JP2004038105A - LCD projector and projection block - Google Patents

Abstract

A liquid crystal projector provided with a liquid crystal panel cooling mechanism having a higher cooling efficiency than an internal heat radiation method or an air cooling method.
A heat sink (34-36) is attached to a liquid crystal panel (30-32) as a heat source of the liquid crystal projector (1), and heat of the heat sink (34-36) is released to the outside by a heat exchange type cooling mechanism (60). . The cooling mechanism 60 includes evaporators 61 to 63 joined to the heat sinks 34 to 36, a compressor 64, and a condenser 65. The condenser 65 performs heat exchange between the refrigerant and the outside air, and The carried heat is released to the outside of the housing 2. The heat generated from the liquid crystal panels 30 to 32 does not remain inside the housing 2, and the liquid crystal panels 30 to 32 can be cooled more efficiently than an air-cooled cooling mechanism using a cooling fan.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a liquid crystal projector, and more particularly, to a liquid crystal projector having a cooling mechanism capable of efficiently cooling a liquid crystal panel used as a light source lamp and a light valve as a heat source.
[0002]
[Prior art]
In a liquid crystal projector, three liquid crystal panels (LCOS panel and DLP panel) for modulating each color light are generally mounted as light valves, and each liquid crystal panel is separated after light emitted from a light source is separated into each color light. Is modulated in accordance with a video signal, and is synthesized as a projection light image via a synthesizing optical system including a dichroic prism and the like, and this is enlarged and projected on a screen by a projection lens. In the liquid crystal projector having this configuration, since the light source lamp and each liquid crystal panel serve as heat sources and the inside of the projector is heated, a heat radiation mechanism for releasing generated heat is incorporated.
[0003]
In general, the heat radiating mechanism of the liquid crystal panel is configured such that a support plate supporting the liquid crystal panel is formed of a metal material having high thermal conductivity, and a heat radiating plate is adhered to the back of the support plate to remove heat generated in the liquid crystal panel. The liquid crystal panel is prevented from falling into an overheated state by being released from the heat sink. In addition, a cooling fan blows air to a heat radiating plate on which a heat radiating portion such as a fin is formed, thereby improving heat radiation efficiency. On the other hand, the heat radiating mechanism of the light source lamp emits heat generated by the lamp by blowing air from below or behind the outer peripheral surface of the reflector surrounding the light source lamp with a cooling fan.
[0004]
[Problems to be solved by the invention]
However, the conventional heat radiating mechanism is configured to radiate the heat generated by the liquid crystal panel via a radiator plate (heat sink), and the radiated heat diffuses into the projector housing to heat the peripheral portion. When the temperature inside the housing is high, there is a problem that the heat dissipation is reduced even when the air is circulated by a cooling fan or the like. Also, if a large cooling fan or a large number of cooling fans are installed to increase the amount of cooling air flowing through the housing to increase the heat radiation efficiency, the possibility of dust entering the housing increases, There is a high possibility that adverse effects such as deterioration of the quality of the projected image due to dust adhering to the surface of the element or the like will increase.
[0005]
In particular, in recent years, the amount of heat generated inside the liquid crystal projector has increased with the increase in the resolution and brightness of the projected image, so it is necessary to further improve the heat radiation efficiency of the liquid crystal panel and the light source lamp. At the same time, dust prevention measures need to be strengthened.
[0006]
In order to increase the heat dissipation using the conventional heat dissipation mechanism, it is necessary to increase the size of the heat sink as a heat sink, increase the size and performance of the cooling fan, increase the number of installations, etc. This leads to an increase in the size and cost of the projector. Furthermore, driving a large-sized cooling fan also increases power consumption. In addition to this, noise due to driving of the cooling fan also increases.
[0007]
Further, in order to enhance the heat radiation, it is necessary to increase the size of the vent hole for releasing the air blown out from the cooling fan and removing heat from each heat source to the outside of the projector housing. It is necessary to enlarge the air discharge path. However, it is not preferable to increase the size of the cooling air discharge path because a large opening needs to be formed in the chassis of the liquid crystal projector, and the strength of the opening decreases. In addition, when a large ventilation hole is formed in the housing, dust and the like easily enter the housing, and adverse effects such as attachment to the internal optical element are likely to occur, which is also undesirable.
[0008]
On the other hand, it is expected that demands for downsizing, high resolution and high brightness, low noise, power saving, and the like of liquid crystal projectors will be more strongly demanded in the future.
[0009]
In view of the foregoing, an object of the present invention is to propose a liquid crystal projector that improves cooling efficiency by releasing heat generated by a liquid crystal panel or a lamp to the outside of a housing, and to provide a projection block thereof. .
[0010]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a light source, a liquid crystal panel that modulates light emitted from the light source according to video information, and a projection lens that projects a modulated projection light image on a screen. In a liquid crystal projector having
A heat sink attached to the liquid crystal panel,
A cooling mechanism for cooling the liquid crystal panel,
The cooling mechanism includes a compressor, a condenser, an expansion valve, and an evaporator that are arranged along a refrigerant circulation path,
The refrigerant exchanges heat with the heat sink in the evaporator, and the refrigerant after the heat exchange is cooled by exchanging heat with the outside air in the condenser.
[0011]
In the present invention, heat generated in the liquid crystal panel is released from the heat sink to the outside via the refrigerant and the capacitor. Therefore, since the heat does not stay inside the housing, the cooling efficiency of the liquid crystal panel can be improved.
[0012]
Here, in order to increase the heat exchange efficiency between the heat sink and the evaporator, the contact surface between the heat sink and the evaporator is made into an uneven shape, and the circulation path of the refrigerant is formed along the contact surface. It is desirable to form in a meandering state.
[0013]
Further, in order to efficiently release the heat generated by the light source to the outside of the housing, a lamp cooling evaporator that exchanges heat with the lamp box of the light source is connected to the cooling mechanism, and the cooling mechanism is connected through the evaporator. The heat exchange may be performed by circulating the refrigerant.
[0014]
Next, a liquid crystal projector generally includes a color separation optical system that separates light emitted from the light source into each color light, and a plurality of the liquid crystal panels that modulate each color light according to video information in order to display a color projection image. And a light combining optical system that combines the modulated color lights.
[0015]
Here, a projection block having a configuration in which the color separation optical system, the liquid crystal panel, the photosynthesis optical system, and the projection lens are mounted on a common chassis may be attached to the projector housing. In this case, to the projection block, the evaporator and a block-side refrigerant flow pipe through which the refrigerant flows through the evaporator are attached, and the projector housing includes the condenser, the compressor, and the It is preferable to attach a housing-side refrigerant circulation pipe through which the refrigerant flows, and connect the housing-side refrigerant circulation pipe and the block-side refrigerant circulation pipe in a detachable manner.
[0016]
Further, it is possible to mount all of the cooling mechanism on this projection block.
[0017]
On the other hand, the present invention relates to a projection block detachably mounted on a liquid crystal projector,
A color separation optical system that separates the light emitted from the light source into each color light, a plurality of liquid crystal panels that modulate each color light according to video information, a color synthesis optical system that synthesizes each color light after modulation, A projection lens for projecting a projection light image on a screen, a heat sink attached to the liquid crystal panel, and a cooling mechanism for cooling the liquid crystal panel, the cooling mechanism being arranged along a refrigerant circulation path. Equipped with compressor, condenser, expansion valve and evaporator,
The refrigerant exchanges heat with the heat sink in the evaporator, and the refrigerant after the heat exchange is cooled by exchanging heat with the outside air in the condenser.
[0018]
In this case as well, it is preferable that the contact surface between the heat sink and the evaporator is formed into an uneven shape so as to enter each other, and the circulation path of the refrigerant is formed in a meandering state along the contact surface.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of a liquid crystal projector to which the present invention is applied will be described with reference to the drawings.
[0020]
(overall structure)
FIG. 1A is a schematic plan view showing a liquid crystal projector (LCOS-type projection display device) of the present example, and FIG. 1B is a schematic side view seen from the direction of an arrow. Referring to these drawings, the liquid crystal projector 1 of the present embodiment has a configuration in which each component is mounted inside a flat rectangular parallelepiped housing 2 shown by a dashed line. That is, inside the housing 2, the projection light source 3, the uniform illumination optical system 10, the color separation optical system 20, the three liquid crystal panels 30 to 32, the photosynthetic optical system 40, and the projection lens unit 50 And a cooling mechanism 60 for the liquid crystal panel.
[0021]
Here, the color separation optical system 20, the liquid crystal panels 30 to 32, the photosynthesis optical system 40, the projection lens unit 50, and a part of the cooling mechanism 60 are configured as a projection block 70 mounted on a common chassis. The projection block 70 is mounted on the housing 2 in a detachable manner.
[0022]
Describing each part in detail, the light source 3 includes a lamp 4 such as a halogen lamp and a reflector 5 for emitting lamp divergent light forward. The light source 3 of this example is configured as a lamp unit in which a reflector 5 to which a lamp 4 is attached is mounted on a lamp box 6 attached to the housing 2.
[0023]
The light emitted from the light source 3 is converted into a parallel light beam having a uniform luminance distribution via the uniform illumination optical system 10. The uniform illumination optical system 10 includes integrator lenses 11 and 12, in which a plurality of microlenses are arranged in a matrix, a condenser lens 13, total reflection mirrors 14 and 15, and the like. The parallel luminous flux is separated by the color separation optical system 20 into R, G, and B color lights, and the respective color lights are guided to reflective liquid crystal panels (LCOS panels) 30, 31, and 32 that function as corresponding light valves. .
[0024]
In the color separation optical system 20, a blue light beam is separated from a white parallel light beam by a dichroic mirror 21 for blue reflection, guided to a dichroic prism 22, and reflected toward a liquid crystal panel 30. The green light passing through the blue reflecting dichroic mirror 21 is reflected by the green reflecting dichroic prism 23 and guided to the liquid crystal panel 31. The red light that has passed through the dichroic prism 23 is guided to the dichroic prism 25 via the total reflection mirror 24, and is reflected toward the liquid crystal panel 32.
[0025]
Each color light is modulated according to the video signal when reflected by the liquid crystal panels 30, 31, 32, passes through the dichroic prisms 22, 23, 25, and is guided to the light combining optical system 40. The photosynthetic optical system 40 has a structure in which four dichroic prisms are bonded to each other, and light of each color is combined via a reflecting surface formed of an X-shaped dielectric multilayer film to form a projected light image. The projection light image is enlarged and projected on a screen (not shown) via the projection lens unit 50.
[0026]
(Liquid crystal panel cooling mechanism)
The cooling mechanism 60 of the liquid crystal panel includes three evaporators 61 to 63 arranged along the circulation path of the refrigerant, and a compression in which the refrigerant after passing through the evaporators 61 to 63 merges and is sucked from the suction port. And a condenser 65 for exchanging heat between the refrigerant discharged from the discharge port of the compressor 64 and the outside air and liquefying the refrigerant, and the refrigerant passing through the condenser 65 is supplied to a gas via an expansion valve (not shown). And supplied to each of the evaporators 61 to 63.
[0027]
Heat sinks 34 to 36 made of a metal material having high thermal conductivity are attached to the liquid crystal panels 30 to 32, respectively. The heat sinks 34 to 36 are in close contact with the evaporators 61 to 63, respectively, and heat exchange is performed between the refrigerant flowing through the evaporators 61 to 63 and the heat sinks 34 to 36, and the liquid crystal panels 30 to 32 Is generated in the condenser 65 and is released outside the housing in the condenser 65. The condenser 65 includes a refrigerant circulation pipe 66, a plurality of cooling fins 67 attached to the circulation pipe 66, and a cooling fan 68 for introducing and blowing outside air to the cooling fins 67. The cooling fan 68 faces the outside air inlet 2 a formed in the housing 2.
[0028]
Next, FIG. 2 shows the shape of the contact surface between the heat sinks 34 to 36 of the liquid crystal panels 30 to 32 and the evaporators 61 to 63, and the state of the circulation of the refrigerant flow pipe inside the evaporator. As shown in these figures, the contact surfaces of the heat sinks 34 to 36 and the evaporators 61 to 63 are formed as concavo-convex joint surfaces that enter each other, and the contact area is increased to increase the heat transfer efficiency. If the contact surfaces of the heat sinks 34 to 36 and the evaporators 61 to 63 are bonded by ceramics, the thermal conductivity between them can be kept good.
[0029]
Further, the refrigerant flow pipes 61a to 63a are routed in a meandering state inside the evaporator so as to be in contact with the back surface of the uneven contact surface, and can uniformly absorb heat from the entire contact surface. As a result, the heat exchange efficiency between the heat sink and the evaporator is improved.
[0030]
Here, in the present example, on the side of the projection block 70, the evaporators 61 to 63 of the cooling mechanism 60, and the block-side refrigerant circulation pipe 72 through which the refrigerant flows are mounted. The compressor 64, the condenser 65, and the housing-side refrigerant flow pipe 69 through which the refrigerant flows are mounted on the housing 2 side. Further, both ends 72a, 72b of the block-side refrigerant flow pipe 72 and both ends 69a, 69b of the housing-side refrigerant flow pipe 69 are connected to each other in a detachable manner by connection fittings 73a, 73b.
[0031]
In the liquid crystal panel cooling mechanism 60 having this configuration, the refrigerant takes heat from the heat sinks 34 to 36 of the liquid crystal panels 30 to 32 in the evaporators 61 to 63, and the taken heat is released to the outside in the condenser 65. Therefore, the heat generated in the liquid crystal panels 30 to 32 is trapped inside the housing 2 and the internal temperature does not rise, so that secondary damage does not reach peripheral parts. Further, since no heat is stored inside the housing 2, the liquid crystal panels 30 to 32 can be cooled more efficiently than the conventional heat dissipation mechanism of the liquid crystal panel.
[0032]
(Another example of a projection block)
In the above-described projection block 70, the condenser 65 and the compressor 64 of the cooling mechanism 60 can also be mounted on the projection block 70. In this case, a self-contained liquid crystal panel cooling system is constructed. Further, the projection block having this configuration may be simply attached to the projector housing. Further, since the projection block can have a sealed structure, it is possible to reliably prevent dust from entering the projection block, which is extremely advantageous for higher resolution in the future.
[0033]
(Cooling mechanism of light source)
The light source 3 can be cooled by bringing the above-described evaporator into contact with a side surface of the light source 3 such as a lamp box as a cooling mechanism of the light source 3. In addition, an air cooling system using a conventionally used cooling fan can be used together with the cooling system.
[0034]
【The invention's effect】
As described above, in the liquid crystal projector of the present invention, heat generated from the liquid crystal panel or the light source, which is a heat source, is released to the outside of the housing via the heat exchange type cooling mechanism. Therefore, the liquid crystal panel and the like can be cooled more efficiently than the conventional cooling mechanism of the heat dissipation system or the air cooling system inside the housing.
[0035]
In addition, if the projection block is equipped with a liquid crystal panel cooling mechanism, a self-contained liquid crystal panel cooling mechanism can be realized, increasing the degree of freedom in equipment layout of the liquid crystal projector, etc. There are advantages such as intrusion of dust can be reliably prevented.
[Brief description of the drawings]
FIG. 1 is a diagram showing a liquid crystal projector to which the present invention is applied, (a) is a schematic plan view, and (b) is a schematic side view when viewed from a direction of an arrow.
2A is an explanatory diagram showing a contact surface shape between a heat sink and an evaporator of the liquid crystal panel of FIG. 1, and FIG. 2B is an explanatory diagram showing a state in which a refrigerant circulation pipe inside the evaporator is drawn.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Liquid crystal projector 2 Housing 3 Light source 4 Lamp 5 Reflector 10 Uniform illumination optical system 20 Light separation optical system 30, 31, 32 Liquid crystal panels 34 to 36 Heat sink 40 Photosynthetic optical system 50 Projection lens unit 60 Liquid crystal panel cooling mechanisms 61 to 63 Evaporators 64 Compressor 65 Condenser 69 Housing side refrigerant flow pipe 70 Projection block 72 Block side refrigerant flow pipe

Claims (8)

In a liquid crystal projector having a light source, a liquid crystal panel that modulates light emitted from the light source according to video information, and a projection lens that projects a modulated projection light image on a screen,
A heat sink attached to the liquid crystal panel,
A cooling mechanism for cooling the liquid crystal panel,
The cooling mechanism includes a compressor, a condenser, an expansion valve, and an evaporator that are arranged along a refrigerant circulation path,
The liquid crystal projector, wherein the refrigerant exchanges heat with the heat sink in the evaporator, and the refrigerant after the heat exchange exchanges heat with the outside air in the condenser to be cooled. In claim 1,
The contact surface between the heat sink and the evaporator has an uneven shape penetrating into each other,
A liquid crystal projector, wherein a circulation path of the coolant is formed in a meandering state along the contact surface. In claim 1 or 2,
The liquid crystal projector, wherein the cooling mechanism includes a lamp cooling evaporator that exchanges heat with a lamp box of the light source. In claim 1, 2 or 3,
A color separation optical system that separates emitted light from the light source into each color light, a plurality of liquid crystal panels that modulate each color light according to video information, and a light combining optical system that combines each color light after modulation. A liquid crystal projector, wherein the projection light image after synthesis is projected on a screen by the projection lens. In claim 4,
The color separation optical system, the liquid crystal panel, the photosynthesis optical system and the projection lens having a configuration in which the projection lens is mounted on a common chassis, and a projector housing to which the projection block is attached,
The projection block includes the evaporator and a block-side refrigerant circulation pipe that distributes a refrigerant via the evaporator,
In the projector housing, the condenser, the compressor, and a housing-side refrigerant flow pipe through which a refrigerant flows are arranged,
A liquid crystal projector, wherein the housing side refrigerant flow pipe and the block side refrigerant flow pipe are detachably connected. In claim 4,
The color separation optical system, the liquid crystal panel, the photosynthesis optical system and the projection lens has a projection block mounted on a common chassis, and a projector housing to which the projection block is attached,
A liquid crystal projector characterized in that the projection block is equipped with the cooling mechanism. A projection block detachably mounted on a liquid crystal projector,
A color separation optical system that separates the light emitted from the light source into each color light, a plurality of liquid crystal panels that modulate each color light according to video information, a photosynthesis optical system that combines each color light after modulation, and projection after synthesis It has a projection lens for projecting an optical image on a screen, a heat sink attached to the liquid crystal panel, and a cooling mechanism for cooling the liquid crystal panel, wherein the cooling mechanism is arranged along a refrigerant circulation path. Equipped with compressor, condenser, expansion valve and evaporator,
The projection block of the liquid crystal projector, wherein the refrigerant exchanges heat with the heat sink in the evaporator, and the refrigerant after the heat exchange cools by exchanging heat with the outside air in the condenser. . In claim 7,
The contact surface between the heat sink and the evaporator has an uneven shape penetrating into each other,
A projection block of a liquid crystal projector, wherein a circulation path of the refrigerant is formed in a meandering state along the contact surface.

Images