JPS62241233A - Liquid cooled projection type picture tube device - Google Patents

Abstract

PURPOSE:To obtain good projection pictures without emergence of a gap in front of an effective picture receiving area, by projecting the upper edge of a window formed by a flange part downward below the liquid level of a coolant. CONSTITUTION:A projection type picture tube 1 has a square shaped face panel part 2, and a phosphor face 4 is provided on the inside face of sideways long rectangular formed front wall 3 of the panel part 2. A radiator 5 which covers the panel part 2 is provided with a metal frame body 6 made of a good heat conductive metal and a transparent body 7 made of glass. And the metal frame body 6 is provided with a ring part 8 which covers a peripheral side of the panel part 2, and a window forming flange part 9 which projects from the ring part 8 to the axis side of the tube, covers the peripheral edge of the front wall 3 so as to demarcate an effective picture receiving area. And a coolant 14 consisting of ethylene glycol solution or the like is sealed in a liquid room 13 which is formed between the panel part 2 and the radiator 5. Thus, a gap part does not emeage in front of the effective picture receiving area so that good projection pictures are obtained.

Description

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

2. Description of the Related Art In general, in a projection type television receiver, a luminescent image projected on a fluorescent screen of a projection type picture tube is enlarged by an optical system and projected onto a projection screen, so that a high luminance luminescent image is produced. It is necessary to project the image on a fluorescent screen.

For this reason, the density of the electron beam that excites the phosphor screen to emit light is more than 10 times that of an ordinary direct-view picture tube, and the temperature of the phosphor that forms the phosphor screen rises considerably, causing a drop in luminous efficiency. Come.

Therefore, as shown in Japanese Patent Application Laid-open No. 58-14504.8, the face panel of the picture tube is covered with a radiator,
A liquid chamber formed between the heat radiator and the face panel is filled with a cooling liquid.

Problems that the invention aims to solve However, even if the coolant is sealed in the liquid chamber, it tends to gradually seep out from the sealed part (after long-term use, the amount of coolant decreases to a considerable extent and the liquid in the liquid chamber leaks out). If this gap widens and reaches the front of the effective image receiving surface area, the projected image from the effective image receiving surface area will be distorted due to the difference in optical refractive index between the gap and the coolant. In addition, the cooling effect on the phosphor screen becomes insufficient, and the brightness characteristics of the phosphor screen partially deteriorate.

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

Means for Solving the Problems According to the present invention, the metal frame of the radiator that covers the face panel portion of the picture tube has an annular portion that covers the side peripheral wall of the face panel portion, and an annular portion that extends toward the tube axis side. and a window-forming flange portion that covers the outer peripheral edge of the rectangular front wall of the face panel portion. Then, the upper edge of the window formed by the flange portion is made to extend below the liquid level of the coolant.

Function With this structure, the metal frame not only acts as a heat dissipator but also as a liquid reservoir, and even if the coolant in the liquid chamber decreases a little, the liquid level is covered by the upper edge of the flange. Therefore, the above-mentioned inconvenience caused by the appearance of a void in front of the effective image receiving surface area can be solved with an extremely compact configuration.

Embodiments Next, the present invention will be explained with reference to embodiments shown in the drawings.

As shown in FIG. 1, a projection type picture tube 1 has a square shape. A radiator 5 that covers the face panel portion 2 includes a frame-shaped metal frame 6 made of a metal with good thermal conductivity such as aluminum or an alloy thereof, and a transparent body 7 made of a glass or acrylic plate. The metal frame 6 includes an annular portion 8 that covers the side peripheral wall of the face panel portion 2, and an annular portion 8 that covers the side peripheral wall of the face panel portion 2.
It has a window-forming flange portion 9 that extends toward the tube axis side and covers the outer peripheral edge of the front wall 3 to define an effective image receiving surface area, and the surface thereof has good heat conduction (and light scattering). As shown in FIG. 2, the annular portion 8 has external cooling fins 8a projecting outward and internal cooling fins 8b having a height h projecting inward. ,
The transparent body 7 is watertightly sealed to the front surface of the flange portion 9 by a silicone resin adhesive layer 10. The rear edge (electron gun side) of the annular portion 8 is connected to the funnel portion 11 of the picture tube 1.
The ethylene is sealed watertightly on the outer circumferential surface of the housing with a silicone resin sealant layer 12, and the ethylene A cooling liquid 14 made of a glycol solution or the like is sealed.

However, a gap a of 2 to 3+mi is provided between the annular portion 8 of the metal frame 6 and the face panel portion 2, and the internal volume A of the liquid chamber 13 is 311II11 to 5IIW11 between wall 3 and transparent body 7
It consists of an outer peripheral portion at a distance C, a front portion at a distance C between the outer surface of the front wall 3 and the sealing agent layer 12, and a portion connecting the image portion. The height h of the internal cooling fins 8b is 0.
8a=0.9a, and the cooling liquid 14 is sealed in the liquid chamber 13 in a substantially full state.

Even if the coolant 14 in the liquid chamber 13 decreases to 95 to 85% of the initial total volume A at the end of the picture tube's life, creating a void in the liquid chamber 13, the picture tube 1 remains in its rectangular shape. In actual use, where the two long sides of the front wall 3 are vertical and the tube axis is kept horizontal, the liquid level of the coolant 14 in the liquid chamber 13 is at the upper edge 15 of the window formed by the flange portion 9. The void portion does not appear in front of the effective image receiving surface area. Moreover, even if the liquid level of the reduced cooling liquid is in contact with the upper edge 15 of the window, since the front wall 3 is not a regular quadrilateral but has an arcuate upper side, the cooling liquid 14 in the liquid chamber and the internal cooling The contact state with the fins 8b can be maintained, and a sufficient cooling effect can be obtained.

If the gap a or the distance C is made large, the entire device becomes large, which is not preferable. In the above-mentioned embodiment, the external cooling fins 8a and the internal cooling fins 8b are provided below the metal frame 8. Therefore, when three projection picture tubes are arranged in a horizontal row, the distance between the picture tubes can be narrowed. can. Three picture tubes vertically
In a receiver arranged in a row, it is preferable to provide both cooling fins on the left and right sides.

Further, in the above-mentioned embodiments, a flat plate-shaped transparent body 7 was used, but this may also be a lens of an optical system.

Effects of the Invention Since the present invention is configured as described above, the metal frame forming the radiator can perform not only a heat dissipation function but also a liquid storage function, and the amount of water that is reduced to the cooling liquid after long-term use of the device can be Even if this occurs, the resulting voids will not appear in front of the effective image receiving surface area, making it possible to obtain a good projected image and efficiently reducing the deterioration of the phosphor on the phosphor screen due to high temperatures. can.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway side view of a projection type picture tube device embodying the present invention, and FIG. 2 is an external perspective view of the device. 2...Face panel part, 3...Front wall, 5...Radiator, 6...Metal frame body,
7... Transparent body, 8... Annular part, 9...
...Flange part, 13...Liquid chamber, 14...
...Cooling liquid. Name of agent: Patent attorney Toshio Nakao and one other person Figure 2

Claims (1)

[Claims] A projection type picture tube having a square face panel part, a radiator covering the face panel part and forming a liquid chamber between the face panel part, and a cooling liquid filled in the liquid chamber. The radiator includes an annular portion that covers a side peripheral wall of the face panel portion, and a window-forming flange portion that protrudes from the annular portion toward the tube axis and covers an outer peripheral edge of the rectangular front wall of the face panel portion. and a transparent body that is fixed to the flange portion and covers most of the front wall, the upper edge of the window formed by the flange portion protruding below the liquid level of the cooling liquid. Liquid-cooled projection picture tube device.