JPH0724185B2 - Liquid-cooled projection type picture tube device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid-cooled projection type picture tube device used in a projection type television receiver.

2. Description of the Related Art Generally, in a projection type television receiver, a luminescent image projected on the fluorescent screen of the projection type CRT is enlarged by an optical system and projected on a projection screen. Needs to be projected on the phosphor screen.
Therefore, the density of the electron beam that excites the phosphor screen to emit light is 10 times or more the electron beam density in a normal direct-view type picture tube, and the phosphor forming the phosphor screen rises to a considerable temperature and the luminous efficiency decreases. Come here.

Therefore, as seen in JP-A-58-145048,
The face panel of the picture tube is covered with a radiator, and a liquid chamber formed between the radiator and the face panel is filled with a cooling liquid.

The problem to be solved by the invention is that even if the cooling liquid is hermetically sealed in the liquid chamber, it is likely to gradually seep out from the sealing portion, and after a long period of use, the amount of the cooling liquid will decrease to a considerable extent, causing a gap in the liquid chamber. Cause Then, if this gap expands and reaches the front of the effective image receiving surface area, a difference in optical refractive index between the void portion and the cooling liquid portion causes distortion in the projected image from the effective image receiving surface area. It will be. Further, the cooling effect on the phosphor screen becomes insufficient, and the brightness characteristics of the phosphor screen are partially deteriorated.

Therefore, it has been proposed to provide a liquid reservoir communicating with the liquid chamber in order to replenish the cooling liquid that has become insufficient due to leakage, but with the conventional configuration, the device becomes complicated and large.

Means for Solving the Problems A liquid-cooled projection type picture tube device according to the present invention is a liquid-cooled projection type picture tube having a radiator and a square face panel section, wherein the radiator is the face panel section. Metal frame body including an annular portion spaced apart from the side peripheral wall and covering only the side peripheral wall, and a window forming flange portion spaced apart from the rectangular front wall of the face panel portion and covering the outer peripheral edge of the rectangular front wall. And a transparent body that is separated from the rectangular front wall and covers the window portion of the flange portion and is fixed to the flange portion. The side peripheral wall of the face panel portion and the metal frame body are provided. Cooling liquid is applied to a space between the annular part, a space between the rectangular front wall of the face panel and the flange of the metal frame, and a space between the rectangular front wall of the face panel and the transparent body. Fill and fill the metal frame The upper edge end face of the window portion of the lunge portion is provided in the liquid of the cooling liquid.

Action Due to this structure, the metal frame not only acts as a heat sink but also acts as a liquid reservoir, and even if the cooling liquid in the liquid chamber slightly decreases, the liquid surface is covered by the upper edge of the flange. That is, it is possible to eliminate the above-mentioned inconvenience caused by the appearance of the void portion in front of the effective image receiving surface area with an extremely compact structure.

EXAMPLES Next, the present invention will be described with reference to the examples shown in the drawings.

As shown in FIG. 1, a projection type picture tube 1 has a square face panel portion 2, and a fluorescent surface 4 is provided on the inner surface of a horizontally long rectangular front wall 3 of the face panel portion 2. The radiator 5 covering the face panel portion 2 is a frame-shaped metal frame body 6 made of a good heat conductive metal such as aluminum or its alloy.
And a transparent body 7 made of a glass or acrylic plate. The metal frame 6 has an annular portion 8 that covers only the side peripheral wall of the face panel portion 2, and a window that extends from the annular portion 8 toward the tube axis and covers the outer peripheral edge of the front wall 3 to define an effective image receiving surface area. It has a forming flange portion 9, and its surface is blackened to improve heat conduction and prevent light scattering. The annular portion 8 has outer cooling fins 8a protruding outward and inner cooling fins 8b protruding inward at a height h as shown in FIG.
Further extends to the flange portion 9. The transparent body 7 is
In order to easily and firmly fix the airtightness, and to easily cope with the airtightness due to the difference in thermal expansion from the flange portion 9,
The window portion of the flange portion 9 is covered, and the front surface of the flange portion 9 is watertightly sealed by a silicone resin-based sealing agent layer 10. The trailing edge of the annular portion 8 (on the side of the electron gun) is located on the outer peripheral surface of the funnel portion 11 of the picture tube 1 and is a silicone resin-based sealing agent layer.
It is watertightly sealed by 12, and the face panel portion 2
A cooling liquid 14 made of ethylene glycol solution or the like is hermetically sealed in a liquid chamber 13 having a total internal volume A formed between the heat radiator 5 and the radiator 5.

However, a gap of 2 mm to 3 mm is provided between the annular portion 8 of the metal frame 6 and the face panel portion 2, and the inner volume A of the liquid chamber 13 is equal to the front wall of the face panel portion 2. 3 between the transparent body 7 and the outer peripheral portion at a distance b of 3 mm to 5 mm, the distance between the front wall 3 corresponding to one end position of the annular portion 8 and the sealing agent layer 12 on the other end side of the annular portion 8. It consists of the front part of c and the part connecting both parts. The height h of the internal cooling fins 8b is set to 0.8a to 0.9a, and the cooling liquid 14 is sealed in the liquid chamber 13 in a substantially full state.

Even if the cooling liquid 14 in the liquid chamber 13 is reduced to 95 to 85% of the initial total volume A at the end of the life of the picture tube to form a void in the liquid chamber 13, the picture tube 1 has the rectangular shape. In the actual use state in which the two long sides of the front wall 3 are set vertically and the pipe axis is kept horizontal, the liquid level of the cooling liquid 14 in the liquid chamber 13 is the upper edge face of the window formed by the flange portion 9. The air gap does not appear in front of the effective image receiving surface area, only by moving down until it contacts 15.
Even when the liquid surface of the reduced cooling liquid is in contact with the upper edge 15 of the window, the front wall 3 is not a regular quadrangle, but the upper side is an arc shape, so that the cooling liquid 14 inside the liquid chamber and the internal cooling are cooled. The contact state with the fins 8b can be maintained, and a sufficient cooling effect can be obtained.

If the gap a and the distance c are large, the entire apparatus becomes large, which is not preferable. In the previous embodiment, the external cooling fins
Since the 8a and the internal cooling fins 8b are provided above and below the metal frame body 8, when three projection type picture tubes are arranged in a horizontal line,
The distance between picture tubes can be reduced. In a receiver in which three picture tubes are arranged in a vertical line, both cooling fins may be provided on the left and right. Further, in the above-described embodiment, the transparent body 7 has a flat plate shape, but it may be an optical system lens.

EFFECTS OF THE INVENTION Since the present invention is configured as described above, the flange portion separates the side peripheral wall of the face panel portion on the upper edge side of the window portion from the annular portion of the metal frame and the rectangular front wall of the face panel portion. A small radiator can perform the action of a liquid reservoir by the space between the metal frame and the flange of the metal frame, and the heat radiation by the metal frame including the upper edge face of the window by the cooling liquid and the flange. Even if the cooling liquid decreases after the device has been used for a long period of time, the resulting void does not appear in front of the effective image receiving surface area, and a good projection image can be obtained. It is possible to efficiently reduce deterioration due to high temperature.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of a projection type picture tube apparatus embodying the present invention, and FIG. 2 is an external perspective view of the apparatus. 2 ... face panel part, 3 ... front wall, 5 ... radiator, 6 ... metal frame, 7 ... transparent, 8 ... annular part, 9
...... Flange part, 13 ...... liquid chamber, 14 ...... cooling liquid.

Claims (1)

[Claims] 1. A liquid-cooled projection type picture tube having a radiator and a square face panel portion, wherein the radiator is spaced apart from a side peripheral wall of the face panel portion and covers only the side peripheral wall. And a metal frame body including a window forming flange portion that is spaced apart from the rectangular front wall of the face panel portion and covers the outer peripheral edge of the rectangular front wall; A transparent body fixed to the flange portion so as to cover the window portion, a space between the side peripheral wall of the face panel portion and the annular portion of the metal frame body, and a rectangular front wall of the face panel portion. And a space between the flange portion of the metal frame body and a space between the rectangular front wall of the face panel portion and the transparent body are filled with a cooling liquid, and on the window portion of the flange portion of the metal frame body. The edge surface is provided in the cooling liquid. Cooling type projection cathode ray tube apparatus characterized by.