JP2013242457A - Optical unit and projection type display device - Google Patents

Abstract

The present invention provides an optical unit and a projection display device capable of suppressing deterioration in image quality even when expansion and contraction due to temperature change occur in a plurality of light modulation devices.
An optical unit and a projection display device include a unit main body including a cross dichroic prism and a projection lens system, and a light modulation device for each color fixed to the unit main body. . The cross dichroic prism 41 synthesizes and emits an image formed by the light modulation device 50G and an image obtained by mirror-inversion of the images formed by the light modulation devices 50R and 50B. Here, the relative position of the fixing portion 59G between the light modulation device 50G and the unit main body 4 with respect to the image forming region 521G, and the fixing portions 59R and 59B between the light modulation devices 50R and 50B and the unit main body 4 with respect to the image forming regions 521R and 521B. Are relative to each other and are line symmetric.
[Selection] Figure 5

Description

  The present invention relates to an optical unit in which a plurality of light modulation devices are fixed to a unit body, and a projection display device including the optical unit.

  In the projection display device, the optical unit includes a plurality of light modulation devices and a combining optical system that combines and emits images displayed by these light modulation devices, and each of the plurality of light modulation devices It is fixed to the unit main body including the synthesis optical system. More specifically, the light modulation device includes an electro-optical panel such as a liquid crystal light valve, and a frame that holds the electro-optical panel, and the light modulation device is fixed to the unit main body via the frame. .

  Here, as a structure for fixing the light modulation device to the unit main body, a structure in which the light modulation device is fixed by a screw at the center position of the side of the frame is proposed in any of the plurality of light modulation devices (see Patent Document 1). . In addition, a structure in which screws are fixed at the corners of the frame has been proposed (see Patent Document 2). According to such a structure, when cooling air is supplied along the light modulation device, the flow of the cooling air is hindered by the screws. There are advantages such as not being able to.

JP-A-2005-241766 JP 2009-210779 A

  However, as shown in FIG. 8, in fixing the light modulation device 50 to the unit body 4 at one of the four corners, the light modulation device 50R for red light, the light modulation device 50G for green light, and In any of the light modulation devices 50B for blue light, if the fixing portions 59R, 59G, and 59B with the unit main body 4 are arranged at the same position of the light modulation device 50, the image quality when the temperature of the light modulation device 50 rises. There is a problem that the deterioration of is large.

  More specifically, among the three light modulation devices 50, the green light emitted from the light modulation device 50G passes through the cross dichroic prism 41 used as the synthesis optical system and is emitted as an image PG. Thus, red light and blue light emitted from the light modulation devices 50R and 50B are reflected by the cross dichroic prism 41 and emitted as images PR and PB. Therefore, in the image emitted from the cross dichroic prism 41, the relationship in which the direction in which the fixing portions 59R and 59B of the light modulation devices 50R and 50B are located and the direction in which the fixing portion 59G of the light modulation device 50G is located is mirror-reversed. It is in. On the other hand, when the temperature of the light modulation device 50 rises, the light modulation device 50 expands starting from the fixing portions 59R, 59G, and 59B and is emitted from the cross dichroic prism 41 as indicated by arrows TR, TG, and TB. PR, PG, and PB extend in the directions indicated by arrows SR, SG, and SB. At that time, since the direction extending in the images PR and PB (direction indicated by arrows SR and SB) is different from the direction extending in the image PG (direction indicated by arrows SG), the images PR, PG and PB are synthesized. The image quality will deteriorate.

  In view of the above problems, an object of the present invention is to provide an optical unit and a projection display capable of suppressing deterioration in image quality even when expansion and contraction due to temperature changes occur in a plurality of light modulation devices. To provide an apparatus.

  In order to solve the above problems, an optical unit according to the present invention includes a first light modulation device including a first image forming region in which a first image is formed, and a second image forming region in which a second image is formed. A second optical modulation device, and a unit main body including a synthesis optical system that synthesizes and emits the first image and an image obtained by mirror-inverting the second image. The relative position of the first fixing portion between the first light modulation device and the unit main body is different from the relative position of the second fixing portion between the second light modulation device and the unit main body with respect to the second image forming region. And it is line symmetric.

  In the optical unit according to the present invention, an image forming region includes a first light modulation device that emits the formed first image without mirror inversion, and a second light modulation device that mirrors the formed second image. The relative positions of the fixing portions of the light modulation device and the unit main body with respect to the are different and are line symmetric. For this reason, even when a temperature change occurs in the light modulation device and the light modulation device undergoes deformation such as expansion or contraction starting from the fixed portion, an image (first image and In the image obtained by mirror-inversion of the second image, the deformation direction is the same. Therefore, even when expansion or contraction due to a temperature change occurs, it is possible to suppress deterioration in quality when the images are combined.

  In the present invention, it is preferable that the first fixing portion is provided at one place and the second fixing portion is provided at one place. According to such a configuration, even if a temperature change occurs in the light modulation device, and the light modulation device undergoes deformation such as expansion or contraction starting from the fixed portion, excessive stress is not applied to the light modulation device. No complicated deformation or the like occurs in the light modulation device.

  In the present invention, the first image forming region and the second image forming region have a rectangular shape in plan view, and the first fixing portion is located adjacent to a corner of the first image forming region, It is preferable that the second fixing portion is at a position adjacent to a corner of the second image forming area.

  In the present invention, the first fixing portion is provided at a position that does not overlap a trajectory when the first image forming area is translated in a direction in which a side extends in the first image forming area. It is preferable that the second fixing portion is provided at a position that does not overlap with the locus when the second image forming area is translated in the direction in which the side extends in the second image forming area. According to such a configuration, when the cooling air is supplied along the first image forming area of the first light modulation device and the second image forming area of the second light modulation device, the fixing portion with the unit main body has the cooling air. Does not block the flow.

  In the present invention, the first image forming area is located at a position deviated from a center position when the first light modulation device is viewed in plan to the first fixed portion side, and the second image forming area is the first image forming area. It is preferable that the two-light modulator is located at a position deviated from the center position when viewed in plan to the second fixed portion side. According to such a configuration, since the distance from the fixing portion to the unit main body is short, the influence of expansion and contraction due to temperature change hardly affects the image forming area.

  In the present invention, each of the first light modulation device and the second light modulation device includes an electro-optical panel and a metal frame that holds the electro-optical panel and is fixed to the unit body. A configuration can be employed. In such a configuration, since the frame is made of metal, deformation such as expansion and contraction due to temperature change is likely to occur. However, according to the present invention, the influence of such deformation is difficult to affect the image.

  In the present invention, in each of the first light modulation device and the second light modulation device, the electro-optical panel and the frame are on the side where the first fixing portion and the second fixing portion are located in the frame. It is preferable that the adhesive is fixed. According to this configuration, even when the thermal expansion coefficients of the electro-optical panel and the frame are different, excessive stress is not applied to the electro-optical panel.

  In the present invention, it is possible to adopt a configuration in which the second image is mirror-inverted by the combining optical system and combined with the first image.

  In the present invention, the second image may be configured to be mirror-reversed in the unit main body and synthesized with the first image by the synthesis optical system.

  The optical unit according to the present invention can be used in a projection display device. In such a configuration, the projection display device supplies light source light to the first light modulation device and the second light modulation device. have.

It is explanatory drawing which shows typically schematic structure of the projection type display apparatus to which this invention is applied. 1 is a perspective view of a light modulation device, a cross dichroic prism, a head body, and the like of a projection display device to which the present invention is applied. It is the disassembled perspective view which looked at the light modulation apparatus, the cross dichroic prism, etc. in the projection type display apparatus to which this invention is applied from diagonally backward. It is the disassembled perspective view which looked at the light modulation apparatus of the projection type display apparatus to which this invention is applied, a cross dichroic prism, etc. from diagonally forward. It is explanatory drawing which shows arrangement | positioning etc. of each of several light modulation apparatus in the projection type display apparatus to which this invention is applied. It is explanatory drawing which shows the fixed position etc. of the some light modulation apparatus in the projection type display apparatus to which this invention is applied. It is explanatory drawing which shows the fixed position etc. of the some light modulation apparatus in the projection type display apparatus which concerns on another embodiment of this invention. It is explanatory drawing which shows each arrangement | positioning, fixed position, etc. of the some light modulation apparatus in the projection type display apparatus which concerns on the reference example of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, red light is R light, green light is G light, and blue light is B light. In the following description, for convenience of description, the direction in which the light beam is emitted from the light source device 31 is defined as + X direction (left direction), and the opposite direction is defined as −X direction. The direction in which the light beam is emitted from the projection lens system 36 is defined as + Y direction (forward direction), and the opposite direction is defined as −Y direction. Further, the upper direction in the stationary posture where the projection display device 1 is placed on a desk or the like is defined as + Z direction (upward direction), and the opposite direction is defined as -Z direction.

[Configuration of Projection Display Device]
FIG. 1 is an explanatory diagram schematically showing a schematic configuration of a projection display device to which the present invention is applied. As shown in FIG. 1, the projection display device 1 includes a housing 2 that constitutes an exterior, a control unit (not shown), an optical unit 3, and a light source device 31 (light source unit). Although not shown, the housing 2 further includes a power supply device that supplies power to the light source device 31 and the control unit, a cooling device that cools the optical unit 3, and the like. The housing 2 is provided with an intake port for taking in outside air, an exhaust port for exhausting warm air in the housing 2 to the outside, and the like. The light source device 31 includes a discharge-type light source 311 made of an ultra-high pressure mercury lamp, a metal halide lamp, and the like, a reflector 312, and the like. Exit toward. The control unit includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and functions as a computer that controls the projection display device 1 and the like. The optical unit 3 includes a unit main body 4 including a cross dichroic prism 41, a projection lens system 36, and the like as a combining optical system, and a light modulation device 50 for each color fixed to the unit main body 4 (light modulation device 50R for R light). , A light modulation device 50G for G light, and a light modulation device 50B) for B light. The optical unit 3 modulates the light beam emitted from the light source device 31 by each light modulation device 50 under the control of the control unit, and then combines the display light emitted from each light modulation device 50 by the cross dichroic prism 41. Then, projection is performed from the projection lens system 36.

[Schematic Configuration of Optical Unit 3 and Light Modulator 50]
FIG. 2 is a perspective view of the light modulation device 50G, the cross dichroic prism 41, the head body, and the like of the projection display device 1 to which the present invention is applied. FIG. 3 is an exploded perspective view of the light modulation device 50G, the cross dichroic prism 41, and the like in the projection display device 1 to which the present invention is applied as viewed obliquely from the rear. FIG. 4 is an exploded perspective view of the light modulation device 50G, the cross dichroic prism 41, and the like of the projection display device 1 to which the present invention is applied as viewed obliquely from the front. The three light modulation devices 50 (light modulation device 50R for R light, light modulation device 50G for G light, and light modulation device 50B for B light) have the same basic configuration, and thus light modulation is performed. The configuration of the device 50 will be described focusing on the light modulation device 50G for G light.

  As shown in FIGS. 2, 3, and 4, the light modulation device 50 (light modulation device 50G) includes a liquid crystal light valve 52 (liquid crystal light valve 52G), a frame 55, and a hook member 57. The liquid crystal light valve 52 is a transmission type electro-optical panel (liquid crystal panel) in which a liquid crystal material as an electro-optical material is held between a pair of light-transmitting substrates. 53 is connected. In the liquid crystal light valve 52, the alignment state of the liquid crystal is controlled based on a drive signal input from the control unit via the flexible wiring board 53. In the liquid crystal light valve 52, a light-transmitting dustproof glass may be attached to the incident side and the emission side of the pair of light-transmitting substrates that hold the liquid crystal layer. It is integrally held by the frame 55.

  The frame 55 is made of a metal such as aluminum and includes a frame portion 551 that supports the liquid crystal light valve 52 and a heat radiating plate portion 553 that extends from the frame portion 551 in the Z direction. In the frame 55, the frame portion 551 is formed in a rectangular shape in plan view, and an opening portion 552 into which light (G light) separated by the color separation optical system 33 enters and a liquid crystal light valve 52 in the center portion. An opening portion 557 for emitting the light modulated by is formed. Here, the position where the liquid crystal light valve 52 overlaps the openings 552 and 557 in a plan view is the image forming area 521. In addition, through holes 555a, 555b, 555c, and 555d penetrating in the Y direction are formed at the four corners of the frame portion 551. The heat radiating plate portion 553 is formed in a rectangular shape in plan view protruding in the Z direction from the upper end of the frame portion 551 and overlaps the flexible wiring board 53 in the Y direction.

  In holding the liquid crystal light valve 52 on the frame 55, in this embodiment, after the liquid crystal light valve 52 is overlaid on the frame 55, the hook member 57 is overlaid on the liquid crystal light valve 52, and the hook 570 of the hook member 57 is attached to the frame 55. The structure engaged with the protrusion formed in the side surface is employ | adopted. At this time, an adhesive is interposed between the frame 55 and the liquid crystal light valve 52, or between the liquid crystal light valve 52 and the hook member 57, and the liquid crystal light valve 52 is bonded and fixed to the frame 55 and the hook member 57.

(Configuration of unit body 4)
In FIG. 1 again, the unit body 4 includes an integrator illumination optical system 32, a color separation optical system 33, a relay optical system 34, a cross dichroic prism 41, and a projection lens system 36, a head body 37, which will be described later with reference to FIG. And a unit case 38 for arranging these members at predetermined positions on the optical path. The unit body 4 is formed in a substantially L shape in plan view, and the light source device 31 is detachably disposed at one end, and the projection lens system 36 is disposed at the other end. In the unit main body 4, an incident side polarizing plate 51 and an outgoing side polarizing plate 54 are respectively disposed on both sides of the light modulation device 50. Note that various optical compensation elements (not shown) such as a retardation plate may be disposed on the light emission side of the light modulation device 50.

  In the unit main body 4, the integrator illumination optical system 32 includes a first lens array 321, a second lens array 322, a polarization conversion element 323, and a superimposing lens 324. The first lens array 321 is an optical element that divides the light beam emitted from the light source device 31 into a plurality of partial light beams, and is matrixed in a plane substantially orthogonal to the optical axis L of the light beam emitted from the light source device 31. A plurality of small lenses arranged in a shape. The second lens array 322 has substantially the same configuration as the first lens array 321, and the partial light beam emitted from the first lens array 321 is superimposed on the liquid crystal light valve 52 together with the superimposing lens 324. The polarization conversion element 323 has a function of aligning randomly polarized light emitted from the second lens array 322 with substantially one type of polarized light that can be used by the light modulation device 50.

  The color separation optical system 33 includes two dichroic mirrors 331 and 332 and a reflection mirror 333, and separates a light beam emitted from the integrator illumination optical system 32 into three color lights of R light, G light, and B light. It has a function to do.

  The relay optical system 34 includes an incident side lens 341, a relay lens 343, and reflection mirrors 342 and 344, and has a function of guiding the R light separated by the color separation optical system 33 to the R light light modulation device 50R. Have. In the optical unit 3 of this embodiment, the relay optical system 34 is configured to guide the R light. However, the present invention is not limited to this, and the relay optical system 34 may be configured to guide the B light.

  The incident-side polarizing plate 51 transmits the polarized light aligned by the polarization conversion element 323 among the respective color lights separated by the color separation optical system 33 and absorbs the polarized light different from the polarized light, thereby modulating the light modulator 50. To exit.

  The exit-side polarizing plate 54 has substantially the same function as the incident-side polarizing plate 51, and has a predetermined direction among the light emitted from the light modulation device 50 on the light exit side of the light beam from the light modulation device 50. The polarized light is transmitted and emitted to the cross dichroic prism 41, while the polarized light different from the polarized light is absorbed.

  As shown in FIGS. 3 and 4, the unit main body 4 has a translucent substrate 85, and the translucent substrate 85 is a plate material having high thermal conductivity such as quartz attached to the cross dichroic prism 41. It is. The translucent substrate 85 has a function of suppressing the temperature rise of the emission side polarizing plate 54. Here, the translucent substrate 85 has a rectangular shape with a size larger than the end surface of the light incident side of the cross dichroic prism 41.

  Among such optical components, the incident-side polarizing plate 51 is attached to a light-transmitting substrate (not shown) different from the light-transmitting substrate 85 and disposed in the unit case 38. The plate 54 is attached to the cross dichroic prism 41 via a fixed plate 62 and the like which will be described later.

  The projection lens system 36 is configured by a combined lens in which a plurality of lenses are combined, and enlarges and projects the light synthesized by the cross dichroic prism 41 onto a projection target member such as a screen.

[Configuration of Head Body 37]
2, 3, and 4, the head body 37 supports the light modulation device 50, the cross dichroic prism 41, the projection lens system 36, and the like described with reference to FIG. 1. The head body 37 includes a prism support portion 371 located below the cross dichroic prism 41 and a lens support portion 372 located in front of the cross dichroic prism 41 (+ Y direction). The prism support portion 371 includes: It is fixed behind the lens support portion 372. The prism support unit 371 supports the cross dichroic prism 41, the light modulation devices 50R, 50G, 50B, and the like by bonding and fixing the lower surface of the cross dichroic prism 41. The lens support portion 372 has the projection lens system 36 fixed to the front (+ Y direction), and the lens support portion 372 has an opening 375 through which light emitted from the cross dichroic prism 41 is transmitted. The head body 37 is attached to the unit case 38.

[Fixed structure of light modulation device 50G]
As shown in FIGS. 3 and 4, the light modulation device 50 </ b> G is fixed to the unit main body 4 via a fixing plate 62 and the like described below. Specifically, first, the unit main body 4 includes a fixed plate 62 and a support member 70 in addition to the emission side polarizing plate 54 and the translucent substrate 85.

  The fixed plate 62 is disposed in front of the light modulation device 50 (on the cross dichroic prism 41 side), and the frame 55 is fixed. The fixed plate 62 is made of a metal plate material, and includes a base portion 621 having a rectangular shape in plan view, and a pair of side plate portions 622 bent from the edge of the base portion 621 toward the front (cross dichroic prism 41 side). Have. In this embodiment, an optical compensation element is attached between the side plate portions 622.

  A rectangular opening 629 through which the light beam emitted from the light modulation device 50 passes is formed at the center of the base 621, and each of the two corners around the opening 629 near the two corners located in the −Z direction. A screw hole 624 is formed in the screw hole. The screw hole 624 is positioned so as to overlap with the two through holes 555 a and 555 b provided in the frame 55. In addition, a small protrusion 626 that protrudes toward the light modulation device 50 is formed around each of the two corners located on the + Z side around the opening 629, and the protrusion 626 is provided on the frame 55. The two through holes 555c and 555d thus overlapped.

  When the light modulation device 50 is fixed to the fixed plate 62 having such a configuration, the screw SC passed through one of the two through holes 555 a and 555 b formed in the frame 55 is screwed into the screw hole 624 of the fixed plate 62. In combination, the light modulation device 50 is fixed to the fixing plate 62. Accordingly, of the through holes 555a and 555b, the through hole in which the screw SC is stopped serves as a fixing portion 59 (the fixing portion 59 between the light modulation device 50 and the unit body 4) between the light modulation device 50 and the fixing plate 62. The fixing part 59 is located outside the image forming area 521. At this time, the two protrusions 626 of the fixing plate 62 are fitted into the through holes 555c and 555d of the frame 55, respectively, but the outer diameter of the protrusion 626 is smaller than the inner diameter of the through holes 555c and 555d. Therefore, as will be described later with reference to FIG. 5, when the light modulation device 50 expands, the light modulation device 50 expands with the fixing portion 59 as a starting point.

  In the fixed plate 62, slit-like insertion holes 628 into which the plate-like portions 73 of the support member 70 are inserted are formed at the four corners of the base portion 621. In contrast, the support member 70 includes a frame portion 71 having a rectangular shape in plan view, a side plate portion 72 bent rearward from the side edge of the frame portion 71, and a plate shape bent rearward from the corner of the frame portion 71. The plate-like portion 73 is inserted into an insertion hole 628 formed in the base portion 621 of the fixed plate 62. In the support member 70, the frame portion 71 is fixed to the translucent substrate 85 by a method such as adhesion. Further, the side plate portion 72 is fixed so as to overlap the side plate portion 622 of the fixed plate 62. As a result, the light modulation device 50 (light modulation device 50G for G light) is fixed to the cross dichroic prism 41 of the unit body 4 via the fixing plate 62 and the support member 70.

  The light modulation device 50R for R light and the light modulation device 50B for B light are also fixed in the same configuration as the light modulation device 50G for G light.

[Arrangement and fixed position of each of the plurality of light modulation devices 50]
FIG. 5 is an explanatory diagram showing the arrangement and the like of each of the plurality of light modulation devices 50 in the projection display device 1 to which the present invention is applied. FIG. 6 is an explanatory diagram showing fixed positions and the like of a plurality of light modulation devices 50 in the projection display device 1 to which the present invention is applied. FIG. 6 shows a state in which the light modulation device 50 is viewed from the cross dichroic prism 41 side.

  As shown in FIGS. 5 and 6, the cross dichroic prism 41 has a substantially cubic shape in which four right-angle prisms are bonded together, and includes three light incident end faces 41R on which the light modulation devices 50 of the respective colors are arranged. 41G and 41B. Among the light incident end surfaces 41R, 41G, and 41B, the light incident end surfaces 41R and 41B are surfaces that face each other in parallel, and the light incident end surface 41G is a surface that is orthogonal to the light incident end surfaces 41R and 41B. With respect to the cross dichroic prism 41 configured as described above, the light modulation device 50G for G light is fixed to the light incident end surface 41G (the first surface of the unit body 1) opposite to the exit end surface of the cross dichroic prism 41. Will be. On the other hand, in the light modulating device 50R for R light and the light modulating device 50B for B light, in the cross dichroic prism 41, the light incident end surfaces 41R and 41B that are adjacent to the exit end surface and the light incident end surface 41G at right angles. It is fixed to the side (the second surface of the unit main body 1). Further, the light modulation device 50R for R light and the light modulation device 50B for B light are respectively fixed to the two light incident end faces 41R and 41B (the second surface of the unit main body 1) facing each other in the cross dichroic prism 41. Is done.

  In the cross dichroic prism 41, dielectric multilayer films 411 and 412 are formed at the interface where the right-angle prisms are bonded together. The dielectric multilayer films 411 and 412 are orthogonal to each other and form an angle of 45 ° with the light incident end faces 41R, 41G, and 41B. In the cross dichroic prism 41, the R light emitted from the light modulation device 50R (liquid crystal light valve 52R) is reflected by the dielectric multilayer film 411 and emitted as an image PR, and is emitted from the light modulation device 50B (liquid crystal light valve 52B). The emitted B light is reflected by the dielectric multilayer film 412 and emitted as an image PB, and the G light emitted from the light modulation device 50G (liquid crystal light valve 52G) is transmitted and emitted as an image PG. Accordingly, the images formed by the three light modulation devices 50 are combined by the cross dichroic prism 41 and emitted from the cross dichroic prism 41 as a color image.

  Therefore, the light modulation device 50G is a first light modulation device in which an image (first image) is formed in the image formation region 521G (first image formation region) of the liquid crystal light valve 52G. In contrast, in the light modulation devices 50R and 50B, an image (second image) that is mirror-inverted with respect to the image (first image) displayed in the image forming region 521G (first image forming region) is a liquid crystal light. This is a second light modulation device formed in the image forming areas 521R and 521B (second image forming areas) of the valves 52R and 52B. The cross dichroic prism 41 has an image (first image) formed by the light modulation device 50G (first light modulation device) and an image (first light modulation device) formed by the light modulation devices 50R and 50B (second light modulation device). The second image) is combined with the mirror-inverted image and emitted. Note that the second image generated by the light modulation devices 50R and 50B is mirror-inverted with respect to the first image generated by the light modulation device 50G from the cross dichroic prism 41 (synthesis optical system). Image components (R image component and B image component) generated by the light modulation devices 50R and 50B and image components (G image component) generated by the light modulation device 50G are mirror-inverted. It means that there is a relationship. For this reason, the R image and the B image generated by the light modulation devices 50R and 50B and the G image generated by the light modulation device 50G are not necessarily in a mirror-inverted relationship.

  In the optical unit 3 and the projection display device 1 configured as described above, in this embodiment, the image forming area 521 of the liquid crystal light valve 52 is the light modulator 50 (light modulator 50R, 50G, 50B). It is located at the center of the light modulation device 50 (the center of the frame 55). However, in this embodiment, the light modulation device 50 (light) by the screw SC shown in FIG. 3 corresponds to the direction of the image formed by the light modulation device 50 and the traveling direction of the display light emitted from the light modulation device 50. The positions of the fixing portions 59 (fixing portions 59R, 59G, 59B) between the modulation devices 50R, 50G, and 50B) and the unit body 4 are optimized for each light modulation device 50. That is, the position of the fixing portion 59 (fixing portion 59G: first fixing portion) between the light modulation device 50G and the unit main body 4 using the screw SC shown in FIG. 3, and the light modulation devices 50R and 50B using the screw SC shown in FIG. The positions of the fixing portions 59 (fixing portions 59R and 59B: second fixing portions) with the unit main body 4 are optimized.

  Specifically, the relative position of the fixing portion 59R between the light modulation device 50R and the unit main body 4 with respect to the image forming region 521R, and the relative position of the fixing portion 59B between the light modulation device 50B and the unit main body 4 with respect to the image forming region 521B. Are the same. However, the relative position of the fixing portion 59G between the light modulation device 50G and the unit main body 4 with respect to the image forming region 521G, and the fixing portions 59R and 59B between the light modulation devices 50R and 50B and the unit main body 4 with respect to the image forming regions 521R and 521B. The relative position is different and the line is symmetrical. That is, in the light modulation device 50G, the light modulation device 50G and the unit main body 4 are fixed by the screw SC that has passed through the through hole 555a among the through holes 555a and 555b of the frame 55 shown in FIG. In the light modulation devices 50R and 50B, the light modulation devices 50R and 50B and the unit main body 4 are fixed by screws SC that pass through the through holes 555b of the through holes 555a and 555b of the frame 55. For example, when viewing the light modulation device 50 from the side from which the modulated light is emitted in the light modulation device 50, the light modulation device 50G is provided with a fixing portion 59G at a position adjacent to the lower right corner of the image forming region 521G. In the light modulation devices 50R and 50B, fixing portions 59R and 59B are provided at positions adjacent to the lower left corner of the image forming region 521G. The symmetry axis in the line symmetry relationship between the fixed portion 59G in the light modulation device 50G and the fixed portions 59R and 59B in the light modulation devices 50R and 50B is an image formed by the cross dichroic prism 41 by the light modulation devices 50R and 50B. Corresponds to the axis of symmetry for mirror inversion.

  For this reason, when the temperature of the light modulation device 50 rises and the light modulation device 50 expands from the fixing portions 59R, 59G, 59B as indicated by arrows TR, TG, TB in FIG. 5, the cross dichroic prism 41 The images PR, PG, and PB emitted from the image extend in the directions indicated by the arrows SR, SG, and SB, but the directions extended by the images PR and PB (the directions indicated by the arrows SR and SB) are all the same direction. . Therefore, it is possible to suppress a reduction in quality in an image obtained by combining the images PR, PG, and PB.

  Here, the fixing part 59 between the light modulation device 50 and the unit main body 4 is provided only at one place. For this reason, even when a temperature change occurs in the light modulation device 50 and the light modulation device 50 undergoes deformation such as expansion or contraction starting from the fixing portion 59, excessive stress is not applied to the light modulation device 50. Therefore, complicated deformation or the like does not occur in the light modulation device 50. The image forming area 521 has a rectangular shape in plan view, and the fixing portion 59 between the light modulation device 50 and the unit main body 4 is located adjacent to the corner of the image forming area 521. The fixing portion 59 is provided at a position that does not overlap the locus when the image forming area 521 is translated in the Z direction in which the side extends in the image forming area 521. For this reason, as shown by the arrow A, when the cooling air is flowed along the light modulation device 50 to cool the light modulation device 50, the fixing portion 59 does not disturb the flow of the cooling air.

(Main effects of this form)
As described above, in the optical unit 3 and the projection display device 1 of this embodiment, the light modulation device 50G (first light modulation device) and the light modulation devices 50R and 50B (second light modulation device) Although the relative position of the fixing portion 59 with respect to the formation region 521 is different, it is line symmetric. For this reason, even when a temperature change occurs in the light modulation device 50 and the light modulation device 50 undergoes deformation such as expansion or contraction starting from the fixing portion 59, in the image emitted from the cross dichroic prism 41, The deformation direction of the image is the same. Therefore, even when expansion or contraction occurs in the light modulation device 50 due to a temperature change, it is possible to suppress degradation in quality when images are combined.

  In particular, in the present invention, since the frame 55 is made of metal, there is an advantage that heat dissipation is high. On the other hand, expansion and contraction due to temperature change are large, but in this embodiment, the position of the fixing portion 59 with respect to the image forming area 521 Since each light modulation device 50 is optimized, even when expansion or contraction occurs in the light modulation device 50 due to a temperature change, it is possible to suppress degradation in quality when the images are combined.

[Another embodiment]
FIG. 7 is an explanatory diagram showing fixed positions and the like of a plurality of light modulation devices 50 in the projection display device 1 according to another embodiment of the present invention.

  In the above-described embodiment described with reference to FIGS. 1 to 6, in any light modulation device 50, the image forming region 521 of the liquid crystal light valve 52 is positioned at the center of the light modulation device 50 (the center of the frame 55). However, as shown in FIG. 7, the present invention may be applied when the image forming region 521 is located at a position deviated from the center of the light modulation device 50.

  Even in this case, the position of the fixing portion 59 is set based on the image forming area 521. That is, the relative position of the fixing portion 59R between the light modulation device 50R and the unit main body 4 with respect to the image forming region 521R and the relative position of the fixing portion 59B between the light modulation device 50B and the unit main body 4 with respect to the image forming region 521B are the same. is there. However, the relative position of the fixing portion 59G between the light modulation device 50G and the unit main body 4 with respect to the image forming region 521G, and the fixing portions 59R and 59B between the light modulation devices 50R and 50B and the unit main body 4 with respect to the image forming regions 521R and 521B. The relative position is different and the line is symmetrical. Further, the image forming area 521 is located at a position deviated from the center position when the light modulation device 50 is viewed in plan to the fixing portion 59 side. According to such a configuration, the image forming area 521 has a short distance from the fixed portion 59, so that the influence of expansion and contraction due to the temperature change hardly affects the image forming area 521.

[Other embodiments]
As described with reference to FIG. 3 and the like, when the liquid crystal light valve 52 is held by the frame 55, an adhesive is interposed between the frame 55 and the liquid crystal light valve 52 to attach the liquid crystal light valve 52 to the frame 55 or the hook. When adhesively fixing to the member 57, it is preferable that the frame 55 is adhesively fixed only on the side where the fixing portion 59 is located. According to this configuration, even when the liquid crystal light valve 52 and the frame 55 have different thermal expansion coefficients, excessive stress is not applied to the liquid crystal light valve 52.

  Further, a configuration may be adopted in which the side where the fixing portion 59 is located is fixed by the screw SC, and the other portion is reinforced by an elastic adhesive. According to such a configuration, it is possible to compensate for a lack of strength at the screw tightening point. Further, a configuration may be adopted in which the side where the fixing portion 59 is located is fixed with a strong adhesive and the other portions are reinforced with an elastic adhesive. According to such a configuration, it is possible to solve the problem of insufficient adhesive strength that is likely to occur when fixing at one place.

  In the above-described embodiment, the optical unit 3 and the projection display device 1 including the transmission type light modulation device 50 are exemplified, but the optical unit 3 and the projection display device 1 including the reflection type light modulation device 50 are exemplified. The present invention may be applied.

  In the above embodiment, the second image generated by the light modulation devices 50R and 50B (second light modulation device) is compared with the first image generated by the light modulation device 50G (first light modulation device). The second image generated by the second light modulation device is the same as the first image generated by the first light modulation device, and is inverted by the unit body 4, and then the combined optical system. The present invention may be applied to an optical unit or a projection display device that is combined with the first image. In this case, the second image generated by the second light modulation device is the same as the first image generated by the first light modulation device. This means that the image component generated by the light modulation device and the image component generated by the first light modulation device have the same relationship. For this reason, the image which a 2nd light modulation apparatus produces | generates and the image which a 1st light modulation apparatus produces | generates do not necessarily have the completely same relationship.

  In the above embodiment, the portion where the light modulation device 50 is fixed in the unit body 4 corresponds to the end face of the cross dichroic prism 41, but the first light modulation device is fixed to the first surface of the unit body 4. The present invention may be applied when the second light modulation device is fixed to a second surface different from the first surface of the unit body 4.

1 .... Projection type display device, 3 .... Optical unit, 4 .... Unit body, 31..Light source device, 36..Projection lens system, 41..Cross dichroic prism (synthesis optical system), 50..Light modulation · 50G · · · Light modulator (first light modulator), 50R, 50B · · Light modulator (second light modulator), 52, 52R, 52G, 52B · · · Liquid crystal light valve, 55 · · frame, 59..Fixing part, 59G..Fixing part (first fixing part), 59R, 59B..Fixing part (second fixing part), 62..Fixing plate, 521..Image forming area, 521G..Image forming Area (first image forming area), 521R, 521B,... Image forming area (second image forming area), L, optical axis, PG, image (first image), PR, PB, image (second image)

Claims (10)

A first light modulation device including a first image forming region in which a first image is formed;
A second light modulation device comprising a second image forming region in which a second image is formed;
A unit main body including a combining optical system for combining and emitting the first image and an image obtained by mirror-inverting the second image;
Have
The relative position of the first fixing portion between the first light modulation device and the unit main body with respect to the first image forming region, and the second fixing between the second light modulation device and the unit main body with respect to the second image forming region. An optical unit characterized in that the relative positions of the parts are different and are line symmetric.   The optical unit according to claim 1, wherein the first fixing portion is provided at one place, and the second fixing portion is provided at one place. The first image forming area and the second image forming area have a rectangular shape in plan view,
The first fixing portion is located adjacent to a corner of the first image forming area;
3. The optical unit according to claim 1, wherein the second fixing portion is located adjacent to a corner of the second image forming area. The first fixing portion is provided at a position that does not overlap a trajectory when the first image forming area is translated in a direction in which the side extends in the first image forming area.
The second fixing portion is provided at a position that does not overlap a locus when the second image forming area is translated in a direction in which the side extends in the second image forming area. The optical unit according to claim 3. The first image forming area is located at a position biased toward the first fixed portion from a center position when the first light modulation device is viewed in plan view.
5. The second image forming area is located at a position biased toward a side of the second fixing portion from a center position when the second light modulator is viewed in plan. The optical unit described in 1.   Each of the first light modulation device and the second light modulation device includes an electro-optical panel, and a metal frame that holds the electro-optical panel and is fixed to the unit main body. The optical unit according to any one of claims 1 to 5.   In each of the first light modulation device and the second light modulation device, the electro-optical panel and the frame are bonded and fixed on a side of the frame where the first fixing portion and the second fixing portion are located. The optical unit according to claim 6.   The optical unit according to claim 1, wherein the second image is mirror-inverted by the combining optical system and combined with the first image.   The optical unit according to any one of claims 1 to 7, wherein the second image is mirror-reversed in the unit main body and is combined with the first image by the combining optical system. A projection type display device comprising the optical unit according to any one of claims 1 to 9,
A projection display device comprising a light source unit that supplies light source light to the first light modulation device and the second light modulation device.

Images