JPS6032237A - Cathode-ray tube with high brightness - Google Patents

Abstract

PURPOSE:To prevent a picture quality from lowering due to leakage of liquid because of exfoliation of adhesives and due to air bubbles generated by ooze of liquid by providing a tank having inside a space for absorbing liquid pressure on the upper peripheral part of an airtight chamber coupled on the airtight chamber. CONSTITUTION:After injection of a coolant 5a, a tank 2d is mounted on an injection port 2b for being sealed, for example, by soldering. The inside of the tank 2d forms a vacant space connecting with an airtight chamber so that, when the coolant 5a in the airtight chamber is expanded, the expanded portion flows into the tank 2d so as to raise its liquid-level, while, when being cooled and contracted, flowing back again into the airtight chamber so as to maintain the liquid pressure in the airtight chamber constant. On the other hand, the air bubbles generated in the airtight chamber due to ooze or the like of the coolant 5a through the adhesives 3 are pushed up inside the tank 2d with the expansion of the coolant 5a without staying in front of the panel so as not to disturb the picture.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] This invention relates to a liquid-cooled high-intensity cathode ray tube used in color projectors and the like.

[Background of the invention]

In a color projector using a cathode ray tube system, 3
Images of each color are obtained by a plurality of monochromatic cathode ray tubes, such as a tube type or a 2W type, and these images are projected onto a projection screen. I'm trying to get a J image.

It is desirable to use cathode ray tubes for high brightness in such projectors, but since high brightness cathode ray tubes have high output, the temperature of the front panel increases during operation. Projection cube on the screen - There is a problem that the white balance of the image becomes out of order.

The solution to this problem! As a method, it has been proposed to provide a sealed chamber in which a liquid is sealed in contact with the front part of the N-ray tube, and to use the flow of liquid to diffuse heat through a heat sink installed in the sealed Tomioka H. Yes (Real 1i-11J 5+-4
3926, Actual R11855-177256 Reference Jtfi G51 and FIG. 2 show the structure of this liquid-cooled high-brightness cathode ray tube. In FIG. 1, a heat sink 2a is bonded to the outer periphery of a panel Ha of a cathode ray ttil via an adhesive 3, and the heat sink 2a and a front glass plate 4 are bonded via an adhesive 3. The heat dissipation plate 2a has an injection port 2b, and the sufficiently degassed refrigerant liquid 5a is injected into the sealed chamber between the panel la and the front glass plate 4, with the air completely removed. By completely sealing the plug with the stopper 2C (Fig. 2 λ), the heat generated from the cathode ray tube panel 1a will be dissipated to the outside through the heat sink 2a due to the convection of the liquid in the closed chamber. The surface temperature is suppressed to about 80"C, making it possible to obtain stable images.

However, in this method, the operation of the cathode ray tube
Depending on the temperature during non-operation, the liquid inside the closed room expands and contracts repeatedly. The temperature of the refrigerant liquid to be injected differs depending on whether it is adjusted during operation or non-operation, but if it is adjusted during operation, the refrigerant liquid will contract when it is not operating, and if it is adjusted during non-operation, it will expand during operation. The interior of the sealed chamber is subject to repeated stress. If this stress exceeds the strength of the adhesive surface formed by the adhesive 3 constituting the sealed chamber, an accident may occur in which the adhesive peels off and liquid leaks. In addition, since adhesive 3 is a silicone-based organic adhesive that absorbs even some of these stresses, the liquid may evaporate from the adhesive after long-term use, causing leakage in the sealed room. There were drawbacks such as the generation of air bubbles 5b and the difference in the refractive index of light passing through the closed chamber, resulting in locally unclear projected images.

[Purpose of the invention]

The present invention was made in view of the above circumstances, and its purpose is to prevent liquid leakage due to peeling of the adhesive constituting the sealed chamber due to thermal expansion of the refrigerant, and to prevent liquid permeation through the adhesive due to long-term use. An object of the present invention is to provide a liquid-cooled high-brightness cathode ray tube that can effectively prevent deterioration in image quality due to air bubbles caused by air leakage.

[Summary of the invention]

In order to achieve such an object, the present invention provides a sealing device for the upper outer periphery of the sealed chamber. A tank is connected to the tank and has a space for absorbing hydraulic pressure inside. Hereinafter, the present invention will be explained in detail using Examples.

[Embodiments of the invention]

FIG. 3 is a partially sectional side view showing one embodiment of the present invention. In the figure, a heat dissipation plate 2a and a front glass plate 4 are bonded to the outer periphery of a nozzle la using an adhesive 3, and a space formed there (a closed chamber in which a refrigerant liquid 5a is sealed is conventionally used). However, after injecting the refrigerant liquid 5a, the injection port 2
The difference is that a tank 2d is attached to the stopper 2C in place of the plug 2C and hermetically sealed by brazing, for example. The inside of the tank 2d forms a space and is connected to the sealed chamber, so when the refrigerant liquid 5a in the sealed chamber expands, the expansion flows into the tank 2d, raising its liquid level and cooling. When it contracts, it flows back into the sealed chamber. In this way, the increase and decrease in volume of the refrigerant liquid in the sealed chamber due to thermal expansion and contraction is absorbed by the rise and fall of the liquid level inside the tank 2d, and the liquid pressure in the sealed chamber is kept constant. Of course, as the gas inside the tank 2d expands and contracts, the pressure will increase or decrease somewhat, but there is no practical problem as long as the mechanical strength of the tank 2d is configured to withstand an internal pressure of about 2 atmospheres. . On the other hand, air bubbles generated in the sealed chamber due to permeation of the refrigerant liquid 5a through the adhesive 3 are pushed up into the tank 2d with the expansion of the refrigerant liquid 5a, and do not remain on the front surface of the flannel. , does not interfere with the image.

FIG. 4 is a partially sectional side view showing another embodiment of the present invention. In this embodiment, an injection port 2f is provided in the liquid pressure absorbing tank 2e so that the refrigerant liquid can be replenished when the refrigerant liquid is depleted due to air bubbles generated in the closed room due to long-term use. After refilling, seal again with a 2g stopper and use. By adopting such a structure that allows replenishment of the refrigerant liquid as appropriate, the life of the cathode ray tube can be improved, even though loss of refrigerant liquid through the adhesive 3 is unavoidable.

〔Effect of the invention〕

As explained above, according to the present invention, by providing a tank for absorbing liquid pressure in connection with the sealing plan on the upper outer periphery of the sealed chamber, changes in the volume of the P1 refrigerant liquid can be adjusted to the liquid level in the tank. The liquid pressure is absorbed by the rise and fall of the liquid, and the liquid pressure can be kept almost constant both during operation and non-operation, so it is possible to prevent the destruction of the sealed chamber due to liquid pressure, and to prevent liquid permeation. The air bubbles that are generated disappear into the tank and disappear from the screen, allowing you to see a stable image.

[Brief explanation of drawings]

Figure N1 and Figure 2 are a partially cross-sectional side view showing a conventional high-intensity cathode ray tube, Figure 3 is a partial cross-sectional side view that does not show an embodiment of the present invention, and Figure 4 is a side view of a conventional high-intensity cathode ray tube. FIG. 7 is a partially cross-sectional side view showing another embodiment. 4. Front glass plate for sealing, 5a. Refrigerant liquid. 1st flash r $Z-kuni

Claims (1)

[Scope of Claims] 1. A sealed chamber filled with a transparent liquid that is in contact with the front surface of the panel and is likely to cause convection is provided, and a portion of the outer periphery of this sealed chamber is made from a good conductor of heat that is partially in contact with the liquid. In a liquid-cooled high-14 cathode ray tube, a tank was provided at the upper outer periphery of the closed chamber, connected to the closed R311 chamber, and having an internal space for absorbing liquid pressure. A high-brightness cathode ray tube with a % characteristic. 2. A high-intensity cathode ray tube according to item 1 of the patent HF', characterized in that the tank has a tightness that can be opened and closed.