JPH10186517A - Cooling device for projection display machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the use of a light source which is portable and whose luminance is high by suppressing the temperature rising of a liquid crystal panel caused by radiant heat from the light source by notching a part of a circular face mirror reflecting the light of a lamp, ventilating and cooling the lamp itself. SOLUTION: Outside air sucked by a sucking side blower 25 passes a ventilation path 28 at the inside of a housing 36, and is ventilated along the inner surface of the circular face mirror 22 and the inner surface of an ellipse face mirror 21, and cools the lamp 20. Warmed outside air passes a ventilation hole 29 provided at the circular face mirror 22, and is discharged to outside from a discharging side blower 26 by passing through the ventilation hole 33 provided at a first lamp case 30. Also, the wall of the ventilation path is rounded by the curvature of >=1/3 of the width measurement of the ventilation path 28 at a bent part, so that the outside air led to the ventilation hole 29 of the circular face mirror 22 becomes a lamina flow by rounding. Thus, the occurrence of a vortex caused by a turbulent flow is prevented, and noise due to ventilation is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cooling means for a projection display.

[0002]

2. Description of the Related Art An example of a projection type display using liquid crystal will be described as an embodiment of a liquid crystal panel. In the projection display, light from a light source is incident on a transmission type liquid crystal panel, and a display image generated on the liquid crystal panel is projected on a screen surface. The liquid crystal used in the projection type display device of this type is easily deteriorated by a change in temperature. For example, the characteristics of the alignment film are reduced by electronic control, and the responsiveness of the image display becomes unstable.

[0003] Since the above-mentioned projection type display device uses a high-voltage discharge lamp such as a halogen lamp, a xenon lamp and a metal halide lamp, radiant heat from these light sources is a problem.

For this reason, conventionally, as disclosed in Japanese Patent Application Laid-Open No. 4-69641, a cooler in which a heat medium is forcibly circulated is integrally formed with a light source or a reflector to directly radiate heat from the light source. Some have been removed.

[0005]

In the prior art as described above, the cooling effect is sufficient with respect to the increase in radiant heat from the light source when the brightness of the device light source is increased. However, since the heat medium is forcibly circulated, pipes for circulating water or ethylene glycol as heat medium, circulation pumps, and radiating fins are required separately from the cooling blower, which makes the entire device larger and inconvenient for portable use. There was a problem.

The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide a projection type liquid crystal display device which is capable of effectively suppressing a temperature rise of a liquid crystal panel due to radiant heat from a light source, and which is portable and can use a high brightness light source.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a light source to which light is incident, a liquid crystal panel to which light emitted from the light source is incident, and a display image from the liquid crystal panel. In a projection type display having a projection lens for projecting on a screen and a cooling unit for cooling the light source and the liquid crystal panel, the cooling unit includes ventilation by a suction side blower and a discharge side blower, and the suction side blower and discharge A circular mirror for guiding the light of the light source to the liquid crystal panel is provided in a ventilation path connecting the side blowers, a ventilation hole is provided in the circular mirror itself, and the light source body passes through the ventilation hole. .

As a light source, a rear portion of a lamp made of a light-emitting body is covered by an ellipsoidal mirror having a substantially hemispherical shape, a front portion is covered by a circular mirror centered on the lamp, and ventilation is applied to the outer shape of the circular mirror itself. A hole is provided and air is blown from the ventilation hole.

The ventilation path has a bend until reaching the discharge-side blower, and the wall of the bend has a radius or an inclination of 1/3 or more of the width of the ventilation hole.

In the light source, a lamp composed of a light emitting body is covered with a substantially hemispherical ellipsoidal mirror at the rear part, a front part is covered with a circular mirror centered on the lamp, and ventilation holes are provided in the circular mirror. The discharge side blower is provided at a rear portion of the elliptical mirror, and ventilation is bent in front of the circular mirror, flows along the inner surface of the elliptical mirror, and flows out of the ventilation hole.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view of a three-panel projection type liquid crystal display according to a first embodiment. Reference numeral 1 denotes a light source, 2 denotes a first dichroic mirror, 3 denotes a second dichroic mirror, 5 denotes a first reflecting mirror, 6 denotes a second reflecting mirror, 7 denotes a third reflecting mirror, and 8 denotes a second reflecting mirror. Four reflecting mirrors, 9 is a first red liquid crystal panel as first liquid crystal display means, 10 is a second green liquid crystal panel as second liquid crystal display means, and 11 is third liquid crystal display means. A blue third liquid crystal panel, 12 is a dichroic prism, 13 is a polarizing plate, 14 is a set of projection lenses, 15 is a first condenser lens, and 16 is a second condenser lens.

In FIG. 1, a light source 1 is a metal halide lamp, which is arranged downward in the figure. Light emitted from the light source 1 passes through a filter (not shown) for cutting off ultraviolet rays and a first condenser lens 15, and passes through a first reflecting mirror 5.
At 90 °, only the red light is reflected by the first dichroic mirror 2, and the others pass. Then, the red light is reflected by the second reflecting mirror 6 and irradiates the first liquid crystal panel 9 for red.

On the other hand, the blue light and the green light passed by the first dichroic mirror 2 pass through the second dichroic mirror 3, and the green light is separated by reflection, and the green light is separated for green. The second liquid crystal panel 10 is irradiated, and the blue light is reflected by the third reflecting mirror 7 and the fourth reflecting mirror 8, respectively, and irradiates the third liquid crystal panel 11 for blue.

The first to third liquid crystal panels 9, 10,
11 is driven by the R, G, and B video signals, so that the transmitted light of each panel is luminance-modulated by the video signal. Then, the red light, the blue light and the green light whose luminance has been modulated are synthesized by the dichroic prism 12 and enlarged by the projection lens set 14. The above is the optical path.

FIG. 2 is a plan view of a cooling path showing an embodiment of the cooling means having the optical path of FIG. 1, and FIG.
FIG. 4 shows a cross-sectional view along the line A. Symbol 2 in each figure
0 indicates a lamp which is the main body of the light source 1, and 21 indicates a lamp 2
An ellipsoidal mirror for reflecting light 0 in the downward direction in the drawing, 22 is a circular mirror emitted by the lamp 20 and returning light leaking to the surroundings to the lamp 20, 25 is a suction side blower, 26 is a discharge side A blower, 28 is a ventilation path, 29 is a ventilation hole provided in a circular mirror, 30 is a first lamp case, 32 is a second lamp case, 36 is a housing, and 37 is a unit case.

In FIG. 3, the outside air is sucked by the suction side blower 25, and the ventilation passage 2 provided in the housing 36 is provided.
8, through the inner surface of the circular mirror 22 (b in the figure), through the inner surface of the elliptical mirror 21, through the lamp 20, and through the ventilation holes 29 provided in the circular mirror 22. , The lamp 20 is air-cooled, and the heat is discharged from the discharge-side blower 26 to the outside through the ventilation holes 33 provided in the first lamp case 30. That is, by sucking, ventilating, and discharging outside air in the order of symbols A, B, and C in the figure, the lamp 20 is mainly air-cooled to prevent heat generation. Further, the wall of the ventilation path 28 has an R of 1/3 or more of the width dimension of the ventilation path 28 at the bent portion,
The air is guided to the ventilation holes 29 of the circular mirror 22, and the ventilation forms a laminar flow by this R, preventing the generation of eddies due to the turbulent flow, smoothing the ventilation, and preventing the generation of sound due to the ventilation. Ventilation path 28
Is provided as a wide ventilation passage 28 below the unit case 37 that covers the optical unit such as the first light collection lens 15 and is effective in compactly integrating the entire apparatus.

[0018]

As described above, according to the present invention, as a means for cooling the heat radiated from the light source by the wind blowing the lamp, a part of a circular mirror for reflecting the light of the lamp is cut out and the ventilation is performed. By cooling itself, it is efficiently cooled by a small-sized device, and by providing a large radius R in a curved ventilation path, the efficiency of ventilation is increased and there is an effect of preventing generation of sound.

[Brief description of the drawings]

FIG. 1 is a schematic view of an entire three-panel projection type liquid crystal display device according to a first embodiment.

FIG. 2 is a plan view of a cooling path showing one embodiment of a cooling unit having the optical path shown in FIG. 1;

FIG. 3 is a sectional view taken along the line AA of FIG. 2;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Light source, 2 ... 1st dichroic mirror, 3 ... 2nd dichroic mirror, 12 ... dichroic prism, 15 ... 1st light collecting lens, 16 ... 2nd light collecting lens, 20 ... lamp, 21 ... ellipse Surface mirror, 22 ... Circular mirror, 2
5: suction side blower, 26: discharge side blower, 29: ventilation hole, 30: first lamp case, 36: housing, 3
7. Unit case.

Claims (3)

[Claims] 1. A light source for inputting light, means for separating light into RGB, and means for combining light, a liquid crystal panel on which light emitted from the light source is incident, and a display image from the liquid crystal panel is projected on a screen. In a projection display having a projection lens, and a cooling unit for cooling the light source and the liquid crystal panel, the cooling unit includes ventilation by a suction-side blower and a discharge-side blower, and ventilation that connects the suction-side blower and the discharge-side blower. A cooling device for a projection display, wherein a circular mirror for returning a part of the light from the light source to the light source is provided in a path, and a ventilation hole is formed in the circular mirror itself. 2. The apparatus according to claim 1, wherein the ventilation path has a bend until reaching the discharge-side blower, and the wall of the bend has an R or an inclination of at least １ ／ of the width of the ventilation hole. 3. A light source for receiving light, a liquid crystal panel on which light emitted from the light source is incident, a projection lens for projecting a display image from the liquid crystal panel onto a screen, and the light source and the liquid crystal panel. In a projection display having a cooling means for cooling, the cooling means comprises an intake-side blower and an exhaust-side blower, and the light source covers a rear portion of a lamp made of a light-emitting body with an ellipsoidal mirror having a substantially hemispherical shape. Covering the front part with a circular mirror centered on the lamp, providing a ventilation hole in the circular mirror, disposing the discharge side blower at the rear part of the elliptical mirror, ventilation is bent in front of the circular mirror, A cooling device for a projection display, characterized in that it flows along an inner surface of an ellipsoidal mirror and flows out of a ventilation hole.