JP5216480B2 - Projection-type image display device - Google Patents

Description

  The present invention relates to a projector that optically modulates a light beam emitted from a light source in accordance with video information to form an image and project it in an enlarged manner.

  Conventionally, projectors have been used for presentations such as conferences, academic conferences, and exhibitions, and in recent years, they are also used for home theaters. As such a projector, a color light separation optical system that separates a light beam emitted from a light source lamp into a plurality of color light beams using a dichroic mirror, a plurality of light modulation means that modulate each color light beam according to image information, and There is also known a projection-type image display device that includes a color light combining optical system that combines light beams of respective colors and a light guide that houses these optical system members.

  Such projectors are required to be lighter and more compact so that they can be easily carried and used at various occasions. For this reason, downsizing and space saving of the light modulation means are being promoted. On the other hand, the brightness of the light source of the projector is being increased so that a clear projected image can be obtained even in a bright place. For this reason, the luminous flux from the light source with high brightness is concentrated on the light modulation element, and the thermal load is increasing.

By the way, as the conventional holding frame of the light modulation element, a metal mold holding frame is generally used to cope with such a heat load. Patent documents describing this include, for example, Patent Document 1 and Patent Document 2.
JP 2004-258621 A JP 2007-298615 A

  However, since the conventional holding frame of the light modulation element has a metal mold property, there is a problem that the shape of the holder is large and the peripheral area of the light modulation element tends to be large. There is also a problem that the production cost is increased.

  The present invention has been made under such a background, and is a projection type capable of reducing the manufacturing cost by downsizing, space saving, and easy manufacturing of the light modulation element constituting the light modulation means. An object is to provide a video display device.

A projection display apparatus according to the present invention includes an illumination optical system including a light source and a polarization conversion element, and a color light separation optical system that separates a light beam emitted from the illumination optical system into red light, green light, and blue light. Liquid crystal light valve for red light, liquid crystal light valve for green light, liquid crystal light valve for blue light, and liquid crystal light for each color, which modulates red light, green light, and blue light separated by the color light separation optical system according to image information In a projection-type image display device having a color light combining optical system for combining light beams modulated by a bulb and a light guide for housing these optical members , green light is incident on the incident side of the liquid crystal light valve for green light. A Ye modulation element for modulating the superimposed yellow light is disposed, and the Ye modulation element is a liquid crystal cell in which liquid crystal is sealed between a plurality of glass substrates formed in a quadrilateral shape when viewed from the optical axis direction. And a wiring board formed so as to protrude from one side of the four sides when viewed from the optical axis direction, and an incident side holding frame and an emission side holding frame combined so as to sandwich the liquid crystal cell from both sides. The entrance-side holding frame and the exit-side holding frame are made of sheet metal with a bent support piece that supports the outer peripheral end face of the liquid crystal cell, and are bonded to the liquid crystal cell at the outer peripheral portion, and the light guide includes the Ye A pair of support frame portions that support two sides orthogonal to the side from which the wiring board in the modulation element protrudes, and a corner portion of the light modulation element formed on each end of the pair of support frame portions. receiving and a groove, further, the Ye modulation element, by the pressing member for pressing the side wiring board protrudes mounted pressed against the resilient cushion material a via the receiving groove portion And wherein the door.

  If comprised in this way, since a holding frame is metal plate-made, while making a holding frame into a thin plate processed product, while being reduced in size and weight and saving space, the heat dissipation performance of a holding frame can be made favorable. Further, the holding frame is composed of an incident side holding frame and an emission side holding frame which are combined so as to sandwich the liquid crystal cell from both sides, and these holding frames are bonded to the liquid crystal cell at the outer peripheral portion. In addition, the sheet metal processing becomes easy and the cost can be reduced.

  In general, a three-plate type using a liquid crystal light valve for red light, a liquid crystal light valve for green light, and a liquid crystal light valve for blue light is frequently used as a projection-type image display device using a liquid crystal panel as a light modulation element. However, in recent years, there is a demand for appropriately securing the brightness of an image by using a color near yellow light. The invention configured as described above meets such a demand. That is, the present invention is based on a conventional three-plate projection type image display device, and a Ye modulation element composed of a light modulation element for modulating yellow light is added to the incident side of the green light liquid crystal light valve. It is what. In addition, in order to add a Ye modulation element that modulates yellow light to a conventional three-plate projection-type image display device, the Ye modulation element that modulates yellow light is required to be downsized. Such a request can be satisfied.

  Moreover, it is preferable that the incident side holding frame is integrally formed with a cooling piece protruding sideward by sheet metal processing. With this configuration, the area for heat exchange with the cooling air is increased, so that the cooling effect by the holding frame is improved. Moreover, since such a cooling piece is provided not on the exit side holding frame but on the incident side holding frame, the cooling effect is improved. Moreover, since such a cooling piece is integrally formed by sheet metal processing, manufacturing cost is reduced.

The incident side holding frame may be configured such that the cooling piece is formed on a plurality of sides. If comprised in this way, the cooling effect by a holding frame can be improved more.
Further, the incident side holding frame or the emission side holding frame has a regulation protrusion for regulating the incident side and the emission side when the light modulation element is attached, and the support frame portion includes the light modulation element. It is preferable that an engagement groove that engages with the restricting projection piece when formed in a normal direction is formed. If comprised in this way, since the said light modulation element is attached without making a mistake in the entrance side and the radiation | emission side, while being able to operate this light modulation element normally, the cooling effect can also be show | played normally.

  According to the projection display apparatus according to the present invention, since the holding frame of the light modulation element constituting the light modulation means is made of sheet metal, the light modulation element is reduced in size and weight and space saving, and the heat dissipation performance of the holding frame. Can be good. In addition, since the holding frame of the light modulation element is formed from the incident side holding frame and the emission side holding frame and is bonded with the liquid crystal cell sandwiched therebetween, a strong holding frame can be formed and the holding frame can be processed. This facilitates the cost reduction.

Hereinafter, a projection type image display apparatus according to an embodiment of the present invention will be described.
FIG. 1 is a plan view of the projection type video display apparatus according to the embodiment of the present invention with the upper case removed and the upper light guide removed. As shown in this figure, this projection type image display apparatus includes an optical unit and a cooling fan 3, 4, 5 etc. for supplying cold air into the optical unit inside a rectangular parallelepiped outer case 1. ing. In addition, devices constituting the optical unit are provided in the light guide 6. In this figure, a control circuit for controlling the projection display apparatus, a drive circuit for driving the lamp, and the like are omitted.

  As shown in the schematic diagram of FIG. 2, the optical unit includes an illumination optical system 10 including a light source and a polarization conversion element, and a color light separation optical system that separates a light beam emitted from the illumination optical system 10 into a plurality of color light beams. 20, a color light combining optical system 30 that synthesizes each color light beam according to video information, and combines the modulated color light beams, and a projection lens optical system 40 that projects the combined video light.

  The illumination optical system 10 includes a light source 11 that emits a substantially parallel light beam, an integrator lens 12, a polarization conversion element 13 that converts incident light into a predetermined linearly polarized light component, condenser lenses 14 and 15, and a total reflection mirror 16. And. The illumination optical system 10 includes a liquid crystal light valve 31 for red light, a liquid crystal light valve 32 for green light, a liquid crystal light valve 33 for blue light, and a Ye modulation element 34, which are four light modulation means that are illuminated areas. It is an optical system for illuminating.

  The light source 11 includes a light source lamp as a radiation light source that emits a radial light beam, and a concave mirror that emits radiation light emitted from the light source lamp as a substantially parallel light beam. A parabolic mirror is used as the concave mirror. As the light source lamp, a halogen lamp that emits white light, a metal halide lamp, or the like is used.

  The integrator lens 12 is composed of a first lens array 12a and a second lens array 12b. The first lens array 12a and the second lens array 12b have a configuration in which small lenses having a substantially rectangular outline are arranged in a matrix.

  The partial light beam emitted from the integrator lens 12 is converted into one type of polarized light by the polarization conversion element 13, enters the condenser lens 14, is reflected by the total reflection mirror 16, and is further colored by way of the condenser lens 15. The light is emitted to the dichroic mirror 21 of the separation optical system.

  The color light separation optical system 20 includes dichroic mirrors 21 and 22, total reflection mirrors 23, 24a, and 24b, relay lenses 25a and 25b, condenser lenses 26, 27, and 28.

  Further, the color light combining optical system 30 is a first to third modulation means, a red light liquid crystal light valve 31 that modulates a red light component, a green light liquid crystal light valve 32 that modulates a green light component, and a blue light. A liquid crystal light valve for blue light 33 that modulates a light component, a Ye modulation element 34 that is a light modulation element that modulates a yellow light component, which is a fourth modulation means, and a cross dichroic prism 35 are included.

  The two dichroic mirrors 21 and 22 have a function as color light separating means for separating the white light that has passed through the condenser lens 15 into red light, green light on which yellow light is superimposed, and blue light. The first dichroic mirror 21 transmits the red light component of the white light beam emitted from the illumination optical system and reflects the green light component, the yellow light component, and the blue light component. The red light transmitted through the first dichroic mirror 21 is reflected by the total reflection mirror 23 and reaches the red light liquid crystal light valve 31 as the first light modulation means via the condenser lens 26.

  The red light liquid crystal light valve 31 modulates red light, and includes an inorganic polarizing plate 31a, an incident polarizing plate 31b, an optical compensation plate 31c, a light modulating element 31d including a liquid crystal cell, a pre-polarizing plate 31e, and an output. It consists of a polarizing plate 31f. In the inorganic polarizing plate 31a, since the light beam reaching the liquid crystal light valve 31 for red light is elliptically polarized, it is polarized into linearly polarized light in a certain direction. The incident polarizing plate 31b allows only polarized light in a certain direction to pass through, and the cooperating action of the output polarizing plate 31f that forms a pair with the incident polarizing plate 31b causes the constant direction of light modulated by the light modulation element 31d. It acts to pass only polarized light. The optical compensator 31c compensates for birefringence in the light modulation element 31d. The light modulation element 31d modulates incident red light based on a video signal. The pre-polarizing plate 31e reduces the burden on the output polarizing plate 31f by reducing the amount of light.

  The green light liquid crystal light valve 32 and the blue light liquid crystal light valve 33 are different in color light to be modulated, but the configuration is basically the same as that of the red light liquid crystal light valve 31. That is, the inorganic polarizing plates 32a and 33a, the incident polarizing plates 32b and 33b, the optical compensation plates 32c and 33c, the light modulation elements 32d and 33d, and the pre-polarizing plate 32e in the green light liquid crystal light valve 32 and the blue light liquid crystal light valve 33. 33e and the output polarizing plates 32f and 33f are the configurations of the inorganic polarizing plate 31a, the incident polarizing plate 31b, the optical compensation plate 31c, the light modulation element 31d, the pre-polarizing plate 31e, and the outgoing polarizing plate 31f in the liquid crystal light valve 31 for red light. Corresponding to

  Of the green light component, the yellow light component, and the blue light component reflected by the first dichroic mirror 21, the green light component and the yellow light component are reflected by the second dichroic mirror 22 and pass through the condenser lens 27. The light is incident on a Ye modulation element 34 that modulates yellow light, which is fourth light modulation means.

  The Ye modulation element 34 may be a light modulation element that selectively switches whether to rotate the incident linearly polarized light by 90 degrees or not according to the applied voltage, or outputs 0 to 0 depending on the applied voltage. It may be a light modulation element that rotates and emits within a range of 90 degrees, and modulates the yellow light component based on the video signal. Such a Ye modulation element 34 is a light modulation element including a liquid crystal cell in which liquid crystal or the like is sealed between a plurality of glass substrates, and modulates and emits a yellow light component based on a video signal. The emitted yellow light has only a light component that coincides with the transmission axis of the incident polarizing plate 32b of the green light liquid crystal light valve 32 constituting the second light modulation means disposed on the light emission side. The light enters the valve 32. As a result, the amount of yellow light component that passes through the Ye modulation element 34 and enters the liquid crystal light valve 32 for green light is controlled. The green light component passes through the green light liquid crystal light valve 32 as it is.

  The yellow light component and the green light component that have passed through the Ye modulation element 34 are incident on the green light liquid crystal light valve 32 as the second modulation means. The green light component incident on the green light liquid crystal light valve 32 is modulated based on the video signal in the light modulation element 32 d and is emitted to the cross dichroic prism 35. Further, the yellow light component incident on the green light liquid crystal light valve 32 is superimposed on the modulated green light component and emitted to the cross dichroic prism 35. The inorganic polarizing plate 32a, the incident polarizing plate 32b, the optical compensation plate 32c, the pre-polarizing plate 32e, and the outgoing polarizing plate 32f in the green light liquid crystal light valve 32 are the inorganic polarizing plates in the red light liquid crystal light valve 31 described above. 31a, the incident polarizing plate 31b, the optical compensation plate 31c, the pre-polarizing plate 31e, and the output polarizing plate 31f function in the same manner.

  The blue light component reflected by the first dichroic mirror 21 is transmitted through the second dichroic mirror 22, the two relay lenses 25 a and 25 b, the total reflection mirrors 24 a and 24 b, and the condenser lens 28. The light enters the liquid crystal light valve 33 for blue light, which is a modulation means. The blue light component incident on the blue light liquid crystal light valve 33 is modulated based on the video signal in the light modulation element 33 d and is emitted to the cross dichroic prism 35. The inorganic polarizing plate 33a, the incident polarizing plate 33b, the optical compensator 33c, the pre-polarizing plate 33e, and the outgoing polarizing plate 33f in the blue light liquid crystal light valve 33 are inorganic in the red light liquid crystal light valve 31 as described above. The polarizing plate 31a, the incident polarizing plate 31b, the optical compensation plate 31c, the pre-polarizing plate 31e, and the output polarizing plate 31f function in the same manner.

  The cross dichroic prism 35 is a color combining unit that combines the three color lights modulated by the red light liquid crystal light valve 31, the green light liquid crystal light valve 32, and the blue light liquid crystal light valve 33 to form a color image. It has the function of. For this purpose, the cross dichroic prism 35 is formed with a reflection film 35a for red light and a reflection film 35b for blue light in a cross shape. Accordingly, the red light modulated by the red light liquid crystal light valve 31 is reflected by the red light reflecting film 35 a and is emitted in the direction of the projection lens optical system 40. Further, the blue light modulated by the blue light liquid crystal light valve 33 is reflected by the blue light reflecting film 35 b and emitted in the direction of the projection lens optical system 40. On the other hand, the green light modulated by the green light liquid crystal light valve 32 and the yellow light superimposed on the green light pass through the reflection film 35a for red light and the reflection film 35b for blue light as they are. The light is emitted to the projection lens optical system 40.

  The light beam thus color-combined is projected from the projection lens optical system 40 and projected onto the screen. In this case, since the yellow light component is modulated and superimposed based on the video signal, the luminance of the projected video is improved.

  As described above, the projection display apparatus according to the present embodiment modulates the yellow light component on the incident side of the green light liquid crystal light valve 32 in the conventional general three-plate projection display apparatus. Since the Ye modulation element 34 which is the fourth modulation means is provided, the space allowed for the Ye modulation element 34 tends to be narrowed, and it is necessary to reduce the size. Moreover, since it is attached to a narrow space, it is necessary to have good heat dissipation characteristics.

  Next, the overall configuration of the Ye modulation element that constitutes the main part of the present invention will be described with reference to FIGS. 8A and 8B are explanatory diagrams of the Ye modulation element, where FIG. 8A is a perspective view and FIG. 8B is an exploded perspective view. FIG. 9 is a perspective view of the emission side holding frame constituting the Ye modulation element as viewed from the liquid crystal cell side.

  The Ye modulation element 34 includes a substantially quadrangular liquid crystal cell 51 in which liquid crystal is sealed between a plurality of glass substrates, and an incident side holding frame 52 and an emission side that are combined so as to sandwich the liquid crystal cell 51 from both sides. It consists of a holding frame 53. The entrance-side holding frame 52 and the exit-side holding frame 53 are obtained by sheet metal processing of a light metal plate material such as aluminum, and quadrilateral light transmission holes 52a and 53a are formed at the center. At the same time, bent support pieces 54 and 55 for supporting the end faces of the four sides of the liquid crystal cell 51 are formed on each of the four sides. The bending support pieces 54 and 55 are bent by sheet metal, and are formed to have a height approximately half the thickness of the liquid crystal cell 51. The incident side holding frame 52 and the emission side holding frame 53 are overlapped with the liquid crystal cell 51 so as to sandwich the liquid crystal cell 51 from the incident side and the emission side. At this time, the liquid crystal cell 51 is surrounded by the bent support pieces 54 and 55. Further, in such a superposed state, the bonding surface between the incident side holding frame 52 and the liquid crystal cell 51 and the bonding surface between the emission side holding frame 53 and the liquid crystal cell 51 in the outer periphery of the quadrilateral are heated. Bonded with an adhesive having good conductivity.

  In the liquid crystal cell 51, a flexible wiring board 56 projects from one end surface. The incident-side holding frame 52 is integrally formed with cooling pieces 57 and 58 that protrude from the end face on the side where the wiring board 56 protrudes and on both sides of the wiring board 56. Further, a regulation projection piece 59 bent in a bowl shape is integrally formed on a side perpendicular to the side from which the cooling pieces 57 and 58 protrude in the emission side holding frame 53. When the Ye modulation element 34 is definitely attached to the light guide 6 with respect to the light guide 6, the restriction projection piece 59 is provided on the support frame 65 (see FIG. 5) on the right side of the light guide 6. It is comprised so that it may engage with the provided engaging groove 68 (refer FIG. 6).

  Next, an attachment structure on the light guide 6 side to which the Ye modulation element 34 configured as described above is attached will be described with reference to FIGS. 3 is a perspective view of the light guide, FIG. 4 is a state diagram in which the Ye modulation element is removed in FIG. 3, FIG. 5 is a perspective view of the lower light guide, and FIG. FIG. 7 is a horizontal cross-sectional view of the mounting portion of the modulation element, and FIG. 7 is a cross-sectional view taken along line AA in FIG.

  The optical unit in the present embodiment is configured as described above. Each device constituting the optical unit is arranged and attached to the light guide 6 as shown in FIG. As shown in the perspective views of FIG. 3 and FIG. 4, the light guide 6 is a container-shaped lower light guide 61 having an open upper surface, and a flat shape formed so as to close the upper surface of the lower light guide 61. An upper light guide 62 is included. 3 to 5 showing the configuration of the light guide 6, spaces 11S, 12S, 20S, and 35S indicate spaces in which the light source 11, the integrator lens 12, and the cross dichroic prism 35 are attached, respectively. Further, in FIG. 5, a space 20 </ b> S surrounding the space 35 </ b> S indicates a mounting space for devices constituting the color light separation optical system 20.

  In this specification, the side on which the projection lens optical system 40 is located is the front surface, the projection lens optical system 40 is the front surface, the left and right sides viewed from the front side are the left and right directions, and the upper light guide side is The upward direction and the lower light side are the downward direction.

  The Ye modulation element 34 as the fourth modulation means is attached to the incident side of the green light liquid crystal light valve 32 as the second modulation element as shown in FIG. Further, as shown in FIG. 4, the upper light guide 62 is formed with a cut portion 63 where the Ye modulation element 34 is attached. For this reason, the attachment part of the Ye modulation element 34 in the lower light guide 61 is in an open state. Further, as the mounting portion of the Ye modulation element 34 in the lower light guide 61, two sides perpendicular to the side from which the wiring substrate 56 of the Ye modulation element 34 protrudes are located at the lower positions around the left and right sides of the cut portion 63, that is, two sides on the left and right A pair of left and right support frame portions 64 and 65 are formed to support the end surfaces.

  As shown in FIG. 6, the pair of left and right support frame portions 64 and 65 are formed such that the left and right intervals are slightly larger than the horizontal dimension of the Ye modulation element 34, and the longitudinal dimension is the Ye modulation element. It is slightly larger than the dimension in the front-rear direction on the end face of 34 and is formed so as to protrude to the rear part. Further, as shown in FIGS. 5 and 7, the lower end portions of the pair of left and right support frame portions 64 and 65 have a substantially triangular shape in front view for supporting the lower end corner portion of the Ye modulation element 34 at a predetermined position. Receiving groove portions 66 and 67 are formed. The receiving groove portions 66 and 67 are formed to have a groove width having an appropriate dimension for inserting the lower end corner portion of the Ye modulation element 34 and include a wall that supports the lower end surface of the lower end corner portion of the Ye modulation element 34. ing. Further, as shown in FIG. 6, a vertical engagement groove 68 into which the restriction projection piece 59 is inserted is formed on the emission side of the Ye modulation element 34 in the right support frame portion 65, that is, the front surface side.

  In FIG. 6, an attachment portion 321 of the inorganic polarizing plate 32a, an attachment portion 322 of the incident polarizing plate 32b, and an attachment portion 323 of the optical compensation plate 32c are formed in front of the pair of left and right support frame portions 64 and 65. Yes.

  With respect to the lower light guide 61 configured as described above, the Ye modulation element 34 is attached by inserting the Ye modulation element 34 downward from the cut portion 63 of the upper light guide 62. At this time, the restriction projection piece 59 is inserted into the engagement groove 68. Thereby, the orientation of the Ye modulation element 34 is corrected correctly. By inserting the left and right lower corners of the Ye modulation element 34 into the receiving grooves 66 and 67, the height position, the front-rear direction position, and the left-right direction position of the lower end part of the Ye modulation element 34 are held at predetermined positions. The Next, the pressing member 7 is attached from above via the cushion material 73, and the Ye modulation element 34 is fixed while being pressed downward from above. The pressing member 7 is formed with a pressing groove 71 into which the upper end of the Ye modulation element 34 is inserted. In the state where the Ye modulation element 34 is attached, the cushion material 73 is elastic between the upper end portion of the Ye modulation element 34 and the upper surface in the push groove portion 71 of the pressing member 7 as shown in FIG. It is compressed and intervenes. As a result, the Ye modulation element 34 is pressed downward, and the front, rear, left and right, and vertical height positions of the upper end portion are also held at predetermined positions. The holding member 7 has screw insertion holes 72 formed at both left and right ends, and screws (see FIG. 4) from the screw insertion holes 72 to the screw holes 69 (see FIG. 4) of the screw seat formed in the upper light guide 62. It is attached by fastening (not shown).

Since the projection display apparatus according to the present embodiment is configured as described above, the following effects can be obtained.
(1) The Ye modulation element 34 as the fourth light modulation means is combined with a substantially quadrangular liquid crystal cell 51 in which liquid crystal is sealed between a plurality of glass substrates so as to sandwich the liquid crystal cell 51 from both sides. The entrance-side holding frame 52 and the exit-side holding frame 53 are formed, and the entrance-side holding frame 52 and the exit-side holding frame 53 are formed by sheet metal processing. As a result, the incident-side holding frame 52 and the emission-side holding frame 53 can be made into thin plate products, can be reduced in size and weight, and the heat radiation performance of the incident-side holding frame 52 and the emission-side holding frame 53 is improved. be able to.

  (2) In addition, the incident side holding frame 52 and the emission side holding frame 53 include bending support pieces 54 and 55 that support the end surfaces of the four sides of the liquid crystal cell 51, and are combined so as to sandwich the liquid crystal cell 51 from both sides. The structure is bonded to the liquid crystal cell 51 at the outer periphery. Therefore, the incident-side holding frame 52 and the emission-side holding frame 53 are formed as a holding frame that is firmly combined via the substrate of the liquid crystal cell 51, and sheet metal processing is facilitated, so that cost reduction can be achieved.

  (3) Further, the projection type video display device adds yellow modulation light 34 to the conventional three-plate projection type video display device on the incident side of the liquid crystal light valve for green light, thereby adding yellow light. The brightness of the video is appropriately secured by using the nearby colors. For this reason, the Ye modulation element 34 that modulates yellow light is required to be downsized, but this need can be met by making the holding frame made of sheet metal.

  (4) In the Ye modulation element 34, which is a light modulation element that modulates yellow light, the upper end portions of the incident side holding frame 52 and the emission side holding frame 53 are inserted into the push groove portion 71, and the corner portion of the lower end portion is a receiving groove portion. Although it is inserted in 66, 67, it is set as the structure where another holding frame part touches cooling air directly in a wide range. For this reason, the heat dissipation effect by the incident side holding frame 52 and the emission side holding frame 53 is improved.

  (5) Since the cooling pieces 57 and 58 projecting sideways are integrally formed on the incident side holding frame 52, the heat radiation area is increased and the cooling effect is improved. Further, since the cooling pieces 57 and 58 are provided not on the emission side holding frame 53 but on the incident side holding frame 52, the cooling effect is improved. Moreover, since the cooling pieces 57 and 58 are integrally formed by sheet metal processing, the manufacturing cost is reduced.

  (6) The output-side holding frame is formed with a restriction projection piece 59 for restricting the incident side and the emission side when the Ye modulation element 34 is attached, and the support frame portion 65 has this restriction projection piece 59. Since the engaging groove 68 that engages with the Y modulation element 34 is formed, it can be avoided that the Ye modulation element 34 is attached with the incident side and the emission side being mistaken. As a result, the Ye modulation element 34 can be operated normally, and the cooling effect can also be exhibited normally.

(Modification)
The present invention can be modified as follows in the above embodiment.
In the embodiment, the holding frame of the Ye modulation element 34 is formed as described above. However, the holding frame of the light modulation element constituting another light valve is configured as described above, and You may attach as follows.

  In the above-described embodiment, the projection type image display apparatus includes the Ye modulation element 34 on the incident side of the green light liquid crystal light valve 32, but includes another color light separation optical system and color light synthesis optical system. You may apply the structure of this invention with respect to the modulation element which shines in a projection type video display apparatus.

  In the above embodiment, the cooling pieces 57 and 58 are formed only on one side of the Ye modulation element 34 on the side where the wiring board 56 protrudes, but may be formed on the other side, or a plurality of cooling pieces 57 and 58 may be formed. You may form in the side of this, for example, the upper and lower sides.

  In the embodiment described above, the restricting protrusions 59 are provided on the emission side holding frame 53, but they may be formed on the incident side holding frame 52. Moreover, in the said embodiment, although the regulation protrusion piece 59 was provided below so that FIG. 8 may show, you may make this provide above the position in embodiment. Moreover, the shape is not limited to the above-described saddle shape.

It is a top view of the projection type video display apparatus concerning an embodiment of the invention, and is a top view in the state where an upper case was removed and an upper light guide was removed. It is a schematic diagram of the optical unit in the projection type video display apparatus. It is a perspective view of the light guide in the projection type video display. FIG. 4 is a state diagram in which a Ye modulation element is removed in FIG. 3. It is a perspective view of the lower light guide in the projection type video display. It is a horizontal sectional view of the attachment part of Ye modulation element in the projection type video display. It is AA sectional drawing in FIG. It is explanatory drawing of the Ye modulation element in the projection type video display apparatus. (A) is a whole perspective view, (b) is an exploded perspective view. It is the perspective view seen from the liquid crystal cell side of the output side holding frame which comprises the same Ye modulation element.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 6 ... Light guide, 7 ... Holding member, 10 ... Illumination optical system, 11 ... Light source, 13 ... Polarization conversion element, 20 ... Color light separation optical system, 30 ... Color light synthesis optical system, 31 ... Liquid crystal light valve for red light, 31d , 32d, 33d ... light modulation element, 32 ... green light liquid crystal light valve, 33 ... blue light liquid crystal light valve, 34 ... Ye modulation element, 51 ... liquid crystal cell, 52 ... incident side holding frame, 53 ... emission side holding Frame, 54, 55 ... bent support piece, 56 ... (flexible) wiring board, 57, 58 ... cooling piece, 59 ... regulating projection piece, 64, 65 ... support frame part, 66, 67 ... receiving groove part, 68 ... engagement Groove, 71 ... push groove, 73 ... cushion material.

Claims (4)

An illumination optical system including a light source and a polarization conversion element, a color light separation optical system that separates a light beam emitted from the illumination optical system into red light, green light, and blue light, and red light separated by the color light separation optical system A liquid crystal light valve for red light, a liquid crystal light valve for green light, a liquid crystal light valve for blue light that modulates green light and blue light according to video information, and a color that combines each color beam modulated by the liquid crystal light valve for each color In a projection-type image display device comprising a light combining optical system and a light guide that houses these optical system members,
On the incident side of the liquid crystal light valve for green light, a Ye modulation element for modulating yellow light superimposed on green light is disposed,
The Ye modulation element is formed such that a liquid crystal cell in which liquid crystal is sealed between a plurality of glass substrates formed in a quadrilateral shape when viewed from the optical axis direction and protrudes from one side of the four sides when viewed from the optical axis direction. And an incident side holding frame and an emission side holding frame which are combined so as to sandwich the liquid crystal cell from both sides, and the incident side holding frame and the emission side holding frame support the outer peripheral end surface of the liquid crystal cell. It is made of sheet metal with a bent support piece, and is adhered to the liquid crystal cell at the outer periphery.
The light guide is formed of a pair of support frame portions that support two sides orthogonal to the side from which the wiring substrate protrudes in the Ye modulation element, and ends of the pair of support frame portions. A receiving groove for supporting the corner,
Further, the Ye modulation element is attached by being pressed into the receiving groove portion via an elastic cushion material by a pressing member that presses a side from which the wiring board protrudes. . 2. The projection type image display device according to claim 1, wherein the incident side holding frame is integrally formed with a cooling piece protruding sideward by sheet metal processing . The projection type image display device according to claim 2, wherein the incident side holding frame has the cooling pieces formed on a plurality of sides . The entrance-side holding frame or the exit-side holding frame has a regulation protrusion for regulating the entrance side and the exit side when the Ye modulation element is mounted, and the Ye modulation element is provided on the support frame portion. The projection-type image display device according to claim 1, wherein an engagement groove that engages with the restricting projection piece when formed in a normal direction is formed .

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