JPH01314287A - Cooler for projection type display device - Google Patents

Abstract

PURPOSE:To improve cooling efficiency by providing a compressor as well as a radiator and expander which constitute a refrigerating cycle with the compressor into the cooler and cooling a polarizing plate by the refrigerant cooled by this cooling system. CONSTITUTION:The cooler is provided for the purpose of cooling the polarizing plate. The heat generated on the polarizing plate 102 accumulates in the upper part of a hermetic chamber 205 absorbed by freon 112 which is the refrigerant. The refrigerant is introduced through a suction port into the compressor 201, by which the refrigerant is compressed. The compressed and condensed refrigerant is cooled by radiation from the surface of the radiator 202. The radiator is cooled by the air which is circulated by a fan motor 204 in order to allow the efficient radiation from the radiator. The refrigerant cooled by the radiator is expanded by the expander 203, by which the temp. thereof is lowered down to room temp. or blow. This refrigerant is introduced again into the hermetic chamber in contact with the polarizing plate. The polarizing plate is cooled by such refrigerating cycle.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a cooling device for a projection display device.

[Prior Art] Air cooling systems using fans are often used as cooling devices for projection display devices.

[Problem to be solved by the invention] When light emitted from a light source passes through a polarizing plate, a portion of it is absorbed and converted into heat, so the organic polarizing film is decomposed by this heat and the polarization characteristics deteriorate. However, the display performance of the image itself projected onto the screen also deteriorates. Therefore, a powerful temperature control system is required in this area.

However, in the air cooling method, which is one of the conventional technologies, the cooling efficiency is poor due to the low heat transfer coefficient of gas, and when trying to realize a high-brightness projection display device, as the amount of light increases,
Since the amount of heat absorbed by the polarizing plate also increases, it becomes necessary to cool the polarizing plate using a very large cooling device. Therefore, in order to realize a small projection display device with high brightness, a small and highly efficient cooling device is required.

SUMMARY OF THE INVENTION The present invention is intended to solve these problems, and its purpose is to provide a compressor inside a cooling device, and a radiator and an expander that constitute a refrigeration cycle with the compressor. By cooling the polarizing plate, cooling efficiency can be improved.

[Means for Solving the Problems] A cooling device for a projection type display device of the present invention is a projection type display device composed of a light source, a polarizing plate, a liquid crystal light valve, and a projection lens. The cooling device is characterized in that the inside of the cooling device is provided with a compressor and a radiator and an expander that constitute a refrigeration cycle with the compressor.

[Embodiments] Embodiment 1 FIG. 1 is a block diagram showing an embodiment of a projection display device of the present invention.

The light source 101 is a lamp with a high output luminous flux such as a halogen lamp, a Xe lamp, or a metal halide lamp, and the polarizing plate 1
03 is irradiated with light. The color filter 102 has three primary colors red, blue, and green arranged in a mosaic pattern selectively deposited.

The polarizing plate 103 is an organic polarizing film, and a transparent coolant 106 is filled between the polarizing plate 103 and the color filter 102 .

The light valve 107 is a liquid crystal TN mode light valve, and is configured with a simple matrix liquid crystal panel or an active matrix display using active elements (MIM, TPT, etc.). Second polarizing plate 10
5 is in close contact with the light valve 107, and the projection lens 10
8, the image formed on the light valve 107 is enlarged and projected onto the screen 109.

In this example, Freon 113 was used as a refrigerant for cooling the polarizing plate.
It was used. Furthermore, since a light source with a total luminous flux of 20,000 lumens was used, the light absorption heat by the polarizing plate was approximately 8.5 W. The heat generated on the polarizing plate is absorbed by the refrigerant Freon 11.
3 and accumulates in the upper part of the sealed chamber 205. The refrigerant is introduced into the compressor 201 through the suction port and compressed. The compressed and condensed refrigerant radiates heat from the surface of the radiator 202 and is cooled. In order to efficiently radiate heat in the radiator, air is circulated and cooled by a fan motor 204.

The refrigerant cooled by the radiator expands in the expander 203 and its temperature drops below room temperature. This refrigerant is again introduced into the sealed chamber in contact with the polarizing plate.

It is cooled by the refrigeration cycle as described above.

In this example, Freon 113 was used as the refrigerant, but other Freon gases and water can also be used as the refrigerant. The light valve 108 is a liquid crystal TN mode light valve, and is configured with a simple matrix liquid crystal panel or an active matrix display using active elements such as MIM-TPT.

Embodiment 2 FIG. 2 is a block diagram showing an embodiment of a three-plate shut-valve type projection display apparatus of the present invention.

Light source 201 such as halogen, xenon, metal halide, etc.
The emitted light is separated into blue, green, and
Separated into red primary color light.

Each color light passes through a polarizing plate 250 and passes through a blue light valve 2.
16, green light bulb 216, red light bulb 21
After the light intensity is modulated by 7 and transmitted through the second polarizing plate 220, the light is combined by the dichroic prism 230 and projected onto the screen by the projection lens 231.

A cooling tank 270 is provided between the polarizing plate 213 and the blue light valve 215, green light valve 216, and red light valve 217, respectively, and is cooled and driven in the same manner as in the first embodiment. Therefore, 213.215.216.21
The heat generated at 7 is quickly removed by 250.

In this example, a light source with a total luminous flux of 20,000 lumens is used, and the amount of heat absorbed by each of the blue, red, and green polarizing plates is 5. 2W, 4. 8W.

It was 2.6W.

[Effects of the Invention] As described above, according to the present invention, a projection type display device includes a compressor inside a cooling device, and a radiator and an expander that constitute a refrigeration cycle together with the compressor. Cooling efficiency could be improved by cooling the polarizing plate with the coolant cooled by the system.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of a single-panel projection display device and a cooling device. 101 Light source 102 Color filter 103 G base plate 105 Polarizing plate 106 Refrigerant 10 Flight valve 108 Projection lens 109 Screen 201 Compressor 202 Heat sink 203 Expander 204 Fan 205 Cooling groove Figure 2 shows a three-panel projection display device and cooling device. Conceptual diagram. 201 Light source 211 Blue reflective dichroic mirror 212 Green reflective dichroic mirror 213 1 light plate 215 Blue light valve 216 Green light valve 217 Red light valve 220 Polarizing plate 230 Dichroic prism 231 Projection lens 250 Polarizing plate 270 Cooling groove 271 Screen Figure 1 Figure 2

Claims (1)

[Claims] (1) A projection display device consisting of a light source, a polarizing plate, a liquid crystal light valve, and a projection lens is equipped with a cooling device for cooling the polarizing plate, and a compressor is provided inside the cooling device, and a refrigeration cycle is operated by the compressor. 1. A cooling device for a projection display device, comprising a radiator and an expander.