JP2540833B2 - Display device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a display device including a display panel.

[Prior Art] As a display device having a display panel, there is one in which outside air is taken into the device body to cool the display panel in the device body by air, and examples of this type of display device include a liquid crystal projector and the like. It has been known.

In this liquid crystal projector, a transmissive liquid crystal display panel for displaying television images and the like is provided in the main body of the device, a light source is arranged behind the display panel, and a projection lens is arranged in front of the display panel. This is a method for enlarging and projecting the display image of the display panel on the screen surface by the projection lens. In this liquid crystal projector, the liquid crystal display panel is heated by the heat from the light source, and its display contrast is lowered or the life of the liquid crystal is shortened. In order to prevent this, a display panel air-cooling unit that takes in outside air into the main body of the apparatus to cool the display panel by air is provided to suppress the temperature rise of the display panel.

[Problems to be solved by the invention]

However, the display panel air-cooling means provided in the display device such as the liquid crystal projector described above simply cools the display panel by flowing cooling air taken in from the outside into the main body of the device. Insufficient cooling is possible, and because the air that has hit the display panel surface and cooled the display panel stays around the display panel and reduces the cooling efficiency of the display panel, the temperature rise of the display panel is ensured. I had a problem that I could not prevent.

The present invention has been made in view of the above circumstances, and an object of the present invention is to sufficiently and efficiently cool a display panel to reliably prevent a temperature rise of the display panel. The present invention is to provide a display device.

[Means for solving problems]

According to the present invention, a plurality of heat radiation fins are provided in a device body provided with a display panel air cooling means for taking in outside air to cool an internal display panel, and heat generated between the heat radiation fins and cooling air taken in the device body. A display panel cooling body that is cooled by replacement is provided, and the display panel is arranged in contact with or close to the display panel cooling body, and each radiating fin of the display panel cooling body is connected to the air that cools the display panel. It is characterized in that it is provided in a posture in which it is guided in the exhaust direction.

[Action]

That is, in the display device of the present invention, not only the display panel is air-cooled by the cooling air taken in from the outside, but also the display panel cooling body is cooled by the heat exchange between the radiation fins and the cooling air taken in the device body. In addition to forcibly cooling the display panel, the air that has cooled the display panel is guided in the exhaust direction by the radiation fins of the display panel cooling body. According to this display device, the display panel is cooled by air. It can be doubly cooled by cooling with 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 not exhausted in the periphery of the display panel in the exhaust direction. The air flow for cooling the display panel can be improved to improve the air cooling efficiency of the display panel. Channel can be reliably prevented sufficiently and a temperature rise in the efficiently cooled to the display panel.

〔Example〕

An example of applying the present invention to a liquid crystal projector for enlarging and projecting a television image on a screen surface will be described with reference to the drawings.

First, the overall structure of the liquid crystal projector will be described.
In FIG. 2 and FIG. 2, 10 is a rectangular box-shaped projector main body, and a projection lens 20 is provided on the front surface of the projector main body 10. The projection lens 20 is provided in a lens barrel 22 screwed into a barrel body 21 that is fixed to the front of the projector body 10 by penetrating it, and by turning the barrel 22, the projection lens 20 of the screen 100 (see FIG. 3) is displayed. The focus is adjusted according to the position. Reference numeral 30 denotes a transmissive dot matrix liquid crystal display panel for displaying a television image which is provided vertically on the front side of the projector body 10 so as to face the projection lens.
Is attached to a display panel cooling body 31, which is vertically provided in the projector main body 10 and has a configuration described later. Also,
40 is a condenser Fresnel lens arranged between the liquid crystal display panel 30 and the projection lens 20. This condenser Fresnel lens
Reference numeral 40 is for condensing the display image of the liquid crystal display panel 30 on the projection lens 20, and this converging Fresnel lens 40 is formed by concentrically forming a large number of annular convex lens portions on one surface of a transparent plate made of acrylic resin or the like. The condensing Fresnel lens 50 is held by a lens holding frame 11 provided in the projector body 10. Reference numeral 50 denotes a light source device provided on the rear side of the projector body 10. Illumination light from the light source device 50 passes through the display panel cooling body 31 and enters the liquid crystal display panel 30 from the back side thereof, and the liquid crystal display panel The light transmitted through 30, that is, the display image of the liquid crystal display panel 30, is condensed on the projection lens 20 by the condensing Fresnel lens 40 and enlarged and projected on the screen surface by the projection lens 20.

The light source device 50 includes a light source lamp 52, a light source box 51 formed of a metal plate having a circular opening formed on a front surface thereof, and a reflector 53 for reflecting illumination light from the light source lamp 52 toward the liquid crystal display panel 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 optical axis O. The reflector 53 is screwed to the light source box 51. And the like. Further, as the light source lamp 52, a high voltage arc lamp such as a xenon lamp having high emission brightness is used, and the light source lamp 52 is supported by the reflector 53 by inserting the base portion thereof into the neck portion of the reflector 53. At the same time, the anode terminal 52a and the cathode terminal 52b at both ends are connected to the light source box 51 by the lead wires 54a and 54b.
It is connected to a light source power supply circuit board 55 which is vertically arranged on the side of.

Next, the structure of the display panel cooling body 31 will be described.
The display panel cooling body 31 is for cooling the liquid crystal display panel 30 which is heated by the temperature rise of the projector body 10 caused by the radiant heat from the light source device 50 (heat generated by the light source lamp 52). The body 31 is a transparent cooling medium 35 such as an ethylene glycol aqueous solution in a hermetically sealed cooling container in which both sides of a vertical frame 32 having an outer shape sufficiently larger than that of the liquid crystal display panel 30 are closed by transparent plates 33 and 34 such as glass. 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 an adhesive or the like. Reference numeral 36 denotes a cooling pipe provided in the display panel cooling body 31 while avoiding a portion corresponding to the liquid crystal display panel 30, and this cooling pipe is provided.
36 is inserted into the upper part of the cooling container with both ends thereof protruding outward from both side surfaces of the cooling container. The cooling pipe 36 releases the heat absorbed by the cooling medium 35 in the display panel cooling body 31, to the outside.
The center part inserted into the cooling container is a heat absorbing part, and both end parts protruding outside the cooling container are heat radiating parts.A plurality of heat radiating fins 37, 37 are provided in each heat radiating part. ing. The heat radiating fins 37, 37 are long strip-shaped large-area fins, and each of the heat radiating fins 37, 37 satisfactorily exhausts the air flowing through the projector body 10 to cool the liquid crystal display panel 30. In order to guide it, the plate surface is made to extend in a direction perpendicular to the display surface of the liquid crystal display panel 30, and is inclined so as to incline inward from the lower end side toward the upper end side (center side of the display panel cooling body 31). And are provided in parallel with each other. The structure of the cooling pipe 36 is not shown, but like a general heat pipe, a small amount of working fluid (heat transfer medium) is enclosed in a metal pipe having both ends closed and a vacuum inside. , This cooling pipe
An asbestos-like wick that guides the working fluid in the pipe from the heat radiating portion side to the heat absorbing portion side by capillarity is formed on the entire inner surface of 36. The working fluid transfers heat by reversible two-phase change of evaporation / condensation. As the working fluid, for example, a fluid having a high latent heat coefficient and excellent permeability such as CFC is used. This working fluid is
In the heat absorbing portion of the cooling pipe 36, the temperature is increased by heat exchange with the cooling medium 35 in the display panel cooling body 31 to evaporate and become vapor to rise in the pipe 36, and at the heat radiating portion, heat is radiated to the outside. It is condensed and liquefied, and the working fluid liquefied by depriving latent heat permeates the wick and is again guided to the heat absorbing part by its capillary phenomenon. The cooling pipe 36 has a central portion that guides the working fluid evaporated at the heat absorbing portion to the heat radiating portions at both ends of the pipe, and guides the working fluid liquefied at the heat radiating portion and permeating the wick to the heat absorbing portion again. It is bent so as to be the lowest and both ends are inclined obliquely upward.

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

In FIG. 1, reference numeral 38 denotes a main circuit board vertically arranged on one side in the projector main body 10. The main circuit board 38 processes television radio waves received by an antenna (not shown) to generate an image signal. A liquid crystal display panel 30 is connected to the display drive circuit section of the main circuit board 38 by a sheet-shaped flexible connector (not shown).

On the other hand, the front and rear surfaces of the projector main body 10 and the lower edge sides of both side surfaces are provided with slit-shaped intake holes 12, 12 for taking in outside air into the projector main body 10, and the upper surface of the projector main body 10 is provided. A plurality of slit-shaped exhaust holes 13 are provided in the center thereof, and the slit-shaped exhaust holes 13 are further provided in the upper part of the projector body 10.
A blower fan 14 is installed below the forming portion of 13. The blower fan 14 sucks the outside air into the projector body 10 through the intake holes 12 and 12 and discharges the cooling air taken in from the outside through the exhaust hole 13. Intake hole 1
Cooling air taken into the projector main body 10 from 2, 12 flows in the projector main body 10 as shown by an arrow in FIG. 2 and cools the condenser Fresnel lens 40, the liquid crystal display panel 30, the main circuit board 38, and the like. In addition, heat exchange with the heat radiation fins 37, 37 of the display panel cooling body 31 is performed and the exhaust hole 1
Emitted from 3. Further, the cooling air taken into the projector main body 10 through the intake holes 12 on the rear surface of the projector main body 10 cools the light source device 50 from the rear side thereof to partition the outer surface of the light source box 51 into the professional main body 10. It flows from between the wall 15 and the front of the light source device 50, is taken in through the intake holes 12 on both side surfaces of the projector body 10, and is exhausted from the exhaust hole 13 together with the cooling air that has cooled the light source device 50 from the front side thereof.

Further, between the light source device 50 and the display panel cooling body 31, a heat insulating wall 60 for partitioning the space is vertically provided so as to be biased toward the display panel cooling body 31 side. The heat insulating wall 70 is provided to suppress the heating of the display panel cooling body 31 and the liquid crystal display panel 30 due to the radiant heat from the light source device 50. The heat insulating wall 60 is illuminated by the light source device 50. An opening 61 for transmitting light is provided, and a transparent plate 62 made of an infrared absorption filter or heat resistant glass is attached to the opening 61.

Reference numeral 56 is an explosion-proof wall made of a metal plate provided around the front side of the light source device 50. The explosion-proof wall 56 is a light source lamp 52 made of a high voltage arc lamp such as a xenon lamp.
When abnormal temperature occurs and bursts, scattered fragments (glass fragments) scatter around and the circuit board inside the projector body 10
It is provided to prevent damage to 38, 55, etc.

Reference numeral 70 denotes a stand body for supporting the projector main body 10 in an obliquely upward direction when the liquid crystal projector is placed on a desk or the like and used, and the stand body 70 is provided on the front end side of the projector main body 10. This stand body 70
Is a vertically movable screw shaft 72 that is vertically provided in the projector body 10 by turning an operation knob 71 for adjusting the height of a stand provided on the outer surface of the projector body 10. Is rotated via the gears 73 and 74 by the rotation of the operation knob 71. 75 is a moving member that is screwed into the screw shaft 72 and is moved up and down by the rotation of the screw shaft 72. The moving member 75 is prevented from rotating by a guide plate 76 provided vertically in the projector body 10. The guide plate 76 moves up and down while being guided. The stand body 70 is made of one round steel rod having a leg portion 70b protruding below the bottom surface of the projector body 10 at the lower end of a vertical portion 70a parallel to the screw shaft 72. Is the projector body 10
It is extended horizontally in the width direction of the table so as to come into stable contact with the projector mounting surface a such as a desk. The stand body 70 is fixed to the moving member 75 at the upper end of the vertical portion 70a, and moves vertically along with the moving member 75 while being guided by the stand body insertion hole 77 provided on the bottom surface of the projector body 10. It is supposed to be done.

Further, an infrared sensor 81 for receiving an infrared signal from the remote controller 80 shown in FIG. 3 is provided on the front surface of the projector main body 10, and the main circuit board is provided.
38 is adapted to perform a tuning operation in response to a tuning command received by the infrared sensor 81 and display the television image on the liquid crystal display panel 30. In FIG. 3, 90 is a feeder line for an antenna connected to the projector main body 10, and 91 is a power cord. In addition, the projector body 10
As shown in FIG. 3, a handle 92 for carrying a liquid crystal projector is provided on the upper surface of the handle 92. The handle 92 is provided on both sides of the upper surface of the projector main body 10, and the handle mounting portions 16, 16 are provided. Both ends of which are axially supported so that they can be undulated.

The liquid crystal projector projects the television image displayed on the liquid crystal display panel 30 on the external screen 100 as shown in FIG.
When the power key 0 is operated, the light source lamp 52 of the light source device 50
Is turned on, the linear circuit and the display drive circuit are activated, and the television image of the station selected by the remote controller 80 is displayed on the liquid crystal display panel 30, and the television displayed by the liquid crystal display panel 30. The image is enlarged and projected on the screen 100 by the projection lens 20. The screen 100 is, for example, a 50-inch screen (length about 80 cm, width about 100 cm), and in this embodiment, as the screen 100, the upper and lower frame bodies 101, 101 and 102, 102 that bend in an arc shape have a thickness of about 0.25 mm. A spherical screen is used in which the periphery of a screen sheet 103 made of an aluminum sheet or the like is supported and the screen sheet 103 is curved in a spherical shape. Incidentally, 104 is a reinforcing member that connects the frame bodies 102, 102 on both sides on the back surface side of the screen sheet 103, and the screen 100 is the reinforcing member 1
04 is attached to a stand (not shown) and supported by this stand.

Therefore, in the liquid crystal projector, not only the liquid crystal display panel 30 is air-cooled by the cooling air taken into the projector body 10 from the outside, but also the radiation fins 37, 3
Since the liquid crystal display panel 30 is forcibly cooled by the display panel cooling body 31 which is cooled by heat exchange between 7 and the cooling air taken in the projector body 10,
The liquid crystal display panel 30 can be doubly cooled by air cooling and cooling by the display panel cooling body 31. Moreover, in this liquid crystal projector, the radiation fins 37, 37 of the display panel cooling body 31 are provided with their plate surfaces along the direction perpendicular to the display surface of the liquid crystal display panel 30, and the Since the air that has flowed through the liquid crystal display panel 30 and has cooled the liquid crystal display panel 30 is guided to the exhaust direction by the heat radiation fins 37, 37, the air that hits the surface of the liquid crystal display panel 30 and cools the display panel 30 is the heat radiation fins. Since the air flows in the exhaust direction without being stagnated around the display panel 30 by being guided by the 37, 37, it is possible to improve the air flow for cooling the display panel 30 and improve the air cooling efficiency of the display panel 30. In addition, the heat exchange efficiency between the cooling air and the radiation fins 37, 37 can be improved, and the cooling efficiency of the display panel cooling body 31 can be improved. Therefore, according to this liquid crystal projector, the display panel 30 can be cooled sufficiently and efficiently to reliably prevent the temperature rise of the display panel 30, so that the display panel 30 is heated and its display contrast is lowered. There is no concern that the life of the liquid crystal will be reduced.

FIG. 4 shows another embodiment of the present invention. In this embodiment, the blade portions 37a, which extend directly below the blower fan 14, are provided on the upper end sides of the respective radiation fins 37, 37 of the display panel cooling body 31. By forming 37a, the cooling air can be guided more satisfactorily in the exhaust direction, and the heat dissipation areas of the heat dissipation fins 37, 37 can be increased to further improve the cooling efficiency of the display panel cooling body 31. .

Although the liquid crystal display panel 30 is brought into contact with the display panel cooling body 31 in the above embodiment, the display panel 30 may be arranged close to the display panel cooling body 31, or the blower fan 14 may be provided. May be provided on the intake hole 12 side instead of the exhaust hole 13 side. Further, although the liquid crystal projector that projects the display image of the display panel 30 onto the external screen 100 has been described in the above embodiment, the present invention can be applied to a liquid crystal projector in which a semitransparent screen is provided on the front surface of the projector body, and the liquid crystal It is needless to say that the present invention can be widely applied to not only a projector but also a display device having a display panel inside.

〔The invention's effect〕

According to this invention, the display panel can be doubly cooled by air cooling and cooling by the display panel cooling body, and the air that has hit the display panel surface and cooled the display panel dissipates heat from the display panel cooling body. Since the air flows in the exhaust direction without being stagnant around the display panel guided by the fins, the flow of air for cooling the display panel can be improved to improve the air cooling efficiency of the display panel. In addition, it is possible to surely prevent the temperature rise of the display panel by cooling efficiently and efficiently.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 and FIG. 2 are a cutaway perspective view and a vertical side view of a liquid crystal projector showing an embodiment of the present invention, FIG. 3 is a state of use of the liquid crystal projector, and FIG. It is a cut-away perspective view of a liquid crystal projector showing another embodiment of the invention. 10 …… Projector body, 30 …… Liquid crystal display panel, 31…
… Display panel cooling body, 35 …… cooling medium, 36 …… cooling pipe, 37 …… radiating fin.

Claims (1)

(57) [Claims] 1. A display device having a display panel, wherein a plurality of heat radiation fins are provided in a device body provided with a display panel air cooling means for taking in outside air to cool the inner display panel by air. A display panel cooling body that is cooled by heat exchange with cooling air taken in is provided, and the display panel is arranged in contact with or close to this display panel cooling body, and each heat radiation of the display panel cooling body is performed. A display device characterized in that the fins are provided in a posture in which air that has cooled the display panel is guided in the exhaust direction.