JPH06281906A - Liquid crystal projector - Google Patents

Abstract

PURPOSE:To excellently cool a liquid crystal pannel, to prevent the reduction in contrast of the liquid crystal pannel due to the temperature rise and to excellently project an image by passing air flow by a cooling fan through the gap between a display device and a first wall part and the gap between the display device and a second wall part. CONSTITUTION:The cooling air introduced from an intake hole 12a cools a light source device 50, and the cooling air introduced from the intake hole 12b lowers a temperature in a case passing between the light source device 50 and the display device 30 and cools a Fresnel lens 22 for correcting an optical flux. Further, the cooling air introduced from the intake hole 12c cools the display device 30 from the outside passing through between the light source device 50 and the display device 30 and cools a cooling liquid 36 in a display pannel refrigerator 31 by exchanging heat with a heat pipe 37, and the cooling air intorduced from the intake hole 12d is introduced from an air hole 13 between a wind limiting wall 11 and a display unit 40, and cools the display unit 40 from the front surface side and a condensate Fresnel lens 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal projector.

[0002]

2. Description of the Related Art A liquid crystal projector displays an image by using a transmissive liquid crystal display panel and magnifies and projects a display image of the liquid crystal display panel onto a screen surface by a projection lens. It has become a structure.

FIG. 12 shows the principle of a liquid crystal projector. In the figure, 1 is a case of the projector,
A projection lens 2 formed by combining a plurality of optical lenses is provided on the front surface of the case 1.

Reference numeral 3 is a transmissive dot matrix liquid crystal display panel provided in the case 1, and 4 is a liquid crystal display panel 3.
Is a light source device that is located in the rear of the case and provided in the case 1. The light source device 4 includes a light source lamp 5 and a reflector 6 that reflects illumination light from the light source lamp 5 toward the liquid crystal display panel 3. Has become.

Illumination light from the light source device 4 enters the liquid crystal display panel 3, and the light transmitted through the liquid crystal display panel 3, that is, the display image of the liquid crystal display panel 3 is projected by a condenser lens (Fresnel lens in the figure) 7. The light is focused on the lens 2, enlarged by the projection lens 2, and projected on the screen S surface arranged in front of the projector.

This liquid crystal projector enlarges the display image of the liquid crystal display panel and projects it on the screen surface. According to this liquid crystal projector, the display image of the liquid crystal display panel having a small display screen is greatly enlarged. be able to.

[0007]

However, in the liquid crystal projector, the heat radiated from the light source device 4 to the periphery thereof causes the temperature inside the case 1 to rise and the liquid crystal display panel 3 to be heated. The temperature of the liquid crystal in the liquid crystal panel rises, and due to the influence, the display contrast of the liquid crystal display panel 3 is lowered, so that a clear image cannot be projected on the screen S surface, and the life of the liquid crystal in the liquid crystal display panel 3 is shortened. Had a problem.

Although the temperature rise in the case 1 can be suppressed to some extent by air-cooling the case 1 by ventilation in the case 1, the liquid crystal projector has a cooling fan because of its structure. Since it is difficult to set freely, it is difficult to cool the liquid crystal display panel well.

The present invention has been made in view of the above situation, and an object of the present invention is to cool a liquid crystal display panel satisfactorily to prevent a decrease in contrast of the liquid crystal display panel due to a temperature rise. It is to provide a liquid crystal projector capable of projecting various images.

[0010]

The present invention comprises a light source, a display device in which a drive circuit for driving the liquid crystal display panel is arranged around the liquid crystal display panel, and a projection lens. Light is incident on the liquid crystal display panel,
A liquid crystal projector for projecting light transmitted through the liquid crystal display panel by the projection lens, wherein a first wall portion and a second wall portion are provided in front of and behind the display device, apart from the display device. A cooling fan for air-cooling the display device, and an air flow by the cooling fan,
It is characterized in that they are circulated in a gap between the display device and the first wall portion and a gap between the display device and the second wall portion.

[0011]

That is, in the liquid crystal projector of the present invention, by providing the first wall portion and the second wall portion in front of and behind the display device, the air flow by the cooling fan is made to flow to the display device and the first and second walls. The liquid crystal display panel of the display device can be satisfactorily cooled by circulating the liquid crystal display panel in the gap between the liquid crystal display panel and the display device by air-cooling the display device from both sides thereof. It is possible to prevent deterioration of the contrast of the liquid crystal display panel due to the rise and to project a good image.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

First, the overall structure of the liquid crystal projector will be described. In FIGS. 1 and 2, reference numeral 10 denotes a projector case, and the front surface of the projector case 10 includes:
A projection lens 20 having a plurality of lenses (not shown) arranged in a lens barrel is provided.

A display device 30 is provided on the front side of the case 10 and a light source device is provided on the rear side thereof.
50 is provided, and between the light source device 50 and the display device 30, a luminous flux compression Fresnel lens 21 that compresses the luminous flux of the illumination light from the light source device 50 to increase the brightness of the illumination light, and this luminous flux. A light flux correcting Fresnel lens 22 for correcting the illumination light that has passed through the compression Fresnel lens 21 into parallel light parallel to the optical axis O of the projector and making it enter the transmissive liquid crystal display panel 43 of the display device 30 is provided. .

The front side of the display device 30 (projection lens 20
On the side), a light-collecting Fresnel lens 23 that collects the light transmitted through the liquid crystal display panel 43, that is, the display image of the liquid crystal display panel 43 on the projection lens 20 is provided. The luminous flux compression Fresnel lens 21 is arranged close to the light source device 50, and the luminous flux correction Fresnel lens 22 is arranged close to the back surface of the display device 30.
Are arranged close to the front surface of the display device 30.

3 to 5 show the display device 30. The display device 30 includes a display panel cooler 31 and a display unit 40 attached to one surface of the display panel cooler 31.
It consists of

The display panel cooler 31 has a thin box-shaped cooling container on both sides of which a transparent area having a larger area than the display area 43a of the liquid crystal display panel 43 (see FIG. 6) is formed. The cooling container is filled with a cooling liquid 36, and the cooling container has a frame body 32 having an outer shape sufficiently larger than that of the liquid crystal display panel 43, and a transparent plate (glass plate or acrylic resin plate or the like) 34 for closing both sides of the frame body 32. , 35 is a sealed structure.

The frame 32 has a liquid crystal display panel on one surface thereof.
The display unit mounting plate 32a has a window 33 having a slightly larger area than the display region 43a of the display area 43a, and the transparent plate 34 closing one surface of the frame 32 is the window 33.
The transparent plate 35, which is sized so as to cover the display unit mounting plate 32a and closes the other surface of the frame body 32, has substantially the same size as the outer shape of the frame body 32 and is attached to the other surface of the frame body 32. It is glued.

Further, 37 is a heat pipe inserted into the cooling container of the display panel cooler 30 while avoiding the portion corresponding to the window 33, and both ends of the heat pipe 37 are on both sides of the cooler. It is inserted in the upper part in the cooling container in a state of protruding from the outside.

This heat pipe 37 is a display panel cooler.
The heat absorbed by the cooling liquid 36 in 31 is released to the outside of the cooler 31, and the central portion of the heat pipe 37 inserted into the cooler serves as a heat absorbing portion a, and both ends projecting outside the cooler. The side portions are heat radiating parts b, b, and large-area heat radiating fins 38, 38 in the form of vertically elongated strips are provided on the outer circumference of the heat radiating parts b, b.

The heat pipe 37 is a metal pipe in which both ends are closed, and a volatile working fluid (heat transfer medium) is enclosed therein, and the working fluid in the heat pipe 37 is capillarized over the entire inner surface thereof. As a result, an asbestos-like wick 37a that leads from the heat radiating portion b side to the heat absorbing portion a side is provided.

The working fluid transfers heat by reversible two-phase changes of evaporation and condensation. As the working fluid, for example, a fluid having a high latent heat coefficient and excellent permeability such as CFC is used. There is. This working fluid is heated in the heat absorbing portion a of the heat pipe 37 by heat exchange with the cooling liquid 36 in the display panel cooler 31, evaporates, becomes vapor, and rises in the heat pipe 37. In the heat radiation part b of 37, it is condensed and liquefied by heat radiation to the outside, and the working fluid liquefied by depriving latent heat is wicked.
It penetrates into 37a and is guided again to the heat absorbing portion a by its capillary phenomenon.

The heat pipe 37 guides the working fluid evaporated in the heat absorbing portion a to the heat radiating portions b and b at both ends of the heat pipe, and liquefies the working fluid in the heat radiating portions b and b to permeate the wick 37a. In order to guide it to the heat absorbing portion a again, the center portion is bent to the lowest shape and both end sides are inclined obliquely upward.

On the other hand, the display unit 40 mounted on one surface of the display panel cooler 31 has a liquid crystal display panel 43 on both surfaces.
A liquid crystal display panel 43 and a display drive circuit board 44 for the liquid crystal display panel 43 are housed in an extremely thin case-shaped housing 41 provided with transparent windows 42a and 42b corresponding to the housing 41. Has become.

That is, in FIG. 6 to FIG.
Reference numeral b denotes a pair of metal cases forming the housing 41. The metal cases 41a and 41b are provided with the transparent windows 42a and 41a.
42b is opened. Of the transparent windows 42a and 42b,
The transparent window 42a on the cooler mounting surface side is
The transparent plate 34 adhered to the display unit mounting plate 32a is inserted into the display unit mounting plate 32a, and the opening 42b on the opposite side is formed to have substantially the same size as the display area of the liquid crystal display panel 43.

The display drive circuit board 44 has a light-transmitting window on the cooler mounting surface side of the housing 41 at the center thereof.
It has a shape in which an opening 44a having substantially the same size as that of 42a is formed.
SI chips 45, 45 are arranged so as to surround the opening 44a.

These LSI chips 45, 45 are attached to the circuit board 44 by soldering their electrodes to wiring (not shown) on the surface of the circuit board 44. The circuit board 44 is adhesively fixed to the inner surface of the metal case 41a on the cooler mounting surface side of the housing 41 by a double-sided adhesive sheet (not shown).

On the other hand, the liquid crystal display panel 43 is a transmissive dot matrix liquid crystal display panel for displaying a television image, and the liquid crystal display panel 43 is the circuit board 44.
A large number of display panel connection terminals (not shown) arranged in the outer peripheral edge of the sheet and a sheet-like flexible connector 4
Connected by 6,46. In addition, the liquid crystal display panel 43 has a transparent window 42a on both sides thereof in the housing 41.
, 42b, and are fixed to the inner surface of the housing 41 by a frame-shaped double-sided adhesive sheet (not shown).

In the display unit 40, the liquid crystal display panel 43 inside the display unit 40 is attached to the display unit mounting plate 32a of the display panel cooler 31 in a state of being in contact with the fixing screw 4
It is fixed to the mounting plate 32a by 7, 47.

The display device 30 in which the display unit 40 is attached to the display panel cooler 31 is
The housing of the display unit 40 is arranged inside the projector case 10 as shown in FIGS. 1 and 2 with the side facing the projection lens 20 and the side facing the cooler 31 facing the light source device 50.
A mounting plate 48 formed by cutting and raising 41 is screwed to the inner bottom surface of the projector case 10 and fixed in the case 10.

In FIG. 2, 49a is a linear circuit unit for processing television radio waves received by an antenna section and a tuner (not shown) provided in the projector case 10 and outputting an image signal, and 49b is the above-mentioned linear circuit unit. An image display control circuit unit connected to the linear circuit unit 49a, and the display drive circuit board 44 in the display unit 40 is connected to the image display control circuit unit 49b by a connection cable (not shown).

Next, the light source device 50 will be described. Figure 9
11 shows a light source device 50, in which 51 is a rectangular box-shaped light source box made of a metal plate having a circular opening 51a formed on the front surface. Inside this light source box 51 is a light source lamp
52 and a reflector 53 that reflects the illumination light from the light source lamp 52 toward the display device 30.

The reflector 53 is a parabolic mirror reflector that reflects the illumination light from the light source lamp 52 as parallel light parallel to the reflector optical axis.
Is fixed in the light source box 51 by means such as screwing, with its opening surface facing the opening 51a on the front surface of the light source box.

Further, as the light source lamp 52, a high voltage arc lamp such as a xenon lamp having a high emission brightness is used, and the high voltage arc lamp 52 has its base portion inserted into the neck portion 53 of the reflector 53. It is fixed by the ceramic adhesive 54 filled in the neck portion 53. Note that 52a and 52b are terminal portions projecting at both ends of the high-voltage arc lamp 52, and these terminal portions 52a and 52b are connected to power supply connection terminals provided on the outer surface of the light source box 51 by lead wires (not shown). ing.

The direction of the arc generated between the electrodes of the high voltage arc lamp 52 is located outside the neck portion 53 of the reflector 53 and diagonally above the light emitting portion 52a of the high voltage arc lamp 52. Is provided with a permanent magnet 55 that stabilizes the magnet.The permanent magnet 55 is attached to the tip of a magnet support member 55a made of a metal plate whose base is inserted into the neck 53 of the reflector 53 and fixed by the ceramic adhesive 54. It is fixed.

Reference numeral 56 denotes a rectangular tube-shaped explosion-proof cylinder made of a metal plate attached to the front surface of the light source box 51 so as to project to the front thereof. The front end of the explosion-proof cylinder 56 is transparent and covers the opening surface of the explosion-proof cylinder 56. Explosion-proof glass 57 is installed. This explosion-proof glass 57 is fitted to the front end of the explosion-proof cylinder 56 to
It is held and fixed by bending pieces 58 formed on both side surfaces of the.

The explosion-proof cylinder 56 and the explosion-proof glass 57 are device parts (Fresnel lenses 21, 22) inside the projector due to scattered fragments (glass fragments) when the high-voltage arc lamp 52 bursts due to abnormal overheating. It is provided to prevent the display device, the circuit unit, and the like) from being damaged. As the explosion-proof glass 57, for example, chemically strengthened blue glass having a thickness of about 5 mm is used.

In addition, intake ports 59 and 60 are provided on the lower surfaces of the light source box 51 and the explosion-proof cylinder 56, and the inside of the light source box 51 and the explosion-proof cylinder 56 are provided at the four corners of the front surface of the light source box 51.
Vent hole 6 for communicating the inside with the outside of the reflector 53
1 and 61 are provided, and exhaust holes 62 and 62 are formed in the upper surface of the explosion-proof cylinder 56.

The air inlets 59, 60, the air vents 61, 61 and the air exhaust holes 62, 62 are provided for air-cooling the light source device 50, and are taken into the light source box 51 from the air inlet 59 on the lower surface thereof. The cooled air passes through the inside of the light source box 51 to cool the reflector 53 from its outer surface side, as shown by the arrow in FIG. 9, and enters the explosion-proof cylinder 56 through the ventilation holes 61, 61 on the front surface of the light source box to prevent explosion. It is discharged from the exhaust holes 62, 62 on the upper surface of the cylinder.
Further, the cooling air taken into the explosion-proof cylinder 56 through the intake port 60 on the lower surface thereof cools the reflector 53 and the explosion-proof glass 57 from the inner surface side thereof, and is discharged from the exhaust holes 62, 62.

This light source device 50 is used in the projector case 10.
The power supply unit 63 and the power supply cable are installed in the rear part of the inside as shown in FIG. 1 and FIG.
Connected by 64. In addition, this power cable 64
Is connected to the above-mentioned power supply connection terminal provided on the outer surface of the light source box 51.

Further, the light source device 50 is designed so that when the high-voltage arc lamp 52 bursts, the light source box 51 and the explosion-proof cylinder 56 are replaced as a whole. Therefore, the light source device 50 is replaced with a projector case. It is removably fixed in the inside 10 by means such as screwing.

On the other hand, in FIGS. 1 and 2, 70 is a heat insulating wall provided in the projector case 10. The heat insulating wall 70 is a vertical wall portion that partitions the inside of the case 10 into the display device 30 side and the light source device 50 side near the display device 30, and extends from the upper end of the vertical wall portion to near the light source device 50. The vertical wall portion is provided with an opening 71 through which the illumination light from the light source device 50 passes.

Further, in the projector case 10, a lower partition wall 11a standing upright from the bottom surface of the case, close to the front surface of the display unit 40 of the display device 30, and an upper partition wall 11b hanging from the upper surface of the case. Is provided.

The lower partition wall 11a has a frame shape that also serves as a support frame for the light collecting Fresnel lens 23 arranged on the front surface side of the display device 30, and the light collecting Fresnel lens 23
Is bonded and fixed to the lower partition wall 11a. Also,
The lower end of the upper partition wall 11b is formed so as to have a drooping height that is close to or in contact with the upper edge of the light-collecting Fresnel lens 23. The upper partition wall 11b, the light-collecting Fresnel lens 23, and the lower partition wall 11a. Thus, the wind control wall 11 for flowing the cooling air along the front surface of the display unit 40 is configured.

On the lower surface of the projector case 10,
Intake portions 12a, 12b, 12c are provided in the arrangement portion of the light source device 50, the portion between the light source device 50 and the display device 30, the arrangement portion of the display device 30, and the portion in front of the wind control wall 11, respectively. ， 12d
Is installed in the lower part of the wind control wall 11 (lower partition wall 11a
The portion below the light collecting Fresnel lens 23) has a vent hole 13 for introducing the air taken in from the intake hole 12d in front of the wind control wall 11 into the air passage between the wind control wall 11 and the display unit 40. It is provided.

On the other hand, in the upper part of the projector case 10,
A blower fan 73 driven by a motor 72 is provided above the upper wall portion of the heat insulating wall 70, and exhaust holes 14, 14 are provided on the upper surface of the case in this portion.

The blower fan 73 is provided with a suction hole 12 on the bottom surface of the case.
The outside air is drawn from a, 12b, 12c, and 12d into the projector case 10 as shown by the arrow in FIG. 1 to cool the inside of the projector, and the cooling air taken in through the intake hole 12a is the light source device 50. The cooling air that has passed through the inside to cool the light source device 50 and has been taken in from the air intake hole 12b passes between the light source device 50 and the display device 30 to lower the temperature inside the case between them, and at the same time, the Fresnel lens 22 for light flux correction. To cool.

Further, the cooling air taken in through the intake holes 12c cools the display device 30 from the outside thereof, and at the same time, cools the cooling liquid 36 in the display panel cooler 31 by exchanging heat with the heat pipe 37, so that the intake air is taken in. The cooling air taken in from the hole 12d is introduced between the wind control wall 11 and the display unit 40 through the ventilation hole 13 provided in the lower part of the wind control wall 11, and cools the display unit 40 from the front side thereof. Fresnel lens for condensing
Cool 23 as well.

The air that has cooled these parts is exhausted to the outside of the case 10 through the exhaust holes 14, 14. The intake hole
The cooling air taken in from 12b passes between the light source device 50 and the display device 30, and the air bypasses the tip of the upper wall of the heat insulating wall 70 and both sides to the outside of the case 10 through the exhaust holes 14 and 14. Exhausted.

Further, in FIGS. 1 and 2, reference numerals 15 and 16 denote air guide walls provided around the blower fan 73, and the air guide wall 15 on the light source device 50 side extends in the width direction of the projector case 10. It is a straight wall, and the wind guide wall 16 on the display device 30 side is a semicircular wall.

In the liquid crystal projector of this embodiment, the inside thereof is air-cooled and the light source device of the display device is used.
Since the heat insulating wall 70 is provided on the side facing the light source 50,
It is possible to prevent the display device 30 from being heated to some extent by radiant heat from the display device 30.

However, even in this case, the radiant heat from the light source device 50 leaks from the opening 71 of the heat insulating wall 70 and the periphery of the heat insulating wall 70 to the display device 30 side and the display unit of the display device 30.
The liquid crystal display panel 43 provided in 40 is heated.

Therefore, in the liquid crystal projector, the display device 30 is separated from the display device 30 before and after the display device 30 by the first and second wall portions, that is, the display unit 40 of the display device 30.
Of the windshield wall 11 adjacent to the front surface of the display device 30 and the vertical wall portion of the heat insulation wall 70 adjacent to the rear surface of the display device 30. The airflow by the cooling fan 73 is displayed by the display device 30 and the windshield wall. The gap between the display device 30 and the heat insulating wall 70 is circulated in the gap between the display device 30 and the heat insulating wall 70 to cool the display device 30 from both sides thereof.

Therefore, according to the liquid crystal projector, the display device 30 is air-cooled from both sides thereof, so that the liquid crystal display panel 43 provided in the display unit 40 of the display device 30 can be cooled well. Therefore, since the temperature rise of the liquid crystal display panel 43 due to the radiant heat from the light source device 50 can be suppressed to a low level, it is possible to prevent the contrast decrease of the liquid crystal display panel 43 due to the temperature rise and project a good image. It is also possible to prevent the life of the liquid crystal from being shortened.

Moreover, in the above-described embodiment, the transparent cooling liquid 36 is filled in a container having a transparent area larger than the display area of the liquid crystal display panel 43 on both sides, and the cooling liquid is filled in the container.
A display unit 40 accommodating a liquid crystal display panel 43 and its display drive circuit board 44 is attached to one surface of a display panel cooler 31 in which a heat pipe 37 for discharging the heat absorbed by 36 is inserted, and the display unit On the other surface side of 40, a wind control wall 11 in which a converging Fresnel lens 23 is provided in a portion facing the liquid crystal display panel 43 and this portion is made transparent is provided in close proximity to the display unit 40. Since the passage of the cooling air blown by the blower fan 73 is formed between the wind wall 11 and the display unit 40, the temperature rise of the liquid crystal display panel 43 can be suppressed more effectively.

That is, the cooling liquid in the display panel cooler 31
Since the 36 exchanges heat with the heat pipes 37, 37 while convection in the cooler 31, the heat absorbed by the cooling liquid 36 is released to the outside by the heat pipes 37, 37, and the display panel cooler is provided.
The cooling effect of the display unit 40 by 31 can always be kept high. The display panel cooler 31 is one in which a transparent cooling liquid 36 is filled in a container in which a transparent area having a larger area than the display area of the liquid crystal display panel 43 is formed on both sides.
Further, since the wind control wall 11 also has a transparent portion facing the liquid crystal display panel 43, light passing through the liquid crystal display panel 43 is not blocked by the display panel cooler 31 or the wind control wall 11.

Further, since the cooling air flowing through the air passage between the display unit 40 and the wind control wall 11 flows at a high flow rate due to the narrow passage, the cooling air can also efficiently cool the display unit 40. Therefore, the display panel in the display unit 40 is effectively cooled from both sides thereof.

In the above embodiment, the liquid crystal display panel 43
Is housed in the housing 41 together with the display drive circuit board 44 to form the display unit 40, and the display unit 40 is attached to the display panel cooler 31 to form the display device 30. The structure is not limited to the structure of the above embodiment as long as a drive circuit for driving the liquid crystal display panel is arranged around the panel 43.

Further, in the above embodiment, the liquid crystal display panel 43
The transparent portion of the wind control wall 11 provided in close proximity to the front face of the liquid crystal display panel 43 and facing the liquid crystal display panel 43 is formed by the light collecting Fresnel lens 23. May be placed separately, in which case the wind control wall
The portion of 11 facing the liquid crystal display panel 43 may be formed of a transparent plate such as a glass plate, or the wind control wall 11 may be entirely formed of a transparent plate.

[0060]

According to the liquid crystal projector of the present invention, a first wall portion and a second wall portion are provided in front of and behind a display device in which a drive circuit for driving the liquid crystal display panel is arranged around the liquid crystal display panel. Accordingly, the air flow by the cooling fan is circulated in the gap between the display device and the first and second wall portions, and the display device is air-cooled from both sides thereof. The liquid crystal display panel can be satisfactorily cooled, and therefore, it is possible to prevent deterioration of the contrast of the liquid crystal display panel due to temperature rise and project a good image.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of a liquid crystal projector according to an embodiment of the present invention.

FIG. 2 is a partially cutaway plan view of a liquid crystal projector.

FIG. 3 is a front view of a display device.

FIG. 4 is a plan view of a display device.

FIG. 5 is a vertical side view of a display device.

FIG. 6 is a partially cutaway front view of the display unit.

7 is an enlarged cross-sectional view taken along line VII-VII of FIG.

8 is an enlarged sectional view taken along the line VIII-VIII in FIG.

FIG. 9 is a vertical sectional front view of the light source device.

FIG. 10 is a partially cutaway plan view of the light source device.

FIG. 11 is a partially cutaway side view of the light source device.

FIG. 12 is a principle configuration diagram of a conventional liquid crystal projector.

[Explanation of symbols]

 10 ... Projector case 11 ... Wind control wall (first wall part) 20 ... Projection lens 30 ... Display device 31 ... Display panel cooler 43 ... Liquid crystal display panel 50 ... Light source device 70 ... Thermal insulation wall (second wall part) 73 ... Blower fan

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H05K 7/20 R 8727-4E H 8727-4E

Claims (1)

[Claims] 1. A light source, a display device in which a drive circuit for driving the liquid crystal display panel is arranged around the liquid crystal display panel, and a projection lens, and the light from the light source is incident on the liquid crystal display panel. And a liquid crystal projector that projects the light transmitted through the liquid crystal display panel by the projection lens, the first and second display devices being separated from the display device before and after the display device.
Is provided with a wall part and a second wall part, and a cooling fan for air-cooling the display device is provided, and an air flow by the cooling fan is generated in the gap between the display device and the first wall part. And a liquid crystal projector, wherein the liquid crystal projector is circulated in a gap between the display device and the second wall portion.