first embodiment, and description thereof will be omitted below.
[0060]
As shown in FIG. 11C, the third projection light reflecting mirror MR3 is arranged to reflect the projection light from the projection unit PJ traveling in the + y direction in the −z direction. Specifically, the normal line n3 on the reflecting surface of the third projection light reflecting mirror MR3 is arranged so as to be parallel to the yz plane and inclined 45 degrees counterclockwise with respect to the y axis. Has been. As shown in FIG. 11 (B), the second projection light reflecting mirror MR2 is configured to cause the projection light from the third projection light reflecting mirror MR3 traveling in the −z direction to be α in the counterclockwise direction with respect to the + z direction. It is arranged so as to reflect in a direction tilted. Specifically, the normal line n2 on the reflecting surface of the second projection light reflecting mirror MR2 is α / 2 degrees (0 <α <0) parallel to the xz plane and counterclockwise with respect to the z axis. 90). Further, as shown in FIG. 11B, the first projection light reflection mirror MR1 reflects the projection light from the second projection light reflection mirror MR2 that is inclined by α degrees with respect to the + z direction in the + x direction. Are arranged to be. Specifically, the normal line n1 on the reflecting surface of the first projection light reflecting mirror MR1 is parallel to the xz plane and has an inclination of (45 + α / 2) degrees in the clockwise direction with respect to the z axis. Are arranged as follows. That is, the second projection light reflection mirror MR2 and the third projection light reflection mirror MR3 are arranged at twist positions where the normal lines n2 and n3 do not intersect each other on the respective reflection surfaces. The rear screen SCR is disposed in parallel to the yz plane.
[0061]
By disposing the projection unit PJ and the three projection light reflection mirrors MR1 to MR3 as described above, the projection light from the projection unit PJ is transmitted from the third projection light reflection mirror MR3 to the first projection light reflection mirror MR1. Reflected and incident on the rear screen SCR.
[0062]
Here, the two projection light reflecting mirrors MR3 and MR2 indicate the orientation of the long side in the screen of the image projected from the projection unit PJ in the screen of the reflected image, that is, the image projected on the rear screen SCR. Rotate 90 degrees clockwise around the central axis perpendicular to the screen so that the direction of the long side at is. The first projection light reflection mirror MR1 reflects in the direction of the rear screen SCR without causing rotation of the image reflected by the second projection light reflection mirror MR2. As a result, as shown in FIG. 11A, the horizontal arrow image projected from the projection unit PJ becomes an upward arrow figure by the two projection light reflecting mirrors MR3 and MR2 arranged at the twisted positions. And is projected onto the rear screen SCR. Thereby, also in the present embodiment, the long side direction of the image forming area of the three light valves 400R, 400G, and 400B of the projection unit PJ is matched with the direction of the intersection line 530 of the cross dichroic prism 500. A plane perpendicular to the direction of the short side of the image projected on the screen SCR (the z direction in FIG. 11A) is the xy plane in FIG. It is possible to project and display a general horizontally long image while being arranged along the line.
[0063]
Further, since the rear projector 30 of the present embodiment is configured to reflect the projection light from the projection unit by the three projection light reflection mirrors MR1 to MR3, even when a projection lens having a long projection distance is used, Compared to a rear projector configured to reflect the projection light from the projection unit by one projection light reflecting mirror, the overall size of the apparatus can be reduced.
[0064]
The first projection light reflecting mirror MR1 has a normal line n1 on the reflecting surface thereof that is parallel to the xz plane and has an inclination of (45 + α / 2) degrees counterclockwise with respect to the z axis. And depends on the inclination α of the projection light from the second projection light reflection mirror MR2. Accordingly, similarly to the second embodiment, the inclination of the first projection light reflection mirror MR1 with respect to the yz plane can be changed in accordance with the inclination of the projection light from the second projection light reflection mirror MR2. Compared to the rear projector 10 of the embodiment, the configuration can be reduced.
[0065]
D. Fourth embodiment:
In the first to third embodiments, the case where the projection unit PJ using a transmissive liquid crystal panel as a light valve is described as an example, but a projection unit using a reflective liquid crystal panel is used. You can also.
[0066]
FIG. 12 is a schematic plan view showing the main part of the optical system of the projection unit PJ ′ using the reflective liquid crystal panel as a light valve. The projection unit PJ ′ includes an illumination optical system 100, a color light separation optical system 200 ′, a relay optical system 300 ′, polarization beam splitters 700R, 700G, and 700B, light valves 400R ′, 400G ′, and 400B ′. A dichroic prism 500 and a projection lens 600 are provided. Each component is arranged in a substantially horizontal direction around the cross dichroic prism 500.
[0067]
The light emitted from the bright optical system 100 enters the color light separation optical system 200 ′ and is separated into three color lights. The first dichroic mirror 210 ′ reflects the B light and reflects the color light (G light and R light) longer than the B light.
[0068]
Of the G light and R light transmitted through the first dichroic mirror 210 ′, the R light also transmits through the second dichroic mirror 220 ′, and enters the R polarizing beam splitter 700R through the field lens 240. The G light is reflected by the second dichroic mirror 220 ′, passes through the field lens 250, and enters the G polarization beam splitter 700G.
[0069]
The B light reflected by the first dichroic mirror 210 ′ passes through the relay optical system 300 ′, that is, the incident side lens 310, the relay reflecting mirror 320, and the relay lens 330, and further passes through the emission side lens 350 for the B light. Is incident on the polarizing beam splitter 700B.
[0070]
Each color light incident on the polarization beam splitters 700R, 700G, and 700B for each color is converted into two types of polarized light (s-polarized light and p-polarized light) on the polarization separation surfaces 710R, 710G, and 710B of the corresponding polarization beam splitters 700R, 700G, and 700B. Light). The light valves 400R ′, 400G ′, and 400B ′ for the respective colors are arranged on the optical axis of one of the polarized lights emitted from the corresponding polarizing beam splitters 700R, 700G, and 700B. In the illustrated example, the polarization separation surfaces 710R, 710G, and 710B of the polarization beam splitters 700R, 700G, and 700B reflect the s-polarized light and transmit the p-polarized light, and the light valves 400R ′ and 400G ′ for the respective colors. , 400B ′ are arranged on the optical axis of the s-polarized light. Accordingly, each color light of the s-polarized light enters the corresponding light valves 400R ′, 400G ′, 400B ′ as illumination light.
[0071]
Each color light valve 400R ′, 400G ′, 400B ′ modulates each color light incident as illumination light according to a corresponding color signal (image information) and emits it as reflected light. As such reflection type light valves 400R ′, 400G ′, and 400B ′, reflection type liquid crystal panels are used.
[0072]
The light valves 400R ′, 400G ′, and 400B ′ for the respective colors are arranged vertically in the same manner as the light valves 400R, 400G, and 400B for the respective colors in the projection unit PJ.
[0073]
The light emitted from the light valves 400R ′, 400G ′, and 400B ′ for each color reenters the corresponding polarization beam splitters 700R, 700G, and 700B. Each color light incident again is a mixed light including modulated light (p-polarized light) and unmodulated light (s-polarized light). Accordingly, only the modulated light among the emitted lights of the respective colors is transmitted through the polarization separation surfaces 710R, 710G, and 710B of the corresponding polarization beam splitters 700R, 700G, and 700B and is incident on the cross dichroic prism 500.
[0074]
The color lights incident on the cross dichroic prism 500 are combined and emitted toward the projection lens 600. As a result, a color image represented by the light synthesized by the cross dichroic prism 500 is projected by the projection lens 600. However, the direction of the color image synthesized by the cross dichroic prism 500 is a horizontally oriented image that faces the x or z direction corresponding to the vertically long arrangement of the light valves 400R ′, 400G ′, and 400B ′ for each color.
[0075]
In the projection unit PJ ′ of this example, the signal input terminal of the light valve 400G ′ can be arranged in a space surrounded by the relay lens 330, the incident side lens 310, and the polarization beam splitter 700G. A light valve having a signal input terminal on the side can be used.
[0076]
E. Variation:
The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.
[0077]
(1) In the above embodiment, a rear projector using two or three projection light reflecting mirrors is described as an example, but the present invention is not limited to this, and a rear projector using four or more projection light reflecting mirrors is described. It may be a projector. That is, the present invention can be applied to a rear projector including a plurality of projection light reflecting mirrors. Then, the plurality of projection light reflecting mirrors that cause the rotation of the image need only be arranged at twist positions where the respective normal lines do not intersect with each other.
[0078]
(2) In the above embodiment, the rear projector is described as an example. However, the present invention can be applied to a front projection type projector (front projector). In the case of a rear projector, an image is displayed by light transmitted through the rear screen SCR. On the other hand, in the case of a front projector, an image is displayed by light reflected from the screen. Since the projection unit and the screen cannot be integrated in the front projector, it is necessary to arrange all of the projection light reflecting mirrors before and after the projection lens or inside the projection lens.
[0079]
FIG. 13 is an explanatory diagram showing an example in which two projection light reflecting mirrors MR1 and MR2 are arranged in the projection lens. In the projection lens 600 ″, two projection light reflecting mirrors MR1 and MR2 are disposed between the second partial lens 612 and the third partial lens 613 among the three partial lenses 611, 612, and 613. It has the structure. The two reflecting mirrors MR1 and MR2 may be disposed between the first partial lens 611 and the second partial lens 612. Further, the second projection light reflection mirror MR2 is disposed between the first partial lens 611 and the second partial lens 612, and the first projection light reflection mirror MR1 is disposed between the second partial lens 612 and the third partial lens. You may make it arrange | position between 613. That is, the plurality of projection light reflecting mirrors may be arranged at any position within the projection lens. The two projection light reflecting mirrors MR1 and MR2 are not necessarily arranged in the projection lens, and are projected on the incident surface side of the first partial lens 611 or the emission surface side of the third partial lens 613. You may make it arrange | position integrally with a lens. Also, one of the two projection light reflecting mirrors MR1 and MR2 is disposed in the projection lens, and the other is disposed on the incident surface side of the first partial lens 611 or the exit surface side of the third partial lens 613. You may make it arrange | position integrally with a projection lens.
[0080]
Note that the two projection light reflecting mirrors MR1 and MR2 disposed in the projection lens 600 ″ are configured by total reflection prisms, like the second projection light reflecting mirror MR2 in the projection lens 600 ′ of FIG. Is preferred.
[0081]
(3) In the above embodiment, the cross dichroic prism is used as the color synthesizing means, but a cross dichroic mirror can be used instead.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a schematic configuration of a rear projector as a first embodiment of the invention.
FIG. 2 is a schematic plan view showing a main part of an optical system of a projection unit PJ.
FIG. 3 is a schematic perspective view showing a cross dichroic prism 500 and light valves 400R, 400G, and 400B for respective colors.
FIG. 4 is an explanatory diagram showing an example in which a second projection light reflecting mirror MR2 is arranged in a projection lens of a projection unit PJ.
FIG. 5 is an enlarged schematic plan view showing a periphery of a cross dichroic prism 500. FIG.
6 is a schematic front view of the light valves 400R, 400G, and 400B for each color in the arrangement shown in FIG. 5 as viewed from the light incident surface side.
FIG. 7 is an explanatory diagram showing a signal input terminal 410G of a G light valve 400G.
FIG. 8 is another schematic plan view showing the periphery of the cross dichroic prism 500 in an enlarged manner.
9 is a schematic front view of the light valves 400R, 400G, and 400B in the arrangement shown in FIG. 8 as viewed from the light incident surface side.
FIG. 10 is an explanatory diagram showing a rear projector 20 according to a second embodiment in comparison with the rear projector 10 according to the first embodiment.
FIG. 11 is an explanatory diagram showing a schematic configuration of a rear projector as a third embodiment.
FIG. 12 is a schematic plan view showing a main part of an optical system of a projection unit PJ ′ using a reflective liquid crystal panel as a light valve.
FIG. 13 is an explanatory diagram showing an example in which two projection light reflecting mirrors MR1 and MR2 are arranged in a projection lens.
[Explanation of symbols]
10 ... Rear projector
20 ... Rear projector
30 ... Rear projector
100: Illumination optical system
110: Light source
120. Integrator optical system
130: Illumination light reflecting mirror
140: Polarization conversion optical system
200: Color light separation optical system
200 '... color light separation optical system
210, 220 ... Dichroic mirror
210 ', 220' ... Dichroic mirror
230 ... reflecting mirror
240, 250 ... Field lens
300: Relay optical system
300 '... Relay optical system
310 ... Incident side lens
320, 340 ... Relay reflection mirror
330 ... Relay lens
350: Ejection side lens (field lens)
400R, 400G, 400B ... Light valve
410R, 410G, 410B ... signal input terminals
400R ', 400G', 400B '... Light valve
500 ... Cross dichroic prism
510 ... first dichroic surface
520 ... Second dichroic surface
530 ... line of intersection
550 ... 1st side surface (injection surface)
560 ... 2nd side surface (1st incident surface)
570 ... Third side surface (second incident surface)
580 ... Fourth side surface (third incident surface)
600 ... Projection lens
600 '... projection lens
600 ″… Projection lens
700R, 700G, 700B ... Polarizing beam splitter
710R, 710G, 710B ... polarization separation plane
PJ ... Projector
PJ '... Projector
MR1, MR2, MR3 ... Projection light reflection mirror
SCR ... Rear screen

Claims (6)

A projector that displays a substantially rectangular image as a projected image on a projection surface,
Three electro-optic devices for forming three color component images;
A color synthesizing unit having two types of dichroic surfaces arranged in a substantially X shape, and synthesizing the three color component images to form a color image;
A projection lens for projecting a color image formed by the color synthesizing means,
The color synthesizing means is arranged so that the direction of the line of intersection by the two types of dichroic surfaces is substantially parallel to the direction of the short side of the projected image,
Each of the electro-optical devices has a substantially rectangular image forming area, and the color synthesizing means parallel to the intersecting line so that the direction of the long side of the image forming area coincides with the direction of the intersecting line The three incident surfaces are arranged to face the corresponding incident surfaces,
The three electro-optical devices and the color synthesizing means are arranged along a plane substantially perpendicular to the direction of the short side of the projected image,
The projector further includes:
A plurality of mirrors for reflecting the color image formed by the color composition unit so that the direction of the long side of the color image formed by the color composition unit is directed to the direction of the long side of the projection image; And
Each of the three electro-optical devices has a signal input terminal on the side having the long side of the image forming region,
The three electro-optical devices include an electro-optical device disposed on a first incident surface side parallel to an emission surface of the color synthesizing unit, and second and third incident surfaces perpendicular to the first incident surface. And an electro-optical device arranged on the side, the projector comprising two types of electro-optical devices in which the driving directions with respect to the long side direction of each image forming region are opposite to each other. A projector that displays a substantially rectangular image as a projected image on a projection surface,
Three electro-optic devices for forming three color component images;
A color synthesizing unit having two types of dichroic surfaces arranged in a substantially X shape, and synthesizing the three color component images to form a color image;
A projection lens for projecting a color image formed by the color synthesizing means,
The color synthesizing means is arranged so that the direction of the line of intersection by the two types of dichroic surfaces is substantially parallel to the direction of the short side of the projected image,
Each of the electro-optical devices has a substantially rectangular image forming area, and the color synthesizing means parallel to the intersecting line so that the direction of the long side of the image forming area coincides with the direction of the intersecting line The three incident surfaces are arranged to face the corresponding incident surfaces,
The three electro-optical devices and the color synthesizing means are arranged along a plane substantially perpendicular to the direction of the short side of the projected image,
The projector further includes:
A plurality of mirrors for reflecting the color image formed by the color composition unit so that the direction of the long side of the color image formed by the color composition unit is directed to the direction of the long side of the projection image; And
Each of the three electro-optical devices has a signal input terminal on the side having the long side of the image forming region,
In the three electro-optical devices, the electro-optical device disposed on the first incident surface side parallel to the emission surface of the color combining unit is a first electro-optical device, and the first electro-optical device is perpendicular to the first incident surface. The electro-optical device disposed on the second incident surface side is the second electro-optical device, and the electro-optical device disposed on the third incident surface side parallel to the second incident surface is the third electro-optical device. Then, the driving direction with respect to the long side direction of the image forming area of the second electro-optical device is opposite to the first electro-optical device, and the image forming area of the third electro-optical device is short. A projector comprising three types of electro-optical devices whose driving directions with respect to the side direction are opposite to the first electro-optical device. The projector according to claim 1 or 2 , wherein
The plurality of mirrors are rotated at a predetermined angle so that the direction of the long side in the screen of the color image formed by the color synthesizing unit is the direction of the long side in the screen of the projected image. Have two mirrors,
The projector, wherein the at least two mirrors are arranged such that normals passing through the centers of the respective reflecting surfaces do not intersect each other. The projector according to claim 3 , wherein
The projector, wherein the predetermined angle is 90 degrees. The projector according to claim 1 or 2 , wherein
At least one of the plurality of mirrors is a projector arranged integrally with the projection lens. The projector according to claim 5 , wherein
The projector, wherein at least one mirror arranged integrally with the projection lens is configured by a total reflection prism.

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