JP2008083499A - Light modulation device and projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light modulation device designed such that the effect of heat on an optical system that attains a high dynamic range is reduced and the high dynamic range characteristic of the optical system is maintained, and to provide a projector. <P>SOLUTION: The light modulation device 100 includes: a light valve 51, serving as a first light modulating element, which modulates light from a lamp 31 for use as a light source; a light valve 81, serving as a second light modulating element, which modulates light from a light valve 51; a relay lens section 70 disposed between the light valves 51 and 81; and a fixing member 200 that fixes the light valves 51 and 81 and relay lens section 70 integrally in a prescribed place. The projector 1 is composed of this light modulating device 100. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a light modulation device that modulates light from a light source and emits the modulated light, and a projector having the light modulation device.

  In recent years, electronic display devices such as LCD (Liquid Crystal Display), EL (Electro-luminescence) displays, plasma displays, CRTs (Cathode Ray Tubes), and projectors have been remarkably improved, and the resolution and color gamut have become human visual characteristics. Devices with nearly comparable performance are being realized. However, the reproduction range of the luminance dynamic range in the display device is narrow compared to the range of the luminance dynamic range that can be perceived at a time by human vision, and in addition, the gradation of the shadow part and highlight part is insufficient. You will feel unsatisfactory with the reality and power of the displayed image.

  Among display devices, a projection display device (projector) such as a liquid crystal projector or a DLP (Digital Light Processing) projector can display a large screen, and reproduces a realistic display image. It is an effective display device. In this field, a proposal as in Patent Document 1 has been made in order to increase the luminance dynamic range and increase the number of gradations.

  The image display device or projector disclosed in Patent Document 1 is a device that displays an image by modulating light from a light source based on display image data, and includes a first light modulation element that modulates light from the light source, and first light. And a second light modulation element that modulates light from the modulation element. A relay lens is disposed between the first light modulation element and the second light modulation element. With this configuration, light from the light source is modulated by two-stage image formation processes via two light modulation elements (first light modulation element and second light modulation element) optically arranged in series. As a result, it is possible to increase the luminance dynamic range and increase the number of gradations. Further, the optical aberration can be reduced by providing the relay lens. In other words, since the light from the first light modulation element can be transmitted to the second light modulation element with relatively high accuracy, the optical image modulated by the first light modulation element can be transmitted to one surface of the second light modulation element with high accuracy. To form an image. Therefore, it is possible to obtain a display image with small luminance reduction and luminance unevenness, a wide dynamic range, and excellent gradation characteristics.

JP 2005-345864 A

  When the above-described configuration of Patent Document 1 is adopted and a projector or the like is commercialized, the first light modulation element, the relay lens, and the second light modulation element include other optical elements that constitute other optical systems. It is common to be accommodated in each place of a common accommodation case. As described above, when the first light modulation element, the relay lens, the second light modulation element, and the optical elements constituting the other optical system are accommodated in one accommodation case, the accommodation case expands due to a temperature change. -Shrinkage and expansion / contraction occurs between the optical elements. As a result, there is a problem in that it is difficult to obtain a display image that has a low luminance nonuniformity and luminance unevenness that the original optical system has, a wide dynamic range, and excellent gradation characteristics.

  The present invention has been made in view of the above-described problems, and includes a light modulation device and a projector that reduce the influence of heat on an optical system that realizes a high dynamic range and maintain the high dynamic range characteristics of the optical system. Is to provide.

  In order to achieve the above-described object, a light modulation device of the present invention is a light modulation device that modulates light from a light source and emits the modulated light, and first light modulation that modulates light from the light source. An element, a second light modulation element that modulates light from the first modulation element, a relay lens unit disposed between the first light modulation element and the second light modulation element, a first light modulation element, and a relay And a fixing member that integrally fixes the lens unit and the second light modulation element at a predetermined position.

According to such a light modulation device, the first light modulation element is fixed on the basis of the fixed member by fixing the first light modulation element, the relay lens unit, and the second light modulation element at predetermined positions by the fixing member. The relay lens unit and the second light modulation element can be unitized and fixed as a unit.
The distance between the relay lens unit and the first light modulation element and the distance between the relay lens unit and the second light modulation element can be accurately positioned with respect to the thus configured light modulation device. That is, the flange distance between the relay lens unit and the first light modulation element and the conjugate distance between the first light modulation element and the second light modulation element with the relay lens unit as the center can be ensured with high accuracy. In addition, when a temperature load is applied, it is not fixed by a common housing case with other optical elements, so the influence of expansion and contraction can be minimized, and changes in flange back and conjugate distance can be minimized. It becomes possible to do. Therefore, it is possible to realize an optical modulation device that reduces the influence of temperature on an optical system that realizes a high dynamic range and maintains the high dynamic range characteristics of the optical system.

  Further, in the above-described light modulation device, three first light modulation elements that respectively modulate red light, green light, and blue light, and first light modulation element housing portions that respectively house the three first light modulation elements; A color synthesizing optical element that synthesizes the respective color lights emitted from the three first light modulation elements, and a first light modulation element housing portion that holds the first light modulation element so that the first light modulation element is positioned at a predetermined position in the color synthesis optical element A first light modulation element fixing portion fixed to the color synthesizing optical element, a color combining optical element fixing portion fixing the color combining optical element to the fixing member, a second light modulation element holding portion containing the second light modulation element, It is desirable to have a second light modulation element fixing portion that holds the two light modulation element accommodating portions and fixes the second light modulation element to the fixing member so that the second light modulation element is at a predetermined position.

  Three first light modulation elements that modulate light corresponding to each color light (red light, green light, and blue light) by separating (spectral) light from the light source are provided in the first light modulation element housing portion. The first light modulation element is fixed to a predetermined position on a color synthesis optical element that is accommodated and synthesizes each color light emitted from the first light modulation element via the first light modulation element fixing unit. . The color synthesis optical element is fixed to the color synthesis optical element fixing unit. The color combining optical element fixing portion is fixed to a fixing member. The second light modulation element is housed in the second light modulation element housing portion, and is fixed to the fixing member by the second light modulation element fixing portion so that the second light modulation element is at a predetermined position.

  With such a configuration, the light modulation device can integrally fix the first light modulation element, the relay lens unit, and the second light modulation element with the fixing member as a reference. Can be played.

In the light modulation device described above, it is desirable that the first light modulation element is optically adjusted and fixed to the color synthesis optical element.
The first light modulation element is optically adjusted and fixed to the color synthesis optical element, so that the flange back can be secured with high accuracy. Further, by performing alignment for matching the corresponding pixels with respect to the pixels constituting the three first light modulation elements, it is possible to reduce the occurrence of pixel shift, image blur, luminance change, color unevenness, and the like.

In the light modulation device described above, it is preferable that the second light modulation element performs optical adjustment using the emitted light emitted through the first light modulation element, the color synthesis optical element, and the relay lens unit.
Thereby, the conjugate distance between the first light modulation element and the second light modulation element can be ensured with high accuracy with the relay lens portion as the center. Further, this adjustment can reduce the occurrence of pixel shift, image blur, luminance change, color unevenness, and the like.

In the light modulation device described above, the relay lens unit is preferably fixed to the fixing member in the vicinity of the center of gravity of the relay lens unit.
With such a configuration, the relay lens unit can be stably fixed to the fixing member without being affected by the size and weight of the relay lens unit configured by various lens groups.

In the light modulation device described above, it is desirable that the color synthesis optical element fixing portion is formed of a plastic member.
With such a configuration, even when the heat generated in the first light modulation element is transferred to the color synthesis optical element, it is possible to prevent the heat from transferring to the fixing member.

In the light modulation device described above, it is desirable that the second light modulation element fixing portion is formed of a plastic member.
With such a configuration, it is possible to suppress heat generated in the second light modulation element from being transferred to the fixing member.

In the light modulation device described above, it is desirable that the fixing member is formed of a metal member.
With such a configuration, since the fixing member can have rigidity, for example, a relay lens unit or the like can be reliably and stably fixed. Further, when a temperature load is applied to the fixing member, the influence of expansion / contraction can be reduced, so that the change in the flange back and the conjugate distance can be reduced. Therefore, it is possible to realize an optical modulation device that further reduces the influence of temperature on the optical system that achieves a high dynamic range and maintains the high dynamic range characteristics of the optical system.

In the above-described light modulation device, it is desirable that the light modulation device includes an emission-side polarization element that polarizes light emitted from the second light modulation element and an emission-side polarizing plate fixing portion that fixes the emission-side polarization element to a fixing member.
With such a configuration, higher contrast and brightness can be obtained by controlling the polarization axis direction of the light emitted from the second light modulation element by the emission-side polarization element. In addition, by fixing the exit-side polarizing element to the fixing member, workability can be improved when the light modulation device is incorporated into a projector, for example.

  In order to achieve the above-described object, a projector according to the present invention includes a light source device that emits light, the light modulation device described above, and a projection unit that projects an optical image emitted from the light modulation device. It is characterized by having.

  According to such a projector, by using the light source device that emits light and any of the light modulation devices described above for the projector, the influence of temperature on the light modulation device is reduced, and the high dynamic range of the optical system is achieved. Since an optical image having characteristics can be projected from the projection unit, a large-screen display can be performed and a realistic display image can be reproduced.

In the projector described above, it is desirable that the projection unit has an optical adjustment mechanism for the first light modulation element and the second light modulation element.
According to such a projector, the projection unit has an optical adjustment mechanism, so that, for example, the flange back can be accurately adjusted with respect to the first light modulation element and the second light modulation element constituting the light modulation device. Therefore, it is possible to further reduce the occurrence of luminance change and color unevenness, and project an optical image having high dynamic range characteristics from the projection unit.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment)

FIG. 1 is a schematic diagram showing a configuration of an optical system of a projector according to the first embodiment of the present invention.
The configuration and operation of the optical system 5 of the projector 1 will be described with reference to FIG.
The projector 1 includes an optical component housing 7 that houses the optical system 5, a power supply unit (not shown), a circuit configuration unit (not shown), a cooling configuration unit (not shown), and the like. Is housed inside the housing 8. Further, the external shape of the projector 1 is a substantially rectangular parallelepiped shape.

  As shown in FIG. 1, the optical system 5 of the projector 1 includes a light source device 30, an illumination optical system 40, a first light modulation unit 50, a color synthesis optical unit 60, a relay lens unit 70, a second light modulation unit 80, and a projection. Part 90. The illumination optical system 40 includes an integrator illumination optical system 41, a color separation optical system 42, and a relay optical system 43.

  The optical component housing 7 accommodates the light source device 30 and the illumination optical system 40. Further, the first light modulation unit 50, the color synthesis optical unit 60, the relay lens unit 70, and the second light modulation unit 80 are integrally configured as a light modulation device 100 and unitized. The light modulation device 100 is configured to be accommodated in the optical component casing 7. In addition, the illumination optical system 40 which comprises the optical system 5 in this embodiment can be suitably changed or omitted depending on the optical system used. The light modulation device 100 will be described later.

  The projector 1 provided with such an optical system 5 makes the luminance distribution of the light emitted from the light source device 30 uniform by the illumination optical system 40 (integrator illumination optical system 41). In the wavelength region of the light emitted from the integrator illumination optical system 41, color separation is performed into three primary colors of R (red) light, G (green) light, and B (blue) light. The color-separated R light, G light, and B light are modulated by the first light modulation unit 50. The modulated R light, G light, and B light are combined by the color combining optical unit 60 to form an optical image. This optical image is relayed by the relay lens unit 70. The relayed optical image is modulated in luminance in the entire wavelength region by the second light modulator 80. The modulated optical image is projected from the projection unit 90 onto a projection surface such as a screen (not shown).

The configuration and operation of the optical system 5 will be described.
The light source device 30 includes a discharge lamp 31 as a light source, an explosion-proof glass 32, and a light source housing 33 that houses and fixes the lamp 31 and the explosion-proof glass 32. The lamp 31 includes an arc tube 31a that emits light by discharge and emits light radially, and a reflector 31b that emits radial light emitted from the arc tube 31a in the direction of the illumination optical system 40 as substantially parallel light. It is configured. In the present embodiment, a high-pressure mercury lamp is used as the lamp 31 (the arc tube 31a), and a parabolic mirror is used as the reflector 31b. Note that the lamp 31 is not limited to a high-pressure mercury lamp, and for example, a metal halide lamp or a halogen lamp may be employed. Moreover, although the parabolic mirror is employ | adopted as the reflector 31b, it is not restricted to this, You may employ | adopt the structure which has arrange | positioned the collimating concave lens in the exit surface of the reflector which consists of an ellipsoidal mirror.

  The integrator illumination optical system 41 constituting the illumination optical system 40 is an optical system for making the luminance of light emitted from the light source device 30 uniform in a plane orthogonal to the illumination optical axis L (illustrated by a one-dot chain line). . The integrator illumination optical system 41 includes a first lens array 41a, a second lens array 41b, a polarization conversion element 41c, and a superimposing lens 41d.

  The first lens array 41a has a configuration in which small lenses having a substantially rectangular outline as viewed from the illumination optical axis L direction are arranged in a matrix. Each small lens divides the light emitted from the light source device 30 into partial light beams and emits the light in a direction along the illumination optical axis L.

  The second lens array 41b has substantially the same configuration as the first lens array 41a, and has a configuration in which small lenses are arranged in a matrix. The second lens array 41b, together with the superimposing lens 41d, has a function of forming an image of each small lens of the first lens array 41a on a light valve 51 as a first light modulation element to be described later.

  The polarization conversion element 41c is an optical element that converts (aligns) the polarization direction of each partial light beam divided by the first lens array 41a and the second lens array 41b into a substantially uniform polarization light beam. The polarization conversion element 41c in the present embodiment has a configuration in which polarization separation films (not shown) and reflection films (not shown) that are inclined with respect to the illumination optical axis L are alternately arranged. The polarization separation film transmits one polarized light beam among the P-polarized light beam and S-polarized light beam included in each partial light beam, and reflects the other polarized light beam. The other polarized light beam reflected is bent by the reflecting film and emitted in the emission direction of one polarized light beam, that is, the direction along the illumination optical axis L. The emitted polarized light beam is polarized by a phase difference plate (not shown) disposed on a light beam exit surface (not shown) of the polarization conversion element 41c, and almost all of the polarized light beams are polarized light beams in which the polarization direction is one direction. Aligned.

  In the projector 1 using the light valve 51 of the type that modulates a polarized light beam, only a polarized light beam in one direction can be used, and therefore approximately half of the light beam from the arc tube 31a that emits a polarized light beam in a random direction is not used. For this reason, the use efficiency of the light in the 1st light modulation part 50 is raised by converting the light inject | emitted from the light source device 30 into the polarized light beam of a substantially one direction by using the polarization conversion element 41c.

  The superimposing lens 41d condenses a plurality of partial light beams converted into polarized light beams in substantially one direction by the polarization conversion element 41c and superimposes them on image forming areas of three light valves 51 (to be described later) of the first light modulation unit 50. This is an optical element. The light beam emitted from the superimposing lens 41 d is emitted to the color separation optical system 42.

  The color separation optical system 42 includes two dichroic mirrors 42a and 42b and a reflection mirror 42c. A plurality of partial light beams emitted from the integrator illumination optical system 41 are separated (split) into three primary color lights of R light, G light, and B light by two dichroic mirrors 42a and 42b.

  The relay optical system 43 includes an incident side lens 43a, a relay lens 43c, and reflection mirrors 43b and 43d. In this embodiment, the relay optical system 43 substantially preserves the intensity distribution of the B light, which is the color light separated by the color separation optical system 42, up to the B light light valve 51 </ b> B described later of the first light modulator 50. And has a function of guiding light loss with little optical loss.

  At that time, the dichroic mirror 42a of the color separation optical system 42 transmits the G light component and the B light component and reflects the R light component among the light beams emitted from the integrator illumination optical system 41. The R light reflected by the dichroic mirror 42a is reflected by the reflection mirror 42c, passes through the collimating lens 41e, and reaches the light valve 51R for R light. The collimating lens 41e converts each partial light beam emitted from the second lens array 41b into a light beam substantially parallel to the central axis (principal ray). It has a function of narrowing the angle distribution of the converted light beam and improving the display characteristics of the light valve 51R for R light. The same applies to the collimating lens 41e provided on the light incident side of the light valves 51B and 51G for B light and G light.

  Of the B light and G light transmitted through the dichroic mirror 42a, the G light is reflected by the dichroic mirror 42b, passes through the collimating lens 41e, and reaches the light valve 51G for G light. On the other hand, the B light passes through the dichroic mirror 42b, passes through the relay optical system 43, passes through the collimating lens 41e, and reaches the light valve 51B for B light. The reason why the relay optical system 43 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 light, thereby preventing a decrease in light use efficiency due to light divergence or the like. It is to do. That is, the partial light beam incident on the incident side lens 43a is transmitted as it is to the parallelizing lens 41e. The relay optical system 43 is configured to pass B light out of the three color lights, but is not limited thereto, and may be configured to pass R light, for example.

  The first light modulator 50 modulates the incident light beam based on image information to form an optical image (color image). The first light modulation unit 50 includes three incident-side polarizing plates 52 (an R-side incident-side polarizing plate 52R and a G-light) as incident-side polarizing elements on which the respective color lights separated by the color separation optical system 42 are incident. Incident side polarizing plate 52G and B light incident side polarizing plate 52B). In addition, three light valves 51 (R light valve 51R, G light valve 51G, and B light valve 51B) are provided as first light modulation elements installed at the subsequent stage of each incident-side polarizing plate 52. . Further, three exit side polarizing plates 53 (an exit side polarizing plate 53R for R light, an exit side polarizing plate 53G for G light, and an exit side for B light) as exit side polarizing elements installed at the subsequent stage of each light valve 51. Polarizing plate 53B).

  The light valve 51 (51R, 51G, 51B) uses a transmissive high-temperature polysilicon TFT (Thin Film Transistor) as a switching element. The light valve 51 (51R, 51G, 51B) seals and encloses liquid crystal in a pair of opposed transparent substrates. It is configured. The light valve 51 modulates a light beam incident via the incident-side polarizing plate 52 based on image information to form and emit modulated light including an optical image.

  The incident-side polarizing plate 52 transmits a polarized light beam in one direction and absorbs other light beams among the respective color lights separated by the color separation optical system 42. It is closely fixed to the flat surface of the substrate. Similarly to the incident-side polarizing plate 52, the emission-side polarizing plate 53 is closely fixed to the plane of a flat rectangular transparent substrate, and transmits a polarized light beam in a predetermined direction out of the light beams emitted from the light valve 51. The other light beam is absorbed, and the polarization axis of the polarized light beam to be transmitted is set to be orthogonal to the polarization axis of the polarized light beam to be transmitted by the incident side polarizing plate 52.

  The color synthesis optical unit 60 includes one cross dichroic prism 61 as a color synthesis optical element. The cross dichroic prism 61 is an optical element that forms a color optical image by synthesizing modulated light that is emitted from the emission-side polarizing plate 53 and includes an optical image modulated for each color light. The cross dichroic prism 61 has a substantially square shape in plan view in which four right angle prisms are bonded together. A dielectric multilayer film is formed along the interface at the substantially X-shaped interface where the right-angle prisms are bonded together. One of the substantially X-shaped dielectric multilayer films reflects red light, the other dielectric multilayer film reflects blue light, and red light and blue light correspond to the corresponding dielectric multilayer films. Reflected and bent by the film. Green light is transmitted through both dielectric multilayer films. Thereby, the advancing direction of R light and B light can be aligned with the advancing direction of G light, and three color lights are synthesize | combined. The optical image synthesized by the cross dichroic prism 61 is emitted in the direction of the relay lens unit 70.

  The relay lens unit 70 has an optical image (light intensity distribution) from the light valves 51R, 51G, and 51B synthesized by the cross dichroic prism 61 on the surface of the light valve 81 constituting the second light modulation unit 80 described later. An optical element for transmission.

FIG. 2 is a diagram illustrating a schematic configuration of the relay lens unit.
Here, the configuration and operation of the relay lens unit 70 will be described with reference to FIG.
The relay lens unit 70 forms an optical image of the light valves 51R, 51G, and 51B for light modulation of each color light on the pixel surface of the light valve 81. As shown in FIG. This is an equal-magnification imaging lens composed of a front lens group 70a and a rear lens group 70b arranged substantially symmetrically. In addition, it is desirable to have both-side telecentric characteristics in consideration of the viewing angle characteristics of the liquid crystal. The front lens group 70a and the rear lens group 70b are configured to include a plurality of convex lenses and concave lenses. However, the shape, size, arrangement interval and number of lenses, telecentricity, magnification and other lens characteristics can be appropriately changed depending on required characteristics, and are not limited to the example of FIG. Since the relay lens unit 70 is composed of a large number of lenses, aberration correction is good, and the luminance distribution formed by the light valves 51R, 51G, 51B for light modulation of each color light is accurately transmitted to the light valve 81. be able to.

  Returning to FIG. 1, the light beam of the optical image as the emitted light emitted from the relay lens unit 70 is transmitted onto the display surface of the light valve 81 as the second light modulation element constituting the second light modulation unit 80.

  The light valve 81 as the second light modulation element has the same configuration as the light valve 51 described above, and modulates the luminance of all wavelength regions of the incident light based on the image information and includes the final optical image. The modulated light is emitted. The modulated light including the final optical image that has been emitted constitutes the second light modulation unit 80, is polarized by the emission-side polarizing plate 83 as the emission-side polarizing element, and is emitted to the projection unit 90.

  The projection unit 90 is composed of a plurality of lens groups (not shown) including the projection lens 91, and projects an optical image formed on the display surface of the light valve 81 onto a screen (not shown) to display a color image.

  Here, each of the light valve 51 (51R, 51G, 51B) as the first light modulation element and the light valve 81 as the second light modulation element modulates the intensity of the transmitted light, and an optical image corresponding to the degree of modulation. It is the same in that it contains. However, the latter light valve 81 modulates light in the entire wavelength range (white light), whereas the former light valve 51 (51R, 51G, 51B) is a dichroic mirror 42a, 42b which is a color separation optical system 42. The two are different in that the light in the specific wavelength region (R light, G light, B light, etc.) separated in (1) is modulated. Therefore, the light intensity modulation performed by the light valve 51 (51R, 51G, 51B) is distinguished by color modulation and the light intensity modulation performed by the light valve 81 is referred to as luminance modulation for convenience.

  From the same point of view, in the following description, the light valve 51 (51R, 51G, 51B) may be referred to as a color modulation light valve, and the light valve 81 may be referred to as a luminance modulation light valve. In this embodiment, the color modulation light valve and the luminance modulation light valve have the same resolution. The resolution of the color modulation light valve may be higher than that of the luminance modulation light valve, or vice versa.

  As described above, in the projector 1 according to the present embodiment, a final display image is obtained by using the modulated light in which the optical image (image) is formed by the light valve 51 (51R, 51G, 51B) as the first light modulation element. Is formed with a light valve 81 as a second light modulation element. Then, the light from the lamp 31 as a light source is modulated by two-stage image forming processes through two light modulation elements (color modulation light valve and luminance modulation light valve) arranged in series. As a result, the projector 1 realizes expansion of the luminance dynamic range and increase of the number of gradations.

  The light modulation device 100 in this embodiment includes a light valve 51 (51R, 51G, 51B) as a first light modulation element, a cross dichroic prism 61, a relay lens unit 70, and a light valve as a second light modulation element. 81 is integrated and unitized. In other words, the light modulation device 100 is configured by unitizing important optical components for realizing the above-described expansion of the luminance dynamic range and increase of the number of gradations.

FIG. 3 is a schematic side view of the light modulation device. FIG. 4 is a schematic assembly diagram of the light modulation device.
In the present embodiment, three light valves 51 (51R, 51G, 51B) are fixed to the three side surfaces of the cross dichroic prism 61 constituting the light modulation device 100. For the sake of simplicity, only the light valve 51G for G light is illustrated.
The configuration of the light modulation device 100 will be described with reference to FIGS.

  As illustrated in FIGS. 3 and 4, the light modulation device 100 includes a first light modulation unit 50, a color synthesis optical unit 60, a relay lens unit 70, and a predetermined position on the fixed member 200 with the fixed member 200 as a base. By fixing each of the second light modulators 80, they are integrally configured and unitized.

  In the case of the present embodiment, the configuration as an optical element includes a light valve 51 (51R, 51G, 51B) as a first light modulation element, an exit side polarizing plate 53 (53R, 53G, 53B), and a color synthesis optical element. A cross dichroic prism 61, a relay lens unit 70, a light valve 81 as a second light modulation element, and an exit side polarizing plate 83.

A schematic configuration of the light modulation device 100 will be described with reference to FIG. 3.
The light valve 51 (51G) as the first light modulation element is housed in the color modulation light valve housing frame 110 as the first light modulation element housing portion. The color modulation light valve housing frame 110 is fixed to the side surface portion of the cross dichroic prism 61 by optical adjustment with respect to the light valve 51 (51G) by the color modulation light valve fixing frame 130. The emission-side polarizing plate 53 (53G) is also fixed to the color modulation light valve fixing frame 130.

  This configuration is the same as that of the light valve 51G for the R light valve 51R and the B light valve 51B, and the optical elements for the light valves 51R and 51B are provided on the other side surfaces of the cross dichroic prism 61, respectively. Adjust and fix. The R light exit side polarizing plate 53R and the B light exit side polarizing plate 53B are also fixed in the same manner. Note that the side surface portions for fixing the R light valve 51R, the G light valve 51G, and the B light valve 51B of the cross dichroic prism 61 are side surfaces 61R, 61G, and 61B.

  The cross dichroic prism 61 is fixed at a predetermined position of the fixing member 200 with a bottom surface portion fixed by a prism fixing plate 160 as a color synthesizing optical element fixing portion.

  The relay lens portion 70 is fixed to the fixing member 200 by fixing the fixing protrusion 76 formed on the side surface side to the fixing protrusion portion 230 formed on the fixing member 200.

The light valve 81 as the second light modulation element is housed in the luminance modulation light valve housing frame 120 as the second light modulation element housing portion. The luminance modulation light valve housing frame 120 is fixed to a predetermined position of the fixing member 200 by performing optical adjustment with respect to the light valve 81 by the luminance modulation light valve fixing frame 140. Further, the exit side polarizing plate 83 is fixed at a predetermined position of the fixing member 200 by the exit side polarizing plate fixing frame 150.
The light modulation device 100 is configured as described above.

A detailed configuration and assembling method of the light modulation device 100 will be described with reference to FIG.
First, description will be made until the light valve 51 (51R, 51G, 51B) is fixed to the cross dichroic prism 61.

  The color modulation light valve housing frame 110 includes a housing frame main body 111 and a presser plate 117. The housing frame main body 111 is formed in a box shape with a flat rectangular shape, and a rectangular opening 112 through which a light beam passes is formed at a portion protruding one step. In addition, adjustment holes 113 that are circular through holes are formed in the four corner portions of the housing frame main body 111, respectively. Further, on the left and right (X direction) side surface portions, projections 114 each having a wedge-shaped cross section that are engaged with an engagement piece 118 of a presser plate 117 described later are formed. Further, a cutout portion 115 for guiding a cable 55 for transmitting a drive signal from the control board is formed on the upper side surface portion of the housing frame main body 111 in order to drive the light valve 51 (51G).

  The housing frame main body 111 is formed of an aluminum alloy having a high thermal conductivity. In addition to the aluminum alloy, a metal material such as a magnesium alloy having a high thermal conductivity or a synthetic resin having a high thermal conductivity may be used. By being formed of such a material, the heat radiation efficiency can be improved with respect to the heat generated by the light valve 51.

  The holding plate 117 is formed of a substantially rectangular flat plate member (not shown), and has a shape in which four corner portions are cut out. Engagement pieces 118 for engaging with the projections 114 formed on the housing frame main body 111 are formed on the left and right (X direction) end surfaces, respectively, by being bent substantially vertically.

  The light valve 51 (51G) is housed in the housing frame main body 111 formed as described above, and the engaging piece 118 of the presser plate 117 is formed on the protrusion 114 while pressing the light valve 51 (51G) from the rear with the presser plate 117. By engaging, the light valve 51 (51G) is housed and fixed in the color modulation light valve housing frame 110.

  The color modulation light valve fixed frame 130 has a fixed frame main body 131 having a rectangular flat plate shape, and a rectangular opening 132 through which a light beam passes is formed in the fixed frame main body 131. In addition, a pair of exit-side polarizing plate fixing portions 133 are formed on the left and right (X-direction) edges of the opening portion 132 so as to stand in the incident direction of the light flux and whose tips are bent in the left and right outer peripheral directions. Each of the four corners of the fixed frame main body 131 is provided with a fixing pin 134 having a cylindrical shape so as to protrude in the incident direction of the light beam. The fixing pin 134 is disposed so as to be fitted into the adjustment hole 113 formed in the color modulation light valve housing frame 110. The color modulation light valve fixing frame 130 is formed of a plastic member having low thermal conductivity, and heat generated by the light valve 51 is transferred to the cross dichroic prism 61 via the color modulation light valve fixing frame 130. To prevent that.

  The exit-side polarizing plate 53 (53G) is attached to the surface of the transparent rectangular substrate 58. The substrate 58 is attached to the surfaces of the two exit side polarizing plate fixing portions 133 of the color modulation light valve fixing frame 130. As a result, the emission-side polarizing plate 53 (53G) is fixed to the color modulation light valve fixing frame 130. In the present embodiment, a sapphire substrate having high thermal conductivity is used as the substrate 58. A quartz substrate may be used in addition to the sapphire substrate.

  The prism fixing plate 160 for fixing the cross dichroic prism 61 has a prism fixing plate main body 161 formed in a rectangular plate shape. Further, a pair of guide legs 162 extending diagonally from the two corners positioned diagonally of the prism fixing plate main body 161 and having a substantially disk shape at the tip are formed. In addition, guide holes 162a are formed in the disk-shaped portions. Further, a pair of fixing legs 163 extending diagonally from the other two corners positioned diagonally of the prism fixing plate body 161 and having a substantially disk shape at the tip are formed. Further, fixing holes 163a are respectively formed in the disk-shaped portions. The prism fixing plate 160 is formed of a plastic member having low thermal conductivity, and prevents heat generated by the light valve 51 from being transferred to the fixing member 200 via the prism fixing plate 160. It fixes to the upper surface of the prism fixing plate 160 comprised in this way using a ultraviolet curing agent so that the bottom face of the cross dichroic prism 61 may become a predetermined position.

  The prism fixing plate 160 to which the cross dichroic prism 61 is fixed is placed with the guide protrusions 210 formed on the fixing member 200 fitted into the guide holes 162 a of the prism fixing plate 160. Accordingly, the fixing hole 163 a of the prism fixing plate 160 is positioned in the fixing screw hole 220 formed in the fixing member 200. Here, the prism fixing plate 160 is fixed to the fixing member 200 by being inserted into the fixing hole 163 a using the fixing screw 300 and screwed into the fixing screw hole 220.

  The relay lens unit 70 includes a cylindrical casing 75 that houses the lens groups 70a and 70b. The casing 75 is formed on the side surface of the casing 75 facing the position of the approximate center of gravity of the relay lens unit 70, with a pair of fixing protrusions 76 that are parallel to each other in the direction of the illumination optical axis L. Yes. Each fixing protrusion 76 is formed with one guide hole 78 and two fixing holes 79.

  The fixing member 200 has a rectangular cross section that is a base for fixing the relay lens unit 70 so as to correspond to each fixing projection 76 of the relay lens unit 70, and a pair of fixing members formed in a columnar shape. A protruding portion 230 is protruded. In addition, one relay lens part guide protrusion 231 and two relay lens part fixing screw holes 232 are formed on the top surface of each fixing protrusion 230.

Here, the relay lens portions 70 are placed on the top surface of the fixing projection portion 230 by fitting the respective guide holes 78 of the relay lens portion 70 into the respective relay lens portion guide protrusions 231. Then, the relay lens unit 70 is fixed to the fixing member 200 by being inserted into the fixing holes 79 using the fixing screws 310 and screwed into the relay lens unit fixing screw holes 232.
With this configuration, the relay lens unit 70 is fixed to the fixing member 200 in the vicinity of the center of gravity of the relay lens unit 70.

  Each light valve 51 (51G, 51R, 51B) is fixed to the side surface portions 61R, 61G, 61B of the cross dichroic prism 61 while performing optical adjustment using the light modulation device 100 assembled so far.

Here, an optical adjustment and fixing procedure for the light valve 51 (51G, 51R, 51B) will be described.
Here, the optical adjustment means that the pixels constituting each light valve 51 (51G, 51R, 51B) are aligned so that the corresponding pixels coincide with each other, and each light valve is placed in the back focus plane of the relay lens unit 70. This refers to back focus adjustment for aligning the focus surfaces (liquid crystal surfaces) 51 (51G, 51R, 51B).

  First, the light modulation device 100 in the state described above is installed in an adjustment device (not shown). Next, as described above, an ultraviolet curing agent is applied to the fixing pin 134 of the color modulation light valve fixing frame 130 for the G light light valve 51G, and the adjustment hole 113 of the color modulation light valve fixing frame 130 is applied. Mating. Also, an ultraviolet curing agent is applied to the back surface of the fixed frame body 131 of the color modulation light valve fixing frame 130 facing the cross dichroic prism 61, and temporarily fixed to the side surface 61 </ b> G of the cross dichroic prism 61. Temporary fixing is temporarily fixing with the initial adhesive force of the ultraviolet curing agent. In this state, the color modulation light valve housing frame 110 is installed in a chucking portion (not shown) of the adjustment device.

  Next, green light is emitted from the front of the color modulation light valve housing frame 110 by the light source of the adjustment device, and an image emitted through the G light light valve 51G, the cross dichroic prism 61, and the relay lens unit 70 is displayed. The focus surface (liquid crystal surface) of the G light valve 51G is aligned with the back focus surface of the relay lens unit 70. This adjustment is performed by the chucking unit holding the color modulation light valve housing frame 110 and moving it in the six-axis directions. Note that alignment is also performed so that the pixels constituting the light valve 51G for G light are located at predetermined positions.

  The six-axis direction is described using the coordinate system shown in FIG. 4. The three-axis directions of the X, Y, and Z directions and the three-axis directions of the XY, YZ, and ZX planes are adjusted. Show. This 6-axis direction adjustment is performed.

  In this way, when the optical adjustment of the G light valve 51G is completed, ultraviolet rays are irradiated to adjust the adjustment hole 113, the fixing pin 134, the color modulation light valve fixing frame 130, and the cross dichroic prism 61. The side part 61G is fixed. Accordingly, the light valve 51G for G light is permanently fixed to the side surface portion 61G of the cross dichroic prism 61.

  Next, as with the light valve 51G for G light, the light valve 51B for B light is temporarily fixed to the side surface portion 61B of the cross dichroic prism 61, and optical adjustment is performed. In this case, light is also emitted from the front of the color modulation light valve housing frame 110 that houses the B light bulb 51B. Then, using the image emitted through the light valve 51B for B light, the cross dichroic prism 61, and the relay lens unit 70, the position of each pixel of the light valve 51G for G light fixed previously is used as a reference. Alignment for making each pixel constituting the light valve for light 51B coincide with the corresponding pixel of the light valve for G light 51G and back focus adjustment similar to that for the light valve for G light 51G are performed. Also in this case, the adjustment in the 6-axis direction is performed in the same manner as the light valve 51G for G light. When optical adjustment is completed. The ultraviolet light is irradiated in the same manner, and the light valve 51B for B light is permanently fixed to the side surface portion 61B of the cross dichroic prism 61.

  Next, the R light valve 51R is temporarily fixed to the side surface portion 61R of the cross dichroic prism 61 and adjusted in the same manner as the G light valve 51G. Similarly to the B light valve 51B, red light is emitted from the front of the color modulation light valve housing frame 110 that houses the R light valve 51R so as to coincide with the position of each corresponding pixel of the G light valve 51G. (In this case, no light is emitted for blue light). Then, optical adjustment is performed using an image emitted through the R light valve 51R, the cross dichroic prism 61, and the relay lens unit 70. Also in this case, the adjustment in the 6-axis direction is performed in the same manner as the light valve 51G for G light. When optical adjustment is completed. The ultraviolet light is similarly irradiated, and the R light valve 51 </ b> R is permanently fixed to the side surface 61 </ b> R of the cross dichroic prism 61.

  As described above, the light valves 51 (51R, 51G, 51B) for the respective color lights are optically adjusted (alignment and back focus adjustment) and are fixed to the cross dichroic prism 61.

Next, a fixing method and optical adjustment of the light valve 81 as the second light modulation element will be described.
A configuration of the luminance modulation light valve housing frame 120 as a second light modulation element housing portion that houses the light valve 81 will be described.

  The luminance modulation light valve housing frame 120 has substantially the same configuration as the color modulation light valve housing frame 110 described above. The brightness modulation light valve housing frame 120 is composed of a housing frame main body 121 and a pressing plate 127. The housing frame main body 121 and the presser plate 127 correspond to the housing frame main body 111 and the presser plate 117 of the color modulation light valve housing frame 110.

  The housing frame main body 121 has an opening 122, an adjustment hole 123, a protrusion 124, and a notch 125 formed in the same manner as the opening 112, the adjustment hole 113, the protrusion 114, and the notch 115 of the housing frame main body 111. Yes. Further, the presser plate 127 has an engagement piece 128 and the like formed in the same manner as the engagement piece 118 and the like of the presser plate 117.

  By accommodating the light valve 81 in the housing frame main body 121 formed as described above, and engaging the engagement piece 128 of the press plate 127 with the protrusion 124 while pressing the light valve 81 with the press plate 127 from the rear, The light valve 81 is housed and fixed in the luminance modulation light valve housing frame 120. The light valve 81 is connected with a cable 56 for transmitting a drive signal from the control board to drive the light valve 81 and extends upward from the notch 125.

  The luminance modulation light valve fixed frame 140 has a fixed frame main body 141 having a rectangular flat plate shape, and a rectangular opening 142 through which a light beam passes is formed in the fixed frame main body 141. Each of the four corners of the fixed frame main body 141 is provided with a fixing pin 144 having a cylindrical shape so as to protrude in contact with the light emission direction. The fixing pin 144 is disposed so as to be fitted into the adjustment hole 123 formed in the luminance modulation light valve housing frame 120. A pair of fixed portions 145 each having a rectangular plate shape are formed at both ends of the lower end surface of the fixed frame main body 141. In addition, fixing holes 146 are formed in the surface portion of the fixing portion 145. The luminance modulation light valve fixing frame 140 is formed of a plastic member having low thermal conductivity, and heat generated by the light valve 81 is prevented from being transferred to the fixing member 200 via the luminance modulation light valve fixing frame 140. is doing.

  Note that a fixing screw hole 240 is formed in the fixing member 200 so as to face the position where the luminance modulation light valve fixing frame 140 is fixed. Here, the fixing portion 145 of the luminance modulation light valve fixing frame 140 is placed on the fixing member 200, and the fixing hole 146 of the luminance modulation light valve fixing frame 140 is inserted into the fixing screw hole 240 formed in the fixing member 200. Position. Then, the luminance modulation light valve fixing frame 140 is fixed to the fixing member 200 by being inserted into the fixing hole 146 using the fixing screw 320 and screwed into the fixing screw hole 240.

  The exit side polarizing plate fixing frame 150 includes a fixed frame main body 151 having a rectangular flat plate shape, and a rectangular opening 152 through which a light beam passes is formed in the fixed frame main body 151. A pair of rectangular plate-shaped fixing portions 155 are formed at both ends of the lower end surface of the fixed frame main body 151. In addition, fixing holes 156 are formed in the surface portion of the fixing portion 155. The exit side polarizing plate fixing frame 150 is formed of a plastic member having low thermal conductivity, and heat generated by the exit side polarizing plate 83 is transferred to the fixing member 200 through the exit side polarizing plate fixing frame 150. Is preventing.

  The exit side polarizing plate 83 is attached to the surface of the transparent rectangular substrate 59. Further, the substrate 59 is attached to the surface of the fixed frame main body 151 of the exit side polarizing plate fixing frame 150. Thereby, the exit side polarizing plate 83 is fixed to the exit side polarizing plate fixing frame 150. In the present embodiment, a sapphire substrate having high thermal conductivity is used as the substrate 59. A quartz substrate may be used in addition to the sapphire substrate.

  A fixing screw hole 250 is formed in the fixing member 200 so as to face the position where the exit side polarizing plate fixing frame 150 is fixed. Here, the fixing portion 155 of the exit side polarizing plate fixing frame 150 is placed on the fixing member 200, and the fixing hole 156 of the exit side polarizing plate fixing frame 150 is inserted into the fixing screw hole 250 formed in the fixing member 200. Position. Then, the exit-side polarizing plate fixing frame 150 is fixed to the fixing member 200 by being inserted into the fixing hole 156 using the fixing screw 330 and screwed into the fixing screw hole 250.

  Using the light modulation device 100 assembled so far, the light valve 81 is fixed to the luminance modulation light valve fixing frame 140 while performing optical adjustment.

Here, an optical adjustment and fixing procedure for the light valve 81 will be described.
The optical adjustment here is an alignment that matches the corresponding pixels of the light valve 81 with respect to the pixels constituting the light in the entire wavelength range (white light) as the emitted light emitted from the relay lens unit 70; Focus adjustment is to adjust the focus surface (liquid crystal surface) of the light valve 81 within the focus surface of the relay lens unit 70.

  First, each light valve 51 (51R, 51G, 51B) described above is optically adjusted and fixed to the cross dichroic prism 61, and the emission side on which the luminance modulation light valve fixing frame 140 and the emission side polarizing plate 83 are attached. The light modulation device 100 in a state where the polarizing plate fixing frame 150 is fixed to the fixing member 200 is installed in an adjustment device (not shown). Next, an ultraviolet curing agent is applied to the fixing pin 144 of the luminance modulation light valve fixing frame 140 and the adjustment hole 123 of the luminance modulation light valve housing frame 120 is fitted. In this state, the luminance modulation light valve housing frame 120 is installed in a chucking portion (not shown) of the adjustment device.

  Next, light of each corresponding color light is emitted from the front of the color modulation light valve housing frame 110 for each color light. Then, using the image emitted from the light valve 81, the pixels constituting the light beam emitted via the relay lens unit 70 are positioned at predetermined positions of the pixels constituting the luminance modulation light valve 81. Align. Also, focus adjustment is performed. This adjustment is performed by the chucking unit holding the luminance modulation light valve housing frame 120 and moving it in the six-axis directions.

  Here, the adjustment in the six-axis direction is the same as the adjustment in the six-axis direction in the color modulation light valve 51. Each color modulation light valve 51 (51R, 51G, 51B) has been optically adjusted as described above, and each pixel is matched. The conjugate distance between the relay lens unit 70 and the luminance modulation light valve 81 is adjusted by this optical adjustment, and the optical image emitted from the relay lens unit 70 is formed on the pixel surface of the luminance modulation light valve 81.

When adjustment of the luminance modulation light valve 81 is completed. The adjustment hole 123 and the fixing pin 144 are fixed by irradiating with ultraviolet rays. Thereby, the luminance modulation light valve housing frame 120 that houses the light valve 81 is permanently fixed to the luminance modulation light valve fixing frame 140.
Thus, the light modulation device 100 is completed.

  As described above, the fixing member 200 is a member for fixing the optical element constituting the light modulation device 100, and a member having rigidity is preferable. In order to prevent the fixing position of the optical element from being changed by heat, it is preferable to use a metal member having a low coefficient of linear expansion relative to the plastic member. In this embodiment, an Invar alloy plate material is processed and used. Note that other metal members are used for the fixing protrusion 230 for fixing the relay lens unit 70 and the like.

  The completed light modulation device 100 is accommodated in a predetermined position of the optical component casing 7 and fixed with screws.

FIG. 5 is a schematic cross-sectional view of the projection unit.
With reference to FIG. 5, the fixing structure of the projection part 90 is demonstrated.

  The projection unit 90 accommodates and fixes the projection lens group including the projection lens 91 inside the housing 95. The casing 95 has a flange 96 formed in a disc shape in the vicinity of the end on the incident side. And the projection part 90 is hold | maintained by the cylindrical projection part holding member 400 installed in the incident side. Specifically, the projection unit holding member 400 has a holding part 410 that is formed so as to protrude toward the inner surface side of the end part, and has a plurality of fixing screw holes 411 that are formed at predetermined positions of the holding part 410. . On the other hand, a fixing hole 97 is formed in the flange 96 of the housing 95 at a position facing the fixing screw hole 411.

  When the projection unit 90 is fixed to the projection unit holding member 400, the fixing hole 97 formed in the flange 96 of the projection unit 90 is replaced with the fixing screw hole 411 formed in the holding unit 410 of the projection unit holding member 400. The screw is fixed by tightening with a fixing screw 350.

  In this case, in this embodiment, the flange back adjustment is performed by installing a spacer 500 as an optical adjustment mechanism between the holding portion 410 and the flange 96 and tightening the screw. The spacer 500 has a predetermined plate thickness and is formed in a disc shape having a circular through hole at the center. In this embodiment, a spacer 500 having a thickness of about 0.1 mm is used as the predetermined thickness.

  The flange back adjustment is an adjustment in which the focus surfaces (liquid crystal surfaces) of the light valve 51 as the first light modulation element and the light valve 81 as the second light modulation element are aligned in the back focus surface of the projection unit 90.

  In this embodiment, the light modulation device 100 and the projection unit 90 are installed in an adjustment device (not shown), the light of each color light is emitted from the incident side of the light valve 51, and an optical image projected from the projection unit 90 is obtained. The back focus adjustment is performed by moving and adjusting the projection unit 90 in the front-rear direction. When the back focus adjustment is completed, the distance between the light valve 81 and the flange 96 of the projection unit 90 is measured, and the light modulation device 100 actually used for the measurement is incorporated in the projector 1. Then, when the projection unit 90 is assembled, the space between the holding unit 410 and the flange 96 is adjusted using the spacer 500 so that the distance between the light valve 81 and the flange 96 of the projection unit 90 is the measured distance. In this way, the back focus adjustment is performed, and the projection unit 90 is fixed while ensuring an appropriate conjugate distance.

According to the embodiment described above, the following effects can be obtained.
(1) According to the light modulation device 100 of this embodiment, with the fixing member 200 as a reference, the color modulation light valve 51 as the first light modulation element, the relay lens unit 70, and the luminance as the second light modulation element The modulation light valve 81 can be fixed as a unit. Specifically, three color modulation lights that modulate light corresponding to each of three colors (red light, green light, and blue light) by separating (spreading) light from the light source device 30 by the color separation optical system 42. The valves 51R, 51G, and 51B are housed in the color modulation light valve housing frame 110, and the color modulation light valves 51R, 51G, and 51B are placed at predetermined positions on the cross dichroic prism 61 via the color modulation light valve fixing frame 130. It is fixed to become. The cross dichroic prism 61 is fixed to the prism fixing plate 160. The prism fixing plate 160 is fixed to the fixing member 200. The luminance modulation light valve 81 is housed in the luminance modulation light valve housing frame 120, and is fixed to the fixing member 200 so that the luminance modulation light valve 81 is at a predetermined position by the luminance modulation light valve fixing frame 140.

  According to such a light modulation device 100, the distance between the relay lens unit 70 and the color modulation light valve 51 and the distance between the relay lens unit 70 and the luminance modulation light valve 81 can be accurately positioned. That is, the flange distance between the relay lens unit 70 and the color modulation light valve 51 and the conjugate distance between the color modulation light valve 51 and the luminance modulation light valve 81 around the relay lens unit 70 can be ensured with high accuracy. In addition, when a temperature load is applied, it is not fixed by a common housing case with other optical elements, so the influence of expansion and contraction can be minimized, and changes in flange back and conjugate distance can be minimized. It becomes possible to do. Therefore, it is possible to realize the light modulation device 100 that reduces the influence of temperature on the optical system that realizes a high dynamic range and maintains the high dynamic range characteristics of the optical system.

  (2) According to the light modulation device 100 of this embodiment, since the color modulation light valve 51 performs optical adjustment and is fixed to the cross dichroic prism 61, it is possible to ensure a flange back with respect to the relay lens unit 70 with high accuracy. it can. In addition, the alignment of matching the pixel positions of the color modulation light valves 51R, 51G, and 51B for each color light can reduce the occurrence of pixel shift, image blur, luminance change, color unevenness, and the like.

  (3) According to the light modulation device 100 of this embodiment, the luminance modulation light valve 81 performs optical adjustment using the emitted light emitted through the color modulation light valve 51, the cross dichroic prism 61, and the relay lens unit 70. Therefore, the conjugate distance between the color modulation light valve 51 and the luminance modulation light valve 81 with the relay lens unit 70 as the center can be ensured with high accuracy. In addition, pixel misalignment, image blurring, luminance change, color unevenness, and the like are generated by aligning the corresponding pixels of the luminance modulation light valve 81 with the pixels constituting the emitted light emitted from the relay lens unit 70. Can be reduced.

  (4) According to the light modulation device 100 of the present embodiment, the relay lens unit 70 is fixed to the fixing member 200 by the fixing protrusions 76 formed in the vicinity of the center of gravity of the relay lens unit 70, and thus various lens groups. The relay lens unit 70 can be stably fixed to the fixing member 200 without being affected by the size and weight of the relay lens unit 70 configured as described above.

  (5) According to the light modulation device 100 of the present embodiment, since the prism fixing plate 160 is formed of a plastic member, the heat conductivity is lower than that of the metal member, and among them, the plastic having low heat conductivity. Since it is formed of a member, even when the heat generated in the color modulation light valve 51 is transferred to the cross dichroic prism 61, the transfer of the heat to the fixed member 200 can be suppressed. Further, since the color modulation light valve fixing frame 130 is also formed of the same plastic member, heat generated in the color modulation light valve 51 can be prevented from being transferred to the cross dichroic prism 61. Further, since the luminance modulation light valve fixing frame 140 is also formed of the same plastic member, it is possible to suppress heat generated in the luminance modulation light valve 81 from being transferred to the fixing member 200. In addition, since the exit side polarizing plate fixing frame 150 is also formed of the same plastic member, it is possible to suppress the heat generated in the exit side polarizing plate 83 from being transferred to the fixing member 200.

  (6) According to the light modulation device 100 of the present embodiment, the fixing member 200 is formed of a metal member. Thereby, since the fixing member 200 can strengthen rigidity, other optical elements including the relay lens unit 70 can be reliably and stably fixed. In addition, the linear expansion coefficient of a metal member is generally smaller than that of a plastic member. As a result, when a temperature load is applied to the fixing member 200, the influence of expansion / contraction can be reduced as compared with the plastic member, so that changes in the flange back and the conjugate distance can be reduced. Therefore, it is possible to realize the light modulation device 100 that further reduces the influence of temperature on the optical system that realizes a high dynamic range and maintains the high dynamic range characteristics of the optical system. In addition, it is formed of a metal member having a low linear expansion coefficient among the metal members, and in this embodiment, it is formed of an Invar alloy. Therefore, the influence of expansion / contraction on the temperature load can be further reduced, and flange back and conjugate The change in distance can be further reduced.

  (7) Since the light modulation device 100 of this embodiment includes the emission side polarizing plate 83 and the emission side polarizing plate fixing frame 150 that fixes the emission side polarizing plate 83 to the fixing member 200, the luminance modulation light valve. By controlling the polarization axis direction of the light emitted from 81 with the exit-side polarizing plate 83, higher contrast and brightness can be obtained. In addition, by fixing the emission-side polarizing plate 83 to the fixing member 200, workability can be improved when the light modulation device 100 is incorporated into the projector 1.

  (8) Since the projector 1 according to the present embodiment includes the light modulation device 100 that exhibits the above-described effects, an optical image having a high dynamic range characteristic that the optical system has and the effect of temperature on the light modulation device 100 is reduced. Projection can be performed from the projection unit 90, and a large-screen display can be performed to reproduce a realistic display image.

  (9) In the projector 1 according to the present embodiment, the projection unit 90 performs the flange back adjustment by installing the spacer 500 as an optical adjustment mechanism. This makes it possible to accurately adjust the flange back for the color modulation light valve 51 and the luminance modulation light valve 81 constituting the light modulation device 100, further reducing the occurrence of luminance changes and color unevenness, An optical image having high dynamic range characteristics can be projected from the projection unit 90.

(10) In the light modulation device 100 of the present embodiment, the color modulation light valve 51, the relay lens unit 70, and the luminance modulation light valve 81 that realize high dynamic range characteristics are unitized as a unit by the fixing member 200. Therefore, when high-precision optical adjustment such as pixel position adjustment and back focus adjustment is performed, these high-precision adjustments between the optical elements can be efficiently performed in this unit. Further, in the incorporation into the projector 1 or the like, the handling becomes easy and the assemblability of the projector 1 can be improved. Further, even when the light modulation device 100 breaks down, the unit can be replaced, so that the maintainability is improved.
Conventionally, the color modulation light valve 51, the relay lens unit 70, and the luminance modulation light valve 81 are generally housed in a common housing case including optical elements constituting other optical systems. . Therefore, when optical adjustment is performed on the color modulation light valve 51, the relay lens unit 70, and the luminance modulation light valve 81, other optical elements may interfere with the operation of the adjustment jig, or may be adjusted depending on the housing case. This has hindered the operation of the jigs and the like, and the workability such as optical adjustment has been reduced. However, the light modulation device 100 according to the present embodiment has a great merit that the highly accurate adjustment can be efficiently performed and the workability is improved.

  (11) In the light modulation device 100 of the present embodiment, the luminance modulation light valve 81 is disposed through the relay lens unit 70 at the subsequent stage of the color modulation light valve 51 and the cross dichroic prism 61. Since the members for fixing these optical elements to the fixing member 200 are made as small as possible between the color modulation light valve 51 and the luminance modulation light valve 81, they are unitized. The distance can be shortened. Thereby, the optical aberration of the transmitted light is reduced, and the imaging (transmission) accuracy is improved.

  (12) The light modulation device 100 of the present embodiment uses a sapphire substrate having high thermal conductivity as the substrates 58 and 59 for fixing the emission-side polarizing plates 53 and 83. Accordingly, the heat generated by the exit-side polarizing plates 53 and 83 due to incident light is easily transferred to the sapphire substrate, and is easily dissipated by the sapphire substrate, thereby preventing the quality deterioration of the exit-side polarizing plates 53 and 83. The optical characteristics can be maintained for a long time.

  The present invention is not limited to the above-described embodiments, and various changes and improvements can be added. A modification will be described below.

  (Modification 1) In the light modulation device 100 of the above-described embodiment, the fixing member 200 uses an Invar alloy. However, the fixing member 200 is not limited thereto, and a metal member such as an aluminum alloy or a magnesium alloy can also be used.

  (Modification 2) In the light modulation device 100 of the above embodiment, the luminance modulation light valve fixing frame 140 for holding and fixing the luminance modulation light valve 81 and the emission side polarizing plate fixing frame 150 for fixing the emission side polarizing plate 83 are It is formed as a separate fixed frame. However, by adopting a configuration such as the color modulation light valve fixing frame 130, it is also possible to fix the luminance modulation light valve 81 and the emission side polarizing plate 83 to one fixed frame.

  (Modification 3) Although the projector 1 in the above embodiment is a front type projector 1, it can also be applied as a rear type projector.

  (Modification 4) The light modulation device 100 in the above embodiment is configured by using a transmissive light modulation element. However, the present invention is not limited thereto, and a color modulation light valve or a luminance modulation light valve may be a DMD (Digital Micromirror Device) or the like. The reflection type light modulation element can also be used.

  (Modification 5) In the embodiment described above, the optical system 5 uses a single light source (lamp 31) that emits white light to the light source device 30, and the white light is converted into three primary colors of R light, G light, and B light. It is separated (spectroscopic) into light. However, the present invention is not limited to this, and three light sources corresponding to the three primary colors of R light, G light, and B light, a light source that emits red light, a light source that emits green light, and a light source that emits blue light, respectively. And a means for separating white light (color separation optical system 42) may be removed.

  (Modification 6) In the above-described embodiment, the optical system 5 employs a so-called three-plate method using three color modulation light valves 51R, 51G, and 51B. You may do it.

  (Modification 7) In the above-described embodiment, the optical system 5 is configured to modulate the luminance of light in two stages using the color modulation light valve 51 and the luminance modulation light valve 81. However, the present invention is not limited to this. Two sets of modulation light valves can be used to modulate the luminance of light in two stages.

  (Modification 8) In the light modulation device 100 of the above-described embodiment, a polarization compensation optical system that compensates the polarization state of the modulated light may be provided before or after the relay lens unit 70. As the polarization compensation optical system, for example, a rectifier or the like is preferably employed. The rectifier can mainly compensate for the rotation of the polarization vibration plane (polarization plane rotation).

  (Modification 9) In the above embodiment, the optical system 5 uses the emission side polarizing plate 53 on the emission side of the color modulation light valve 51 and does not use the polarizing plate on the incident side of the luminance modulation light valve 81. . However, the present invention is not limited to this, and it is also possible to adopt a configuration in which the exit side polarizing plate 53 is not used on the exit side of the color modulation light valve 51 and a polarizing plate is used on the entrance side of the luminance modulation light valve 81. Note that polarizing plates can be used on both the emission side of the color modulation light valve 51 and the incident side of the luminance modulation light valve 81.

  Although the best mode for carrying out the present invention has been disclosed in the above description, the present invention is not limited to this. That is, the present invention mainly illustrates and describes a specific embodiment, but the detailed configuration of the above-described embodiment without departing from the scope of the technical idea and object of the present invention. Various modifications (changes and improvements) can be made by those skilled in the art in the shape, material, quantity, etc. of the members and components. Accordingly, the present invention also includes a case where a person skilled in the art performs various modifications in the detailed constituent members and the shapes, materials, and quantities of the constituent members.

1 is a schematic diagram showing a configuration of an optical system of a projector according to a first embodiment of the invention. The schematic structure of a relay lens part. The schematic side view of a light modulation apparatus. 1 is a schematic assembly diagram of a light modulation device. FIG. 3 is a schematic sectional view of a projection unit.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Projector, 5 ... Optical system, 51 ... Light valve as 1st light modulation element, 61 ... Cross dichroic prism, 70 ... Relay lens part, 81 ... Light valve as 2nd light modulation element, 83 ... Emission side polarization Plate 90: Projection unit 100 Light modulation device 110 Color modulation light valve housing frame 120 Brightness modulation light valve housing frame 130 Color modulation light valve fixing frame 140 Brightness modulation light valve fixing frame 150 ... Exit side polarizing plate fixing frame, 160... Prism fixing plate, 200... Fixing member, 500.

Claims (11)

A light modulation device that modulates light from a light source and emits the modulated light,
A first light modulation element for modulating light from the light source;
A second light modulation element that modulates light from the first modulation element;
A relay lens unit disposed between the first light modulation element and the second light modulation element;
A light modulation device comprising: a fixing member that integrally fixes the first light modulation element, the relay lens unit, and the second light modulation element at a predetermined position. The light modulation device according to claim 1,
Three first light modulation elements that respectively modulate red light, green light, and blue light;
A first light modulation element housing portion for housing each of the three first light modulation elements;
A color synthesizing optical element that synthesizes each color light emitted from the three first light modulation elements;
A first light modulation element fixing portion for holding the first light modulation element housing portion and fixing the first light modulation element to the color synthesis optical element so that the first light modulation element is at a predetermined position;
A color combining optical element fixing portion for fixing the color combining optical element and fixing the color combining optical element to the fixing member;
A second light modulation element housing portion for housing the second light modulation element;
A light modulation device comprising: a second light modulation element fixing portion that holds the second light modulation element housing portion and fixes the second light modulation element to the fixing member so that the second light modulation element is positioned at a predetermined position. . The light modulation device according to claim 2,
The first light modulation element performs optical adjustment and is fixed to the color synthesis optical element. The light modulation device according to claim 3,
The second light modulation element performs optical adjustment using emitted light emitted through the first light modulation element, the color synthesis optical element, and the relay lens unit. The light modulation device according to any one of claims 1 to 4,
The light modulation device, wherein the relay lens unit is fixed to the fixing member in the vicinity of the center of gravity of the relay lens unit. The light modulation device according to any one of claims 2 to 5,
The color modulation optical element fixing portion is formed of a plastic member. The light modulation device according to any one of claims 2 to 6,
The light modulation device, wherein the second light modulation element fixing portion is formed of a plastic member. The light modulation device according to any one of claims 1 to 7,
The light modulation device, wherein the fixing member is formed of a metal member. The light modulation device according to any one of claims 1 to 8,
An exit-side polarization element that polarizes light emitted from the second light modulation element;
An optical modulation device comprising: an exit-side polarizing plate fixing portion that fixes the exit-side polarizing element to the fixing member. A projector,
A light source device for emitting light;
The light modulation device according to any one of claims 1 to 9,
A projector having a projection unit that projects an optical image emitted from the light modulation device. The projector according to claim 10, wherein
The projector has an optical adjustment mechanism for the first light modulation element and the second light modulation element.

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