KR20000050982A - Cooling Apparatus In Projection System - Google Patents

Abstract

PURPOSE: A cooling apparatus for projection systems is provided to use the temperature of a liquid crystal display and a polarization plate. CONSTITUTION: A cooling apparatus for projection systems includes a 3-sheet liquid crystal display(34) as well as a polarization plate(6). The 3-sheet liquid crystal display(34) is implemented so as to be adjacent to a prism synthesizing images. The polarization plate(6) is implemented on an opposite position of the liquid crystal display and supplies the light of 3 basic lights to the liquid crystal display. The cooling apparatus for projection systems further includes a guide(4) as well as a cooling member(30). The guide(4) confines a region which is closed by being formed in a form of surrounding the image synthesizer. The cooling member(30) cools off the inner portion of the guide by using a peltier theorem. The guide is implemented on one side of the guide..

Description

Cooling Apparatus of Projection System {Cooling Apparatus In Projection System}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video projection system, and more particularly to a cooling device for a liquid crystal display (LCD) and a polarizing plate inserted into a basic optical component in a projection system.

In general, a projection system is a device composed of a light source and an optical system to enlarge an image and project it on a screen. Recently, a projection system equipped with a cathode ray tube (CRT) is followed by an LCD projection system equipped with an LCD. It is spreading. The LCD projection system is a basic optical component that includes a lamp, an LCD and a polarizer.

1 is a view schematically showing the structure of a conventional LCD projection system, wherein the LCD projection system of FIG. 1 includes a light generating lamp 2 and a light tube into which a lens group such as a reflector and a focusing lens is inserted in an optical path; (4), a composite system consisting of three polarizing plates, an LCD module (6) and a prism (8), a projection lens (10) for projecting an image incident from the prism (8) onto the screen (10), and a lamp It is provided with a ballast (Ballast) 14 to maintain the brightness of the stable.

In the LCD projection system shown in FIG. 1, a high power metal halide lamp is usually used as the lamp 2. The light beam of high power emitted from the lamp 2 is divided into three primary color light beams through the lens group inserted in the light tube 4. Each of the divided light beams is transmitted to the prism 8 through the three polarizing plates and the LCD module 6 in a state where the light transmittance is adjusted according to the input image information. The prism 8 synthesizes images of three primary colors transmitted through the three polarizing plates and the LCD 6 toward the projection lens 10, and the projection lens 10 screens the image from the prism 8. It is projected to (12).

In this configuration of the LCD projection system, the greater the intensity of the light beam projected on the screen 12, the more comfortable the user can enjoy the image. Accordingly, many efforts have been made to reduce the loss of the light beam emitted from the lamp 20 to increase the amount of the light beam incident on the polarizing plate and the LCD module 6, and the technical development continues. In addition, the LCD projection system uses a high power light source, a metal halide lamp, to improve the brightness. As a result, a large amount of heat is generated inside the LCD projection system. This heat increases the temperature of the LCD panel and the polarizer, which are the optical components of the image synthesis system of the LCD projection system, thereby causing damage to the components as well as adversely affecting the circuit portion. Accordingly, in order to cool the heat due to radiation applied to the LCD panel and the polarizer according to the brightness of the LCD projection system, a forced convection method using an axial fan 18 is conventionally used as shown in FIG. 2. Getting drunk.

In Fig. 2, the image synthesizing unit of the LCD projection system is adjacent to the three sides of the rectangular prism 8 and has three LCDs corresponding to three primary colors, i.e., red (R), green (G), and blue (B), respectively. An LCD and a polarizing plate module 8 are arranged on the rear side of the LCD and constitute three polarizing plates for supplying each of the three primary light beams to the LCD. An axial flow fan 18 and an air suction port are further provided on the image synthesizing part to discharge heat applied to the LCD and the polarizer module 8 by forced convection. In this case, the lower the outside air temperature, the greater the cooling capacity, but typically, since the use environment of the LCD projection system is indoor, it can be seen as about 25 ° C to 30 ° C. In addition, the air filter 20 is used together to prevent dust and pollutants from coming in when the outside air is sucked in. The air filter 20 acts as a resistance source in the suction air volume of the fan 18. There is a disadvantage that the cooling capacity is lowered by the suction air volume is reduced. Furthermore, in the case of using for a long time, the air filter 18 becomes dusty and the flow resistance becomes large, so that the cooling capacity is further reduced.

As described above, the forced convection cooling has a disadvantage in that the cooling efficiency is insignificant, and when the size of the cooling fan is increased to increase the cooling efficiency, the size of the entire projection system is increased as well as the noise is increased.

Accordingly, an object of the present invention is to provide a cooling system of a projection system that can increase the stability of the system by maintaining a constant temperature at all times regardless of the external temperature of the LCD and the polarizing plate by using the hermetic cooling element.

Another object of the present invention is to provide a cooling device of a projection system by using a sealed cooling element, there is no fear of accumulation of contaminants in the optical component without the need for an air filter.

1 is a view schematically showing the structure of a conventional LCD projection system.

2 is a view showing a cooling principle of the image synthesis unit shown in FIG.

2 is a view showing the structure of an LCD projection system cooling apparatus according to an embodiment of the present invention.

<Description of the code | symbol about the principal part of drawing>

2: lamp 4: light tube

6: polarizer and LCD module 8, 22: prism

10: projection lens 12: screen

14 ballast 18, 24 fan

20: air filter 26: cooling unit

28: heating part 30: Peltier cooling element

32: heat sink 34: LCD

36: polarizing plate 23: heat insulating material

In order to achieve the above object, the cooling system of the projection system according to the present invention is formed in a form surrounding the image synthesis unit, the guide unit for providing a closed space, the guide unit is installed on one side of the guide unit using the Peltier principle It is characterized by including a cooling element for cooling the inside.

Other objects and advantages of the present invention in addition to the above objects will be apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to FIG. 3.

2 is a view showing a cooling device of the LCD projection system according to an embodiment of the present invention, the cooling device shown in Figure 2 is attached to a portion of the heat insulating material 23 and the heat insulating material surrounding the compound compound portion 23; The Peltier cooling element 30, the fan 24 for circulating the air cooled by the cooling unit 26 of the Peltier cooling element 30 in the image synthesis unit, and the Peltier cooling element 30 The heat sink 32 attached to the heat generating part 28 side of the is provided.

In the cooling device of the LCD projection system shown in FIG. An LCD and a polarizing plate module comprising a sheet of LCD 34 and three polarizing plates 36 arranged on the rear side of the LCD 34 and supplying each of the three primary light beams to the LCD are provided. The heat insulator 23 is formed in a shape surrounding the image synthesis unit to seal the internal space in which the image synthesis unit is located so that the image synthesis unit is not affected by the external temperature. A portion of the heat insulator 223 is drilled to mount the cooling device 30 using the Peltier principle. The cooling unit 26 of the Peltier cooling element 30 is positioned on the heat insulating material 23 side, and the fan 24 is mounted at the front end thereof. Accordingly, by circulating the air cooled in the cooling unit 26 of the Peltier cooling element 30 through the fan 24 therein, it is possible to lower the temperature of the LCD 34 and the polarizing plate 36 module.

In detail, the Peltier cooling element 30 is an element divided into the cooling unit 26 and the heat generating unit 28 when electric power is applied, and is used in a product for cooling and also in a product for heat generation. When the air is flowed by the driving of the fan to the cooling unit 26 of the Peltier cooling element 30, the temperature of the air is very low. For example, the cooling section 26 of the Peltier cooling element 30 can generally be lowered to -50 ° C under optimum conditions. In addition, by attaching a separate heat sink 32 having good efficiency to the heat generating unit 28 of the Peltier cooling element 30, the heat generated from the heat generating unit 28 can be leaked to the outside. In addition, the image synthesis unit is blocked from the outside by the heat insulator 23 so that dust and contaminants do not accumulate in the optical component of the image synthesis unit.

As such, the cooling method using the Peltier cooling element and air circulation in an enclosed space as a method for cooling the LCD and the polarizing plate module has a better cooling efficiency than the forced convection cooling by the conventional fan.

Meanwhile, in the above-described embodiment of the present invention, the LCD projection system is described as an example, but the present invention may be applied to the LCD projection TV as it is.

As described above, according to the cooling apparatus of the projection system according to the present invention, after sealing the image synthesis unit so as not to be affected by the external temperature, the cooling efficiency is increased by cooling the LCD and the polarizing plate using a cooling element using the Peltier principle. In addition to being able to maintain a constant low temperature regardless of the outside temperature. Further, according to the cooling apparatus of the projection system according to the present invention, there is no fear of accumulation of dust and contaminants from the outside in the optical component of the image synthesis unit without the need for an air filter.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (3)

An image comprising three liquid crystal displays arranged adjacent to three surfaces of a prism for synthesizing an image, and three polarizing plates arranged on the back side of the liquid crystal display for supplying each of three primary color light beams to the liquid crystal display. In each device of the projection system having a compounding unit, A guide part formed in a shape surrounding the image synthesis part to provide a closed space; Cooling device of the projection system, characterized in that provided on one side of the guide portion and provided with a cooling element for cooling the inside of the guide portion using the Peltier principle. The method of claim 1, And a fan installed at the cooling unit side of the cooling element to circulate the air cooled by the cooling unit in the guide unit. The method of claim 1, Cooling device of the projection system characterized in that it further comprises a heat sink installed on the heat generating side of the cooling element for dissipating heat.