JP5879707B2 - Reflective liquid crystal display device and projection display device - Google Patents

Description

  The present disclosure relates to a reflective liquid crystal display device and a projection display device.

  For example, some projection display devices such as projectors include a reflective liquid crystal display device that functions as a light valve. A reflective liquid crystal display device generally has a liquid crystal display panel having a silicon substrate, a counter substrate disposed opposite to the silicon substrate, and a liquid crystal layer sealed between the silicon substrate and the counter substrate. . The reflective liquid crystal display device modulates and reflects light incident from a light source of a projector. The projector displays an image by enlarging and projecting the light modulated by the reflective liquid crystal display device on a screen. In order to enlarge and project an image on a screen, a projection display device such as a projector enters relatively strong light into a reflective liquid crystal display device.

  As described above, since relatively strong light is incident on the reflective liquid crystal display device, the temperature of the reflective liquid crystal display device rises due to light irradiation. When the temperature of the reflective liquid crystal display device rises, birefringence occurs due to thermal distortion such as thermal expansion. When this birefringence occurs, shading appears in the image projected on the screen and the image quality deteriorates.

Therefore, as a method for suppressing thermal distortion of the reflective liquid crystal display device, a method using a heat radiating member having high thermal conductivity and high Young's modulus has been proposed (for example, see Patent Document 1).
The reflective liquid crystal display device disclosed in Patent Document 1 has a thermal conductivity of 140 to 180 (W / m · ° C.) and a thermal expansion coefficient of 20 × 10 ⁷ to 70 × 10 ⁷ / ° C. of the metal substrate and the heat dissipation member. And the Young's modulus of the heat dissipating member is set to 206 Gpa or more. Thereby, thermal distortion is reduced without forced cooling.

JP 2005-181719 A

  However, since materials with high thermal conductivity and high Young's modulus are expensive, there is a problem that the manufacturing cost of the reflective liquid crystal display device increases when used as a heat dissipation member.

  Therefore, the present disclosure provides a reflective liquid crystal display device and a projection display device that can reduce thermal distortion at low cost.

A reflective liquid crystal display device according to the present disclosure has a substantially rectangular shape including a silicon substrate, a counter substrate disposed opposite to the silicon substrate, and a liquid crystal layer sealed between the silicon substrate and the counter substrate . A reflective liquid crystal display panel, a heat radiating member in contact with one surface of the silicon substrate and radiating heat generated by the reflective liquid crystal display panel, and the reflective liquid crystal display panel and the heat radiating member are held in a substantially rectangular frame. A holding member, and an adhesive that bonds the holding member and the reflective liquid crystal display panel. The holding member has a Young's modulus higher than that of a material having a thermal expansion coefficient substantially equal to a thermal expansion coefficient of the silicon substrate. consists of a material with a small, a plurality of fixing holes for fixing to the mounting object is provided in the peripheral portion, the adhesive material is place remote from the fixing hole of the side of the reflective liquid crystal display panel It is applied to retain the reflective liquid crystal display panel relative to the retaining member.

  By using a material having a Young's modulus smaller than a material having a thermal expansion coefficient substantially equal to that of the silicon substrate as the holding member, thermal strain can be reduced at a low cost.

  A projection display device according to the present disclosure includes the above-described reflective liquid crystal display device, a light source that generates light, a condensing optical system that guides the light to the reflective liquid crystal display device, and the reflective liquid crystal display device. A projection optical system for projecting the light-modulated light in an enlarged manner.

  According to the present technology, thermal distortion can be reduced at low cost.

1 is a diagram showing a projector according to a first embodiment. The figure which shows the reflection type liquid crystal display device which concerns on 1st Embodiment. The figure which shows the reflection type liquid crystal display device which concerns on 1st Embodiment. The figure explaining the material of the panel holder which concerns on 1st Embodiment. The figure which shows the stress added to the reflection type liquid crystal display device which concerns on 1st Embodiment. The figure which shows the stress added to the reflection type liquid crystal display device which concerns on 1st Embodiment. The figure which shows the reflection type liquid crystal display device which concerns on 2nd Embodiment. The figure which shows the reflective liquid crystal display device which concerns on a comparative example. The figure which shows the stress distribution of a comparative example. The figure which shows the stress distribution of the reflection type liquid crystal display device which concerns on 2nd Embodiment. The figure which shows the reflection type liquid crystal display device of the other example of 2nd Embodiment. The figure which shows the stress distribution of the reflection type liquid crystal display device of the other example of 2nd Embodiment. The figure which shows the reflection type liquid crystal display device which concerns on 3rd Embodiment. The figure which shows the stress distribution of the reflection type liquid crystal display device which concerns on 3rd Embodiment. The figure which shows the reflection type liquid crystal display device which concerns on 4th Embodiment. The figure which shows the stress distribution of the reflection type liquid crystal display device which concerns on 4th Embodiment. The figure which shows the whole temperature gradient of the reflection type liquid crystal display device of the other example of 4th Embodiment. The figure which shows the stress distribution of the reflection type liquid crystal display device of the other example of 4th Embodiment. The figure which shows the stress distribution of the reflection type liquid crystal display device of the other example of 4th Embodiment.

(First embodiment)
A configuration of a projector 1 will be described with reference to FIG. 1 as an example of a projection display device including the reflective liquid crystal display device according to the present embodiment. The projector 1 according to the present embodiment is a so-called three-sheet type that performs color image display by using three reflective liquid crystal display devices as the liquid crystal display device. In other words, the projector 1 separates the light from the light source into the three primary colors of red, green, and blue, and performs color image display using one reflective liquid crystal display device for each color. The three reflective liquid crystal display devices corresponding to each color have substantially the same configuration.

  As shown in FIG. 1, the projector 1 includes a light source 101 that generates light, and a first fly-eye lens 103 and a second fly-eye lens 104 that are a pair of lenses arranged to face each other. The first fly-eye lens 103 and the second fly-eye lens 104 each have a plurality of micro lenses 103a and 104a that are two-dimensionally arranged. The first fly-eye lens 103 and the second fly-eye lens 104 are for making the light illuminance distribution incident from the light source 101 uniform, and have a function of dividing the incident light into a plurality of small light beams. The projector 1 further includes a UV (Ultraviolet) / IR (Infrared) cut filter 102 disposed between the light source 101 and the first fly-eye lens 103.

  The light source 101 emits white light including red light, green light, and blue light required for color image display. The light source 101 includes a light emitter that emits white light, and a concave mirror (reflector) that reflects and collects light emitted from the light emitter (not shown). The light emitter is composed of, for example, a halogen lamp, a metal hydride lamp, a xenon lamp, or the like. In order to obtain good light collection efficiency, the concave mirror has a rotationally symmetric surface shape such as a spheroidal mirror or a parabolic mirror.

  The light emitted from the light emitter of the light source 101 becomes substantially parallel light by the concave mirror and is incident on the first fly-eye lens 103 via the UV / IR cut filter 102. The light transmitted through the first fly-eye lens 103 is incident on the second fly-eye lens 104. For example, by providing a mirror or the like, the light transmitted through the first fly-eye lens 103 may be bent by approximately 90 ° and incident on the second fly-eye lens 104.

  The projector 1 includes a PS combining element 105, a condenser lens 106, and a cross dichroic mirror 107 on the emission side of the second fly's eye lens 104. The PS synthesizing element 105, the condenser lens 106, and the cross dichroic mirror 107 are sequentially arranged from the second fly's eye lens 104 side in the light emitting direction from the second fly's eye lens 104.

  The PS combining element 105 includes a plurality of retardation plates 105a. The plurality of retardation plates 105 a are disposed at positions corresponding to the plurality of microlenses 104 a of the second fly-eye lens 104. The retardation plate 105a is a half-wave plate, for example. The PS combining element 105 has a function of separating incident light into two types of polarized light, a P-polarized component and an S-polarized component. In addition, the PS combining element 105 emits one of the two separated polarized lights (for example, P-polarized light) while maintaining the polarization direction, and outputs the other polarized light (in this case, S-polarized light). By this function, it has a function of converting to another polarized light (in this case, P-polarized light) and emitting it.

  The light emitted from the PS combining element 105 is collected by the condenser lens 106 and enters the cross dichroic mirror 107. The cross dichroic mirror 107 transmits the red light LR and the green light LG out of the light collected by the condenser lens 106, reflects the blue light LB, and transmits the blue light LB, and transmits the red light LR. And a dichroic mirror 107b that reflects the green light LG. The dichroic mirror 107a and the dichroic mirror 107b are coupled so as to intersect at 90 °.

  The projector 1 includes a mirror 108a, a field lens 110, a trimming filter 111, and a polarization beam splitter 112 along the optical path of the blue light LB separated by the cross dichroic mirror 107. A total reflection mirror is preferably used as the mirror 108. The mirror 108 a reflects the blue light LB separated by the cross dichroic mirror 107 toward the polarization beam splitter 112. The polarization beam splitter 112 transmits one of the two polarized lights (in this case, S-polarized light) and reflects the other polarized light (in this case, P-polarized light). Since the light emitted from the PS synthesizing element 105 is P-polarized component polarized light, the blue light LB reflected by the mirror 108a is reflected by the polarization beam splitter 112 and reflected through the quarter wavelength plate 113. It enters into 114B.

  The reflective liquid crystal display device 114B receives a video signal of the blue light LB incident from the polarization beam splitter 112 via the quarter-wave plate 113, and controls the light transmittance of the two-dimensionally distributed pixels. Outputs image light. That is, the reflective liquid crystal display device 114B has a function of spatially modulating the blue light LB incident through the quarter wavelength plate 113 in accordance with an image signal (image data) input from a control unit (not shown). Have. The reflective liquid crystal display device 114B functions as a liquid crystal display device for the blue light LB that modulates the blue light LB.

  The quarter wavelength plate 113 is provided between the polarization beam splitter 112 and the reflective liquid crystal display device 114B. The quarter wavelength plate 113 has a function of shifting the phase of incident light by a quarter wavelength. The blue light LB passes through the quarter-wave plate 113 before being incident on the reflective liquid crystal display device 114B and after being reflected. That is, the blue light LB after light modulation is light whose phase is 1/4 + 1/4 = 1/2 wavelength shifted from the blue light LB before light modulation. The blue light LB that is one polarized light (in this case, P-polarized light) before light modulation passes through the quarter-wave plate 113 twice, and is converted to another polarized light (in this case, S-polarized light). Accordingly, the blue light LB before light modulation is reflected by the polarization beam splitter 112, but the blue light LB after light modulation passes through the polarization beam splitter 112 and enters the cross prism 116.

  The projector 1 includes a mirror 108 b and a dichroic mirror 109 along the optical paths of the red light LR and the green light LG separated by the cross dichroic mirror 107. A total reflection mirror is preferably used as the mirror 108b. The mirror 108 b reflects the red light LR and the green light LG separated by the cross dichroic mirror 107 toward the dichroic mirror 109. For example, the dichroic mirror 109 reflects the green light LG out of the incident light and transmits the red light LR, thereby separating the incident light into the red light LR and the green light LG.

  The projector 1 includes a field lens 110, a trimming filter 111, and a polarization beam splitter 112 along the optical path of the separated green light LG. The polarization beam splitter 112 transmits one of the two polarized lights (in this case, S-polarized light) and reflects the other polarized light (in this case, P-polarized light). Since the light emitted from the PS synthesizing element 105 is polarized with a P-polarized component, the green light LG is reflected by the polarization beam splitter 112 and enters the reflective liquid crystal display device 114G via the quarter-wave plate 113.

  The reflective liquid crystal display device 114G receives a video signal from the green light LG incident from the polarizing beam splitter 112 via the quarter-wave plate 113, controls the light transmittance of the two-dimensionally distributed pixels, and Outputs image light. That is, the reflective liquid crystal display device 114G has a function of spatially modulating the green light LG incident through the quarter-wave plate 113 according to an image signal (image data) input from a control unit (not shown). Have. The reflective liquid crystal display device 114G functions as a liquid crystal display device for the green light LG that modulates the green light LG.

  Further, the projector 1 is provided with a quarter-wave plate 113 between the polarizing beam splitter 112 and the reflective liquid crystal display device 114G. Therefore, the green light LG that is one polarized light (in this case, P-polarized light) before light modulation passes through the quarter-wave plate 113 twice, and is converted to another polarized light (in this case, S-polarized light). The green light LG before light modulation is reflected by the polarization beam splitter 112, but the green light LG after light modulation passes through the polarization beam splitter 112 and enters the cross prism 116.

  The projector 1 includes a field lens 110, a trimming filter 111, and a polarization beam splitter 112 along the optical path of the red light LR separated by the dichroic mirror 109. The polarization beam splitter 112 transmits one of the two polarized lights (in this case, S-polarized light) and reflects the other polarized light (in this case, P-polarized light). Since the light emitted from the PS synthesizing element 105 is P-polarized light, the red light LR is reflected by the polarization beam splitter 112 and enters the reflective liquid crystal display device 114R via the quarter-wave plate 113.

  The reflective liquid crystal display device 114R receives the video signal of the red light LR incident from the polarizing beam splitter 112 via the quarter-wave plate 113, controls the light transmittance of the two-dimensionally distributed pixels, and Outputs image light. That is, the reflective liquid crystal display device 114R has a function of spatially modulating the red light LR incident through the quarter-wave plate 113 according to an image signal (image data) input from a control unit (not shown). Have. The reflective liquid crystal display device 114R functions as a liquid crystal display device for the red light LR that modulates the red light LR.

  Further, the projector 1 is provided with a quarter-wave plate 113 between the polarizing beam splitter 112 and the reflective liquid crystal display device 114R. Therefore, the red light LR that is one polarized light (in this case, P-polarized light) before light modulation passes through the quarter-wave plate 113 twice and is converted to the other polarized light (in this case, S-polarized light). The red light LR before light modulation is reflected by the polarization beam splitter 112, but the red light LR after light modulation passes through the polarization beam splitter 112 and enters the cross prism 116.

  The projector 1 includes a cross prism 116 at a position where the optical paths of the red light LR, the green light LG, and the blue light LB intersect. The cross prism 116 has a function of combining light of three colors, red light LR, green light LG, and blue light LB. The cross prism 116 emits combined light obtained by combining the incident red light LR, green light LG, and blue light LB to the projection lens 117.

  The projector 1 includes a projection lens 117 for enlarging and projecting the combined light emitted from the cross prism 116 toward a screen (not shown) constituting the projection surface. The projection lens 117 is composed of, for example, a plurality of lenses, and has a zoom function, a focusing function, and the like that adjust the size of an image projected on the screen.

  Thus, the three liquid crystal display devices of the projector 1 are the reflective liquid crystal display device 114R for the red light LR, the reflective liquid crystal display device 114G for the green light LG, and the reflective liquid crystal display device 114B for the blue light LB. Are illuminated by light of corresponding colors. Then, the output lights emitted from the three reflective liquid crystal display devices 114R, 114G, and 114B are combined by the cross prism 116 and enlarged and projected onto the screen by the projection lens 117. In the following description, “reflective liquid crystal display device 114” is used as a common name for the reflective liquid crystal display device 114R, the reflective liquid crystal display device 114G, and the reflective liquid crystal display device 114B.

  As described above, the projector 1 according to the present embodiment includes the condensing optical system that guides the light emitted from the light source 101 to the reflective liquid crystal display device 114. That is, the projector 1 includes a first fly-eye lens 103, a second fly-eye lens 104, a PS combining element 105, a condenser lens 106, and a cross dichroic mirror 107 as a condensing optical system, and for the blue light LB. The reflective liquid crystal display device 114B includes a mirror 108a, a field lens 110, and a trimming filter 111. The reflective liquid crystal display device 114G for green light LG includes a mirror 108b, a dichroic mirror 109, a field lens 110, and a trimming filter 111. The liquid crystal display unit reflective liquid crystal display device 114R for the red light LR further includes a field lens 110 and a trimming filter 111.

  In addition, the projector 1 of the present embodiment includes a projection optical system that enlarges and projects light modulated by the reflective liquid crystal display device 114. That is, the projector 1 includes a configuration including a cross prism 116 and a projection lens 117 as a projection optical system.

  The configuration of the reflective liquid crystal display device 114 will be described with reference to FIG. The reflective liquid crystal display device 114 includes a dustproof glass 201, a reflective liquid crystal display panel 210, and a transparent adhesive 202 that bonds the dustproof glass 201 and the reflective liquid crystal display panel 210. The reflective liquid crystal display device 114 is a holding member that holds the reflective liquid crystal display panel 210 and a panel holder 205 that is held by the panel holder 205, and serves as a heat dissipation material that radiates heat generated by the reflective liquid crystal display panel 210. A back heat sink 206 is provided. The panel holder 205 is made of a material having a Young's modulus smaller than that of a material having a thermal expansion substantially equal to that of the silicon substrate 204 of the reflective liquid crystal display panel 210.

  The reflective liquid crystal display panel 210 is a reflective liquid crystal display element. The reflective liquid crystal display panel 210 has a substantially rectangular shape. The reflective liquid crystal display panel 210 includes a pair of counter substrates 203 and a silicon substrate 204 that are disposed to face each other. The counter substrate 203 and the silicon substrate 204 are both substantially rectangular. The reflective liquid crystal display panel 210 includes a liquid crystal layer 209 that is sealed between the counter substrate 203 and the silicon substrate 204. The liquid crystal layer 209 is sealed in a gap formed by bonding the counter substrate 203 and the silicon substrate 204 with a sealant at a predetermined interval. The liquid crystal layer 209 functions as a light modulation layer.

  The counter substrate 203 is, for example, a glass substrate. A transparent common electrode made of, for example, ITO (Indium Tin Oxide) is formed on the surface of the counter substrate 203 on the liquid crystal layer 209 side. Further, for example, a reflection reducing film is formed on the surface of the counter substrate 203 opposite to the liquid crystal layer 209 side.

  On the surface of the silicon substrate 204 on the liquid crystal layer 209 side, a plurality of reflective pixel electrodes made of, for example, an aluminum alloy are arranged in a matrix. Similarly, a drive circuit is formed on the surface of the silicon substrate 204 on the liquid crystal layer 209 side. The drive circuit includes a MOS transistor for driving the pixel electrode of the silicon substrate 204, and is formed corresponding to each pixel electrode. The pixel circuit applies a signal voltage to each corresponding pixel electrode.

  The light incident on the reflective liquid crystal display panel 210 is transmitted through the counter substrate 203 and incident on the liquid crystal layer 209, is reflected by the pixel electrode formed on the silicon substrate 204, and is emitted from the counter substrate 203. Thereby, an image display operation is performed by the reflective liquid crystal display panel 210. Whether or not incident light is reflected varies depending on a signal voltage applied between the common electrode of the counter substrate 203 and the pixel electrode of the silicon substrate 204. The reflective liquid crystal display panel 210 performs two-dimensional image display by selectively driving a plurality of pixel electrodes that are two-dimensionally arranged in a matrix, for example, on the silicon substrate 204.

  The dust-proof glass 201 is made of a translucent material such as quartz or glass. The dustproof glass 201 is formed in a rectangular shape. The dustproof glass 201 is attached to the surface of the reflective liquid crystal display panel 210 with a transparent adhesive 202 so as to follow the outer shape of the substantially rectangular reflective liquid crystal display panel 210. That is, the dust-proof glass 201 is attached to the surface of the counter substrate 203 of the reflective liquid crystal display panel 210 opposite to the liquid crystal layer 209 side.

  The dust-proof glass 201 reduces the amount of dust and dirt that hinders image display by the reflective liquid crystal display panel 210 from adhering to the surface of the reflective liquid crystal display panel 210. The dustproof glass 201 functions as a transmissive dustproof plate that protects the surface of the reflective liquid crystal display panel 210.

  The rear heat sink 206 is a heat radiating member that radiates heat generated by the reflective liquid crystal display panel 210. The rear heat sink 206 is made of a material that can promote heat dissipation of the reflective liquid crystal display panel 210, such as a resin material such as a heat conductive plastic or a metal material such as aluminum. The back heat sink 206 is provided on the back surface opposite to the light incident surface of the reflective liquid crystal display panel 210. The rear heat sink 206 has a screw hole 207 a for fixing to the panel holder 205. The rear heat sink 206 is fixed to the panel holder 205 by a heat sink fixing screw 207b that passes through the screw hole 207a. The back heat sink 206 may be fixed to the panel holder 205 via a spring member.

  FIG. 3 is a view of the reflective liquid crystal display device 114 as seen from the back side where the back heat sink 206 is installed. The panel holder 205 is provided with a fixing hole 208 for fixing the reflective liquid crystal display device 114 to a mounting plate (not shown) or the like. The rear heat sink 206 is attached to the rear surface of the panel holder 205 so as to avoid the vicinity of the fixing hole 208. The rear heat sink 206 has a substantially rectangular shape with corner portions cut away in order to avoid the vicinity of the fixing hole 208. Specifically, the back heat sink 206 has a cross shape with a wide line width. The rear heat sink 206 includes a plurality of plate-like heat radiation fins 211 provided substantially in parallel along the direction of a pair of sides facing each other in a substantially rectangular shape in order to dissipate heat. The rear heat sink 206 has a plurality of heat radiation fins 211 to increase the surface area and efficiently radiate the heat of the reflective liquid crystal display panel 210.

  Returning to FIG. The panel holder 205 is a holding member that holds the reflective liquid crystal display device 114 and the rear heat sink 206. The panel holder 205 is configured in a substantially rectangular frame shape so as to surround the periphery of the substantially rectangular reflective liquid crystal display panel 210. The panel holder 205 has a concave portion 218 on one side of a substantially quadrangular frame shape in order to connect the reflective liquid crystal display panel 210 and a flexible cable (not shown). The panel holder 205 holds the back heat sink 206 by screwing a heat sink fixing screw 207 b penetrating through the screw hole 207 a of the back heat sink 206 into the screw hole 205 b through the back heat sink 206.

  The fixing portion of the panel holder 205 to the rear heat sink 206 by the heat sink fixing screw 207b is the side where the flexible cable is located, that is, the side where the concave portion 218 is provided in the panel holder 205 configured in a substantially rectangular frame shape. It is arrange | positioned in two places of the approximate center position in each of a pair of side part which does not contain. However, the number and arrangement of the fixing portions of the panel holder 205 in the heat sink fixing screws 207b are not limited to this embodiment.

  The panel holder 205 has an opening 205a for the back heat sink 206 and the reflective liquid crystal display panel 210 to contact each other. The opening 205 a is formed so that the panel holder 205 surrounds a part of the heat sink in a state where the panel holder 205 is attached to the rear heat sink 206, and the rear heat sink 206 faces the reflective liquid crystal display panel 210.

  FIG. 4 is a diagram showing the Young's modulus and thermal conductivity of the material constituting the panel holder 205. The panel holder 205 is made of a material having rigidity, that is, Young's modulus, smaller than that of a material having a thermal expansion coefficient substantially equal to that of the silicon substrate. The panel holder 205 is made of a material having a lower thermal conductivity than a material having a thermal expansion coefficient substantially equal to that of the silicon substrate.

An example of a material having a thermal expansion coefficient substantially equal to that of the silicon substrate is Kovar. Kovar's Young's modulus is approximately 1.36 × 10 ¹¹ (Pa). The thermal conductivity of Kovar is approximately 100 (W / mK). In the present embodiment, aluminum having a Young's modulus smaller than that of Kovar is used as a material for the panel holder 205. The Young's modulus of aluminum is approximately 7.10 × 10 ¹¹ (Pa). The thermal conductivity of aluminum is approximately 10 (W / mK). The thermal conductivity of aluminum is smaller than Kovar. A material having a smaller Young's modulus is cheaper than a material having a coefficient of thermal expansion substantially equal to the coefficient of thermal expansion, such as aluminum. Therefore, the panel holder 205 can be manufactured at a lower cost by using a material having a smaller Young's modulus than a material having a thermal expansion coefficient substantially equal to the thermal expansion coefficient.

FIG. 5 shows the stress applied to the silicon substrate 204 when aluminum is used as the material for the panel holder 205 and when Kovar is used. The stress applied to the silicon substrate 204 when aluminum was used as the material of the panel holder 205 and when Kovar was used was calculated by simulation. As shown in FIG. 5, when Kovar is used as the panel holder 205, a stress of about 4.2 × 10 ⁷ (Pa) is applied to the silicon substrate 204. On the other hand, when aluminum is used for the panel holder 205, a stress of approximately 3.7 × 10 ⁷ (Pa) is applied to the silicon substrate 204. In this way, by using aluminum as the material of the panel holder 205, the stress applied to the silicon substrate 204 can be reduced by about 0.5 × 10 ⁷ (Pa) compared to the case of using Kovar.

The stress applied to the dust-proof glass 201 when aluminum was used as the material of the panel holder 205 and when Kovar was used was calculated by simulation. As shown in FIG. 6, when Kovar is used as the panel holder 205, a stress of approximately 1.7 × 10 ⁷ (Pa) is applied to the dustproof glass 201. On the other hand, when aluminum is used as the panel holder 205, a stress of approximately 1.6 × 10 ⁷ (Pa) is applied to the dustproof glass 201. Thus, by using aluminum as the material of the panel holder 205, the stress applied to the dust-proof glass 201 can be reduced by about 0.1 × 10 ⁷ (Pa) as compared with the case of using Kovar.

  As described above, the panel holder 205 is made of aluminum having rigidity smaller than that of Kovar having a thermal expansion coefficient substantially equal to that of the silicon substrate, that is, Young's modulus, thereby being added to the reflective liquid crystal display device 114. Stress can be reduced. Thereby, the thermal distortion of the reflective liquid crystal display device 114 can be reduced. Further, since aluminum is inexpensive, the reflective liquid crystal display device 114 can be manufactured at low cost. As described above, the material of the panel holder 205 is made of a material having rigidity, that is, Young's modulus, smaller than that of a material having a thermal expansion coefficient substantially equal to that of the silicon substrate. The thermal distortion of can be reduced.

In the present embodiment, the material whose Young's modulus is smaller than the material having a thermal expansion coefficient substantially equal to that of the silicon substrate is aluminum, but other materials may be used. For example, a high thermal conductive resin can be given as another material. The high thermal conductive resin is a resin having a Young's modulus of about 3.5 × 10 ¹⁰ (Pa) and a thermal conductivity of about 30 (W / mK). As shown in FIG. 5, when a high thermal conductive resin is used as the panel holder 205, a stress of about 3.2 × 10 ⁷ (Pa) is applied to the silicon substrate 204. Thus, by using a high thermal conductive resin as the material of the panel holder 205, the stress applied to the silicon substrate 204 can be reduced by about 1.0 × 10 ⁷ (Pa) compared to the case of using Kovar. As shown in FIG. 6, when a high thermal conductive resin is used as the panel holder 205, a stress of about 1.4 × 10 ⁷ (Pa) is applied to the dustproof glass 201. Thus, by using a high thermal conductive resin as the material of the panel holder 205, the stress applied to the dust-proof glass 201 can be reduced by about 0.3 × 10 ⁷ (Pa) compared to the case of using Kovar.

(Second Embodiment)
The configuration of the reflective liquid crystal display device 214 according to this embodiment will be described with reference to FIG. The reflective liquid crystal display device 214 is different from the first embodiment in that the reflective liquid crystal display device 214 has an adhesive 212 that is applied to the sides of the reflective liquid crystal display panel 210 and adheres the panel holder 205 and the reflective liquid crystal display panel 210. The other components are the same as those of the reflective liquid crystal display device 114 of the first embodiment. The same components as those of the reflective liquid crystal display device 114 of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The adhesive 212 is, for example, a resin adhesive having heat resistance. Adhesive 212 is adhered to the vicinity of the approximate middle point of each of the three sides 210b, 210c, and 210d (the region indicated by a circle in FIG. 7) excluding the side 210a where the electrode (not shown) of the reflective liquid crystal display panel 210 is provided. The The adhesive 212 bonds the reflective liquid crystal display panel 210 and the panel holder 205. Thereby, the panel holder 205 holds the reflective liquid crystal display panel 210.

  Hereinafter, the effect of the reflective liquid crystal display device 214 according to the present embodiment will be described using a comparative example. In the description of the reflective liquid crystal display device as a comparative example, portions common to the reflective liquid crystal display device 214 of the above-described embodiment are denoted by the same reference numerals for convenience, and description thereof is omitted.

  A reflective liquid crystal display device 14 as a comparative example will be described with reference to FIG. The adhesive 213 is, for example, a resin adhesive having heat resistance. The adhesive 213 is bonded to the vicinity of the corner portion where the two sides of the reflective liquid crystal display panel 210 are in contact (region indicated by a circle in FIG. 8). Specifically, in the reflective liquid crystal display panel 210, a corner portion 1A where two adjacent side portions 210a and 210b are in contact with each other, a corner portion 2A where two adjacent side portions 210b and 210c are in contact with each other, and two adjacent corner portions 2A are also adjacent. The corner portion 3A is in contact with two side portions 210c and 210d, and the corner portion 4A is in contact with two adjacent side portions 210d and 210a. The adhesive 213 bonds the reflective liquid crystal display panel 210 and the panel holder 205 together.

  FIG. 9A is a perspective view of the reflective liquid crystal display device 14 of FIG. FIG. 9B shows the stress distribution in the cross section of the reflective liquid crystal display device 14 taken along A-A ′ in FIG. As shown in FIG. 9B, a large force is applied to the panel holder 205. In particular, since the fixing hole 208 of the panel holder 205 is fixed to a mounting plate (not shown) or the like, a large stress is generated around the fixing hole 208. As shown in FIG. 9B, the reflective liquid crystal display panel 210 and the back heat sink 206 are greatly curved due to the influence of stress acting on the peripheral portion of the fixing hole 208.

  Therefore, in the reflective liquid crystal display device 14 according to the present embodiment, the adhesive 212 is provided at three positions away from the fixing hole 208 of the panel holder 205, so that the reflective liquid crystal display device 14 reflects from the fixing hole 208 portion of the panel holder 205. The stress transmitted to the liquid crystal display panel 210 is reduced.

A stress simulation was performed in which a constant external force was applied to the panel holder 205 of the reflective liquid crystal display device 214 according to the present embodiment in FIG. 7 and the reflective liquid crystal display device 14 in FIG.
FIG. 10 is a stress distribution diagram showing the stress simulation result. FIG. 10A is a diagram showing the stress distribution of the reflective liquid crystal display device 214 according to this embodiment shown in FIG. As shown in FIG. 10A, when an external force is applied to the panel holder 205, a strong stress is generated in the vicinity of the adhesive 212. In FIG. 10A, a stress of about 3.50 (Mpa) is generated near the side 210 b of the reflective liquid crystal display panel 210. FIG. 10B is a diagram showing the stress distribution of the reflective liquid crystal display device 14 of FIG. In FIG. 10B, a large stress is generated near the corner of the reflective liquid crystal display panel 210 provided with the adhesive 213. The stress generated near the corner portion 4A of the reflective liquid crystal display panel 210 is about 4.59 (Mpa). As described above, by applying the adhesive 212 to the vicinity of the substantially midpoint of the three sides of the reflective liquid crystal display panel 210, the stress applied to the reflective liquid crystal display panel 210 can be reduced by about 1.09 (Mpa). .

  As described above, the reflective liquid crystal display device 214 according to the present embodiment can obtain the same effects as those of the first embodiment, and reflects the adhesive 212 that bonds the panel holder 205 and the reflective liquid crystal display panel 210. By providing the liquid crystal display panel 210 in the vicinity of the substantially middle point on each of the three sides, distortion due to an external force applied to the reflective liquid crystal display device 214 can be reduced.

  Note that the adhesive 212 may be provided at a position away from the fixing hole of the panel holder 205 to which a strong stress is applied. When the adhesive 212 is provided in the vicinity of the middle point of each of the three sides of the reflective liquid crystal display panel 210 as in this embodiment. Not limited to. That is, the adhesive material 212 may be provided on any of the three side portions 210b, 210c, and 210d excluding the corner portion of the reflective liquid crystal display panel 210.

  FIG. 11 shows a modification of the present embodiment. In the reflective liquid crystal display device 314 shown in FIG. 11, two adhesives 312 are provided on each of the two side portions 210 b and 210 d of the reflective liquid crystal display panel 210. The other configuration is the same as that of the reflective liquid crystal display device 214 of the second embodiment shown in FIG. FIG. 12 is a diagram illustrating a stress simulation result in which a constant external force is applied to the panel holder 205 of the reflective liquid crystal display device 314. In this simulation, an external force having the same magnitude as that of the simulation whose result is shown in FIG. 10 is applied. As shown in FIG. 12, a large stress is generated in the vicinity of the side portion 210b of the reflective liquid crystal display panel 210 on which the adhesive 312 is provided. The stress generated in the vicinity of the side portion 210b of the reflective liquid crystal display panel 210 is about 4.51 (Mpa). As described above, even when two adhesives 312 are provided on each of the two side portions 210b and 210d of the reflective liquid crystal display panel 210, the stress applied to the reflective liquid crystal display panel 210 is reduced by about 0.08 (Mpa). Can do.

  As described above, even when the adhesive 312 is disposed at a position away from the fixing hole 208 of the panel holder 205, distortion due to external force applied to the reflective liquid crystal display device 314 can be reduced. Note that the more the adhesive 312 is away from the fixing hole 208 of the panel holder 205, the easier it is to reduce the influence of external force applied to the reflective liquid crystal display device 314. Therefore, the side of the reflective liquid crystal display panel 210 as shown in FIG. It is desirable to provide the adhesive 212 in the vicinity of the substantially middle point.

(Third embodiment)
The configuration of the reflective liquid crystal display device 414 according to this embodiment will be described with reference to FIG. The reflective liquid crystal display device 414 has the same configuration as the reflective liquid crystal display device 114 of the first embodiment except for the configuration of the rear heat sink 406 that is a heat dissipation member. The same components as those of the reflective liquid crystal display device 114 of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The rear heat sink 406 is made of, for example, a resin-based material such as heat conductive plastic or a metal material such as aluminum. The rear heat sink 406 includes a plurality of heat radiation fins 211 provided on the surface opposite to the surface attached to the panel holder 205. The radiating fins 211 are formed so as to avoid the fixing holes 208 similarly to the rear heat sink 206 of FIG. Further, the rear heat sink 406 includes first reinforcing ribs 416 as reinforcing portions provided at the corners of the surface where the radiation fins 211 are provided. The first reinforcing rib 416 is provided so as to surround the periphery of the fixing hole 208 of the panel holder 205. The first reinforcing rib 416 is a part formed integrally with the heat radiation fin 211 of the rear heat sink 406 and has substantially the same height as the heat radiation fin 211. Here, the “height” of the first reinforcing rib 416 is a dimension in the protruding direction from the surface where the heat radiation fins 211 are formed in the rear heat sink 406. However, the 1st reinforcement rib 416 and the radiation fin 211 may be formed as a different body. The rear heat sink 406 has a substantially rectangular shape that is substantially the same shape as the panel holder 205.

  As described in the second embodiment, a strong stress is generated in the fixing hole 208 of the panel holder 205. Therefore, in the present embodiment, the first reinforcing rib 416 is provided so as to surround the periphery of the fixing hole 208 of the panel holder 205, so that the distortion of the reflective liquid crystal display device 414 due to strong stress generated around the fixing hole 208 is reduced. It can be effectively reduced.

  FIG. 14 shows a result of stress simulation in which a constant external force is applied to the panel holder 205 of the reflective liquid crystal display device 414. An external force having the same magnitude as the simulation shown in FIG. 10 was applied to the panel holder 205 of the reflective liquid crystal display device 414. As shown in FIG. 14, a large stress is generated near the corner portion of the reflective liquid crystal display panel 210. The stress generated near the corner of the reflective liquid crystal display panel 210 is about 3.91 (Mpa). Compared to the comparative example shown in FIG. 10B, the stress applied to the reflective liquid crystal display device 414 is reduced by about 0.69 (Mpa).

  As described above, the reflective liquid crystal display device 414 according to the present embodiment provides the same effects as those of the first embodiment, and is provided with the reinforcing ribs 416 so as to surround the periphery of the fixing hole 208 of the panel holder 205. Thus, distortion due to an external force applied to the reflective liquid crystal display device 414 can be reduced.

(Fourth embodiment)
The configuration of the reflective liquid crystal display device 514 according to this embodiment will be described with reference to FIG. The reflective liquid crystal display device 514 is the third embodiment except that the back heat sink 506 includes a second reinforcing rib 516 as a reinforcing portion provided so as to be substantially orthogonal to the heat radiation fin 211 in addition to the first reinforcing rib 416. The reflective liquid crystal display device 414 has the same configuration. The same components as those of the reflective liquid crystal display device 414 of the fourth embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The back heat sink 506 includes a plurality of plate-like second reinforcing ribs 516 provided in a plurality in parallel. The second reinforcing ribs 516 and the radiating fins 211 are arranged so as to be substantially orthogonal to each other. That is, the second reinforcing ribs 516 and the heat radiation fins 211 are arranged in a lattice pattern. Specifically, as shown in FIG. 15, in the present embodiment, the second reinforcing ribs 516 are substantially parallel along a pair of side directions facing each other in a substantially rectangular shape that is a planar view shape of the rear heat sink 506. This is a plate-like portion provided so as to be substantially orthogonal to the plate-like heat radiation fins 211 provided in a plan view. That is, in the substantially rectangular shape that is the shape of the rear heat sink 506 in a plan view, when the direction along which the radiation fins 211 are along the first direction, the second reinforcement is along the second direction substantially orthogonal to the first direction. Ribs 516 are formed.

  More specifically, in the example shown in FIG. 15, the second reinforcing ribs 516 are provided so as to cross the large number of heat dissipating fins 211 at three positions at substantially equal intervals in the first direction. Accordingly, the second reinforcing rib 516 located at the center of the three locations is provided at substantially the same position as the screw hole 207a of the rear heat sink 506 in the first direction.

  The second reinforcing rib 516 is a portion formed integrally with the heat radiation fin 211 of the rear heat sink 506 and has substantially the same height as the heat radiation fin 211. Here, the “height” of the second reinforcing rib 516 is a dimension in the protruding direction from the surface of the rear heat sink 506 where the radiation fins 211 are formed. However, the 2nd reinforcement rib 516 and the radiation fin 211 may be formed as a different body.

  By providing the second reinforcing ribs 516 so as to be substantially orthogonal to the radiation fins 211, the back heat sink 506 is not only distorted in a direction parallel to the radiation fins 211 but also distorted in a direction orthogonal to the radiation fins 211 or in a diagonal direction. Can also be reduced.

  FIG. 16 shows the result of stress simulation in which a constant external force is applied to the panel holder 205 of the reflective liquid crystal display device 514. An external force having the same magnitude as the simulation shown in FIG. 10 was applied to the panel holder 205 of the reflective liquid crystal display device 514. As shown in FIG. 16, a large stress is generated near the corner portion of the reflective liquid crystal display panel 210. The stress generated in the corner portion of the reflective liquid crystal display panel 210 is about 3.48 (Mpa). Compared with the comparative example shown in FIG. 8, the stress applied to the reflective liquid crystal display device 314 is reduced by about 1.11 (Mpa).

  As described above, the reflective liquid crystal display device 514 according to the present embodiment provides the same effects as those of the third embodiment, and is provided with the plate-like reinforcing ribs 516 so as to be substantially orthogonal to the heat radiating fins 211. Further, distortion due to external force applied to the reflective liquid crystal display device 414 can be further reduced.

  In the present embodiment, the example in which the plate-shaped reinforcing rib 516 is combined with the reflective liquid crystal display device 414 of the third embodiment has been described, but a part or all of the first to fourth embodiments may be combined. . 17 to 19 show thermal stress simulation results of the reflective liquid crystal display device 614 in which all of the first to fourth embodiments are combined. The reflective liquid crystal display device 614 is configured by further including an adhesive 212 and reinforcing ribs 416 and 516 in addition to the reflective liquid crystal display device 114 of the first embodiment.

  FIG. 17A is a diagram showing an overall temperature gradient of the reflective liquid crystal display device 614. The temperature difference between the highest temperature and the lowest temperature of the reflective liquid crystal display panel 210 is about 4.56 ° C. FIG. 17B shows an overall temperature gradient of the reflective liquid crystal display device 14 of FIG. 8 as a comparative example. Kovar is used as the material of the panel holder 205 of the reflective liquid crystal display device 14. The temperature difference between the highest temperature and the lowest temperature of the reflective liquid crystal display panel 210 is about 7.68 ° C. Thus, the overall temperature gradient of the reflective liquid crystal display device 614 is reduced by about 2 ° C. compared to the reflective liquid crystal display device 14.

FIG. 18A is a diagram showing the stress distribution of the silicon substrate 204 of the reflective liquid crystal display device 614. FIG. The stress applied to the silicon substrate 204 of the reflective liquid crystal display device 614 is 6.06 × 10 ⁶ Pa at the maximum. FIG. 18B shows a stress distribution of the silicon substrate 204 of the reflective liquid crystal display device 14 of FIG. 8 as a comparative example. The stress applied to the silicon substrate 204 of the reflective liquid crystal display device 14 is 18.0 × 10 ⁶ Pa at the maximum. Thus, the stress transmitted to the silicon substrate 204 of the reflective liquid crystal display device 614 is reduced by about 87% compared to the reflective liquid crystal display device 14.

FIG. 19A is a diagram illustrating the stress distribution of the dust-proof glass 201 of the reflective liquid crystal display device 614. The stress applied to the dust-proof glass 201 of the reflective liquid crystal display device 614 is 0.23 × 10 ⁶ Pa at the maximum. FIG. 19B shows a stress distribution of the dust-proof glass 201 of the reflective liquid crystal display device 14 of FIG. 8 as a comparative example. The stress applied to the dust-proof glass 201 of the reflective liquid crystal display device 14 is 0.55 × 10 ⁶ Pa at the maximum. As described above, the stress transmitted to the dustproof glass 201 of the reflective liquid crystal display device 614 is reduced by about 58% compared to the reflective liquid crystal display device 14.

  In this way, by combining the reflective liquid crystal display devices of the first to fourth embodiments, thermal distortion can be reduced at a lower cost than the reflective liquid crystal display device 14 of FIG. 8, and distortion due to external force is also reduced. be able to.

  Finally, the description of each embodiment described above is an example of the present technology, and the present technology is not limited to the above-described embodiment. For this reason, it is a matter of course that various modifications can be made in accordance with the design and the like as long as they do not deviate from the technical idea according to the present technology other than the embodiments described above.

114 Reflective liquid crystal display device 201 Dust-proof glass 203 Counter substrate 204 Silicon substrate 205 Panel holder 206 Back heat sink 209 Liquid crystal layer 210 Reflective liquid crystal display panel 211 Radiation fin 212 Adhesive

Claims (7)

A substantially rectangular reflective liquid crystal display panel having a silicon substrate, a counter substrate disposed opposite to the silicon substrate, and a liquid crystal layer sealed between the silicon substrate and the counter substrate;
A heat dissipating member that contacts one surface of the silicon substrate and dissipates heat generated by the reflective liquid crystal display panel;
A holding member that holds the reflective liquid crystal display panel and the heat dissipation member in a substantially rectangular frame;
An adhesive that bonds the holding member and the reflective liquid crystal display panel;
The holding member is made of a material having a Young's modulus smaller than a material having a thermal expansion coefficient substantially equal to the thermal expansion coefficient of the silicon substrate, and a plurality of fixing holes for fixing to a mounting target are provided in a peripheral portion. And
The reflective liquid crystal display device, wherein the adhesive is applied at a position away from the fixed hole on the side of the reflective liquid crystal display panel, and holds the reflective liquid crystal display panel with respect to the holding member.   2. The reflective liquid crystal display device according to claim 1, wherein the material having a coefficient of thermal expansion substantially equal to that of the silicon substrate is Kovar.   The reflective liquid crystal display device according to claim 1, wherein the holding member is made of a material containing aluminum.   The reflective liquid crystal according to any one of claims 1 to 3, wherein the adhesive is applied in the vicinity of a substantially middle point of each of at least three sides excluding the side on which the electrode of the reflective liquid crystal display panel is provided. Display device.   The said heat radiating member is provided with the plate-shaped heat radiating fin provided in multiple numbers substantially parallel in order to radiate | emit the said heat | fever, and the reinforcement part provided in the corner part of the surface in which the said heat radiating fin was provided. The reflective liquid crystal display device according to claim 4.   The heat dissipating member includes a plurality of plate-like heat dissipating fins provided substantially in parallel to dissipate the heat, and a reinforcing portion provided on a surface provided with the heat dissipating fins so as to be substantially orthogonal to the heat dissipating fins. A reflective liquid crystal display device according to any one of claims 1 to 4, further comprising: A substantially rectangular reflective liquid crystal display panel having a silicon substrate, a counter substrate disposed opposite to the silicon substrate, and a liquid crystal layer sealed between the silicon substrate and the counter substrate;
A heat radiating member that radiates heat generated by the reflective liquid crystal display panel; and
A holding member that holds the reflective liquid crystal display panel and the heat dissipation member in a substantially rectangular frame;
An adhesive that bonds the holding member and the reflective liquid crystal display panel;
The holding member is made of a material having a Young's modulus smaller than a material having a thermal expansion coefficient substantially equal to the thermal expansion coefficient of the silicon substrate, and a plurality of fixing holes for fixing to a mounting target are provided in a peripheral portion. And the adhesive is applied at a position away from the fixing hole on the side of the reflective liquid crystal display panel, and holds the reflective liquid crystal display panel with respect to the holding member. When,
A light source that generates light;
A condensing optical system for guiding the light to the reflective liquid crystal display device;
A projection display system comprising: a projection optical system that magnifies and projects the light modulated by the reflective liquid crystal display device.

Images