JPH0469641A - Light source device for projection type liquid crystal 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] [Industrial application field] The present invention relates to a light source device for a projection type liquid crystal display device.

[Conventional technology]

A projection display device using a liquid crystal is one in which light from a light source is incident on a transmissive liquid crystal panel, and a display image generated on the liquid crystal panel is projected onto a screen surface.

The liquid crystal used in this type of liquid crystal projector is
It easily deteriorates due to temperature changes, and for example, deteriorates the characteristics of an electronically controlled alignment film and makes the responsiveness of image display unstable.

Since the projection type display device described above uses high voltage discharge lamps such as halogen lamps, xenon lamps, and metal halide lamps, radiant heat from these light sources poses a problem.

For this reason, conventionally, as disclosed in Japanese Unexamined Patent Publication No. 62-1.59], No. 20, a cooling panel containing a heating medium is provided directly adjacent to the liquid crystal panel, and the cooling panel Devices have been proposed that cool liquid crystal panels and protect them from heat from light sources.

[Problem to be solved by the invention]

However, with the above-mentioned conventional techniques, it cannot be said that it is necessarily sufficient to protect the liquid crystal against an increase in radiant heat from the light source when the device is downsized or the brightness of the light source is increased.

The present invention was conceived in consideration of the above circumstances, and its purpose is to effectively suppress the temperature rise of the liquid crystal panel due to radiant heat from the light source, and to enable miniaturization of the device and use of high-intensity light sources. An object of the present invention is to provide a projection type liquid crystal display device that provides a projection type liquid crystal display device.

[Means to solve the problem]

In order to achieve the second object, the present invention attempts to remove the radiant heat generated by the light source in the vicinity of the light source without removing it with a liquid crystal panel, and the means for this purpose is to forcibly circulate a heat medium. The cooler is integrated with the light source and the reflector to directly remove the radiant heat from the light source.

Further, the reflecting mirror has a function of selectively reflecting wavelengths of light, and is configured to transmit infrared rays, which are easily converted into heat.

[Effect]

According to the present invention, the light source is surrounded by a heating medium, and the heating medium is forcedly circulated by a pump. Therefore, the heat radiated from the light source can be reliably removed, and a similar cooling device is also provided for the reflecting mirror. This makes it possible to remove most of the radiant heat near the light source.

〔Example〕

Embodiments of the present invention will be described below regarding a projection type liquid crystal display device that projects television images onto a screen.

FIG. 2 is a diagram showing the principle of a projection type liquid crystal display device to which the present invention is implemented. Light emitted from a light source 1 is collimated by a condenser lens 3, illuminates a liquid crystal panel 4, is magnified by a projection lens 5, and forms an image on a screen 6.

FIG. 1 is a side sectional view showing one embodiment of the present invention. 1 is a light source, and a high-intensity lamp such as a xenon lamp, a halogen lamp, or a metal halide lamp is used. Reference numeral 7 denotes a reflecting mirror that directs the light emitted from the light source 1 to the condenser lens 3.
The light is focused on.

Reference numeral 8 denotes a cooling device integrally constructed with the light source 1 with a space 8a provided outside the light source 1, and communication holes 8b and 8c communicating with an external circulation pipe 9 are provided at both ends of the cooling device.

A part of the circulation pipe 9 includes a heat radiation section 10 having heat radiation fins lOa, and a pump 11 for circulating a heat medium such as water or ethylene glycol through the cooling device 8 and the circulation pipe 9. A fan 14 is configured to blow air to the heat radiation section 10.

Further, the cooling device 8 includes a temperature sensor such as a thermistor or a bimetallic temperature sensor 12.

In the light source device 13 having the above configuration, when power is applied to the light source 1, the light source 1 starts emitting light and dissipating heat. Immediately after the power is turned on, the pump 11 and the fan 14 are stopped, and are driven only when the temperature exceeds the temperature set by the temperature sensor 12 as the temperature of the cooling device increases. Along with the light emission from the light source 1, the cooling device 8
The temperature of the heating medium inside begins to rise, and the heating medium is circulated by the drive of the pump 11, but the heat from the light source 1 is radiated to the outside of the light source device 13 by the fan 14 in the heat radiating section 10 as shown by the arrow. Ru. The cooled heat medium returns to the cooling device 8 via the pump II and repeats the thermal cycle.

In order to increase the efficiency of removing heat emitted from the light source 1, an inorganic material such as calcium or silica may be mixed into the heat medium, which is the circulating fluid, as a heat absorbing material 2. The material may be transparent and absorb only infrared wavelengths.

In this embodiment, the fan 14 is driven in conjunction with the pump 11, but it can also be driven independently of the pump 11, and its rotational speed is determined by the temperature sensor 12 of the cooling device 8. Correspondingly, it can also be controlled arbitrarily.

FIG. 3 is a side sectional view showing another embodiment of the present invention. The present invention relates to a cooling device for a reflecting mirror, and components having the same functions as those in FIG. 1 are given the same reference numerals.

7 is a reflecting mirror for condensing the light emitted from the light source 1 onto the condenser lens 3. On the back surface of the reflecting mirror 7, a cooling device 7a that is connected to the circulation pipe 9 is arranged in a spiral shape. In this embodiment, 7b is the inlet of the spiral cooling device, which spreads outward from the center and extends from the heat dissipation section 10.7c. It communicates with the pump 11. Similar to the embodiment shown in FIG. 1, a heat medium such as water or ethylene glycol is appropriately circulated through this circulation system by a pump 11.

In the light source device 13 having the above configuration, when the light source 1 is powered on, the heat medium in the cooling device is immediately transferred to the pump 1.
1 starts the circulation. Therefore, the heat radiated from the light source 1 is carried by the heat medium to the heat radiating section 10 without being accumulated in the reflecting mirror, and is radiated to the outside by the fan 14 as shown by the arrow.

The reflecting mirror 7 of this embodiment may be a mirror that reflects only the visible light necessary for liquid crystal display out of the light from the light source 1, and selectively transmits wavelengths of 760 nm or more, for example.

As shown in FIGS. 1 and 3, the method for removing radiant heat from a light source has been described above using two examples. Although the above-mentioned embodiments have disclosed the case where each is used independently, the heat medium circulation system path of the light source and the reflecting mirror is the same, and 1
A system may also be used in which circulation is performed using two pumps.

Further, although this embodiment discloses an example of a single lamp as a light source, the object of the present invention can be achieved even if the cooling device of the present invention is constructed using a plurality of light sources. be.

〔Effect of the invention〕

As described above, according to the present invention, the heat dissipated from the light source is removed within the light source device, and the influence of temperature on surrounding structures and the liquid crystal panel can be reduced.

The heat removal effect is efficient because a liquid heating medium is used, and the heat is removed directly from the light source, which is the source of the heat, so it is effective to keep the heat dissipated within the light source device.

This has the advantage that the liquid crystal and the light source can be provided closer to each other than in the past, and the size of the entire projection apparatus can be reduced.

Conventionally, this type of device was generally used indoors and in dark places, but according to the present invention, even if the amount of light from the light source is increased,
Since radiant heat can be efficiently removed, projection can be performed in bright places such as outdoors without increasing the size of the device, and therefore a high-output, high-brightness light source can be used.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing one embodiment of the present invention, FIG. 2 is a schematic diagram showing the configuration of a projection type liquid crystal display device to which the present invention is implemented, and FIG. 3 is another embodiment of the present invention. A side sectional view showing
It is. 1... Light source 2... Absorbing material 7... Reflecting mirror 8... Cooling device 9 ゛10... Heat dissipation part 11... ... Pump 12 ... Temperature sensor 13 ... Light source device] 4 ... Fan 15 ... Heat medium) 7 Deshi 7 7 α-11 Oki fP Kofu b-one population

Claims (1)

[Scope of Claims] 1. In a light source device for a projection type liquid crystal display device, an enclosure member that surrounds a high voltage discharge lamp as a light source and forms a space for sealing a heat medium between it and the lamp; A heating medium circulation path for taking out the heating medium sealed in the space from one end of the space and guiding it to the other end of the space and returning it from there into the space, and a heating medium circulation operation in the heating medium circulation path. A driving pump to be realized, a radiation fin and its cooling fan formed in the heat medium circulation path, a temperature sensor that senses the temperature of the surrounding member and controls the operation of the driving pump and the cooling fan; A light source device for a projection type liquid crystal display device, comprising: 2. In a light source device of a projection type liquid crystal display device, a heating medium circulation path is formed around a reflecting mirror for projecting light from a lamp as a light source, and a heating medium circulation operation in the heating medium circulation path is realized. What is claimed is: 1. A light source device for a projection type liquid crystal display device, comprising: a driving pump for driving the heat medium; and a heat radiation fin formed in the heat medium circulation path and a cooling fan for the heat radiation fin. 3. In a light source device for a projection type liquid crystal display device, an enclosure member surrounds a high-voltage discharge lamp as a light source and forms a space for sealing a heat medium between the lamp and the lamp, and a light beam from the lamp as a light source is provided. The heating medium sealed in the space is taken out from one end of the heating medium sealing space and guided to the other end of the space through the periphery of the reflecting mirror. a heat medium circulation path for returning the heat medium from the heat medium circulation path to the space; a driving pump that realizes a circulating operation of the heat medium in the heat medium circulation path; radiation fins formed in the heat medium circulation path and a fan for cooling the heat medium circulation path; A light source device for a projection type liquid crystal display device, comprising: a temperature sensor that senses the temperature of the surrounding member and controls the operation of the drive pump and the cooling fan. 4. In the light source device for a projection type liquid crystal display device according to claim 2 or 3, the reflecting mirror reflects visible light, and
A light source device for a projection type liquid crystal display device, comprising a mirror that transmits infrared wavelengths of m or more.