JP2008217041A - Projection-type display device and method for cooling liquid crystal unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for cooling a liquid crystal unit, having low noise and high cooling efficiency, and to provide a long lifetime and a quiet projection-type display device that copes with size reduction and turning higher in luminance. <P>SOLUTION: Heat of an incidence-side polarizing plate and a liquid crystal panel is cooled intensively by forced air cooling by an air-cooling module 26a, and heat of an emission-side polarizing plate 18a is thermally conducted to upper and lower holder members 28a, 28b via a frame member 30a from an incident surface and via a color composite prism 14 from an emission surface; and a jacket part 35c that is to be connected to the upper holder member 28a is cooled by a liquid-cooling module 27a, where a radiator 37 is arranged in the vicinity of an inlet of a cooling fan 20b of the air-cooling module 26b; and a heat sink 38 engaged in a panel duct 21c of the air-cooling module 26b and cooled by a cooling wind 24c is provided in the lower holder member 28b. Thus, a cooling margin can be secured in the air-cooling module with respect to increasing to higher luminance, and silent cooling becomes available. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a projection display device that projects and displays an image using a liquid crystal panel, and more particularly to a cooling mechanism that effectively cools a liquid crystal panel and a polarizing plate, and a cooling method thereof.

  The liquid crystal projector device, which is a projection display device, has dramatically improved the projected image quality by improving the lamp luminous efficiency, increasing the definition of the light bulb, increasing the aperture ratio, and improving the illumination optical system. Widely used for business presentations.

  A basic configuration of the liquid crystal projector apparatus will be described. FIG. 11 is a schematic diagram showing a basic configuration of a general liquid crystal projector apparatus of the prior art. Since the liquid crystal projector apparatus of the present invention is also assembled based on this configuration, common elements are indicated by the same reference numerals. As shown in FIG. 11, the basic configuration of the liquid crystal projector device 1 includes three blocks: 1) an illumination optical system 2, 2) a color separation optical system 7, and 3) an imaging optical system 12.

  Among them, the illumination optical system 2 includes a light source 3 composed of a high-intensity lamp such as an ultra-high pressure mercury lamp, a reflector 4 that reflects light from the light source 3, and light for making the illuminance distribution of the reflected light from the reflector 4 uniform. Integrators 5a and 5b, a polarizing beam splitter (PBS) 6 for aligning random polarized light from the lamp with linearly polarized light, and a field lens 11a are included.

  The color separation optical system 7 following the illumination optical system 2 separates the total light flux from the field lens 11b and the illumination optical system 2 into each color light flux composed of red (R), green (G), and blue (B), and corresponds. It has dichroic mirrors 8a and 8b, reflection mirrors 9a, 9b, 9c and 9d, and relay lenses 10a and 10b for entering each liquid crystal panel.

  The imaging optical system 12 following the color separation optical system 7 is a light modulation unit 13 that modulates each color light beam incident from the color separation optical system 7 according to given image information, and a color that combines the modulated color light beams. It has a synthesis prism 14 and a projection lens 15 that projects the synthesized light onto the screen.

  Among them, the light modulation unit 13 of the imaging optical system 12 includes three liquid crystal panels 16a, 16b, and 16c that are transmission display devices, and incident-side polarizing plates 17a that are disposed on the incident surface side of the respective liquid crystal panels. 17b, 17c, and emission side polarizing plates 18a, 18b, 18c arranged on the emission surface side of the respective liquid crystal panels.

  Since a TN (Twisted Nematic) liquid crystal panel can only handle a specific linearly polarized light component, the light beams from the color separation optical system 7 are aligned in a predetermined polarization direction (P-polarized light) in the incident-side polarizing plates 17a, 17b, and 17c. After the P-polarized light is modulated by the liquid crystal panels 16a, 16b, and 16c, only the S-polarized component of the modulated light is transmitted from the exit-side polarizing plates 18a, 18b, and 18c.

  The optical configuration described here is a three-plate type liquid crystal projector that separates the lamp light into three primary colors and modulates each of them with three liquid crystal panels. However, it is low brightness and inexpensive using only one liquid crystal panel. In such a single-plate liquid crystal projector, a light modulation unit having the same configuration is prepared.

  In the light modulator 13 having such a configuration, the incident-side polarizing plates 17a, 17b, and 17c and the outgoing-side polarizing plates 18a, 18b, and 18c each pass only uniaxially polarized light and shield other polarized light. Therefore, the liquid crystal panels 16a, 16b, and 16c are also likely to generate heat due to light absorption, and the liquid crystal panels 16a, 16b, and 16c also generate heat during operation because the transmitted light is blocked by the black matrix at the boundary of each pixel.

  Organic materials are often used for these liquid crystal panels and polarizing plates. When light with a short wavelength is irradiated for a long time or when exposed to a high temperature environment, the alignment film of the panel is damaged, and the polarization selection characteristic is The function may be remarkably impaired, such as being lowered. As a result, as the product life is shortened, the running cost increases due to unit replacement, and the composite projected image is deteriorated due to fluctuations in the characteristics of each color light. Become.

  Hereinafter, an incident side polarizing plate, an outgoing side polarizing plate, and a liquid crystal panel (hereinafter, a combination of these members is referred to as a liquid crystal unit, and a configuration in which three liquid crystal units and a color combining prism are combined is a liquid crystal. A conventional cooling method will be briefly described in order to suppress the temperature rise of the unit portion).

  12A and 12B are schematic views showing an example of a liquid crystal unit cooling method by forced air cooling in Conventional Example 1, wherein FIG. 12A is a perspective view and FIG. 12B is a schematic cross-sectional view. The cooling fan 120 takes outside air from an air inlet of a liquid crystal projector housing (not shown), and cools from the fan outlet to the duct openings 122a, 122b, and 122c directly below the liquid crystal units 119 of the liquid crystal unit 123 through the panel duct 121. Wind 124 is guided.

  At this time, since the respective members of the incident side polarizing plate 117, the liquid crystal panel 116, and the outgoing side polarizing plate 118 constituting each of the three liquid crystal units 119 are arranged apart from each other, the gaps from the lower side to the upper side are arranged. When the cooling air 124 passes, heat is taken away from the surface to be cooled by forced convection heat transfer, and exhaust heat is performed.

  Patent Document 1 and Patent Document 2 disclose a liquid crystal unit cooling mechanism using a refrigerant container filled with a refrigerant liquid. 13 is a schematic cross-sectional view of the liquid crystal unit cooling mechanism of Conventional Example 2 described in Patent Document 1, and FIG. 14 is a schematic perspective view of the liquid crystal unit cooling mechanism of Conventional Example 3 described in Patent Document 2.

  In Conventional Example 2 shown in FIG. 13, the refrigerant liquid 233 is filled between the emission-side polarizing plate 218 and the shield substrate 244 of the liquid crystal unit 223 by the refrigerant container 243, and the refrigerant container 243 is used as a holder for the color synthesis prism 214. It is fixed to the side wall of the member 228, and the configuration of the refrigerant container 243 is characterized. 14 is characterized in that the refrigerant liquid is filled by the refrigerant container 343 of the liquid crystal unit 323 and the optical member to be cooled is extended to the liquid crystal panel 316 in addition to the output side polarizing plate. Yes.

  Patent Document 3 discloses a liquid crystal unit cooling mechanism in which a heat sink is provided in a circulation duct. FIG. 15 is a schematic perspective view of a liquid crystal unit cooling mechanism of Conventional Example 4 described in Patent Document 3. In this conventional example 4, when the liquid crystal unit part 423 having the incident side polarizing plate, the liquid crystal panel, and the outgoing side polarizing plate is cooled by forced air cooling, the air flowing in the closed system is set with a closed circulation type. A heat sink 438 is provided in the middle of the closed circulation duct 446 to cool the flow.

Patent Document 4 discloses a liquid crystal unit cooling mechanism in which a heat sink via a Bertier element is provided in a duct. FIG. 16 is a schematic perspective view of a liquid crystal unit cooling mechanism of Conventional Example 5 described in Patent Document 4. In this conventional example, a first heat sink 538a for cooling connected to the Peltier element 539 is fitted into a passage in the middle of the duct 521 from the cooling fan 520, and a second heat sink for heat dissipation is disposed on the heat generating side of the Peltier element 539. By connecting 538b and lowering the temperature of the air sent to the liquid crystal unit (not shown) in advance, the effect of enhancing the cooling effect is aimed.
JP 2002-287244 A JP 2003-195253 A JP-A-11-160793 Japanese Patent Laid-Open No. 2000-269694

  In recent years, demands for miniaturization and high brightness of liquid crystal projectors have promoted an increase in lamp output and miniaturization of display devices, leading to an increase in thermal load due to an increase in the density of light flux incident on the liquid crystal unit.

For example, in a 2000 lm class liquid crystal projector (1.0 type-XGA), the total calorific value of the liquid crystal unit is around 15 W, and the exit side polarizing plate heat flux is about 0.6 W / cm ^2. Then, the total calorific value of the liquid crystal unit reaches 35 W or more, and the exit side polarizing plate heat flux reaches 1.4 W / cm ² or more.

  In such a case, the forced air cooling as in the conventional example 1 increases the air flow rate of the fan to increase the air speed around the heating element, improves the heat transfer efficiency, and increases the heat transfer amount from the heating element. The performance has been raised to accommodate the increasing heat load.

  For increasing the fan air flow rate, methods such as using a large-diameter fan and increasing the rotational speed are taken, but the latter is often used for cooling the liquid crystal unit due to restrictions on the mounting structure. However, since the increase in the number of fan rotations directly leads to an increase in noise, the comfort of the user is hindered and the product value is lowered. For this reason, various countermeasures have been taken as in Conventional Examples 2-5.

  Conventional techniques 2 and 3 that perform heat diffusion by bringing the refrigerant liquid filled in the refrigerant containers 243 and 343 into contact with the output-side polarizing plate and the liquid crystal panel 317 to dissipate heat have the following problems.

  The first problem is image quality. When the liquid layer is interposed in the light transmission space by filling the liquid coolant between the liquid crystal unit members (for example, between the liquid crystal panel and the output side polarizing plate as disclosed in Patent Document 2 above), Polarization of light transmitted through the liquid layer is disturbed due to fluctuations in refrigerant density due to generation of bubbles and heat transport, and convection fluctuations caused by the fluctuation, resulting in disturbance in image information passing through the exit-side polarizing plate 118, resulting in improved projected image quality. to degrade.

  The second problem is reliability and difficulty in mounting. When heat is released from the liquid crystal unit members of the liquid crystal unit portions 223 and 323 via the sealed refrigerant liquid, the refrigerant liquid repeatedly expands and contracts depending on the use conditions. In order to cope with this, the refrigerant container is provided with a pressure regulating mechanism, but there is a risk of liquid leakage due to breakage of the pressure regulating member with long-term use. Further, when the sealing structure and pressure regulating structure of the refrigerant containers 243 and 343 are complicated, the assembly of the liquid crystal unit is hindered.

  An object of the present invention is to provide a liquid crystal unit cooling method with low noise and high cooling efficiency, and thereby to provide a long-life and quiet projection type display device corresponding to downsizing and high brightness.

The projection display device of the present invention is
A projection-type display device having a liquid crystal unit part composed of a plurality of liquid crystal panels, an incident-side polarizing plate and an outgoing-side polarizing plate arranged before and after the liquid crystal panel, and a color synthesis prism, and a cooling fan and a duct A first cooling means for cooling the liquid crystal panel and the incident side polarizing plate by blowing air from the opening of the duct, a holder member for holding the outgoing side polarizing plate and the color combining prism, and a connection to the holder member And a second cooling means comprising a heat exchanger.

  The heat exchanger may be connected to a surface of the holder member that is opposite to the surface that contacts the color combining prism. The holder member holds the color combining prism in pairs from above and below, and the heat exchanger includes a pair of heat exchangers. Similarly, a pair of holder members may be connected to the surface opposite to the surface holding the color combining prism.

  The second cooling means is provided with a water passage through which the refrigerant liquid passes inside the heat exchanger, and further includes a circulation means for circulating the refrigerant liquid and a refrigerant liquid cooling means for cooling the refrigerant liquid. The second cooling means may include a first heat exchanger and a second heat exchanger, and the first heat exchanger is provided with a water passage through which the refrigerant liquid passes. The second heat exchanger further includes a fin that is connected to the holder member, and further includes a circulation unit that circulates the refrigerant liquid and a refrigerant liquid cooling unit that cools the refrigerant liquid. The part may be inserted into the duct of the first cooling means.

  The refrigerant liquid cooling means may be an air-cooled heat exchanger having fins, and the air-cooled heat exchanger may be provided in the vicinity of the air intake, and the output side polarizing plate is sandwiched between the transparent substrate and the color synthesis prism. It may be connected to a pair of holder members via a frame member, and the thermal conductivity of the member constituting the color synthesis prism is preferably larger than the thermal conductivity of the output side polarizing plate.

The method for cooling the liquid crystal unit of the present invention includes:
Cooling method of liquid crystal unit in liquid crystal unit section composed of a plurality of liquid crystal units, a plurality of liquid crystal units composed of incident-side polarizing plates and outgoing-side polarizing plates arranged before and after the plurality of liquid crystal panels, and a color combining prism A first cooling method for cooling an incident side polarizing plate and a liquid crystal panel by heat transfer with cooling air, a frame member for connecting heat generated by the outgoing side polarizing plate to the outgoing side polarizing plate, and the frame And a second cooling method for cooling by heat transfer between the heat exchanger and the cooling medium via a holder member connected to the member.

  In the second cooling method, the heat exchanger is a pair of heat exchangers, and the pair of heat exchangers has a liquid passage inside, and the space between the refrigerant liquid cooling means having the radiation fin and the liquid passage. Heat exchange in the heat exchanger may be performed by heat transfer by circulating refrigerant liquid. In the second cooling method, the first heat exchanger of the pair of heat exchangers has a liquid path inside. The heat exchange in the heat exchanger is performed by the refrigerant liquid that circulates between the refrigerant liquid cooling means having the radiation fins and the liquid path, and the second heat exchanger is a fin portion provided in connection with the holder member The fin portion is fitted into the cooling duct used in the first cooling method, and the fin portion may be cooled by cooling air passing through the inside of the cooling duct. In the second cooling method, The refrigerant cooling means is an air-cooled heat exchanger having radiating fins. The air cooling heat exchanger may be provided in the vicinity of the air intake port of the cooling fan of the first cooling method, and the radiating fins may be cooled by the intake air of the cooling fan.

  Among the objects to be cooled, the liquid crystal panel and the incident side polarizing plate are cooled by the air cooling method, so that there is a degree of freedom of position setting, and the position fixing exit side polarizing plate is a color synthesizing prism through a frame member with high thermal conductivity. Since the heat is transferred to the heat exchanger attached to the holder member by heat conduction between solids by connecting to the holder member having a high thermal conductivity, it can be efficiently cooled by air cooling or water cooling.

  In order to achieve the above-described object, in the liquid crystal projector of the present invention, the following operation can be obtained by configuring the cooling mechanism of the liquid crystal unit as described above.

  That is, the liquid crystal panel constituting the liquid crystal unit, and the liquid crystal panel that is difficult to be integrated with the holding material because of the need for optical adjustment of XYθ with respect to the optical axis at the time of bonding, among the incident side polarizing plate and the outgoing side polarizing plate The incident-side polarizing plate that requires adjustment of the polarization axis of the liquid crystal panel is cooled by forced air cooling, while the outgoing-side polarizing plate that does not need to be adjusted via a holder member that holds the color combining prism, Heat can be transferred to an external heat exchanger such as a water-cooled module or a heat pipe for cooling by heat conduction between solids.

  In this case, since the forced air cooling unit can concentrate the air flow only on the incident side polarizing plate and the liquid crystal panel, it is possible to perform cooling corresponding to high brightness without adding a fan air volume, and cooling can be performed silently. .

  On the other hand, since the solid heat conduction part is limited to the output side polarizing plate close to the color synthesis prism, heat conduction to the heat exchanger is possible with a simplified holding structure without interfering with the air cooling operation described above. Become.

  At this time, in fixing the output side polarizing plate, it is held between the light-transmitting substrate having a higher thermal conductivity than the polarizing plate and the color synthesizing prism so as to be sandwiched without a space, and has a high thermal conductivity. By fixing to the upper and lower holder members of the color synthesis prism with the frame member, the thermal diffusion of the polarizing plate is promoted from both sides of the color synthesis prism and the translucent substrate, and heat spots are reduced. Heat transfer efficiency is improved because solid heat conduction is performed through two paths, ie, color synthesis prism → holder member → heat exchanger and 2) polarizing plate → transparent substrate → thermal conductive frame → holder member → heat exchanger.

  In addition, by adopting a structure in which a heat sink is provided in the holder member on the forced air cooling panel duct side among the holder members thermally connected to the output side polarizing plate, and the radiating fins are fitted inside the forced air cooling panel duct. Since the cooling mechanism of the output side polarizing plate can be simplified and the cooling load of the other heat exchanger can be halved, the cooling method is small, low cost and excellent in assemblability.

  Furthermore, by installing the radiator section of the heat exchanger near the inlet side of the incident side polarizing plate and the forced air cooling fan for cooling the liquid crystal panel, the air flow of the air cooling fan can be used together with the radiator heat dissipation, and the fan of the entire cooling system The mounting capacity can be suppressed, and the cooling method can be reduced in size and cost.

  As described above, the projection type display device and its liquid crystal unit cooling mechanism of the present invention intensively cools the incident side polarizing plate and the liquid crystal panel by forced air cooling, and the output side polarizing plate by the solid heat conduction. The system is cooled by conducting heat to the heat source, so the cooling margin can be secured without increasing the fan output against the increase in heat generation due to light absorption due to the higher brightness of the device, so it can be cooled silently. There is an effect of becoming.

  At this time, the exit-side polarizing plate is transferred to the upper and lower holder members while being subjected to the action of thermal diffusion from both the incident side surface and the exit side surface by the light-transmitting substrate having excellent thermal conductivity and the color synthesis prism. Therefore, there is an effect that efficient cooling with less in-plane temperature gradient becomes possible.

  In addition, the heat exchanger connected to the lower holder member is replaced by a heat sink, and the heat sink fins are fitted into the panel duct for forced air cooling that is used together to dissipate heat. There is an effect that it is possible to provide a liquid crystal projector apparatus having a cooling system excellent in assemblability at a low cost.

  In addition, the radiator of the heat exchanger is installed in the vicinity of the inlet of the cooling fan for forced air cooling that is used together, and the intake air flow is used for heat dissipation, so that the entire cooling system can be mounted in a small size, with low noise and low cost. There is an effect that it becomes possible to plan.

  Hereinafter, a first embodiment of a liquid crystal unit cooling mechanism according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view of a liquid crystal unit cooling mechanism in the first embodiment of the present invention, and FIG. 2 is an exploded view of a part of the liquid crystal unit cooling mechanism in the first embodiment of FIG. . 3A and 3B are explanatory views showing a structure for holding the exit-side polarizing plate in the first embodiment, wherein FIG. 3A is a partial cross-sectional view of the liquid crystal unit cooling mechanism, and FIG. (C) is an exploded view of the holding structure of the output side polarizing plate. FIG. 4 is a cross-sectional view showing another holding structure example of the output-side polarizing plate in the first embodiment of the present invention. FIG. 5 is a cross-sectional view showing the operation of the first exemplary embodiment of the present invention. The present embodiment shown in FIGS. 1 to 5 embodies the contents of claims 1 to 4 and claims 7 and 8. Here, parts having the same functions as those of the general liquid crystal unit cooling mechanism described in the prior art with reference to FIGS. 11 and 12 will be described with the same reference numerals.

  Here, as described above, a combination of one set of the incident side polarizing plate, the outgoing side polarizing plate and the liquid crystal panel is referred to as a liquid crystal unit 19, and a configuration in which a color synthesis prism and a holding material are combined with three liquid crystal units. Is referred to as a liquid crystal unit 23.

  1 and 2, the liquid crystal unit cooling mechanism 25a according to the present invention includes a liquid crystal unit 23a, an air cooling module 26a, and a liquid cooling module 27a used as a heat exchanger.

  Among them, the liquid crystal unit 23a includes the three liquid crystal panels 16 corresponding to the respective color lights, the three incident side polarizing plates 17, and the three outgoing lights, as described in detail with reference to FIGS. The side polarizing plate 18, the color combining prism 14, and a pair of holder members 28 a and 28 b that hold the color combining prism 14 from above and below, and the three output side polarizing plates 18 are shown in FIGS. 3 and 4. As shown in FIG. 5A, the color synthesis prism 14 and the respective light-transmitting substrates 29 are sandwiched, and the frame members 30 are pressed and fixed to the upper and lower holder members 28a and 28b.

  At this time, the holder members 28a and 28b are made of a material having excellent thermal conductivity and good workability such as aluminum or magnesium alloy, and the color synthesizing prism 14 is formed by means such as UV bonding. It is fixed from above and below. For this reason, a through-hole 31a for UV irradiation is provided in the central part of either the upper or lower side of the holder members 28a, 28b.

  The frame member 30 is also formed of a material excellent in thermal conductivity and workability, but its shape does not shield the panel transmitted light, and the transmission side polarizing plate 18 and the optical compensation film 32 are pasted on both sides. Any substrate that can securely hold the optical substrate 29 and can be thermally connected to the holder members 28a and 28b may be used. If necessary, the contact thermal resistance may be designed to be smaller at the interface between the frame member 30 and the holder members 28a and 28b via a thermal interface such as a high thermal conductive sheet, silicon grease, or a phase change sheet.

  On the other hand, the liquid cooling module 27a is assumed to be a general-purpose water cooling module employed for CPU cooling in a personal computer. That is, the liquid cooling module 27a is based on the pump 34 that circulates the refrigerant liquid 33 having propylene alcohol or ethylene glycol in the composition, jacket portions 35a and 35b provided with flow paths therein, and volatilization from the fiber holes of the connection tube. It comprises a reserve tank 36 for compensating for a decrease in the amount of liquid and mitigating an increase in internal pressure due to thermal expansion, and a radiator 37 for radiating the refrigerant liquid 33 that has absorbed heat to a high temperature to the outside air.

  At this time, the pair of jacket portions 35a and 35b are connected to the surfaces of the holder members 28a and 28b opposite to the adhesion surfaces of the color combining prism 14, respectively, and the heat generated by the output side polarizing plates 18a, 18b and 18c, Heat is received through the holder members 28a, 28b, and 28c, and the refrigerant liquid 33 is circulated to the radiator 37 to radiate heat.

  An air cooling module 26a including a cooling fan 20b and a panel duct 21b is disposed below the liquid crystal unit 23a, and is concentrated only on the liquid crystal panels 16a, 17b, 16c and the incident side polarizing plates 17a, 17b, 17c. The duct openings 22d, 22e, and 22f are set so as to send the fan air volume.

  Next, the cooling operation of the liquid crystal unit 23a will be described with reference to FIG. The incident-side polarizing plates 17a, 17b, 17c and the liquid crystal panels 16a, 17b, 16c set in the same optical arrangement as in the prior art are in surface contact with the cooling air 24b from the panel duct 21b of the air-cooling module 26a. Absorption heat generation is forced air cooling.

At this time, since the duct openings 22d, 22e, and 22f of the panel duct 21b are opened only by the incident side polarizing plates 17a, 17b, and 17c and the liquid crystal panels 16a, 16b, and 16c, the conventional incident side polarizing plates are provided. Compared to forced air cooling of each of the liquid crystal panel and the output side polarizing plate, there is no need to consider cooling of the output side polarizing plate,
1) Because the cooling air volume can be concentrated on the incident side polarizing plate and the liquid crystal panel, the cooling efficiency of forced air cooling can be increased.
2) Since the total calorific value to be air-cooled can be reduced, a cooling margin can be secured.
Can be obtained. In other words, since it is possible to cope with the increase in light absorption and heat generation due to the increase in brightness without increasing the fan output, it is possible to suppress an increase in operating noise.

  On the other hand, as described above, the output-side polarizing plates 18a, 18b, and 18c are sandwiched by the color synthesis prism 14 and the light-transmitting substrates 29a, 29b, and 29c without a space therebetween, and the frame members 30a, 30b. , 30c are connected (press-fixed) to the holder members 28a, 28b.

  At this time, the light absorption heat generated in the output side polarizing plates 18a, 18b, and 18c is diffused from both the incident side and the output side of the light transmission surface by contact with the light transmitting substrates 29a, 29b, and 29c and the color synthesis prism 14. At the same time, heat is transferred to the holder members 28a and 28b disposed above and below through the paths of both the color synthesizing prism 14 and the frame members 30a, 30b and 30c (see the black arrows in FIG. 5).

  The amount of heat transmitted to the upper and lower holder members 28a and 28b is absorbed by the jacket portions 35a and 35b of the liquid cooling module 27a connected to the side opposite to the color combining prism adhesion surface of the holder members 28a and 28b. The heat is transported to the radiator 37 by the circulation of the air and radiated to the outside air.

  At this time, as a member constituting the frame member 30 and the holder member 28, it is desirable to use a material having high thermal conductivity such as aluminum or magnesium from the viewpoint of the thermal resistance design. On the other hand, the transparent substrate 29 and the color synthesis prism 14 are used. On the other hand, for example, a light transmissive member having higher thermal conductivity than the output side polarizing plate 18 such as sapphire or quartz increases the thermal diffusion effect, reduces the heat spot, and suppresses the polarizing plate temperature. It is desirable from the viewpoint of ensuring the lifetime.

  However, when it is difficult to apply the high thermal conductivity member to the color synthesizing prism due to the limitation of the manufacturing cost, the configuration shown in FIG. A state in which the light transmitting substrate 29d on which the output side polarizing plate 18b and the optical compensation film 32b are adhered is closely held and separated from the color synthesizing prism 14 by frame members 30d and 30e having high thermal conductivity composed of two parts. Thus, a configuration of connecting to the upper and lower holder members 28a, 28b may be substituted.

  Alternatively, as shown in FIG. 4C, the output-side polarizing plate 18b is sandwiched between two light-transmitting substrates 29e and 29f, and the heat diffusion action is promoted on both the incident side and the output side. The translucent substrates 29e and 29f on which the output side polarizing plate 18b and the optical compensation films 32b and 32e are laminated are held in close contact with the constructed high thermal conductivity frame members 30f and 30g, and are separated from the color synthesis prism 14. In such a state, it is possible to substitute a configuration in which the upper and lower holder members 28a and 28b are connected.

By adopting such a cooling mechanism for the output side polarizing plate, the following merits can be obtained. That is,
1) By limiting the cooling target of the liquid cooling module to the output side polarizing plate, the heat receiving structure can be made compact.
2) Since the cooling load can be reduced, it is easy to reduce the size and noise of the radiator.
3) Mounting with minimal interference with the above-described air cooling module becomes possible.
4) The structure in which heat is diffused from both the entrance surface and the exit surface of the exit-side polarizing plate and absorbs heat from above and below, so that the cooling efficiency of the polarizing plate is high and the in-plane temperature distribution can be set uniformly. It can contribute to quality improvement.

  Next, a second embodiment of the liquid crystal unit cooling mechanism according to the present invention will be described in detail with reference to the drawings. FIG. 6 is a perspective view of a liquid crystal unit cooling mechanism showing a second embodiment of the present invention, and FIG. 7 is an exploded view of the liquid crystal unit cooling mechanism similarly showing the second embodiment of the present invention. . FIG. 8 is a perspective view showing the liquid crystal unit portion of the second embodiment of the present invention. FIG. 9 is a cross-sectional view showing the operation of the liquid crystal unit cooling mechanism of the second embodiment of the present invention. The present embodiment shown in FIGS. 6 to 9 embodies the contents of claims 1 to 3, claim 5 and claims 7 and 8.

In the liquid crystal unit cooling mechanism 25a in the first embodiment described above, the following problems can be considered because the jacket portions 35a and 35b of the liquid cooling module 27a are installed in pairs above and below the holder members 28a and 28b. . That is,
1) The multi-jacket configuration increases the cost of the liquid cooling unit.
2) Since the pressure loss of the refrigerant circulation channel is also increased due to the multi-jacket configuration, the thermal resistance of the system is deteriorated.
3) The mounting dimension of the liquid crystal unit is increased by an amount corresponding to the thickness of the jacket.
4) Device assembly becomes complicated and productivity is reduced.
5) Since the number of pipes increases, there are more factors that impair the reliability of the equipment, such as an increase in the amount of refrigerant volatilization due to the extension of the resin tube length (the accompanying increase in the size of the reserve tank) and an increase in the number of potential leak points. .

  Further, the holder member 28 to which the jacket portion 35 is connected is usually provided with a UV-irradiating through hole 31a in the upper or lower central portion for the purpose of bonding the color combining prism 14. The location of the through hole 31a restricts the design of the water channel in the jacket and restricts the jacket connection area, which causes a significant decrease in heat receiving performance.

  In the second embodiment of the liquid crystal unit cooling mechanism according to the present invention, the countermeasure to the problem in the first embodiment described above is considered. 6 and 7, the liquid crystal unit cooling mechanism 25b according to the present invention includes a liquid crystal unit 23b, an air cooling module 26b, and a liquid cooling module 27b used as a heat exchanger.

  Among them, the liquid crystal unit 23b adopts the same configuration as that of the first embodiment described above, and the UV irradiation through hole 31b described above is provided in the holder member 28d below the color combining prism. Yes.

  On the other hand, the liquid cooling module 27b adopts a single jacket configuration in which one jacket portion is omitted from the liquid cooling module 27a used in the first embodiment.

  The jacket portion 35c is bonded to the surface of the upper holder member 28c of the liquid crystal unit portion 23b opposite to the color combining prism bonding side, and the lower holder member 28d having the UV irradiation through hole 31b is provided on the lower holder member 28d. The pin fin type heat sink 38 is connected in the direction of extending the heat dissipating fins toward the inside of a panel duct 21c described later (see FIG. 8).

  On the other hand, an air cooling module 26b including a cooling fan 20b and a panel duct 21c is arranged below the liquid crystal unit 23b, as in the first embodiment described above. At this time, a heat sink projection of the panel duct 21c is provided. A notch 39 is prepared on the surface, and a heat sink 38 connected to the lower holder member 28d is fitted into the panel duct 21c at the time of mounting, and the incident side polarizing plate and the liquid crystal panel are cooled inside the duct. The cooling air 24c (FIG. 9) is received and heat is dissipated.

  Next, the cooling operation of the liquid crystal unit in the second embodiment will be described with reference to FIG. Regarding the holding structure of the output side polarizing plates 18a, 18b, and 18c, the first embodiment described above is followed, and the light absorption heat generated in the output side polarizing plate 18 is also the light transmitting substrates 29a, 29b, 29c. Then, heat is diffused from the light transmission surface by the color synthesizing prism 14, and is transferred to the holder members 28c and 28d disposed above and below via the color synthesizing prism 14 and the frame members 30a, 30b, and 30c (FIG. 9). (See black arrow).

  The amount of heat transferred to the upper holder member 28c is absorbed by the jacket portion 35c of the liquid cooling module 27b connected to the opposite side of the color synthesis prism adhesion surface of the holder member 28c, as in the first embodiment. Then, heat is transported to the radiator 37 by the refrigerant circulation and radiated to the outside air.

  On the other hand, the amount of heat transmitted to the lower holder member 28d is transferred to the heat sink 38 connected to the opposite side of the color synthesizing prism bonding surface of the holder member 28d, and the cooling air 24c inside the panel duct 21c is transferred to the fin portion. The heat is received by forced air cooling. At this time, the fin shape of the heat sink 38 may be a plate fin type or a pin fin type, and a shape matching the characteristics of the air flow inside the panel duct may be selected.

  Further, in the present embodiment, the lower holder member 28d and the heat sink 38 are configured as separate members, but may be integrally configured for simplification. However, in that case, it is necessary to open the fin portion in accordance with the location of the through hole 31b for UV irradiation, and care must be taken in designing because the heat dissipation performance is degraded.

  On the other hand, in the cooling of the incident side polarizing plates 17a, 17b, and 17c and the liquid crystal panels 16a, 17b, and 16c, as in the first embodiment, the fan is blown from the panel duct 21c of the air cooling module 26b and forced air cooling is performed. Is done.

  At this time, the cooling air 24c to the incident side polarizing plate 17 and the liquid crystal panel 16 is subjected to heat radiation work from the heat sink 38 inside the duct, and thus is affected by the temperature rise.

However,
1) The heat dissipation amount of heat sink is for the absorption heat generation of the output side polarizing plate 18 and is limited to the amount of heat (about 1/2) transferred from the lower holder member 28d,
2) Since heat is diffused by the light-transmitting substrate 29, the color synthesizing prism 14, the frame member 30, the holder member 28, etc. having high thermal conductivity, the base portion of the heat sink 38 is not so hot, and the inside of the duct is radiated by fin heat radiation. Therefore, the influence on the cooling of the incident side polarizing plate 17 and the liquid crystal panel 16 is almost in a negligible range, and thus is not significantly affected.

By adopting the liquid crystal unit cooling mechanism 25b as shown in this embodiment, in addition to the advantages in the first embodiment, the number of jacket portions of the liquid cooling module 27b can be reduced and simplified,
1) Reduce costs,
2) The assembly is improved because the jacket mounting is limited to the upper holder member,
3) Since the circulation system is shortened, the flow resistance is reduced and the system thermal resistance design of the liquid cooling module becomes easy.
4) Since the cooling load of the liquid cooling module is approximately halved, the radiator can be made smaller and quieter.
5) Since simplification of the piping system is performed at the same time, the amount of refrigerant volatilized from the resin tube can be suppressed, and the reserve tank can be downsized.
6) Equipment reliability is improved by simplifying the piping system,
7) Since the heat sink corresponding to the lower holder member connecting jacket is substantially accommodated inside the panel duct, the mounting height can be suppressed.
The merit is obtained.

  Next, a third embodiment of the liquid crystal unit cooling mechanism according to the present invention will be described in detail with reference to the drawings. 10A and 10B are diagrams for explaining a liquid crystal unit cooling mechanism according to the third embodiment of the present invention, in which FIG. 10A is a perspective view, FIG. 10B is a side view, and FIG. FIG.

  The present embodiment shown in FIG. 10 is particularly described based on claim 6, but is implemented in combination with the first or second embodiment. Hereinafter, description will be made assuming a combination with the second embodiment.

  That is, in the second embodiment, heat exchange for performing heat conduction cooling of the air-cooling module 26b (see FIGS. 6 and 7) that performs forced air cooling of the incident-side polarizing plate 17 and the liquid crystal panel 16 and the output-side polarizing plate 18 is performed. In the third embodiment, the radiator 37 for heat dissipation of the heat exchanger is connected to the air cooling fan 20b of the air cooling module 26b. Arranged at a position close to the intake port 40, the flowing air 41 by the intake air of the cooling fan 20b is used for heat radiation by the forced convection heat transfer of the radiator section 37.

  At this time, the radiator 37 adopts a stack fin shape in consideration of the intake resistance of the air-cooled fan 20b. However, the radiator 37 is not limited to this as long as it does not block the fan intake and can obtain a sufficient heat dissipation effect. .

  Also in this case, similarly to the second embodiment, the radiator 37 radiates heat at the air inlet for forced air cooling of the incident side polarizing plate 17 and the liquid crystal panel 16 (the air inlet 40 of the cooling fan 20b). Therefore, the fan air (cooling air 24c) is affected by the temperature rise.

  However, in the liquid cooling modules shown in the first and second embodiments, for example, the refrigerant temperature of the heat radiating section (radiator 37) is higher than the heat generation amount and the system heat with respect to the refrigerant temperature of the heat receiving section (jacket section 35c). Although it depends on the resistance design, it is about 10 ° C. lower and the surface temperature of the radiator is about 5 ° C. lower. Therefore, the rise in the intake air temperature of the cooling fan 20b due to the heat radiation of the radiator 37 is not so large (heat generation amount 30 W In the case of a resistance of 0.5 ° C./W), since the airflow on the fan suction side is low in directivity, the cooling fan 20b simultaneously takes in air that is not used for heat dissipation around the radiator 37. The effect on the cooling performance against forced air cooling of the incident side polarizing plate 18 and the liquid crystal panel 17 is also almost negligible. It stops.

  By arranging the radiator of the heat exchanger as shown in this embodiment, the radiator heat dissipation fan can be omitted, so the cost of the entire cooling system can be reduced and the noise can be reduced, and the device size can be reduced by reducing the mounting volume. Can be realized.

  In the first, second, and third embodiments, the liquid cooling module is adopted as the heat exchanger, but the same effect can be obtained by using another heat exchanger such as a heat pipe or a vapor chamber. It is clear that you can.

  Finally, the difference between the disclosed liquid crystal unit cooling method and the present invention will be described with reference to FIGS.

  In the liquid crystal unit cooling mechanism of Conventional Example 2 shown in FIG. 13, the output side polarizing plate 218 of the liquid crystal unit 223 is brought into contact with the refrigerant container 243 filled with the refrigerant liquid 233, and the refrigerant container 243 is held in the holder member 228 of the color synthesis prism 214. The refrigerant container 143 has a characteristic feature. Further, Conventional Example 3 shown in FIG. 14 is characterized in that a refrigerant container 343 in which the optical member brought into contact with the filled refrigerant liquid is extended to the liquid crystal panel 316 in addition to the output side polarizing plate is configured.

  On the other hand, the first embodiment of the present invention is common in that the heat generated by the emission-side polarizing plate 18 is cooled by conducting heat to the holder member 28 of the color combining prism 14, but the refrigerant liquid is used in between. However, it is different in that heat diffusion is promoted through the translucent substrate 29 and the color synthesizing prism 14 and the amount of heat is transferred by solid heat conduction.

  Conventional Example 2 and Conventional Example 3 in which the filled refrigerant liquid 233 is brought into contact with the output-side polarizing plate 218 and the liquid crystal panel 316 to perform heat diffusion to dissipate heat have the above-described problems. In the case of a structure that uses heat conduction to promote heat diffusion and transfer heat to the heat exchanger, the above problems are overcome. Furthermore, by using the color composition prism for solid heat conduction, the assembly structure is simplified, and the air flow space (gap) on the forced air cooling side (incident side polarizing plate and liquid crystal panel cooling side) is expanded to increase the flow velocity. It is also possible to improve the heat transfer efficiency.

  In addition, the heat radiation of the output-side polarizing plate is different in that a heat exchanger is connected to the upper and lower holders of the color synthesis prism, and heat is radiated from the radiator at a position away from the heating element. It has a structure that can be done.

  Further, in the above-described conventional examples 2 and 3, the heat radiation effect is obtained by providing the heat radiation fins 242 on the holder member 228 on the upper side of the color synthesis prism 215. However, in the second embodiment of the present invention, An air cooling fin (heat sink) is provided, and the fin portion is fitted into the air cooling duct of the air cooling module to be used together, so that a fin heat radiation effect by sufficient forced convection heat transfer is set.

  In addition, in the first and second embodiments of the present invention, a cooling margin for forced air cooling is gained by setting the air cooling modules to be used together so as to collect air only on the incident side polarizing plate and the liquid crystal panel. It is different in that it is.

  The liquid crystal unit cooling structure of Conventional Example 4 shown in FIG. 15 is configured such that when the liquid crystal unit portion 423 (incident side polarizing plate, liquid crystal panel, outgoing side polarizing plate) is cooled by forced air cooling, the duct is set to a closed circulation type. In order to cool the air flow flowing through the closed system, a heat sink 438 is set in the middle of the closed circulation duct 446. On the other hand, in the second embodiment of the present invention, a heat sink is prepared in the holder part on the lower side of the color combining prism in order to dissipate the amount of heat of the output side polarizing plate by solid heat conduction, and the heat dissipating fins are also provided. Contrary to the disclosed example, it is set to extend into the duct and is set to radiate heat from the heat sink in the duct, and the conventional example 4 is configured to radiate the heat of the circulating air in the duct to the outside. Have different structures and actions.

  In Conventional Example 5 shown in FIG. 16, a first heat sink 538 a (for cooling) connected to the Peltier element 539 is fitted into the midway passage of the duct 521, and a second heat sink (for heat dissipation) is also formed on the heat generating side of the Peltier element 539. ) 538b is connected and the temperature of the air blown to the liquid crystal unit (not shown) is lowered in advance, thereby aiming to enhance the cooling effect. Also in this case, as in the case of Conventional Example 4, the connection configuration, operation, and effect are different from the heat sink structure of the lower holder member in the second embodiment of the present invention. In other words, the conventional example 5 is intended to cool the air flow in the duct, and for this purpose, a cooling mechanism (heat sink 538 + Peltier element 539) is installed in the middle of the duct 521 that guides air to the liquid crystal panel. In the second embodiment of the present invention, the purpose is to dissipate heat to the air flow in the duct. For this purpose, a heat absorbing structure (frame member + holder member 28 + heat sink 38) of the output side polarizing plate is provided, and just below the liquid crystal unit. The difference is that a structure in which heat dissipating fins are arranged is employed.

It is a perspective view of the liquid crystal unit cooling mechanism in the 1st Embodiment of this invention. FIG. 2 is an exploded view of a part of a liquid crystal unit cooling mechanism in the first embodiment of FIG. 1. It is explanatory drawing which showed the output side polarizing plate holding structure in 1st Embodiment, (a) is a fragmentary sectional view of a liquid crystal unit cooling mechanism, (b) is a perspective view of the holding structure of the output side polarizing plate, (C) is an exploded view of the holding structure of the output side polarizing plate. It is sectional drawing which showed the other example of holding structure of the output side polarizing plate in the 1st Embodiment of this invention. It is sectional drawing which shows the effect | action of the 1st Embodiment of this invention. It is a perspective view of the liquid crystal unit cooling mechanism which shows the 2nd Embodiment of this invention. It is an exploded view of the liquid-crystal unit cooling mechanism which shows the 2nd Embodiment of this invention. It is a perspective view which shows the liquid-crystal unit part of the 2nd Embodiment of this invention. It is sectional drawing which shows the effect | action of the liquid crystal unit cooling mechanism of the 2nd Embodiment of this invention. It is a figure for demonstrating the liquid crystal unit cooling mechanism which shows the 3rd Embodiment of this invention, (a) is a perspective view, (b) is a side view, (c) is a typical partial cross section upper surface which shows an effect | action. FIG. It is a schematic diagram which shows the basic composition of the general liquid crystal projector apparatus of a prior art. It is a schematic diagram which shows an example of the liquid crystal unit cooling method by the forced air cooling of the prior art example, (a) is a perspective view, (b) is typical sectional drawing. 10 is a schematic cross-sectional view of a liquid crystal unit cooling mechanism of Conventional Example 2 described in Patent Document 1. FIG. FIG. 10 is a schematic perspective view of a liquid crystal unit cooling mechanism of Conventional Example 3 described in Patent Document 2. 10 is a schematic perspective view of a liquid crystal unit cooling mechanism of Conventional Example 4 described in Patent Document 3. FIG. FIG. 10 is a schematic perspective view of a liquid crystal unit cooling mechanism of Conventional Example 5 described in Patent Document 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal projector device 2 Illumination optical system 3 Light source 4 Reflector 5a, 5b Optical integrator 6 Polarizing beam splitter 7 Color separation optical system 8a, 8b Dichroic mirror 9a, 9b, 9c, 9d Reflective mirror 10a, 10b Relay lens 11a, 11b Field lens DESCRIPTION OF SYMBOLS 12 Imaging optical system 13 Light modulation part 14, 114, 214 Color synthesis prism 15 Projection lens 16a, 16b, 16c, 116a, 116c, 216, 316 Liquid crystal panel 17a, 17b, 17c, 117a, 117c, 217 Incident side polarizing plate 18a, 18b, 18c, 118a, 118c, 218 Output side polarizing plates 19a, 19b, 19c Liquid crystal units 20a, 20b, 120, 220, 520 Cooling fans 21a, 21b, 21c, 121 Panel ducts 22d, 22e, 2f, 22g, 22h, 22i, 122a, 122b, 122c Duct opening 23a, 23b, 123, 223, 323, 423 Liquid crystal unit 24b, 24c, 124a, 124c Cooling air 25a, 25b Liquid crystal unit cooling mechanism 26a, 26b Air cooling module Part 27a, 27b Liquid cooling module 28a, 28b, 28c, 28d, 228 Holder member 29a, 29b, 29c, 29d, 29e, 29f Translucent substrate 30a, 30b, 30c, 30d, 30e, 30f, 30g Frame member 31a, 31b Through hole 32a, 32b, 32c, 32d, 32e Optical compensation film 33, 233 Refrigerant liquid 34 Pump 35a, 35b, 35c Jacket 36 Reserve tank 37 Radiator 38, 238, 338 Heat sink 39 Notch 4 Inlet 41 flow air 48 heat transfer path 242, 342 radiating fins 243,343 refrigerant vessel 244 shields the substrate 445 circulating fan 446 closed circulation duct 521 duct 538a first heat sink 538b second heat sink 539 Peltier element

Claims (3)

Of the liquid crystal unit in a liquid crystal unit portion composed of a plurality of liquid crystal units, a plurality of liquid crystal units composed of an incident side polarizing plate and an output side polarizing plate arranged before and after the plurality of liquid crystal panels, and a color composition element. A cooling method,
A first cooling method for cooling the incident-side polarizing plate and the liquid crystal panel by heat transfer with cooling air;
A second cooling unit that cools heat generated by the output-side polarizing plate by heat transfer between the heat exchanger and the cooling medium via a frame member connected to the output-side polarizing plate and a holder member connected to the frame member. And a cooling method of
The heat exchanger is a pair of heat exchangers, and the pair of heat exchangers has a liquid path therein, and a refrigerant liquid that circulates between the liquid path and the refrigerant liquid cooling means having a radiation fin. A method for cooling a liquid crystal unit, wherein heat exchange is performed in the heat exchanger by heat transfer.   In the second cooling method, the first heat exchanger of the pair of heat exchangers has a liquid passage therein, and circulates between the refrigerant liquid cooling means having a radiating fin and the liquid passage. The second heat exchanger is a fin portion connected to the holder member, and the fin portion is used in the first cooling method. 2. The method of cooling a liquid crystal unit according to claim 1, wherein the fin portion is cooled by cooling air that is fitted into the cooling duct and passes through the cooling duct.   In the second cooling method, the refrigerant cooling means is an air-cooled heat exchanger, and the air-cooled heat exchanger is provided in the vicinity of an air intake port of the cooling fan of the first cooling method. The method for cooling a liquid crystal unit according to claim 1, wherein the heat dissipating fins are cooled by intake of a fan.

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