JP2007264340A - Image display device and projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress deterioration in image quality due to relative positional shift among an optical path and each of optical elements. <P>SOLUTION: The image display device, equipped with a light source unit 10 which emits illumination light L and a first optical modulating element 40, which modulates the illumination light L and projects it as a modulated light, is equipped with an optical path shift means 70 of shifting the optical path of the modulated light. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image display device and a projector.

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. Devices with nearly comparable performance are being realized. However, regarding the luminance dynamic range, the reproduction range is about 1 to 10 ² [nit], and the number of gradations is generally 8 bits. On the other hand, human vision has a range of luminance dynamic range that can be perceived at a time of about 10 ⁻² to 10 ⁴ [nit], and the luminance discrimination capability is 0.2 [nit]. It is said to be equivalent to 12 bits. When viewing the display image of the current display device via such visual characteristics, the narrowness of the luminance dynamic range is conspicuous, and in addition, the gradation of the shadow part and highlight part is insufficient. You will feel unsatisfactory with reality and power.

  In CG (Computer Graphics) used in movies, games, etc., display data (hereinafter referred to as HDR (High Dynamic Range) display data) has a luminance dynamic range and gradation characteristics close to human vision. The movement to pursue the reality of depiction is becoming mainstream. However, since the performance of the display device that displays it is insufficient, there is a problem that the expressive power inherent in the CG content cannot be fully exhibited.

  Furthermore, in the next OS (Operating System), for example, WCS (Windows (registered trademark) Color System) installed in WINDOWS (registered trademark) -Vista (registered trademark), adoption of a 16-bit color space is planned. Compared with the current 8-bit color space, the dynamic range and the number of gradations are dramatically increased. Therefore, it is expected that the demand for realizing a high dynamic range and high gradation electronic display device capable of utilizing the 16-bit color space will increase.

  Among display devices, a projection display device (projector) such as a liquid crystal projector or a DLP (Digital Light Processing (trademark)) projector can display a large screen and is effective in reproducing the reality and power of a display image. A display device. In this field, the following proposals have been made to solve the above problems.

  As a display device with a high dynamic range, the contrast ratio is adjusted by double-modulating illumination light from a light source with two light modulation elements (first light modulation element and second light modulation element) arranged in series on the optical path. A so-called HDR (High Dynamic Range) display has been proposed. (For example, refer to Patent Document 1).

In such an HDR display, each of the red illumination light, the green illumination light, and the blue illumination light is modulated by the first light modulation element and then synthesized using a cross dichroic prism (synthesizing means). The combined light is further modulated by the second light modulation element.
JP 2005-250440 A

By the way, in order to accurately modulate the modulated light modulated by the first light modulation element with the second light modulation element, the first light modulation element and the second light modulation element are light paths of light (illumination light, modulation light, etc.). Must be aligned with high accuracy. Further, when a relay lens is installed between the first light modulation element and the second light modulation element, the first light modulation element, the second light modulation element, and further the relay lens are highly accurate with respect to the optical path of light. Need to be aligned. If the installation positions of the first light modulation element and the second light modulation element are deviated from the optical path, the irradiation area of the modulated light emitted from the first light modulation element in the second light modulation element is As a result, the modulated light cannot be accurately modulated. As a result, image quality degradation such as generation of moire occurs.
For this reason, the 1st light modulation element, the 2nd light modulation element, etc. are being fixed in the state where it was correctly aligned to the optical path.

  However, the fixing mechanism that fixes the first light modulation element, the second light modulation element, and the like may be thermally deformed or temporally deformed by heat of illumination light or the like. In such a case, the positions of the first light modulation element, the second light modulation element, and the like are shifted from the optical path, and the modulated light emitted from the first light modulation element is accurately detected by the second light modulation element. Cannot be modulated. Further, the relay lens may be thermally deformed by the heat of illumination light or the like. In such a case, the optical path of the modulated light moves, and as a result, the second modulation element is shifted from the optical path. Similarly, the modulated light emitted from the first light modulation element cannot be accurately modulated by the second light modulation element.

In the HDR display, in order to accurately modulate the modulated light emitted from the first light modulation element by the second modulation element as described above, the first light modulation element, the second light modulation element, etc. are particularly high. It was explained that it is necessary to align the optical path with accuracy. On the other hand, a first light modulation element is installed for each of a plurality of illumination lights, and a display (image display device) that synthesizes and expands the modulated light modulated by each first light modulation element, that is, as described above. Even in a display having a configuration in which the second light modulation element is omitted from the configuration of the HDR display, it is necessary to accurately synthesize the modulated light emitted from each first light modulation element. That is, it is necessary to accurately superimpose the optical path of the modulated light emitted from each first light modulation element by the cross dichroic prism.
Even in such a display that synthesizes a plurality of modulated lights, the fixing means for fixing each first light modulation element may be thermally deformed or temporally deformed by the heat of illumination light or the like. As a result, the optical path of the modulated light emitted from each first light modulation element is shifted and the modulated light cannot be accurately superimposed, resulting in image quality degradation.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to suppress the occurrence of image quality degradation due to the relative displacement between the optical path and each optical element.

  In order to achieve the above object, an image display device according to the present invention is an image display device including a light source device that emits illumination light and a first light modulation element that modulates the illumination light and emits the modulated light. The optical path shift means for shifting the optical path of the modulated light is provided.

  According to the image display apparatus of the present invention having such characteristics, the optical path of the modulated light can be shifted by the optical path shift means. For this reason, for example, when the optical element such as the first light modulation element and the optical path of the modulated light are relatively displaced due to thermal deformation or change with time of the fixing means for fixing the first light modulation element. Also, the optical element and the optical path of the modulated light can be aligned again by shifting the optical path of the modulated light by the optical path shifting means. Therefore, according to the present invention, it is possible to suppress the occurrence of image quality degradation due to the relative displacement between the optical path and each optical element.

The image display device of the present invention further includes a second light modulation element that further modulates the modulated light, and the optical path shift means is disposed between the first light modulation element and the second light modulation element. Can be adopted.
By adopting such a configuration, for example, the first light modulation element, the second light modulation element, or the like is caused by thermal deformation or temporal deformation of the fixing means for fixing the first light modulation element or the second light modulation element. Even when the optical element and the optical path of the modulated light are displaced relative to each other, the optical path of the modulated light is shifted by the optical path shift means, so that the modulated light emitted from the first optical modulator is second modulated. It is possible to accurately guide light to the element. Therefore, it is possible to realize an HDR display in which the occurrence of image quality deterioration due to the relative displacement between the optical path and each optical element is suppressed.

In the image display device of the present invention, when the first light modulation element and the second light modulation element are provided, the modulated light emitted from the first light modulation element is guided to the second light modulation element. It is possible to employ a configuration in which both side telecentric lenses are provided.
By adopting such a configuration, the modulated light becomes parallel light between the first light modulation element and the second light modulation element. Even if the optical path shift means is installed at the position, the optical path of the modulated light can be shifted, and the degree of freedom in design can be increased.

Further, in the image display device of the present invention, a spectroscopic unit that splits the illumination light emitted from the light source device into a plurality of illumination lights, and the first light installed for each of the split illumination lights. A modulation element; and a synthesis unit that synthesizes the modulated lights modulated by the first light modulation element, wherein the optical path shift unit is installed between each of the first light modulation elements and the synthesis unit. It is also possible to adopt a configuration of being performed.
Further, the plurality of light source devices, the first light modulation element installed for each illumination light emitted from each light source device, and each modulated light modulated by the first light modulation element are combined. It is also possible to employ a configuration in which the optical path shift means is installed between each of the first light modulation elements and the synthesis means.
By adopting any one of such configurations, for example, the first light modulation element is fixed by, for example, fixing means for fixing the first light modulation element being thermally deformed or temporally deformed by heat of illumination light or the like. Even when the optical path of the modulated light emitted from the element is shifted with respect to the combining means (optical element), the optical path shift means can shift the shifted optical path of the modulated light to match the combining means. It becomes possible. For this reason, it becomes possible to always superimpose each modulated light accurately by the combining means. Accordingly, it is possible to suppress the occurrence of image quality deterioration due to the relative positional deviation between the optical path and each optical element.

The image display apparatus according to the present invention further includes a control unit that controls the optical path shift unit. The control unit drives the optical path shift unit, and inputs an instruction signal to the drive unit. A configuration including an input unit can be employed.
By adopting such a configuration, the optical path shift means can be controlled by operating the input unit. Therefore, it is possible to suppress the occurrence of image quality degradation by the viewer operating the input unit while viewing the display image.

The image display apparatus according to the present invention further includes a control unit that controls the optical path shift unit, the control unit driving the optical path shift unit, and an instruction signal to the drive unit according to a display image. It is also possible to adopt a configuration comprising display image detecting means for inputting
By adopting such a configuration, an instruction signal corresponding to the display image is input from the display image detection unit to the drive unit, and the optical path shift unit is driven based on the instruction signal. Therefore, it is possible to automatically suppress the occurrence of image quality degradation.

In addition, in the image display apparatus of this invention, when a control means is provided, the structure provided with the memory | storage part which memorize | stores the said instruction | indication signal is employable.
By adopting such a configuration, for example, when the image display apparatus is turned on again after the image display apparatus is turned off, the optical path shift means can be adjusted quickly.

  In the image display device of the present invention, specifically, the optical path shifting means may be a variable apex angle prism or a transmissive liquid crystal device.

Next, a projector of the present invention is a projector including an image display device that emits modulated light obtained by modulating illumination light, and a projection unit that enlarges and projects the modulated light emitted from the image display device onto a screen. The image display device of the present invention is used as the image display device.
According to the image display device of the present invention, it is possible to suppress the occurrence of image quality degradation due to the relative displacement between the optical path and each optical element. Therefore, a projector equipped with such an image display device can exhibit excellent display characteristics.

  Hereinafter, an embodiment of an image display device and a projector according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size.

(First embodiment)
FIG. 1 is a schematic configuration diagram of an optical system provided in the projector according to the present embodiment.
The projector PJ1 of the present embodiment includes a light source device 10 that emits illumination light L, a uniform illumination system 20 that equalizes the luminance distribution of the illumination light L emitted from the light source device 10, and the illumination light L that is red illumination light L1. And the green illumination light L2 and the blue illumination light L3 and the light splitting system 30 (spectral means) for guiding the illumination lights L1 to L3 and the illumination lights L1 to L3 and the illumination lights. A liquid crystal light valve 40 (first light modulation element) that modulates the luminance of L1 to L3 and the illumination light L1 to L3 (modulated light) that has been subjected to luminance modulation in each liquid crystal light valve 40 are combined and emitted as combined light L4. A dichroic prism 50, a relay lens 60 that guides the combined light L4 (bilateral telecentric lens), and a variable apex angle that shifts the optical path of the combined light L4 guided by the relay lens 60. A rhythm 70 (optical path shifting means), a control unit 80 for controlling the variable apex angle prism 70, a liquid crystal light valve 90 (second light modulation element) for modulating the luminance of the combined light L4 emitted from the variable apex angle prism 70, The projection lens 100 that enlarges and projects the combined light L4 whose luminance is modulated in the liquid crystal light valve 90 onto the screen 200 is provided.
In the following description, in the xyz orthogonal coordinate system of the entire optical system, the pixel surface of the liquid crystal light valve 90 is the xy plane, and the combined light L emitted from the cross dichroic prism 50 is directed to the projection lens 100 (x− The direction perpendicular to the y plane) is taken as the z direction.

  The light source device 10 includes a lamp 11 made of an ultra-high pressure mercury lamp, a xenon lamp, or the like, and a reflector 12 that reflects and condenses the light emitted from the lamp 11, and the light emitted from the lamp 11 is reflected by the reflector 12. Then, the light is reflected and condensed and emitted as illumination light L.

  The uniform illumination system 20 includes first and second lens arrays 21 and 22 made of fly-eye lenses, a polarization conversion element 23, and a condenser lens 24. Then, the luminance distribution of the illumination light L emitted from the light source device 10 is made uniform by the first and second lens arrays 21 and 22, and the illumination light L that has passed through the first and second lens arrays 21 and 22 is polarized. The polarized illumination light L polarized in the polarization direction that can enter the liquid crystal light valve 40 by the conversion element 23 is condensed by the condenser lens 24 and emitted to the spectroscopic system 30. The polarization conversion element 23 is composed of, for example, a PBS array and a half-wave plate, and converts random polarization into specific linear polarization.

  The spectroscopic system 30 includes two dichroic mirrors 31 and 32 as light separating means, four mirrors (reflection mirrors 33, 34, and 35), and five field lenses (a lens 36, a relay lens 37, and a collimating lens 38 ( 38R, 38B, 38G)).

The dichroic mirrors 31 and 32 separate the illumination light L from the light source device 10 into three primary color lights of red illumination light L1, green illumination light L2, and blue illumination light L3.
The dichroic mirror 31 is installed at the rear stage of the uniform illumination system 20. The dichroic mirror 31 is formed by forming a dichroic film having a property of reflecting the green illumination light L2 and the blue illumination light L3 and transmitting the red illumination light L1 on a glass plate or the like, and the green illumination light L2 included in the illumination light L. The blue illumination light L3 is reflected in the x direction and the red illumination light L1 is transmitted in the z direction.
The dichroic mirror 32 is installed downstream of the dichroic mirror 31 in the x direction. The dichroic mirror 32 is formed by forming a dichroic film having a property of reflecting the green illumination light L2 and transmitting the blue illumination light L3 on a glass plate or the like, and the green illumination light L2 and blue illumination light reflected by the dichroic mirror 31. Of L3, the green illumination light L2 is reflected in the z direction and guided to the collimating lens 38G, and the blue illumination light L3 is transmitted in the x direction and guided to the lens 36.

The reflection mirror 33 is installed downstream of the dichroic mirror 31 in the z direction, and reflects the red illumination light L1 incident from the z direction in the x direction and guides it to the collimating lens 38R.
The reflection mirror 34 is installed downstream of the dichroic mirror 32 in the x direction, and reflects the blue illumination light L3 incident from the x direction in the z direction and guides it to the reflection mirror 35.
The reflection mirror 35 is installed downstream of the reflection mirror 34 in the z direction, and reflects the blue illumination light L3 incident from the z direction in the x direction and guides it to the collimating lens 38B.

  The lens 36 is installed between the dichroic mirror 32 and the reflection mirror 34, and is for efficiently guiding the blue illumination light L3 to the relay lens 37. The relay lens 37 is installed between the reflection mirror 34 and the reflection mirror 35, and guides the blue illumination light L3.

  The blue illumination light L3 is guided to a longer distance to the liquid crystal light valve 40 than the other illumination lights L1 and L2, but the intensity distribution is almost preserved by the lens 36 and the relay lens 37. In this state, the light is guided with little optical loss.

The collimating lens 38 emits incident illumination light in a substantially collimated state, and is arranged in front of the liquid crystal light valve 40R and the collimation lens 38G just before the liquid crystal light valve 40G. The lens 38G and a collimating lens 38B installed immediately before the liquid crystal light valve 40B are configured.
The illumination lights L1 to L3 are substantially collimated through the collimating lenses 38R, 38G, and 38B, and then enter the liquid crystal light valves 40R, 40G, and 40B. That is, the red illumination light L1 is substantially collimated through the collimating lens 38R and then enters the liquid crystal light valve 40R. The green illumination light L2 is substantially collimated through the collimating lens 38G, and then enters the liquid crystal light valve 40G. Further, the blue illumination light L3 is substantially collimated through the collimating lens 38B, and then enters the liquid crystal light valve 40B.

The liquid crystal light valves 40R, 40G, and 40B each include a pixel substrate and a glass substrate on which switching elements such as thin film transistors and thin film diodes for driving the pixel electrode are formed in a matrix, and a glass substrate on which a common electrode is formed over the entire surface. This is an active matrix type liquid crystal display element in which a TN liquid crystal is sandwiched between and a polarizing plate is disposed on the outer surface. These liquid crystal light valves 60B, 60G, and 60R are normally white mode in which white / bright (transmission) state is applied when no voltage is applied and black / dark (non-transmission) state is applied when voltage is applied, or vice versa. It is driven in the mode, and the gradation between light and dark is analog controlled according to a given control value.
Then, the liquid crystal light valve 40R modulates the luminance of the red illumination light L1 based on display image data input from the outside. Further, the liquid crystal light valve 40G modulates the luminance of the green illumination light L2 based on display image data input from the outside. Further, the liquid crystal light valve 40B modulates the luminance of the blue illumination light L3 based on display image data input from the outside.

  In the cross dichroic prism 50, a liquid crystal light valve 40R is installed on the -x side, a liquid crystal light valve 40G is installed on the -z side, and a liquid crystal light valve 40B is installed on the + x side. The cross dichroic prism 50 has a structure in which four right-angle prisms are bonded together. A dielectric multilayer film 51 that reflects the red illumination light L1 in the z direction and transmits the green illumination light L2 in the z direction is included therein. A dielectric multilayer film 52 that reflects the blue illumination light L3 in the z direction and transmits the green illumination light L2 and reflects it in the z direction is formed in an X-shaped cross section. The illumination lights L1 to L3 (modulated light) modulated by the liquid crystal light valves 40 are all emitted in the z direction by entering the cross dichroic prism 50 from the liquid crystal light valves 40. As a result, the illumination lights L1 to L3 are combined and emitted from the cross dichroic prism 50 in the z direction as combined light L4.

  The relay lens 60 is disposed downstream of the cross dichroic prism 50 in the z direction, and the combined light L4 emitted from the cross dichroic prism 50 is supplied to the liquid crystal light valve 90 (second light modulation element) via the variable apex angle prism 70. ). In the present embodiment, in consideration of the viewing angle characteristics of the liquid crystal light valve, a bilateral telecentric lens having bilateral telecentric characteristics is used as the relay lens 60.

  The variable apex angle prism 70 is installed between the relay lens 60 and the liquid crystal light valve 90. FIG. 2 is a cross-sectional view schematically showing the variable apex angle prism 70. 2A, the variable apex angle prism 70 includes a pair of opposed transparent substrates 71 and 72, a bellows 73 that connects the transparent substrate 71 and the transparent substrate 72, and the transparent substrate 71 and the transparent substrate 72. And a transparent liquid 74 enclosed in a space surrounded by the bellows 73. As the transparent substrates 71 and 72, a glass substrate or a plastic substrate can be used, and as the transparent liquid 74, silicon oil or the like can be used.

In such a variable apex angle prism 70, since the transparent substrates 71 and 72 are connected by the bellows 73, the transparent substrates 71 and 72 can be tilted. Therefore, it is possible to control the incident angle and the emission angle of the combined light L4 that is incident from the −z side and is emitted to the + z side with respect to the variable apex angle prism 70, thereby shifting the optical path of the combined light L4.
For example, as shown in FIG. 2B, the optical path of the illumination light L4 can be shifted upward by tilting the transparent substrate 71 and the transparent substrate 72 so as to approach each other on the lower side. As shown in FIG. 2C, the optical path of the illumination light L4 can be shifted downward by tilting the transparent substrate 71 and the transparent substrate 72 so as to approach each other on the upper side. Furthermore, by tilting the transparent substrate 71 and the transparent substrate 72 so as to approach each other on the front side of the sheet of FIG. 2, the optical path of the illumination light L4 can be shifted to the back side of the sheet of FIG. Further, by tilting the transparent substrate 71 and the transparent substrate 72 so as to approach each other on the back side in FIG. 2, the optical path of the illumination light L4 can be shifted to the front side in FIG. That is, by controlling the tilting of the transparent substrate 71 and the transparent substrate 72, the optical path of the illumination light L4 can be shifted in an arbitrary direction.

The control unit 80 is connected to the variable apex angle prism 70, a drive unit 81 that tilts the transparent substrates 71 and 72 of the variable apex angle prism 70, and an input unit 82 that inputs an instruction signal to the drive unit 81. It has.
The drive unit 81 tilts the transparent substrates 71 and 72 according to the instruction signal input from the input unit 82.
The input unit 82 is operated by a viewer who views an image displayed on the screen 200 by the projector PJ1 of the present embodiment, and outputs an instruction signal according to the operation of the viewer.

  The liquid crystal light valve 90 is installed downstream of the variable apex angle prism 70 in the y direction, and further modulates the luminance of the synthesized light L4 based on display image data input from the outside. As the liquid crystal light valve 90, an active matrix liquid crystal display element can be used as in the liquid crystal light valve 40 described above.

  The projection lens 100 is installed downstream of the liquid crystal light valve 90 in the y direction, and enlarges and projects the combined light L4 whose luminance is modulated by the liquid crystal light valve 90 onto the screen 200.

Next, the overall light transmission flow of the projector PJ1 will be described.
The illumination light L emitted from the light source device 10 is split into red illumination light L1, green illumination light L2, and blue illumination light L3 by the dichroic mirrors 31 and 32.
The red illumination light L1 enters the liquid crystal light valve 40R via the reflection mirror 33 and the collimating lens 38R, and after being modulated in luminance by the liquid crystal light valve 40R, enters the cross dichroic prism 50.
Further, the green illumination light L2 enters the liquid crystal light valve 40G via the collimating lens 38G, and after being modulated in luminance by the liquid crystal light valve 40G, enters the cross dichroic prism 50.
The blue illumination light L3 is incident on the liquid crystal light valve 40B through the lens 36, the reflection mirror 34, the relay lens 37, the reflection mirror 35, and the collimating lens 38B, and after the luminance is modulated in the liquid crystal light valve 40B, cross dichroic. The light enters the prism 50.

The illumination lights L incident on the cross dichroic prism 50 are all guided by being guided in the z direction, and are combined and emitted from the cross dichroic prism 50 as combined light L4.
The combined light L4 is incident on the liquid crystal light valve 90 via the relay lens 60 and the variable apex angle prism 70, and is further subjected to luminance modulation, and then enlarged and projected onto the screen 200 via the projection lens 100. As a result, an image is displayed on the screen 200.

Here, in the projector PJ1 of this embodiment, when image quality deterioration such as moire occurs in the image on the screen 200, the image quality deterioration does not occur while the viewer views the image on the screen 200. The input unit 82 is operated. As a result, an instruction signal is input to the drive unit 81, and the transparent substrates 71 and 72 of the variable apex angle prism 70 are tilted by the drive unit 81. Then, the optical path of the combined light L4 is shifted so that the image quality does not deteriorate.
For example, the fixing means for fixing the liquid crystal light valve 90 is thermally deformed or changes with time due to heat of the synthetic light L4 or the like, so that the liquid crystal light valve 90 is displaced in the x direction as shown in FIG. In this case, the optical path of the combined light L4 is moved upward by the variable apex angle prism 70 following the positional deviation of the liquid crystal light valve 90. As a result, the synthesized light L4 is guided to a desired position of the liquid crystal light valve 90, and the luminance is accurately modulated, so that an HDR display in which the occurrence of image quality deterioration is suppressed is obtained.
Further, for example, even when the relay lens 60 is thermally deformed or changes with time due to heat of the synthetic light L4 or the like, the variable apex angle prism 70 even when the optical path of the synthetic light L4 is shifted from the liquid crystal light valve 90 Thus, it is possible to suppress the occurrence of image quality degradation by shifting the optical path of the combined light L4.

  That is, according to the projector PJ1 of the present embodiment, even if the optical elements such as the liquid crystal light valve 90 and the relay lens 60 and the optical path of the combined light L4 (modulated light) are relatively displaced, By shifting the optical path of the composite light L4 by the angular prism 70, the optical element and the optical path of the composite light L4 can be aligned again. Therefore, according to the projector PJ1 of the present embodiment, it is possible to suppress the occurrence of image quality degradation due to the relative positional deviation between the optical path of the combined light L4 and each optical element.

  Further, in the projector PJ1 of the present embodiment, a bilateral telecentric lens is used as the relay lens 60. Therefore, since the combined light L4 becomes parallel light between the cross dichroic prism 50 and the liquid crystal light valve 90, the variable apex angle prism 70 is installed at any position between the cross dichroic prism 50 and the liquid crystal light valve 90. Even so, the optical path of the combined light L4 can be shifted, and the degree of freedom in design can be increased.

In the projector PJ1 of the present embodiment, an instruction signal is input to the drive unit 81 when the viewer operates the input unit 82. However, the present invention is not limited to this. For example, as shown in FIG. 4, instead of the input unit 82, the control unit 80 captures a display image and outputs an instruction signal corresponding to the display image. It is also possible to employ a configuration in which a display image detection unit 83 is provided.
By adopting such a configuration, an instruction signal corresponding to the display image is input from the display image detection unit 83 to the drive unit 81, and the variable apex angle prism 70 is driven based on the instruction signal. Therefore, it is possible to automatically suppress the occurrence of image quality degradation.

In the projector PJ1 of the present embodiment, the control unit 80 may include a storage unit that stores the instruction signal.
By adopting such a configuration, for example, when the projector PJ1 is once turned off and then restarted, the variable apex angle prism 70 can be quickly adjusted.

In the projector PJ1 of the present embodiment, the optical path of the combined light L4 is shifted by using the variable apex angle prism 70. However, the present invention is not limited to this, and a transmissive liquid crystal device in which the refractive index changes according to the driving voltage can also be used as the optical path shift means.
FIG. 5 is a cross-sectional view schematically showing a transmissive liquid crystal device 110 that can be used as an optical path shifting means. As shown in this figure, the liquid crystal device 110 includes a pair of transparent substrates 111 and 112, a plurality of individual electrodes 113 formed in a stripe shape on the inner surface side of the transparent substrates 111 and 112, an alignment film (not shown), and a transparent substrate. 111 and a homogeneous liquid crystal 114 sealed between the transparent substrate 112 and the transparent substrate 112.
In such a liquid crystal device 110, the refractive index of the homogeneous liquid crystal 114 changes according to the drive voltage applied to the individual electrode 113, and thereby the optical path of the combined light L4 can be shifted.
When the liquid crystal device 110 is used as an optical path shifting unit, a driver that applies a predetermined driving voltage to the individual electrode 113 is used as the driving unit 81.
Further, when the liquid crystal device 110 is used as the optical path shifting means, the polarization direction of the combined light L4 emitted from the liquid crystal device 110 is uniform, so that the polarization direction of the combined light L4 can enter the liquid crystal light valve 90. When the direction is not the direction, it is necessary to install a half-wave plate between the liquid crystal device 110 and the liquid crystal light valve 90.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. In the description of the second embodiment, the description of the same parts as those of the first embodiment will be omitted or simplified.

  FIG. 6 is a diagram showing a schematic configuration of an optical system provided in the projector PJ2 of the present embodiment. As shown in this figure, the projector PJ2 of the present embodiment does not include the relay lens 60 and the liquid crystal light valve 90 included in the projector PJ1 of the first embodiment. A variable apex angle prism 70 is installed between each liquid crystal light valve 40 and the cross dichroic prism 50. A variable apex angle prism 70R is installed between the liquid crystal light valve 40R and the cross dichroic prism 50, and a variable apex angle prism 70G is installed between the liquid crystal light valve 40G and the cross dichroic prism 50, and the liquid crystal light valve 40B. And a cross dichroic prism 50 is provided with a variable apex angle prism 70B. In FIG. 6, illustration of the control unit connected to each variable apex angle prism 70 is omitted.

  In such a projector PJ2 of this embodiment, for example, a fixing means for fixing the liquid crystal light valve 40 is thermally deformed or deformed with heat by illumination light or the like, so that one of the liquid crystal light valves 40R, 40G, Even when the optical paths of the illumination lights L1 to L3 emitted from 40b are shifted with respect to the cross dichroic prism 50, the optical paths of the shifted illumination lights L1 to L3 are shifted by the variable apex angle prism 70 to cross dichroic. It becomes possible to match with the prism 50. For this reason, the illumination lights L1 to L3 can always be accurately superimposed by the cross dichroic prism 50. Therefore, it is possible to generate the combined light L4 in which the illumination lights L1 to L3 are accurately superimposed, and it is possible to suppress the occurrence of image quality deterioration.

  In the projector PJ2 of the present embodiment, the illumination light L is converted into a plurality of illumination lights (red illumination light L1, green illumination light L2, and blue illumination light) in the spectroscopic system 30 as in the first embodiment. L3) and spectroscopy. However, the present invention is not limited to this, and as shown in FIG. 7, a plurality of light source devices 10 (a red light source device 10R, a green light source device 10G, and a blue light source device 10B) may be provided. In this case, the green light source device 10G which does not install the uniform illumination system 20 and the spectroscopic system 30 but arranges the red light source device 10R which emits the red illumination light L1 so as to face the liquid crystal light valve 40R and emits the green illumination light L2. Is disposed opposite to the liquid crystal light valve 40G, and the blue light source device 10B that emits the blue illumination light L3 is disposed opposite to the liquid crystal light valve 40B.

  The preferred embodiments of the image display device and the projector according to the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to the above-described embodiments. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  For example, in the above embodiment, a variable apex angle prism or a liquid crystal device is used as the optical path shift means. However, the present invention is not limited to this, and can be used as an optical path shifting means as long as the optical path of the combined light L4 can be shifted. For example, an acousto-optic element, a galvanometer mirror, a micromirror array device, or the like can be used as the optical path shift means.

  In the above embodiment, a transmissive liquid crystal light valve is used as the first and second light modulation elements. However, the present invention is not limited to this, and it is also possible to use a reflective liquid crystal light valve or a micromirror array device as the first and second light modulation elements.

  For example, in the above embodiment, a projection lens is used as the projection unit. However, the present invention is not limited to this, and a projection mirror can be used as the projection means.

  In addition, for example, the screen of the above-described embodiment is installed in a part of the housing, the configuration other than the screen of the above-described embodiment is housed in the housing, and rear projection is performed on the screen from the inside of the housing. Thus, the present invention can be applied to a so-called rear projector that displays an image.

It is a schematic block diagram of the optical system with which the projector in 1st Embodiment of this invention is provided. FIG. 2 is a cross-sectional view schematically showing a variable apex angle prism included in the projector of FIG. 1. It is a figure for demonstrating operation | movement of the projector in 1st Embodiment of this invention. It is a modification of the projector in 1st Embodiment of this invention. It is sectional drawing which showed typically the liquid crystal device with which the modification of the projector in 1st Embodiment of this invention is provided. It is a schematic block diagram of the optical system with which the projector in 2nd Embodiment of this invention is provided. It is a modification of the projector in 2nd Embodiment of this invention.

Explanation of symbols

PJ1, PJ2 ... projector, 10 ... light source device, 30 ... spectral system (spectral means), 40 ... liquid crystal light valve (first light modulation element), 50 ... cross dichroic prism (synthesizing means), 70 ... ... variable apex angle prism (optical path shifting means), 80 ... control section (control means), 81 ... drive section, 82 ... input section, 83 ... display image detection section (display image detection means), 100 ... Projection lens (projection means), 110... Liquid crystal device (optical path shift means), L... Illumination light, L4.

Claims (11)

An image display device comprising: a light source device that emits illumination light; and a first light modulation element that modulates the illumination light and emits the modulated light.
An image display device comprising optical path shifting means for shifting the optical path of the modulated light. The second light modulation element for further modulating the modulated light, wherein the optical path shift means is disposed between the first light modulation element and the second light modulation element. Image display device. The image display apparatus according to claim 2, further comprising a double-sided telecentric lens that guides the modulated light emitted from the first light modulation element to the second light modulation element. A spectroscopic unit that splits the illumination light emitted from the light source device into a plurality of illumination lights, the first light modulation element that is installed for each of the split illumination lights, and the first light modulation element Combining means for combining each modulated light modulated,
The image display device according to claim 1, wherein the optical path shift unit is installed between each of the first light modulation elements and the combining unit. A plurality of the light source devices, the first light modulation element installed for each illumination light emitted from each light source device, and a combining unit that combines the modulated light modulated by the first light modulation element And
The image display device according to claim 1, wherein the optical path shift unit is installed between each of the first light modulation elements and the combining unit. Control means for controlling the optical path shifting means,
The image display apparatus according to claim 1, wherein the control unit includes a drive unit that drives the optical path shift unit, and an input unit that inputs an instruction signal to the drive unit. . Control means for controlling the optical path shifting means,
The control unit includes a drive unit that drives the optical path shift unit, and a display image detection unit that inputs an instruction signal to the drive unit in accordance with a display image. The image display device described. The image display device according to claim 6, further comprising a storage unit that stores the instruction signal. The image display device according to claim 1, wherein the optical path shift unit is a variable apex angle prism. The image display device according to claim 1, wherein the optical path shift unit is a transmissive liquid crystal device. A projector comprising an image display device that emits modulated light obtained by modulating illumination light, and a projection unit that projects the modulated light emitted from the image display device onto a screen.
A projector using the image display device according to claim 1 as the image display device.

Images