JPH04171637A - Liquid-cooled cathode-ray tube device for projection type picture receiver - Google Patents

Abstract

PURPOSE:To keep the internal liquid pressure constant with high reliability at a low cost by connecting a long tube opened to the outside air at one tip section to one portion of a liquid container formed in a space between a face and a projection lens arranged in front of it. CONSTITUTION:A cooling transparent liquid 3 is filled in a liquid container 4, a liquid injection port 5 is provided at part of the liquid container 4, it is closed by a holder 7 connected with a long tube 6, and the long tube 6 is opened to the outside air at the other end. When a cathode-ray tube 1 is excited and its temperature rises, the temperature of the liquid 3 rises, its volume is expanded, the excess liquid generated by the expansion flows into the long tube 6, and the liquid level 8 in the long tube 6 is moved in the arrow direction. The volume expansion of the liquid 3 is absorbed into the long tube 6, and the pressure rise of the liquid 3 itself can be suppressed small. A liquid-cooled cathode-ray tube with high reliability and a sufficient pressure adjusting function is obtained at a low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a liquid-cooled cathode ray tube device for a projection type receiver that enlarges and projects an image projected on a cathode ray tube using a projection lens.

2. Description of the Related Art In recent years, in projection receivers, it has become mainstream to use a technique in which a transparent cooling liquid is filled between a cathode ray tube and a projection lens for the purpose of improving the contrast on a projection screen.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A liquid-cooled cathode ray tube conventionally used in a projection type receiver will be explained below with reference to the drawings. FIG. 5 is a sectional view showing an example of the configuration of a conventional projection type wave-cold cathode ray tube. A liquid container 4 is formed between the cathode ray tube 1 and the projection lens 2, and is filled with a liquid 3. Incidentally, since the surface temperature of the cathode ray tube face changes several thousand times between when it is left unused and when it is energized, the temperature of the liquid 3 in the vicinity of the cathode ray tube 1 also changes, causing a volume change. If the internal pressure fluctuates due to this volume change, the cathode ray tube 1, the projection lens 2, etc. may be damaged, or the optical performance may be adversely affected. It also had a pressure regulating function.

Problems to be Solved by the Invention However, in such a conventional configuration, there is a risk that the elastic material 10 will be damaged due to aging due to repeated changes in pressure and temperature, and the liquid will flow out. Since the elastic material 10 is required to have a certain level of strength or more, there is a problem in that it is difficult to achieve both pressure regulation function and reliability. Further, the elastic material 10 is required to have heat resistance, liquid stain resistance, and aging resistance, resulting in high cost.

The present invention solves the above problems, and aims to provide a liquid-cooled cathode ray tube that is highly reliable, has a sufficient pressure regulation function, and is inexpensive to use in a projection type receiver.

Means for Solving the Problems In order to achieve the above object, the present invention forms a liquid container in the space between the face surface of a projection type cathode ray tube and a projection lens disposed in front of the face surface of the projection type cathode ray tube, and A long tube with one tip open to the outside air is connected to a portion of the tube.

Operation The present invention has the above-described structure, and by guiding the volume change of the liquid used in the liquid-cooled cathode ray tube into the long tube, the present invention has the function of keeping the internal pressure of the liquid container constant, and achieves high reliability and low cost. This has been achieved.

EXAMPLE Hereinafter, a projection forming cold cathode ray tube according to an example of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing essential parts of an embodiment of the present invention.

Note that the same reference numerals are used for the same constituent members as in the conventional example.

The cathode ray tube 1 and the projection lens 2 are attached to a liquid container 4 whose front and rear surfaces are open using an adhesive 9, and form the front and rear surfaces of the liquid container 4.

The liquid container 4 is filled with a transparent cooling liquid 3, a part of the liquid container 4 is provided with a liquid inlet 5, and is closed by a holder 7 to which a long pipe 6 is connected. . The other end of the long pipe 6 is open to the outside air,
The inside of the liquid container 4 is completely sealed except for this part. The inner diameter of the long tube 6 is set to be less than or equal to the maximum diameter that can maintain the interface between the outside air and the liquid due to the surface tension of the liquid 3.

Next, the pressure regulating effect will be explained. In FIG. 1, as the cathode ray tube 1 is energized and its temperature rises, the temperature of the liquid 3 also rises and its volume expands. The excess liquid generated by the expansion flows into the long tube 6, which is the only open part, and the liquid level 8 within the long tube 6 moves in the direction of the arrow. Therefore, the volume expansion of the liquid is absorbed into the long tube 6, so that the increase in pressure of the liquid 3 itself can be suppressed to an extremely low level.

Conversely, the cathode ray tube 1 changes from the energized state to the OFF state,
When the temperature decreases, the volume of the liquid 3 decreases, and accordingly, the excess liquid in the long pipe 6 is returned to the container 4.
Eventually, it will return to its initial state.

Even if the above ON and OFF states are repeated many times, there is no mechanically moving part such as an elastic material, so fatigue damage does not occur and the reliability is high. In addition, since the material of the long tube 6 does not require any special properties, it may be made of an inexpensive material such as vinyl chloride, and the cost can be reduced.

Note that since the direction in which the long tube extends is not limited to up, down, right, or left, it is possible to store it compactly according to the space inside the set, as shown in the examples shown in FIGS. 2 to 4.

Effects of the Invention As is clear from the second embodiment, the liquid-cooled cathode ray tube used in the projection receiver of the present invention has a liquid-cooled cathode ray tube formed in the space between its face and the projection lens disposed in front of it. By connecting a long tube with one end open to the outside air to a part of the liquid container, it is highly reliable, low cost, and
It is possible to provide a projection-forming cold cathode ray tube that can maintain a constant internal liquid pressure.

[Brief explanation of drawings]

FIG. 1(a) is a sectional view of the main parts of a projection type liquid cold cathode ray tube device according to an embodiment of the present invention, and FIG. 1(b) is a front view of the same.
2 to 4 are side views showing other embodiments in the elongated direction of the long tube, and FIG. 5 is a sectional view of the main parts of a conventional projection-forming cold cathode ray tube. 1... Cathode ray tube, 2... Projection lens,
3... Cooling liquid, 4... Liquid container,
6...Long tube.

Claims (1)

[Claims] A liquid container filled with cooling liquid is formed in the space between the face surface of the cathode ray tube and a projection lens placed in front of the face, and one tip of the liquid container is opened to the outside air. A liquid-cooled cathode ray tube device that is a projection type receiver and consists of connected long tubes.