JPH04191793A - Cooling device of liquid crystal display projector - Google Patents

Abstract

PURPOSE:To eliminate the possibility of inflow of dust without generating a noise by forming a spectroscopic passage from a transparent body, and providing a cooling device charged with a cooling solution in the inner part thereof. CONSTITUTION:The image projecting part 100 of a liquid crystal display projector has a first cooling box 93 between a light source 12 and a red reflecting dichroic mirror 13R and a cooling device 94 between read, blue and green reflecting dichroic mirrors 13R, 13B, 13G and red, blue and green liquid crystal modules 15R, 15B, 15G. In the cooling box 93, a transparent body 931 of glass on the light source 12 side is connected to a transparent body 932 on the dichroic mirror 13R through a frame 933, and a liquid chamber 934 formed by the frame 933 and the transparent bodies 931, 932 is charged with a cooling solution 935. As the generated heat by the light emission of the lamp 12a of the light source 12 is absorbed by the frame 933 and the cooling solution 935 through the transparent body 931, and this heat is radiated from box bodies 71-73 and radiation fins 71a-73a, a sufficient cooling effect can be obtained without a fan, and no noise is generated.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a cooling device for a liquid crystal display projector, and is designed to provide a sufficient cooling effect without the need for a fan. .

(Prior Art) Conventionally, in a liquid crystal display projector using a liquid crystal display panel, illumination light from a light source is collected and transmitted through a liquid crystal panel with polarizing plates arranged on the front and rear to form image light. Images are displayed on the screen by enlarging and projecting them onto the screen via a projection lens. In such a liquid crystal display projector, a high-brightness, high-efficiency lamp (hereinafter referred to as an HID lamp) is used as a light source, so a cooling device must be installed to cool the lamp.6 Figures 9 to 11 9 shows a conventional liquid crystal display projector having such a cooling device, FIG. 9 is a perspective view showing the image projection unit, FIG. 10 is a configuration diagram of the liquid crystal module shown in FIG. 9, and FIG. 11 is a diagram of the liquid crystal display projector. FIG.

In FIG. 9, reference numeral 1 denotes an image projection unit that magnifies image light onto a screen. This image projection unit 1 includes a light source 2 and R (red) using an HID lamp 2a and a reflector 2b.
, B (blue), G (green) dichroic mirror: “I
R, 3B, 3G and polarizing plates 41R, 41B, 44G
And LCD module 5R.

5B and 5G, and lenses 6R, 6B, and 6G are integrally constructed. The light source 2 is attached to the other end of a rectangular cylindrical housing 7 with one end closed. Inside this housing 7 is a dichroic mirror 3R.

3B and 3G are arranged, and the illumination light from the light source 2 is separated into primary color light by these dichroic mirrors 3R, 38, and 3G. On the side of the casing 7 are windows 7R, which correspond to the dichroic mirrors 38, 3B, and 3G, respectively.
7B and 7G are formed. These window parts 7R, 7B
, 7G have polarizing plates 41R, 41B, 41G, respectively.
is installed.

On the front side of the polarizing plate, there are liquid crystal modules 5R and 5B.

5G, and projection lenses 6R, 6B, and 6G are arranged side by side (horizontally), and each color light is transmitted through a polarizing plate 4.
The light enters liquid crystal modules 5R, 5B, and 5G via 1R, 41B, and 41G, respectively. The liquid crystal modules 5R, 5B, and 5G are connected to the liquid crystal panels 8R, 8B, and 8G (see FIG. 10), and the projection screen 6R, respectively.
6B, (-+G side polarizing plate 42R, 42B, 4
2G (see Figure 10).

That is, the liquid crystal panels 8R, 8B, 8G are dichroic mirrors 3R, '3P, as shown in FIG.

Polarizing plates 41R and 41B in the polarization direction or vertical direction on the 3G side.

41G is disposed, and polarizing plates 42R, 42B, and 42G whose polarization direction is horizontal are disposed on the opposite side from this, and drive signals from a drive circuit (not shown) are supplied to each liquid crystal panel. The drive circuit generates R (red), B (blue), and G (green) signals based on the video signal, and the R,
B, G signals and synchronization signals are supplied to the liquid crystal panel 8.
The polarization direction is changed by driving R, 8B, and 8G. As a result, the red liquid crystal panel 8R emits red transmitted image light via the light plate 42R, and the blue liquid crystal panel 8B
emits blue transmitted image light through the polarizing plate 42B, and the green liquid crystal panel 8G emits green transmitted image light through the polarizing plate 42G. The transmitted image light of the three colors is magnified by a red projection lens 6R1, a blue projection lens 6B, and a green projection lens 6G (see FIG. 9), and as shown in FIG. 2 mirror 10b
are reflected and optically synthesized on the screen 10c to display an image.

Here, 50% of the incident light is absorbed by the incident-side polarizing plates 41R, 41B, and 41G, and the light is converted into heat I\. In particular, the center portions of the polarizing plates 41R, 41B, and 41G generate a large amount of heat because the light flux is concentrated therein. Correspondingly, as shown in FIG. 9, a fan 9 is provided as a first cooling device on the diagonal side of the window portions 7R, 7B, and 7G of the housing 7.
1 is provided, and the wind 91a from this fan 91 is directed to the polarizing plates 47R, 41B, 41G and the liquid crystal module 5R,
By being sprayed between 58 and 5G, the housing 7
, polarizing plates 41R, 41B, 41G, and liquid crystal modules 5R, 5B, and 5G. talented,
As a second cooling device accompanying this, as shown in FIG. Air 92a is sent out from.

In a conventional liquid crystal display projector using such a conventional cooling device, during use, a large air volume is required to obtain a cooling effect, and the noise of the fans 91 and 92 is large.
In addition, since air is introduced from the outside into the housing of the LCD projector, dirt and dust may also enter the LCD module 5R.
, 5B, 5G, projection lenses 6R, 6B, 6G, etc., and there is a problem in that dust and the like adhere to the optical systems, making the projected image unclear.

(Problems to be Solved by the Invention) In the conventional liquid crystal display projector described above, a large amount of air is required to obtain a sufficient cooling effect on the incident side polarizing plate, and the fan generates a large noise during use. Furthermore, since air is introduced into the housing from the outside, dirt, dust, etc. also flow in, causing problems in the optical system.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a cooling device for a liquid crystal display projector that can eliminate the above-mentioned problems and can obtain a sufficient cooling effect on the incident-side polarizing plate without providing a fan.

[Evaluation of the invention] (Means for solving the problem) The present invention reflects illumination light from a light source on a three-color tichroic mirror to separate the light into three colors, and each includes a polarizing plate on the incident side, a liquid crystal panel, and a liquid crystal panel. In a cooling device for a liquid crystal display projector in which image light is formed by sequentially passing through a polarizing plate on the output side and this image light is projected onto a screen, either one of the spectral paths before or after the polarizing plate on the input side is used. On the other hand, it is characterized in that a cooling device filled with a cooling liquid as a transparent body is disposed inside.

(Function) According to such a configuration, the heat generated from the light source is absorbed by the casing of the cooling device and the cooling liquid, and the heat absorbed by the casing of the cooling device and the cooling liquid is absorbed by the casing of the cooling device. Since the heat is radiated from the body, little heat reaches the polarizing plate on the incident side, and a sufficient cooling effect can be obtained for the polarizing plate on the incident side without providing a fan.

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

1 to 4 show a cooling device for a liquid crystal display projector according to the present invention, in which FIG. 1 is a perspective view, FIG. 2 is a sectional view, and FIG. 3 is a perspective view of the cooling box of FIG. FIG. 4 is a sectional view of the cooling box of FIG. 3.

In FIG. 1, an image projection unit 1 of a liquid crystal display projector is shown.
00 is a light source 12 and a red reflective dichroic mirror 13
A first cooling box 93 is provided between R, and red, blue, and green reflective dichroic mirrors 13R and 13B are provided.
, 13G and red, blue, green liquid crystal module 15R, 1
5B and 15G, a cooling device 94 (hereinafter referred to as a second cooling box) is provided.

That is, the light source 12 includes an HID lamp 12a and a flapper 1.
2b, and is housed in a rectangular cylindrical housing 71 with a plurality of cooling fins 71a formed on the side surface. Housing 7
The front side of the first reflector 12b is attached to one end of a rectangular cylindrical housing 72. A plurality of cooling fins 72a are formed on the top and side surfaces of the housing 72. 7 bodies 72
The other end is connected to one end of a liquid cooling box 93.

The other end of the cooling box 93 is connected to the other end of the housing 73, which is closed at one end. A plurality of cooling fins 73a are formed on the upper surface of this housing 73. Inside the three housings 73, dichroi V Cumira-13R, 13B, and 13G are arranged, and light is transmitted from the light source 2 through the cooling box 93. These dichroic mirrors 13R, 138, 13G
It is designed to separate light into primary color light. Dichroic mirrors 13R, 13B, 13G are on the side of the housing 73.
Polarizing plate 141R compatible with.

A liquid cooling box 94 is provided in which 141B and 141G are arranged.

As shown in FIG. 2, the cooling box 93 has a structure in which a transparent body (for example, glass) 931 on the light source 12 side and a transparent body 932 on the dichroic mirror 13R side are coupled via a frame 933. A liquid chamber 934 formed by the frame 933 and the transparent bodies 931 and 932 is filled with a cooling liquid 935.

As shown in FIG. 3, the liquid cooling box 94 is a transparent body on the incident side (dichroic mirrors 13R, 13B, 13G side) (in the case of the second embodiment, a condenser lens is used).
41R, 9111B, 941G and output side (liquid crystal module 15R, 158, 15G side) transparent body (dichroic filter is used in this example) 942R
.

942B and 942G are connected via a frame 943. Transparent bodies 942R, 942B,
A polarizing plate 141 is attached to the inner surface of the frame 943 of 942G.
R, 141B, and 141G are installed. Incident side transparent bodies 941R, 941B.

941G is a transparent member such as glass that transmits light formed into a substantially rectangular lens shape, and it collects the light reflected by the dichroic mirrors 13R, 13B, and 13G, and also collects the coolant from the frame 943. Polarizing plates 141R, 14 designed to prevent leakage
1B and 141G are designed to pass only light whose polarization direction is vertical. Output side transparent body 942R
, 942B, and 942G are formed into substantially rectangular shapes to prevent the coolant from leaking from the frame 943, and
These are guichroic filters that allow red, blue, and green light to pass through, respectively.

As shown in FIG. 4, the frame 943 is made of a metal with good thermal conductivity such as a zinc alloy and formed into a box shape, and there are incident side transparent bodies 941R and 941B on the guichroic mirrors 138, 13B, and 13G sides. , 941G are formed, and incident side polarizing plates 141R, 141B are formed on the liquid crystal module 15R, 15B, 15G side.

141G and output side transparent body 942R, 9428, 942
Window portions 945R, 945B, and 945G corresponding to G are formed.

In addition, each of the frames 943 has 946
The incident side transparent bodies 941R, 9418, 941G are connected to each other while maintaining liquid tightness through R, 946B, 946G, and the output side transparent bodies 942R, 942B are connected to each other while maintaining liquid tightness via gaskets 947R, 947B, 947G. , 9
It is designed to combine 42G.

Transparent body 941R, 941B, 941G, 942R,
A liquid chamber 948 formed by 942B, 942G and the frame 943 is filled with a cooling liquid 949.

As shown in FIG. 1, liquid crystal modules 15R, 15B,
15G, and projection lenses 16R, 168, and 16G are arranged side by side (horizontally), and each color light is transmitted through incident side transparent bodies 941R, 941B, 941G, incident side polarizing plates 141R+41B, 141G, and output side. The six liquid crystal modules 15R, 15B, 15G enter the liquid crystal modules 15R, 15B, 15G through the transparent bodies 942R, 9428, 942G, respectively, and the liquid crystal panels 188, 18B, 18G and the output side (projection lens 61, 62, 63). j) Polarizing plates 142R, 142B,
142G (see Figure 10) is superimposed! It is of f4 construction. Liquid crystal module 15R, 15B, 1
The light that passed through 5G is projected into projection lenses 16R and 16B, respectively.
, is projected onto the screen at 16G, and the three colors of crimson are combined.

According to such an embodiment, 1111"'1 of light source 12
The heat generated by the light emission of the lamp 12a is transferred to the transparent body 931.
It is absorbed by the frame 933 and the cooling liquid 935 through the incident side transparent body 941R9941B, 944
G, the heat absorbed by the frame 943 and the coolant 949 is absorbed by the frames 933 and 943.
, the housings 71, 72.73 and their radiation fins 71a,
Since heat is radiated from 72a and 73a, the incident side polarizing plates 141R and 141R do not require a fan unlike the conventional example.
41B and 141G can be obtained. Therefore, no noise is generated, and there is no fear of dirt, dust, etc. flowing in.

FIG. 5 is a cut away perspective view showing a modification of the embodiment shown in FIG.

In this figure, the cooling box provided on the side surface of the housing 74 of the image projection unit 101 is a cooling box 95 for red light.
A cooling box 95B for R9 blue light and a cooling box for green light (not shown) are formed separately. The other parts are the same as the image projection section 100 shown in FIG.

Such a modification also provides the same effects as the embodiment shown in FIG. 1, and is useful for reducing the weight of the liquid crystal display projector.

6 and 7 show other embodiments of the cooling device for a liquid crystal display projector according to the present invention, FIG. 6 is a configuration diagram, and FIG.
The figure is a perspective view of the cooling box.

This embodiment is applied to a liquid crystal display projector in which three color image lights are superimposed by a combining prism and projected onto a screen from one projection lens.

The light source 22 of the image projection unit 102 is composed of a 11D lamp 22a and a reflector 22b, and is attached to the second housing 77, as shown in No. 6I2I. HTD lamp 2
A beam flap 22b is disposed at the rear of the beam 2a, and a filter 22C for absorbing infrared rays is disposed at the front. The reflector 22b reflects the illumination light emitted backward from the HID lamp 22a light source toward the filter 22c. The filter 22c removes a certain amount of infrared rays from the incident illumination light and emits the illumination light toward the inside of the casing 77. On the optical axis 2Oa of the light emitted from the filter 22c, there are four
A red reflective guichroic mirror 238 is fixedly arranged inside the casing 77 and tilted at 5 degrees. The red reflective guichroic mirror 238 reflects only red light and transmits other color lights. Red reflective guichroic mirror 2
The red light reflected from 3R enters an entrance window 962 formed in the frame 961 of the first cooling box 96 . The first cooling box 96 includes a mirror 2 which is inclined at 45 degrees to the optical axis 20b of the red light incident from the window 962.
32R is placed. The red light incident from the window 962 is reflected by this mirror 232R, and is transmitted to the red liquid crystal module 25R via a polarizing plate 241R with a vertical polarization direction provided in the reflection side window 964 of the cooling box. incident.

On the other hand, the colored light other than red transmitted through the red reflective dichroic mirror 23R is transmitted to the frame 9 of the second cooling box 97.
The light enters an incident side window 972 formed at 71 . A blue reflecting dichroic mirror 238 is disposed in the transmission side window 973 of the cooling box 97 and is inclined at 45 degrees to the optical axis 20a of the occluded light incident from the window 972. The dichroic mirror 238 reflects the blue light among the colored lights that entered from the entrance window 972, and passes this blue light through the polarizing plate 241B, which is provided in the reflection window 974 of the cooling box 97 and whose polarization direction is vertical. Blue LCD module 25B
incident on .

Further, the blue reflecting dichroic mirror 23B transmits green light, and this green light is reflected by the mirror 231G arranged at an angle of 45 degrees to the optical axis 20a, and is reflected by the incident light formed on the frame 981 of the third cooling box 98. The light enters the side window 982. In the third cooling box 98, a mirror 232G inclined at 45 degrees to the optical axis 20c of the green light incident through the window 982 is arranged. The green light incident from the window portion 982 is reflected by the mirror 232G and enters the green liquid crystal module 25G via a polarizing plate 241G provided in the reflection side window portion 984 of the cooling box and having a vertical polarization direction. 'LCD module 25R, 25G, 2
5B is the liquid crystal panel 2 on the incident side, as in the conventional case.
8R, 28G.

28B and output side polarizing plates 252R, 252G, 252
It has a structure in which B and B are overlapped.

The synthesis prism 261 includes liquid crystal modules 25R and 25G.
.

The light emitted from the 25B liquid crystal is combined to emit image light.

A projection lens 262 is interposed between the synthesis prism 261 and the screen. The projection lens 262 magnifies the image light from the combining prism 261 and projects it onto a screen.

The above-mentioned second cooling box 97 has a structure in which transparent bodies 976 and 977 and a blue reflective dichroic mirror 23B are coupled via a frame 971, as shown in FIG. The frame 971 is made of a metal with good heat conductivity such as a zinc alloy and is formed into a cylinder shape with a right-angled isosceles triangular cross section closed at both ends.
Window portions 972°, 973, 974 are provided on the side surfaces 971C corresponding to the hypotenuses of the right-angled isosceles triangle, respectively.
The transparent bodies 976, 977 and the dichroic mirror 238 are connected to each of the window portions 972, 973, and 974 through gaskets (not shown) while maintaining liquid tightness. Furthermore, a polarizing plate 241B is provided inside the frame 971 of the transparent body 977. A liquid chamber 978 (see FIG. 6) formed by the frame 971, the transparent bodies 976 and 977, and the Brosch mirror 977 is filled with a cooling liquid 979. The liquid cooling box 97 is arranged with sufficient contact area with the housing 77, and the heat absorbed by the frame 971 and the cooling liquid 979 is conducted to the housing 77 (see FIG. 6) and externally. Heat is dissipated to

Note that the cooling boxes 96 and 98 have a normal mirror attached thereto instead of a dichroic mirror attached to the window portion on the side surface corresponding to the oblique side.

Even in this embodiment, the heat generated by the light source 22 is absorbed by the cooling boxes 96, 97, 98 and radiated from the housing 77, so that the same effect as in the embodiment of FIG. 1 can be obtained.

FIG. 8 shows another embodiment of the present invention. This embodiment is applied to a liquid crystal display projector in which three color image lights are superimposed using a dichroic mirror and projected onto a screen from one projection lens.

In this figure, the light source 32 of the image projection unit 103 is located in the housing 7.
Illumination light is made to enter into the 8. On the optical axis 30a of the illumination light from the light source 32, there are 45
A red reflective dichroic mirror 338 is arranged at an angle. The red reflective dichroic mirror 33R reflects only red light and transmits other color lights. The red light reflected by the red reflective dichroic mirror 33R is
into the cooling box 99. First cooling box 9
At 9, a mirror 332R is arranged which is inclined at 45 degrees to the optical axis 20b of the incident red light. The incident red light is reflected by this mirror 3328 and enters the red liquid crystal module 35H via a polarizing plate 38R provided on the frame 991 of the cooling box 99 and having a vertical polarization direction.

On the other hand, the colored light other than red that is transmitted through the red reflecting mirror 33R enters the entrance side window 902 formed in the frame 901 of the cooling box 90.

Inside the cooling box 90, a blue reflecting gucchroic mirror 338 is arranged which is tilted at 45 degrees to the optical axis 30a of the incident orange light through the window portion 902. The dichroic mirror 338 reflects blue light among the colored light incident through the window, and sends this blue light to the blue liquid crystal module 35B via a polarizing plate 38B provided in the reflective window 903 and having a vertical polarization direction. incident.

Furthermore, the blue reflective mirror 33B transmits green light, and the blue light is transmitted to the H color layer liquid crystal module 35G via a polarizing plate 38G in which the polarization direction of the transmission side window 904 formed in the frame 901 is vertical. On the other hand, driving signals are supplied to the liquid crystal modules 35R, 35B, and 35G from a driving circuit (not shown). As a result, the liquid crystal modules 35R and 35B.

35G emits red image light, blue image light, and green image light, respectively. The green image light from the liquid crystal module 35G is reflected by the mirror 431, and is reflected by the total synthesis mirror 4 at ft.
The red and blue image lights from the liquid crystal modules 35B and 35G are combined in a red and blue combining mirror 433, and then input into a total combining mirror 432.

The total synthesis mirror 432 optically synthesizes red image light, blue image light, and green image light. The image light from the total synthesis mirror 432 is magnified by the projection lens 362 and projected onto the screen.

Although not shown in the drawings, a transparent body for preventing liquid leakage is provided at the entrance side window and the output side window (reflection side window, transmission side window) of the cooling box 99,90. 99.
The inside of 90 is filled with cooling liquid.

Even in this embodiment, the heat generated by the light source 32 is absorbed and radiated by the cooling boxes 99 and 90, so that the same effect as in the embodiment shown in FIG. 1 can be obtained.

In the embodiments shown in Figures 1 to 8, the incident side polarizing plate is provided inside the cooling box, but it may be placed on the optical path between the dichroic mirror side transparent body of the cooling box and the liquid crystal panel. For example, the incident side polarizing plate may be attached to the surface of the liquid crystal panel side transparent body on the outside of the cooling box, or it may be provided at a position outside the cooling box a little apart from the liquid crystal panel side transparent body.

[Effects of the Invention] As described above, according to the present invention, a sufficient cooling effect can be obtained for the polarizing plate on the incident side without using a fan, so that dust and dirt can be removed without generating noise. There is no need to worry about inflows.

[Brief explanation of the drawing]

1 is a perspective view showing a cooling device for a liquid crystal display projector according to the present invention, FIG. 2 is a cross-sectional view of the casing shown in FIG. 1, FIG. 3 is a perspective view of the cooling box shown in FIG. 1, and FIG. is a sectional view of the cooling box shown in FIG. 3, FIG. 5 is a cutaway perspective view showing a modification of the embodiment shown in FIG. 1, and FIG. 6 is a liquid crystal display 70 according to the present invention.
FIG. 7 is a perspective view of the cooling box of FIG. 6, and FIG. 8 is a block diagram showing another embodiment of the cooling device for a liquid crystal display projector according to the present invention. 9 is a perspective view showing the image projection section of a conventional liquid crystal display projector, FIG. 10 is a structure diagram of the liquid crystal module shown in FIG. 9, and FIG. 11 is a perspective view of the liquid crystal display projector shown in FIG. be. 12... Light source, 100... Image projection unit of liquid crystal display projector, 94
3... Frame, 945... Coolant, 13R, 13
B, 13G... dichroic mirror, 18R,
18B, 18G...LCD panel, 141R, 14
1B, 141G..., incident side polarizing plate, +42R, 14
2B, 142G, Output side polarizing plate, 941R, 941
B, 941G...Incidence side transparent body, tank black 4.9ζ
Figure 10 Figure 11

Claims (1)

[Claims of Claims] Image light is formed by reflecting illumination light from a light source on a three-color dichroic mirror to separate the lights into three colors, and transmitting each color sequentially to an input-side polarizing plate, a liquid crystal panel, and an output-side polarizing plate. In a cooling device for a liquid crystal display projector that projects this image light onto a screen, a cooling device is provided on either the front or back surface of the incident-side polarizing plate, and the spectral path is formed inside as a transparent body. 1. A cooling device for a liquid crystal display projector, comprising: a cooling device filled with a cooling liquid.