JPS63183479A - Display device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a display device equipped with a display panel.

[Conventional technology]

There is a display device equipped with a display panel that cools the display panel inside the device body by drawing outside air into the device body.As this type of display device, for example, a liquid crystal projector is known. .

This liquid crystal projector is equipped with a transmissive liquid crystal display panel that displays television images, etc. inside the device body, a light source placed behind this display panel, and a projection lens placed in front of the display panel. The image displayed on the display panel is enlarged and projected onto the screen surface using a projection lens.This LCD projector prevents the liquid crystal display panel from being heated by heat from the light source, reducing the display contrast and shortening the lifespan of the liquid crystal. In order to prevent this, a display panel air cooling means is provided to cool the display panel by drawing outside air into the apparatus main body, thereby suppressing the temperature rise of the display panel.

[Problem that the invention seeks to solve]

However, the display panel air cooling means provided in display devices such as the above-mentioned liquid crystal projectors simply cools the display panel by flowing cooling air taken in from the outside into the device body. It is not possible to cool the display panel sufficiently, and the air that cools the display panel by hitting the display panel surface stagnates around the display panel and reduces the cooling efficiency of the display panel, so the temperature of the display panel does not rise. The problem was that it could not be prevented.

This invention was made in view of the above-mentioned circumstances, and its purpose is to cool the display panel sufficiently and efficiently to reliably prevent the temperature of the display panel from rising. The object of the present invention is to provide a display device with a

[Means to solve problems]

The present invention has a plurality of heat dissipation fins in a device body equipped with a display panel air cooling means that takes in outside air and air-cools an internal display panel, and the heat generated by the heat dissipation fins and the cooling air taken into the device body. A display panel cooling body that is cooled by replacement is provided, and the display panel is disposed in contact with or in close proximity to the display panel cooling body, and each radiation fin of the display panel cooling body is used to cool the display panel. It is characterized by being installed in a position that guides air in the exhaust direction.

[Effect]

That is, the display device of the present invention not only air-cools the display panel using cooling air taken in from the outside, but also uses a display panel cooling body that is cooled by heat exchange between the radiation fins and the cooling air taken into the device body. This display device forcibly cools the display panel and guides the air that has cooled the display panel in the exhaust direction using the heat dissipation fins of the display panel cooling body. According to this display device, the display panel can be cooled by air. Double cooling can be achieved by cooling the display panel by the display panel cooling body, and the air that hits the display panel surface and cools the display panel is guided by the heat radiation fins and is discharged in the exhaust direction without being stagnant around the display panel. This improves the flow of air that cools the display panel and improves the air cooling efficiency of the display panel, thereby cooling the display panel sufficiently and efficiently and reliably preventing the display panel from rising in temperature. be able to.

〔Example〕

Hereinafter, the case where this invention is applied to a liquid crystal projector that enlarges and projects a television image onto a screen will be explained.
An example of its actual flow will be explained with reference to the drawings.

First, the overall structure of a liquid crystal projector will be described. In FIG. 1 and FIG. 2, numeral 10 is a rectangular box-shaped projector body, and a projection lens 20 is provided on the front surface of the projector body 10.

This projection lens 20 is provided in a lens barrel 22 that is screwed onto a barrel 21 that is fixed to the front surface of the projector main body 10. By rotating this lens barrel 22, the screen 100 (see FIG. 3) can be adjusted. The focus can be adjusted depending on the position. Reference numeral 30 denotes a transmissive dot matrix liquid crystal display panel for displaying a television image, which is vertically provided on the front side of the projector body 10 and facing the projection lens. A display panel 1 having a configuration to be described later is installed perpendicularly to a cooling body 31.

Further, 40 is a condensing Fresnel lens arranged between the liquid crystal display panel 30 and the projection lens 20. This condensing Fresnel lens 40 condenses the displayed image of the liquid crystal display panel 30 onto the projection lens 20. This condensing Fresnel lens 40 has a large number of annular convex lens parts on one surface of a transparent plate made of acrylic resin or the like. This condensing Fresnel lens 50 is held in a lens holding frame 11 provided within the projector body 10.

Reference numeral 50 denotes a light source device provided on the rear side inside the projector main body 10, and the illumination light from this light source device 50 passes through the display panel cooling body 31 and enters the liquid crystal display panel 30 from the back side, and the liquid crystal display The light transmitted through the panel 30, that is, the displayed image on the liquid crystal display panel 30, is focused onto the projection lens 20 by the condensing Fresnel lens 40, and can be enlarged and projected onto the screen surface by the projection lens 20.

The light source device 50 includes a light source lamp 52 in a light source box 51 made of a metal plate with a circular opening formed in the front surface.
The illumination light from this light source lamp 52 is transmitted to the liquid crystal display panel 30.
It is equipped with a reflector 53 that reflects the light toward the
This reflector 53 is a parabolic mirror reflector that reflects the illumination light from the light source lamp 52 as parallel light parallel to the optical axis 0, and is fixed to the light source box 51 by screws or other means. ing. Further, as the light source lamp 52, a high voltage arc lamp such as a xenon lamp with high emission brightness is used.The light source lamp 52 is supported by the reflector 53 by inserting its base into the neck portion of the reflector 53. At the same time, the anode terminal 52a and the cathode terminal 52b at both ends thereof are connected to a light source power circuit board 55 which is disposed upright on the side of the light source box 51 via lead wires 54a and 54b.

Next, the configuration of the display panel cooling body 31 will be explained.
This display panel cooling body 31 is for cooling the liquid crystal display panel 30, which is heated by the temperature rising inside the projector body 10 due to radiant heat from the light source device 50 (heat generated by the light source lamp 52). The cooling body 31 is
A transparent cooling medium 35 such as an ethylene glycol aqueous solution is filled in a cooling container with a closed structure in which both sides of a vertical frame 32 having an external shape sufficiently larger than the liquid crystal display panel 30 are closed with transparent plates 33 and 34 made of glass or the like. The liquid crystal display panel 30 is fixed to the outer surface of the projection lens side transparent plate 34 of the display panel cooling body 31 by means of adhesive or the like. Further, 36 is a cooling pipe provided in the display panel cooling body 31, avoiding a portion corresponding to the liquid crystal display panel 30, and both ends of the cooling pipe 36 protrude outside from both sides of the cooling container. It is inserted into the upper part of the cooling container. This cooling pipe 36 is for releasing heat absorbed by the cooling medium 35 in the display panel cooling body 31 to the outside, and the central part of the cooling pipe 136 inserted into the cooling container is a heat absorbing part. Both end portions protruding outside the cooling container are used as heat radiating parts, and each heat radiating part is provided with a plurality of heat radiating fins 37,37. The radiation fins 37.37 are large-area fins in the form of vertically long strips, and each of the radiation fins 37.37 efficiently directs the air that has flowed inside the projector body 10 and cooled the liquid crystal display panel 30 in the exhaust direction. The plate surface is aligned in a direction perpendicular to the display surface of the liquid crystal display panel 30 so as to guide the liquid crystal display panel 30, and the plate surface is inclined inward from the lower end toward the upper end (towards the center of the display panel cooling body 31). and are arranged parallel to each other. This cooling pipe 36 is
Although its structure is not shown, it is similar to a general heat pipe.
A small amount of working fluid (heat transfer medium) is sealed inside a metal pipe with both ends closed and the inside evacuated.The entire inner surface of this cooling pipe 36 is filled with a capillary tube that carries the working fluid inside the pipe. As a result of this phenomenon, an asbestos-like wick is formed that leads from the heat radiating section to the heat absorbing section. The working fluid transfers heat through a reversible two-phase change of evaporation and condensation, and a fluid with a high latent heat coefficient and excellent permeability, such as fluorocarbon, is used as the working fluid.

This working fluid is heated and evaporated by heat exchange with the cooling medium 35 in the display panel cooling body 31 in the heat absorbing part of the cooling pipe 136, and rises in the pipe 36 as steam, and at the same time in the heat radiating part. It condenses and liquefies due to heat radiation to the outside, and the working fluid that has been liquefied by losing its latent heat is
It penetrates the wick and is led back to the heat absorption area by capillary action. Note that this cooling pipe 36 has a central portion in order to guide the working fluid that has evaporated in the heat absorption part to the heat radiation parts at both ends of the pipe, and to guide the working fluid that has liquefied in the heat radiation part and permeated into the wick to the heat absorption part again. It is the lowest and both ends are bent obliquely upward.

That is, the display panel cooling body 31 is cooled from the inside by the cooling medium 35 therein, and forcibly cools the liquid crystal display panel 30 fixed to the display panel cooling body 31. Since the heat is radiated to the outside by the radiating fins 37, 37 provided in the radiating portion of the cooling pipe 36, the temperature of the cooling medium 35 is always maintained at a low temperature.

In FIG. 1, 38 is a main circuit board installed upright on one side of the projector main body 10, and this main circuit board 38 processes television radio waves received by an antenna (not shown). The liquid crystal display panel 30 is connected to the display drive circuit portion of the main circuit board 38 by a sheet-like flexible connector (not shown). There is.

On the other hand, slit-shaped intake holes 12, 12 are provided on the lower edges of the front and rear surfaces and both sides of the projector main body 10, respectively, for taking in outside air into the projector main body 10, and on the upper surface of the projector main body 10, A plurality of slit-shaped exhaust holes 13 are provided in the center of the projector body 10, and a blower fan 1 is provided at the upper part of the projector main body 10 under the formation of the slit-shaped exhaust holes 13.
4 is installed.

The blower fan 14 sucks outside air into the projector body 10 through the intake holes 12 and 12 and exhausts the cooling air taken in from the outside through the exhaust holes 13, and is configured to Cooling air taken into the projector body 10 through the intake holes 12.12 flows through the projector body 10 as shown by arrows in FIG. etc., as well as the heat dissipation fins 37 and 37 of the display panel cooling body 31.
It exchanges heat with the air and is discharged from the exhaust hole 13. Furthermore, the cooling air taken into the projector body 10 through the heron air hole 12 on the rear surface of the projector body 10 cools the light source device 50 from its rear side, and connects the outer surface of the light source box 51 and the partition wall provided inside the projector body 10. 15 to the front of the light source device 50, and is taken in through the intake holes 12 on both sides of the projector body 10 and discharged through the exhaust hole 13 together with the cooling air that air-cools the light source device 50 from its front side.

Further, there is a heat insulation between the light source device 50 and the display panel cooling body 31 to partition the space. 160 is vertically provided and biased toward the display panel cooling body 31 side. This insulation wall 7
0 is provided to suppress the heating of the display panel cooling body 31 and the liquid crystal display panel 30 due to radiant heat from the light source device 50. A transparent plate 62 made of an infrared absorption filter or heat-resistant glass is attached to this opening 61.

Further, 56 is an explosion-proof wall made of a metal plate provided around the front side of the light source device 50, and this smoke-proof wall 56 is used to prevent abnormal overheating of the light source lamp 52 made of a high-voltage arc lamp such as a xenon lamp. When it ruptures, scattered fragments (
This is provided to prevent the circuit board 38, 55, etc. inside the projector main body 10 from being damaged due to glass fragments being scattered around.

Further, 70 is a stand body for supporting the projector body 10 diagonally upward when the liquid crystal projector is placed on a desk or the like, and this stand body 70 is provided on the front end side of the projector body 10. This stand body 70 is moved up and down via a screw shaft 72 provided vertically within the projector body 10 by turning a stand height adjustment operation knob 71 provided on the outer surface of the projector body 10. , the screw shaft 72 is rotated by the gear 73 by rotation of the operating knob 71.
．． 74. 75 is a moving member that is screwed onto the screw shaft 72 and is moved up and down by the rotation of the screw shaft 72;
This moving member 75 is prevented from rotating by a guide plate 76 provided vertically within the projector main body 10, and is configured to move up and down while being guided by this guide plate 76. Further, the stand body 70 includes a screw shaft 7
The projector body 10 is attached to the lower end of the vertical portion 70a parallel to the projector body 10.
The projector body 1 is made of a single round steel bar with a leg portion 70b that protrudes below the bottom surface of the projector body 1.
The projector is extended horizontally in the width direction of the projector so as to stably abut against a projector mounting surface a such as a desk top. and,
This stand body 10 is fixed to the movable member 75 at the upper end of its vertical portion 70a, and is moved up and down together with the movable member 75 while being guided by a stand insertion hole 77 provided on the bottom surface of the projector body 10. It looks like this.

Further, an infrared sensor 81 for receiving an infrared signal from the remote controller 80 shown in FIG. In response to a command, a channel is selected and the television image is displayed on the liquid crystal display panel 30. In FIG. 3, 90 is an antenna feeder line connected to the projector main body 10, and 91 is a power cord. Furthermore, as shown in FIG. 3, the top surface of the projector body 10 is provided with a carrying handle 92 for carrying the liquid crystal projector. Both ends are pivotally supported by the mounting portions 16.16, so that they can be raised and lowered.

The above-mentioned liquid crystal projector enlarges and projects the television image displayed by the liquid crystal display panel 30 onto the external screen 100 as shown in FIG. As the lamp 52 lights up, the linear circuit and the display drive circuit become operational to display the television image of the station selected by the remote controller 80 on the liquid crystal display panel 30. A television image is enlarged and projected onto a screen 100 by a projection lens 20. The screen 10
For example, 0 is a 50-inch screen (about 80 cm tall and about 100 cm wide).
cm+), and in this embodiment, the screen 100 includes upper, lower, left and right frames 101, 10 that curve in an arc shape.
1, 102, and 102 support the periphery of a screen sheet 103 made of an aluminum sheet or the like with a thickness of about 0.25 mm, and a spherical screen is used in which the screen sheet 103 is curved into a spherical shape. In addition, 10
4 is the frame body 102 on both sides, and the screen sheet 1
03, and this screen 100 is supported by the stand (not shown) by attaching the reinforcing material 104 to a stand (not shown).

Therefore, in the above liquid crystal projector, not only the liquid crystal display panel 30 is air-cooled by the cooling air taken into the projector main body 10 from the outside, but also the heat dissipating fins 3
Display panel cooling body 31 is cooled by heat exchange between 7.37 and the cooling air taken into the projector main body 10
Since the liquid crystal display panel 30 is forcibly cooled by this method, the liquid crystal display panel 30 can be cooled doubly by air cooling and cooling by the display panel cooler 31. Moreover, in this liquid crystal projector, each of the heat dissipating fins 37 and 37 of the display panel cooling body 31 is provided with its plate surface along a direction perpendicular to the display surface of the liquid crystal display panel 30, so that The air that cools the liquid crystal display panel 30 through the heat radiation fins 37.37
Since the air that hits the surface of the liquid crystal display panel 30 and cools the display panel 30 is guided by the radiation fins 37 and 37, the air does not stagnate around the display panel 30. Since it flows in the exhaust direction, the flow of air that cools the display panel 30 can be improved and the air cooling efficiency of the display panel 30 can be improved, and the heat exchange efficiency between the cooling air and the radiation fins 37 and 37 can be improved. The cooling efficiency of the display panel cooling body 31 can also be improved. Therefore, according to this liquid crystal projector, the display panel 30 can be sufficiently and efficiently cooled to reliably prevent the temperature of the display panel 30 from rising. There is no need to worry about the lifespan of the LCD being shortened.

FIG. 4 shows another embodiment of the present invention, in which each radiation fin 37.3 of the display panel cooling body 31 is
A wing portion 37 extending directly below the blower fan 14 on the upper end side of the fan 7
By forming the fins 37 and 37a, the cooling air is guided in the exhaust direction even better, and the heat radiation area of the radiation fins 37 and 37 is increased, thereby further improving the cooling efficiency of the display panel cooling body 31. It is.

In addition, in the above embodiment, the liquid crystal display panel 30 is brought into contact with the display panel cooling body 31, but this display panel 30
may be placed close to the display panel cooling body 31, and the blower fan 14 may be placed not on the exhaust hole 13 side but on the intake hole 1 side.
It may be provided on the second side. Furthermore, in the above embodiment, the display panel 3
Although the description has been made regarding a liquid crystal projector that projects a display image of 0 on an external screen 100, this invention can also be applied to a liquid crystal projector that has a translucent screen on the front of the projector body, and is not limited to liquid crystal projectors. Needless to say, the present invention can be widely applied to display devices equipped with display panels.

〔Effect of the invention〕

According to this invention, the display panel can be cooled doubly by air cooling and cooling by the display panel cooling body, and the air that cools the display panel by hitting the display panel surface is radiated by the display panel cooling body. The air that cools the display panel is guided by the fins and flows in the exhaust direction without being stagnant around the display panel, improving the flow of air that cools the display panel and improving the air cooling efficiency of the display panel. It is possible to reliably prevent a rise in temperature of the display panel by cooling the display panel quickly and efficiently.

[Brief explanation of the drawing]

1 and 2 are an exploded perspective view and a vertical sectional side view of a liquid crystal projector showing one embodiment of the present invention, FIG. 3 is a diagram of the liquid crystal projector in use, and FIG. 4 is a diagram showing another embodiment of the invention. FIG. 2 is a cutaway perspective view of the liquid crystal projector shown in FIG. DESCRIPTION OF SYMBOLS 10... Projector main body, 30... Liquid crystal display panel, 31... Display panel cooling body, 35... Cooling medium, 36... Cooling vibrator, 37... Radiation fin.

Claims (1)

[Claims] In a display device equipped with a display panel, a plurality of heat dissipating fins are included in the device body, which is equipped with a display panel air cooling means that takes in outside air and cools the internal display panel. A display panel cooling body that is cooled by heat exchange with cooling air is provided, and the display panel is disposed in contact with or in close proximity to the display panel cooling body, and each radiation fin of the display panel cooling body is connected to the display panel. A display device characterized in that the display device is provided in a position that guides cooled air in an exhaust direction.