JP2009109738A - Projection type display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain high image quality by efficiently cooling a plurality of liquid crystal panel elements with an excellent balance. <P>SOLUTION: The projection type display device 1 includes: a color separating optical system 5 to separate light from a light source 3 into three colors of red, green, and blue; a synthesizing optical system 13 to make three liquid crystal panel elements 7, 9, 11 for respective colors irradiated with separated luminous flux of light and to synthesize modulated light emitted from the respective liquid crystal panel elements; a projection optical system 17 to project the luminous flux of light synthesized with the synthesizing optical system 13 onto the screen; and a base member 19 on which optical members to construct at least the synthesizing optical system 13 out of the color separating optical system 5, the synthesizing optical system 13, and the projection optical system 17 are assembled. The projection type display device 1 is characterized in that the respective three liquid crystal panel elements 7, 9, 11 and the base member 19 are connected with one another via a first heat-conduction sheet 41 and arranged, for the purpose of cooling the respective three liquid crystal panel elements 7, 9, 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a projection display device, and more particularly to an image that is modulated using a liquid crystal modulation element and formed on a screen for image display, and a projection that displays a high-quality image by cooling the liquid crystal panel element. The present invention relates to a type display device.

  Conventionally, as a projection display device, for example, a liquid crystal projector has been widely used.

  Referring to FIGS. 7A and 7B, for example, a liquid crystal projector as the projection display device 101 uses a light beam (white light) from an illumination system light source 103 as a light source for red (R) and an edge (G). , Blue (B), the color separation optical system 105 that separates the three primary colors, and the separated light fluxes are irradiated to the three liquid crystal panel elements 107, 109, and 111 for red, green, and blue. By driving the elements 107, 109, and 111 based on a television signal or an information signal from a personal computer or the like, a combined light that emits a modulated light beam from the liquid crystal panel elements 107, 109, and 111 and combines the modulated light beam. The system 113 and the projection optical system 117 that enlarges and projects the light beam synthesized by the synthesis optical system 113 onto the screen via the projection lens 115 are provided.

  As the liquid crystal panel elements 107, 109, and 111, reflective liquid crystal panel elements are used. Further, the optical members constituting the color separation optical system 105, the synthesis optical system 113, and the projection optical system 117 are fixed to the base plate 119 on the back side of the paper surface of FIGS.

  As the above-described color separation optical system 105, the white light WL emitted from the illumination system light source 103 is emitted after being made uniform by the integrator optical system 121 and converted into S-polarized light. Of the emitted white light WL, red component light (hereinafter referred to as “red light RL”) and edge color component light (hereinafter referred to as “green light GL”) selectively have a polarization plane of 90 degrees. The color polarizer 123 to be converted is transmitted, and in this color polarizer 123, S-polarized blue component light (hereinafter referred to as “blue light BL”) of the white light WL, P-polarized red light RL, and Decomposed into green light GL.

  Then, the blue light BL is reflected by a polarization beam splitter 125 (hereinafter referred to as “PBS”) in a direction orthogonal to the incident light, while the red light RL and the green light GL are transmitted through the PBS 125, so that the blue light BL is transmitted. And separated into red light RL and green light GL.

  Further, the green light GL and the red light RL transmitted through the PBS 125 are color polarizers 127 that convert the polarization plane of the green light GL by 90 degrees, and turn into green light GL of S-polarized light and red light RL of P-polarized light. Disassembled.

  In the PBS 129, the green light GL of the S-polarized light out of the incident light is reflected in a direction orthogonal to the incident light, while the red light RL passes through the PBS 129 and is separated into the green light GL and the red light RL. .

  The optical member constituting the color separation optical system 105 is a member that functions to separate colors of red, green, and blue (R, G, B light). For example, an integrator optical system 121, a color polarizer, and the like. 123, a polarizing beam splitter 125, a color polarizer 127, a PBS 129, and the like.

  As the combining optical system 113, the blue light BL reflected and separated by the PBS 125 is incident from one main surface of the PBS 131 and then reflected in a direction orthogonal to the incident light by the polarization separation surface that reflects the S-polarized component. Then, the light enters the reflective liquid crystal panel element 111 for blue. In the blue reflective liquid crystal panel element 111, the polarization direction of the blue light BL incident on the pixel of the portion to be displayed in blue is rotated by 90 degrees based on the blue image information from a television signal or a personal computer, That is, it is converted into P-polarized light and reflected.

  Therefore, after the P-polarized light component of the blue light BL incident on the PBS 131 again passes through the polarization separation surface, the polarization surface is converted by 90 degrees by the wave plate 133, and the first color of the color composition PBS 135 is converted to S-polarized light. Incident on one main surface.

  On the other hand, the green light GL of the S-polarized light reflected and separated by the PBS 129 is the same as the blue light BL described above, based on the green image information from a television signal or a personal computer, and the like. Pixels to be displayed in green on the panel element 109 are converted to P-polarized light, then emitted from a direction orthogonal to incident light, and incident on the color polarizer 137.

  Further, the red light RL of the P-polarized light that has passed through the PBS 129 is a reflective liquid crystal for red, based on a television signal or red image information from a personal computer or the like, like the blue light BL and the green light GL described above. Pixels to be displayed in red on the panel element 107 are converted to S-polarized light, and then emitted from a direction orthogonal to the incident light, and enter the color polarizer 137 together with the green light GL.

  The color polarizer 137 converts the polarization plane of the red light RL by 90 degrees, and enters the second main surface of the PBS 135 for color synthesis as the same P-polarized light as the green light GL.

  In addition, as an optical member which comprises the synthetic | combination optical system 113, it says the member which functions in order to synthesize | combine red, green, and blue light (R, G, B light), for example, said reflection type liquid crystal panel element 107, 109, 111, PBS 129, 131, wave plate 133, color polarizer 137, color composition PBS 135, and the like.

  As the projection optical system 117, among the red, green, and blue light (RGB light) incident from the first and second main surfaces of the color composition PBS 135, the blue light BL of S-polarized light is the incident light. The green light GL and red light RL of the P-polarized light reflected in the orthogonal direction are transmitted in a straight line and emitted from the third main surface as the three primary colors of red, green, and blue. And it is radiate | emitted from the projection lens 115 and a color image is displayed on the screen which is not shown in figure.

  In addition, as an optical member which comprises the projection optical system 117, members, such as the projection lens 115, are said.

  As described above, most of the luminous fluxes that are separated into the three primary colors of red, green, and blue and are applied to the liquid crystal panel elements 107, 109, and 111 are transmitted in the case of the transmissive liquid crystal panel element, or the reflective liquid crystal panel. In the case of the element, most of the light is reflected, but a part of the irradiated light beam is absorbed by the liquid crystal panel elements 107, 109, and 111 including the optical members around the liquid crystal panel elements 107, 109, and 111. It will generate heat.

  Referring to FIG. 8 together, the reflective liquid crystal panel elements 107, 109, and 111 (LCOS) generally conduct heat through, for example, a silicon base 139 as a liquid crystal element driving IC and the back surface of the silicon base 139. It is a structure comprising a liquid crystal element support 143 attached by thermal bonding via a gel 141.

  More specifically, for example, a flexible cable 145 as an electrode is connected to the silicon base 139, and an IC storage groove 147 for storing the silicon base 139 is provided on the surface side of the liquid crystal element support 143. The back surface of the silicon base 139 is thermally coupled to the bottom of the IC housing groove 147 through a heat conducting gel 141. The surface of the silicon base 139 is covered with the sealing glass 149, and the sealing glass 149 is fixed to the surface of the liquid crystal element support 143 with a fixing member 151. The flexible cable 145 is fixed to the surface of the liquid crystal element support 143 with a flexible fixing member 153.

  Further, the liquid crystal element support 143 is integrally provided with fins 155 for increasing the efficiency of heat release on the back side thereof, and a heat sink for suppressing the temperature rise of the silicon base 139 due to strong illumination light. And a structure that also serves as a support for the silicon base 139.

  Accordingly, in each of the reflective liquid crystal panel elements 107, 109, and 111 (LCOS), the heat of the silicon base 139 is conducted to the liquid crystal element support 143 through the heat conducting gel 141 and is emitted from the fins 155 of the liquid crystal element support 143. It is the composition which is done.

  Further, the temperature rise of each of the above three liquid crystal panel elements 107, 109, 111 is caused by the luminance distribution of the illumination system light source 103 used or the characteristics of the color polarizers 123, 127, 137 (filters) that are separated into the three primary colors. Due to the light absorption characteristics of the liquid crystal panel elements 107, 109, and 111, the temperatures are different. For example, when the three primary colors of red, green, and blue are combined and the levels are adjusted to produce white, usually blue has the highest temperature, and then decreases in order of green and red.

  Therefore, in order to efficiently bring the peripheral optical members including the red, green, and blue liquid crystal panel elements 107, 109, and 111 to a predetermined temperature or less, the liquid crystal elements in the liquid crystal panel elements 107, 109, and 111 are used. The cooling air volume is adjusted (controlled) by changing the distribution of the air volume for cooling the fins 155 of the support 143. That is, although not shown in FIGS. 7A and 7B, a cooling fan and an air duct are provided on the base plate 119 side (back side of the drawing) for fixing the optical member, and the liquid crystal element support is provided. A cooling air outlet is provided in the vicinity of 143 to cool the red, green, and blue liquid crystal panel elements 107, 109, and 111 to a predetermined temperature.

  In another conventional example, as shown in Patent Document 1, a cooling fan is installed in the vicinity of the combining optical system, and cooling air is supplied in the vicinity of the red, green, and blue liquid crystal panel elements. An air outlet was provided, and cooling was performed by applying cooling air around the liquid crystal panel element.

In another conventional example, as shown in Patent Document 2, a plurality of liquid crystal light valves corresponding to the liquid crystal panel elements 107, 109, and 111 for red, green, and blue are provided with high thermal conductivity members. It is the structure connected mutually via.
Japanese Patent No. 2707599 JP 11-133389 A

  By the way, in the conventional projection display device 101, as described above, in order to efficiently cool the three liquid crystal panel elements 107, 109, 111 to a predetermined temperature or less, the liquid crystal panel elements 107, 109, The cooling air volume was adjusted (controlled) by changing the distribution of the air volume for cooling 111.

  However, in recent years, as the liquid crystal panel elements have been improved and the response characteristics of the liquid crystal panel elements with respect to drive signals from television signals, personal computers, etc. have become faster, the liquid crystal panel elements 107 for red, green, and blue, The difference in response characteristics of 109 and 111 has become a problem. Therefore, conventionally, in order to match the response characteristics of the above three liquid crystal panel elements 107, 109, and 111, a high voltage pulse is superimposed on the drive voltage waveform or an electrical delay is changed. There was a problem that it was difficult to match the responses of the three colors.

  Therefore, if there is a difference in the response characteristics of the red, green, and blue liquid crystal panel elements 107, 109, and 111, no problem occurs in the still image, but the image quality is remarkably improved when a moving image is projected. I will drop it. That is, if there is an image moving on the projection screen, for example, a phenomenon occurs in which the leading edge of the moving image is colored. The reason is that the viscosity of a general substance (liquid) decreases as the temperature increases, and the viscosity of the liquid increases in a low temperature range. Similarly, the liquid crystal used in the liquid crystal panel elements 107, 109, and 111 also decreases in viscosity at high temperatures and increases in viscosity at low temperatures. Therefore, a phenomenon occurs in which the response is slow at low temperatures and the response is fast at high temperatures.

  Therefore, it is desirable to control the liquid crystal panel elements 107, 109, and 111 for red, green, and blue so as to have the same temperature as much as possible. In other words, in the conventional projection display device 101 in FIGS. 7A and 7B and Patent Document 1, the cooling air volume is adjusted by changing the distribution of the air volume for cooling the liquid crystal panel elements 107, 109, and 111. However, there is a problem that it is insufficient for the quality of moving images.

  The red, green, and blue liquid crystal panel elements 107, 109, and 111 need to be finely adjusted (registration adjustment) individually in order to match the projected red, green, and blue on the projection screen. Therefore, it cannot be directly fixed to the base plate 119 for structural reasons.

  Furthermore, in the conventional projection display device in Patent Document 2, a plurality of liquid crystal light valves are connected to each other via a high thermal conductivity member, but simply connecting to each other with a high thermal conductivity member. However, there is a problem that it is insufficient for the above-mentioned moving image quality.

  Further, in order to increase the cooling efficiency with the structure of the conventional reflective liquid crystal panel elements 107, 109, and 111 (LCOS) of FIG. 8, the heat conducting gel 141 having a lower thermal conductivity than that of metal is made as thin as possible. It is necessary to release the heat of the base 139 to the liquid crystal element support 143 side. However, when the amount of the heat conductive gel 141 is reduced and the heat conductive gel 141 is made thin, stress is applied to the sealing glass 149 constituting the liquid crystal panel elements 107, 109, and 111, and birefringence of the sealing glass 149 occurs. . Since the liquid crystal panel elements 107, 109, and 111 irradiate and project with polarized light, there is a problem in that shading occurs because the uniformity of the surface image is lost when birefringence occurs in the optical path of the light beam. Therefore, the thickness of the heat conducting gel 141 is set to 0.3 to 0.5 mm.

  Incidentally, the thermal conductivity of the heat conducting gel 141 is about 0.5 to 0.7 W / (m · K), which is considerably smaller than a metal that is a general heat sink material. However, since the thermal conductivity of air is 0.037 W / (m · K), it is a little better than the state without anything.

  An object of the present invention is to efficiently cool a plurality of liquid crystal panel elements in a balanced manner, for example, to obtain high image quality even for moving images, and silicon-based heat is used to form a liquid crystal panel element. It aims at cooling efficiently, without giving stress to a silicon base by escaping to the side of a support body efficiently.

In order to solve the above-described problems, a projection display device according to the present invention includes a color separation optical system that separates light from a light source into three colors of red, green, and blue, and a separated luminous flux for each of the three colors. A composite optical system that irradiates the liquid crystal panel element and synthesizes the modulated outgoing light from the liquid crystal panel elements, a projection optical system that projects the light beam synthesized by the composite optical system onto a screen, and the color separation optical system And a base member assembled with an optical member constituting at least the composite optical system of the composite optical system and the projection optical system,
In order to cool the three liquid crystal panel elements, the liquid crystal panel elements and the base member are connected and arranged with a first heat conductive sheet.

The projection display device of the present invention irradiates the three color liquid crystal panel elements with light beams of three colors of red, green, and blue, and the light beams from the three color light sources. A combining optical system for combining modulated outgoing light from the light, a projection optical system for projecting a light beam combined by the combining optical system onto a screen, and at least the color separation optical system, the combining optical system, and the projection optical system In a projection type display device comprising a base member assembled with optical members constituting a composite optical system,
In order to cool the three liquid crystal panel elements, the liquid crystal panel elements and the base member are connected and arranged with a first heat conductive sheet.

  In the projection display device according to the present invention, in the projection display device, at least two liquid crystal panel elements of the three liquid crystal panel elements are connected to the base member with one first heat conductive sheet. It is preferable that

  In the projection display device according to the present invention, in the projection display device, each of the liquid crystal panel elements has a surface on one end side of the second heat conductive sheet attached to the back surface of the liquid crystal element driving IC, and the second heat It is preferable that the back surface on one end side of the conductive sheet is attached by being bonded to the liquid crystal element support with a heat conductive gel, and the other end side of the second heat conductive sheet is joined and connected to the liquid crystal element support. .

  In the projection display device according to the present invention, in the projection display device, each of the liquid crystal panel elements has a surface on one end side of the second heat conductive sheet attached to the back surface of the liquid crystal element driving IC, and the second heat The back surface on one end side of the conductive sheet is attached and attached to the liquid crystal element support with a heat conductive gel, and the other end sides of the second heat conductive sheet of at least two liquid crystal panel elements of the three liquid crystal panel elements are connected to each other. It is preferable that these are linked and connected.

  As will be understood from the means for solving the above problems, according to the present invention, the liquid crystal panel elements for the three colors are not cooled individually, but are flexible first heat. Heat is transferred to the base member having a large heat capacity by the conductive sheet to cool the base member. As a result, since the base member having a large heat capacity is used as the heat sink as compared with the conventional cooling liquid crystal element support attached to each liquid crystal panel element, the temperature rise can be suppressed low. Further, since the entire base member is cooled, the cooling air can be guided by a simple duct, and even the low-speed air can be efficiently cooled, so that the noise can be suppressed.

  Further, since the first heat conductive sheet having flexibility is used, each of the three liquid crystal panel elements for each color can be easily finely adjusted (registration adjustment) individually. Alternatively, the first heat conductive sheet can be attached to the liquid crystal panel element and the base member after fine adjustment individually.

  Furthermore, by thermally coupling each liquid crystal panel element with the first heat conductive sheet, the temperature of each liquid crystal panel element is brought close to each other, so that the liquid crystal response characteristics can be matched. As a result, by efficiently cooling a plurality of liquid crystal panel elements in a well-balanced manner, for example, high image quality can be obtained even for moving images.

  Further, by replacing the conventional cooling liquid crystal element support provided in each liquid crystal panel element with a base member, the weight and size can be reduced, and the relative positions of the three liquid crystal panel elements fluctuate (over time). It also has an effect of preventing a shift in registration (convergence) caused by a change or environmental change.

  Further, since the liquid crystal element driving IC and the liquid crystal element support are connected by the second heat conductive sheet, most of the heat generated by the liquid crystal element driving IC due to the incident light of strong illumination light passes through the second heat conductive sheet. It can escape to the liquid crystal element support. In addition, part of the heat of the liquid crystal element driving IC can be released to the liquid crystal element support through the heat conduction gel.

  Embodiments of the present invention will be described below with reference to the drawings.

  Referring to FIGS. 1A and 1B, as the projection display apparatus 1 according to this embodiment, for example, there is a liquid crystal projector, and a light beam (white light) from an illumination system light source 3 as a light source is red. (R), edge (G), color separation optical system 5 that separates into three primary colors of blue (B), and three liquid crystal panel elements 7, 9, 11 for red, green, and blue for the separated luminous flux. And driving each of the liquid crystal panel elements 7, 9, and 11 based on a television signal or an information signal from a personal computer or the like to emit a modulated light beam from the liquid crystal panel elements 7, 9, or 11, A combining optical system 13 for combining the modulated light beams and a projection optical system 17 for enlarging and projecting the light beams combined by the combining optical system 13 onto a screen via a projection lens 15 are provided. As the liquid crystal panel elements 7, 9, and 11, reflective liquid crystal panel elements are used. Further, the optical members constituting the three color separation optical systems 5, the synthesis optical system 13, and the projection optical system 17 are, for example, a base plate 19 as a base member on the back side in FIG. 1A and FIG. It is fixed. Note that. In FIGS. 1A and 1B, optical members constituting the three color separation optical systems 5, the synthesis optical system 13, and the projection optical system 17 are fixed to the base plate 19, but at least the synthesis optical system 13 is configured. It is necessary that the optical member to be fixed to the base plate 19.

  As the color separation optical system 5 described above, the white light WL emitted from the light source 3 is emitted after being made uniform by the integrator optical system 21 and converted into S-polarized light. Of the emitted white light WL, red component light (hereinafter referred to as “red light RL”) and edge color component light (hereinafter referred to as “green light GL”) selectively have a polarization plane of 90 degrees. The color polarizer 23 to be converted is transmitted. With this color polarizer 23, S-polarized blue component light (hereinafter referred to as “blue light BL”) of the white light WL, P-polarized red light RL, and Decomposed into green light GL.

  Then, the blue light BL is reflected by a polarization beam splitter 25 (hereinafter referred to as “PBS”) in a direction orthogonal to the incident light, while the red light RL and the green light GL are transmitted through the PBS 25, whereby the blue light BL is transmitted. And separated into red light RL and green light GL.

  Further, the green light GL and the red light RL transmitted through the PBS 25 are color polarizers 27 that convert the polarization plane of the green light GL by 90 degrees, and turn into green light GL of S-polarized light and red light RL of P-polarized light. Disassembled.

  In the PBS 29, the S-polarized green light GL of the incident light is reflected in a direction orthogonal to the incident light, while the red light RL passes through the PBS 29 and is separated into the green light GL and the red light RL. .

  The optical member constituting the color separation optical system 5 is a member that functions to separate red, green, and blue colors (R, G, B light). For example, the integrator optical system 21, color polarization It refers to members such as the polarizer 23, the polarizing beam splitter 25, the color polarizer 27, and the PBS 29.

  As the combining optical system 13, the blue light BL reflected and separated by the PBS 25 is incident from one main surface of the PBS 31 and then reflected in a direction perpendicular to the incident light by the polarization separation surface that reflects the S-polarized component. Then, the light enters the blue reflective liquid crystal panel element 11. In the reflective liquid crystal panel element 11 for blue, the polarization direction of the blue light BL incident on the pixel of the portion to be displayed in blue is rotated by 90 degrees based on the blue image information from a television signal or a personal computer, That is, it is converted into P-polarized light and reflected.

  For this reason, the P-polarized component of the blue light BL incident on the PBS 31 again passes through the polarization separation surface, and then the polarization plane is converted by 90 degrees by the wave plate 33, so that the first color of the color composition PBS 35 is converted into S-polarized light. Incident on one main surface.

  On the other hand, the green light GL of the S-polarized light reflected and separated by the PBS 29 is a reflective liquid crystal for green, based on the green image information from a television signal, a personal computer or the like, similarly to the blue light BL described above. The pixel of the portion to be displayed in green on the panel element 9 is converted into P-polarized light, then emitted from the direction orthogonal to the incident light, and incident on the color polarizer 37.

  Further, the red light RL of the P-polarized light that has passed through the PBS 29 is a reflective liquid crystal for red, based on a television signal or red image information from a personal computer or the like, like the blue light BL and the green light GL described above. Pixels to be displayed in red on the panel element 7 are converted to S-polarized light, then emitted from a direction orthogonal to the incident light, and incident on the color polarizer 37 together with the green light GL.

  In the color polarizer 37, the polarization plane of the red light RL is converted by 90 degrees, and is incident on the second main surface of the PBS 35 for color synthesis as the same P-polarized light as the green light GL.

  In addition, as an optical member which comprises the synthetic | combination optical system 13, it says the member which functions in order to synthesize | combine red, green, and blue light (RGB light), for example, said reflection type liquid crystal panel element 7,9,11, It refers to members such as the PBSs 29 and 31, the wave plate 33, the color polarizer 37, and the color composition PBS 35.

  As the projection optical system 17, among the red, green, and blue light (RGB light) incident from the first and second main surfaces of the color combining PBS 35, the blue light BL of S-polarized light is the incident light. The green light GL and red light RL of the P-polarized light reflected in the orthogonal direction are transmitted in a straight line and emitted from the third main surface as the three primary colors of red, green, and blue. And it is radiate | emitted from the projection lens 15, and a color image is displayed on the screen which is not shown in figure.

  In addition, as an optical member which comprises the projection optical system 17, members, such as the projection lens 15, are said.

  As described above, most of the luminous fluxes that are separated into the three primary colors of red, green, and blue and are applied to the liquid crystal panel elements 7, 9, and 11 are transmitted in the case of the transmissive liquid crystal panel element, or the reflective liquid crystal panel. In the case of the element, most of the light is reflected, but a part of the irradiated light flux is absorbed by the liquid crystal panel elements 7, 9, 11 including the liquid crystal panel elements 7, 9, 11 or the peripheral optical members. It will generate heat.

  Further, the temperature rise of each of the three liquid crystal panel elements 7, 9, 11 is caused by the luminance distribution of the light source 3 to be used, the characteristics of the color polarizers 23, 27, 37 (filter) that decomposes into the three primary colors, and the liquid crystals. Due to the light absorption characteristics of the panel elements 7, 9 and 11, the temperatures are different.

  Therefore, a cooling means 39 for cooling each optical member constituting the combining optical system 13 of the color separation optical system 5, the combining optical system 13, and the projection optical system 17 is provided.

  2 and 3 together, as the cooling means 39 of this embodiment, peripheral optical members including the red, green, and blue liquid crystal panel elements 7, 9, and 11 are efficiently used. In order to make the temperature lower than a predetermined temperature, one end side of, for example, a heat conductive sheet 41 as a first heat conductive sheet is connected to one side of each liquid crystal panel element 7, 9, 11 by thermal coupling, and the heat conductive sheet The other end of 41 is connected to the base plate 19 by thermal coupling. 2 and 3 show a state in which the liquid crystal panel elements 7 and 9 and the base plate 19 are thermally coupled at the end portions of the heat conductive sheets 41A and 41B. Similarly, the liquid crystal panel element 11 is also a heat conductive sheet. It is thermally coupled at the end of 41C.

  In this embodiment, as the heat conductive sheet 41, what is generally called a graphite sheet is used, and the graphite sheet is a sheet having a crystal structure in which carbon atoms are regularly arranged. The thermal conductivity in the lateral direction is extremely high, and it has a thermal conductivity that is, for example, three times that of aluminum.

  As this graphite sheet, for example, “PGS” graphite sheet manufactured by Matsushita Sangyo Co., Ltd. can be used. This graphite sheet is a high-orientation graphite that has a structure close to a single crystal and is a heat-conducting sheet with features such as high thermal conductivity and flexibility. is there.

  The base plate 19 is made of a material such as an aluminum alloy or ceramic as a material having a large heat capacity and good thermal conductivity.

  With the above configuration, for example, the liquid crystal panel element 9 becomes high temperature due to heat generated by irradiation light or element driving power (not shown), but this heat is applied to the heat conductive sheet 41B as shown by the broken arrow in FIG. It conducts heat and moves to the base plate 19 side. Since the base plate 19 has a large heat capacity, the temperature rise can be kept low even if the heat quantity of the liquid crystal panel element 9 is conducted. Moreover, in this embodiment, since it is the cooling system which cools the whole large sized base plate 19, it can cool efficiently even with comparatively weak cooling air. That is, the liquid crystal panel elements 7, 9, and 11 can be cooled with good balance.

  4 and 5, as another embodiment, two liquid crystal panel elements 7 and 9 and a base plate 19 are thermally coupled by a single heat conductive sheet 41D or 41E. The heat conductive sheet 41D is integrated on the two liquid crystal panel elements 7 and 9, and the heat conductive sheet 41E is integrated on the base plate 19 side. As a result, the heat of the two liquid crystal panel elements 7 and 9 is transferred to the base plate 19 and the heat transfer between the two liquid crystal panel elements 7 and 9 is facilitated. Therefore, as shown in FIG. The temperature difference between the liquid crystal panel elements 7 and 9 can be made smaller than when the elements are connected to the base plate 19 by the heat conductive sheets 41A and 41B for each element.

  Further, in the above-described embodiment, the two liquid crystal panel elements 7 and 9 are coupled by the single heat conductive sheet 41D. However, the present invention is not limited to this, and the red, green, and blue liquid crystal panel elements 7 are not limited thereto. , 9, 11 may be coupled by a single heat conductive sheet 41 (not shown). As a result, the temperature difference between the three liquid crystal panel elements 7, 9, 11 can be further reduced, and the single heat conductive sheet 41 reduces the cost.

  In the above-described embodiment, the method using four PBSs 25, 29, 31, and 35 is used. However, the present invention is not limited to this method, and a plurality of liquid crystal panel elements 7, 9, and 11 are used. The system can be applied to all systems such as a reflective liquid crystal panel element and a transmissive liquid crystal panel element.

  Further, when LEDs (light emitting diodes) that are three primary colors of red, green, and blue are used independently for each color as a light source, a color separation system is not necessary, and a liquid crystal panel element of a color corresponding to each color is used. You may comprise so that it may inject.

  Referring also to FIG. 6, the reflective liquid crystal panel elements 7, 9, 11 (LCOS) have a surface on one end side of the second heat conductive sheet 45 attached to the back surface of, for example, a silicon base 43 as a liquid crystal element driving IC. At the same time, the back surface on one end side of the second heat conductive sheet 45 is attached to the liquid crystal element support 49 with a heat conductive gel 47 by thermal coupling. Further, the second heat conductive sheet 45 is joined to the liquid crystal element support 49 at the other end side.

  More specifically, the liquid crystal element support 49 also serves as a support for the sealing glass 51 that is a structure of the liquid crystal panel elements 7, 9, and 11, and is a material having a large heat capacity and good thermal conductivity. For example, it is made of aluminum alloy or ceramic. The liquid crystal is sealed with a predetermined gap between the silicon base 43 and the sealing glass 51. Further, on the surface of the silicon base 43, an element driving semiconductor circuit and a reflective electrode are formed, and are coupled to an external driving circuit (not shown) via, for example, a flexible cable 53 as an electrode. A control signal is transmitted.

  Further, an IC storage groove 55 for storing the silicon base 43 is provided on the front surface side of the liquid crystal element support 49, and one end side of the second heat conductive sheet 45 attached to the back surface of the silicon base 43 is provided. It is thermally coupled to the bottom of the IC housing groove 55 via a heat conducting gel 47. In this embodiment, as described above, a graphite sheet having a thermal conductivity three times or more that of aluminum is used for the second heat conductive sheet 45.

  Note that the silicon base 43 and the second heat conductive sheet 45 are bonded with an adhesive so that no stress is applied to the silicon base 43 side. The surface of the silicon base 43 is covered with the sealing glass 51. In order to reduce the stress applied to the silicon base 43 from the outside of the sealing glass 51 as much as possible, the sealing glass 51 is soft even after curing. It is fixed to the surface of the liquid crystal element support 49 by a fixing member 57 that is an adhesive. The flexible cable 53 is fixed to the surface of the liquid crystal element support 49 by a flexible fixing member 59.

  From the above, the projection display device 1 according to this embodiment has the following effects.

  The liquid crystal panel elements 7, 9, 11 for red, green, and blue are not individually cooled, but heat is transferred to the base plate 19 having a large heat capacity by the heat conductive sheet 41 having flexibility, and this Since the base plate 19 is cooled, the base plate 19 having a larger heat capacity than the liquid crystal element support 49 for cooling the liquid crystal panel elements 7, 9, 11 is used as a heat sink, so that the temperature rise can be kept low.

  Further, since the entire base plate 19 is cooled, the cooling air can be guided by a simple duct, and even the low-speed air can be efficiently cooled, so that low noise can be suppressed.

  Further, the liquid crystal panel elements 7, 9, 11 are thermally coupled by the heat conductive sheets 41 </ b> A, 41 </ b> B, 41 </ b> C to bring the liquid crystal panel elements 7, 9, 11 closer to each other, that is, each liquid crystal panel element 7, Since the temperature difference between 9 and 11 can be reduced, the response characteristics of the liquid crystal can be matched. As a result, by cooling the liquid crystal panel elements 7, 9, and 11 efficiently and in a well-balanced manner, for example, high image quality can be obtained even for moving images.

  Further, by replacing the liquid crystal element support 49 as a conventional heat sink provided in each of the liquid crystal panel elements 7, 9, and 11 with the base plate 19 having a large heat capacity, the weight and size can be reduced. There is also an effect of preventing a shift in registration (convergence) that occurs when the relative position of the liquid crystal panel element fluctuates (due to changes over time, environmental changes, etc.).

  Further, since the red, green, and blue liquid crystal panel elements 7, 9, and 11 need to be finely adjusted (registration adjustment) individually, they cannot be directly fixed to the base plate 19, By connecting the liquid crystal panel elements 7, 9, and 11 to the base plate 19 with flexible heat conductive sheets 41 </ b> A, 41 </ b> B, and 41 </ b> C, the cooling efficiency can be improved without hindering the fine adjustment. Alternatively, the liquid crystal panel elements 7, 9, 11 are finely adjusted individually, and then the heat conduction sheet 41 is easily attached to the liquid crystal panel elements 7, 9, 11 and the base plate 19, thereby improving the cooling efficiency. be able to.

  Further, since the silicon base 43 and the liquid crystal element support 49 are connected by the second heat conductive sheet 45, most of the heat generated by the silicon base 43 due to the incident light of strong illumination light passes through the second heat conductive sheet 45. Thus, the liquid crystal element support 49 escapes. Further, part of the heat of the silicon base 43 is released to the liquid crystal element support 49 through the heat conducting gel 47. Moreover, the heat transferred to the liquid crystal element support 49 is efficiently transferred to the base plate 19 through the heat conductive sheets 41A, 41B, and 41C as described above. As a result, the cooling efficiency of the reflective liquid crystal panel elements 7, 9, and 11 is greatly improved.

  In addition, since the heat of the silicon base 43 can be efficiently cooled with a simple structure by the second heat conductive sheet 45 without changing the thickness of the heat conductive gel 47, the cooling efficiency can be improved without applying stress to the sealing glass 51. Therefore, it is possible to realize downsizing, cost reduction, high brightness, and the like of the apparatus.

  As another embodiment, the other end sides of the second heat conductive sheet 45 of at least two liquid crystal panel elements among the three liquid crystal panel elements 7, 9, and 11 can be coupled. Thereby, the cooling efficiency of the silicon base 43 can be increased.

(A) is a top view of the projection type display apparatus of embodiment of this invention, (B) is a perspective view of (A). It is sectional drawing which shows a part of cooling means of the liquid crystal panel element in the projection type display apparatus of FIG. It is a perspective view which shows an example of FIG. It is a perspective view which shows the other example of FIG. It is a perspective view which shows another example of FIG. (A) is a top view which shows the structure of the liquid crystal panel element of embodiment of this invention, (B) is sectional drawing of the arrow VI-VI line of (A). (A) is a top view of the conventional projection type display apparatus, (B) is a perspective view of (A). FIG. 1 shows an embodiment of the present invention. (A) is a top view which shows the structure of the conventional liquid crystal panel element, (B) is sectional drawing of the arrow VIII-VIII line of (A).

Explanation of symbols

1 Projection Display 3 Lighting System Light Source (Light Source)
5 Color separation optical system 7 Red liquid crystal panel element 9 Green liquid crystal panel element 11 Blue liquid crystal panel element 13 Composite optical system 15 Projection lens 17 Projection optical system 19 Base plate (base member)
21 Integrator optical system 23, 27, 37 Color polarizer 25, 29, 31 Polarizing beam splitter (PBS)
33 Wave plate 35 PBS for color synthesis
39 Cooling means 41, 41A, 41B, 41C, 41D, 41E First heat conductive sheet 43 Silicon base (liquid crystal element driving IC)
45 2nd heat conductive sheet 47 Heat conductive gel 49 Liquid crystal element support body 51 Sealing glass 53 Flexible cable (electrode)

Claims (5)

A color separation optical system that separates the light from the light source into three colors of red, green, and blue, and irradiates the separated light fluxes to the liquid crystal panel elements for the three colors, and the modulated outgoing light from the liquid crystal panel elements A composition optical system for composing the image, a projection optical system for projecting a light beam synthesized by the composition optical system onto a screen, and at least the composition optical system of the color separation optical system, the composition optical system, and the projection optical system. In a projection type display device comprising a base member assembled with an optical member to be
A projection type display device, wherein each liquid crystal panel element and the base member are connected and arranged by a first heat conductive sheet in order to cool the three liquid crystal panel elements. A three-color light source of red, green, and blue, and a combined optical system that irradiates light beams from the three color light sources onto the three liquid crystal panel elements for each color, and synthesizes modulated emission light from the liquid crystal panel elements And a projection optical system for projecting the light beam synthesized by the synthesis optical system onto a screen, and an optical member constituting at least the synthesis optical system among the color separation optical system, the synthesis optical system, and the projection optical system. In a projection display device comprising a base member,
A projection type display device, wherein each liquid crystal panel element and the base member are connected and arranged by a first heat conductive sheet in order to cool the three liquid crystal panel elements.   3. The projection type display according to claim 1, wherein at least two of the three liquid crystal panel elements are connected to the base member with a single first heat conductive sheet. 4. apparatus.   Each liquid crystal panel element has a surface on one end side of the second heat conductive sheet attached to the back surface of the liquid crystal element driving IC, and the back surface on one end side of the second heat conductive sheet is bonded to the liquid crystal element support with a heat conductive gel. 4. The projection type display device according to claim 1, wherein the second heat conductive sheet is attached and joined to the liquid crystal element support by joining to the liquid crystal element support.   Each liquid crystal panel element has a surface on one end side of the second heat conductive sheet attached to the back surface of the liquid crystal element driving IC, and the back surface on one end side of the second heat conductive sheet is bonded to the liquid crystal element support with a heat conductive gel. The other end sides of the second heat conductive sheet of at least two liquid crystal panel elements of the three liquid crystal panel elements are coupled and connected to each other. Or the projection type display apparatus of 3 description.

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