JPH02119029A - Projection type cathode-ray tube - Google Patents

Abstract

PURPOSE:To absorb the expansion and contraction of a cooling medium while attempting the improvement of a heat radiating effect through the simple structure ot the tube in the title, by connecting a variable capacity vessel having its excellent heat conductivity to frame-like members which fix both of a fluorescent screen panel and a frant-face panel for being communicated with the cooling medium seal portion. CONSTITUTION:A fluorescent screen panel 5 and a front-face panel 2 are respectively fixed by frame-like members 11 to which a high heat conductive bellows vessel 12 forming a variable capacity vessel is connected. This vessel 12 that is communicated with a cooling medium 6 filled between the panels 5, 2, has its simple structure requiring reduced number of parts so that the vessel 12 varies in capacity according to the expansion and contraction of the cooling medium for excellently absorbing the expansion and contraction while heat radiating property is heightened by the vessel having its heat conductivity.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is characterized in that a transparent front panel is fixed in front of a fluorescent panel through a frame-like member, and a transparent liquid refrigerant is sealed between both panels. The present invention relates to a liquid-cooled projection cathode ray tube.

[Summary of the invention]

In the projection cathode ray tube of the present invention, the frame-shaped member that fixes the fluorescent surface panel and the front panel at the peripheral edge has a structure that follows the expansion or contraction of the sealed refrigerant and has good heat dissipation characteristics.
In addition, a container that communicates with the liquid refrigerant seal is connected and fixed to suppress the rise in temperature of the fluorescent surface panel.

[Conventional technology]

In the projection cathode ray tube, a high-energy electron beam is applied to the fluorescent surface in order to obtain a bright projected image, so the amount of heat generated at the fluorescent surface is large. On the other hand, the fluorescent panel coated with phosphor is made of glass with relatively low thermal conductivity, so the large amount of heat generated on the fluorescent surface is only transferred to other parts, and only a small amount is transmitted to other parts. As a result, during long-term operation, the temperature at the center of the fluorescent panel increases significantly. This temperature increase has a negative effect on the luminous efficiency and other aspects of the phosphor.

To address this problem, it has been proposed to cool the outer surface of the fluorescent panel with a coolant such as a liquid.

As a conventional example, a projection type cathode ray tube described in Japanese Utility Model Application Publication No. 60-147148 will be described with reference to FIGS. 6 and 7.

In the projection type cathode ray tube shown in FIG. 6, expansion or contraction due to temperature changes of the coolant 6 is absorbed by an easily deformable cylindrical tube 7 installed in the coolant 6. This cylindrical tube 7 has air exchange holes 8 leading to the outside. Further, in order to prevent the temperature of the refrigerant 6 from rising, a heat sink 3 is provided with one end exposed in the refrigerant 6 and the other end exposed in the air.

The projection cathode ray tube shown in FIG. 7 uses a bellows 10 to absorb expansion or contraction of the coolant 6 due to temperature changes.

The temperature rise of the refrigerant 6 is absorbed by the heat sink 3 as in the case of FIG.

Other conventional examples include those described in Japanese Patent Application Laid-open No. 17838/1983 and Japanese Utility Model Application No. 194256/1983.

[Problem to be solved by the invention]

As shown in FIGS. 6 and 7, the conventional technology uses two members: a member for heat radiation and a member for absorbing expansion or contraction of the refrigerant. Therefore, it takes time and effort to manufacture, and the cost increases accordingly.

In order to solve this problem, the present invention aims to improve heat radiation efficiency by integrating a member for heat radiation and a member for absorbing expansion or contraction of a refrigerant.

[Means to solve the problem]

In order to solve the above problems, the present invention arranges a transparent front panel in front of a fluorescent panel at a predetermined interval, and fixes the peripheral edges of both panels with an adhesive via a frame-like member. In a liquid-cooled projection cathode ray tube in which a transparent liquid refrigerant is sealed in a space surrounded by both panels and a frame-like member, the refrigerant expands or contracts in the frame-like member at the periphery of both panels. A container with good thermal conductivity that follows the refrigerant seal and communicates with the refrigerant seal was connected and fixed.

[Effect]

By communicating with the refrigerant seal between the two panels and fixing a wide-mouthed, variable-capacity, and highly thermally conductive container to the frame-like member at the periphery of the panels, the convection within the refrigerant caused by the temperature difference can be reduced. This includes the refrigerant inside the container. As a result, since the fixed container has good thermal conductivity, heat is actively dissipated. Furthermore, since the capacity of the container is variable, it follows the expansion or contraction of the refrigerant.

〔Example〕

Hereinafter, the present invention will be explained based on the drawings. Figures 1 and 2
A first embodiment is shown in FIG. FIG. 1 is a perspective view of a projection type cathode ray tube. FIG. 2 is a sectional view of a main part of the projection cathode ray tube, and FIG. 3 is a sectional view of the projection cathode ray tube taken along the line A--A shown in FIG. In these three figures, 1
2 is a cathode ray tube, 2 is a front panel, 5 is a fluorescent panel, 6 is a refrigerant, lla is a frame member, and 12 is a bellows container.

In FIG. 2, a frame-like member 11a, a fluorescent surface panel 5, and a front panel 2 are fixed together with an adhesive. The bellows container 12 is made of a material with good thermal conductivity (for example, metal), and has a bellows-shaped side surface, and the wall thickness of the bellows portion is made thin. This bellows container I2 is fixed face down on the upper surface of the frame member 11a, and the refrigerant sealing part and the bellows container 1 are surrounded by two panels.
The structure is such that the two internal spaces communicate with each other. Figure 3 is the second
This is a cross-sectional view taken along the line AA shown in the figure. With this configuration, the convection of the refrigerant 6 due to the temperature difference between the fluorescent surfaces extends to the inside of the bellows container 12, and since it is a container with good thermal conductivity, heat radiation efficiency is improved. Furthermore, in order to increase the amount of heat dissipated, the bellows container 12 can be forcedly cooled using a fan. Furthermore, expansion or contraction of the refrigerant 6 due to temperature changes can be easily absorbed because the bellows container 12 has a structure that allows its capacity to be changed.

As the refrigerant 6, a mixture of ethylene glycol and water is usually used, but conventionally the temperature of the fluorescent panel 5 is still around 70 to 80°C even after being cooled, and the temperature of the refrigerant 6 and adhesive is also low. It has risen to a value close to this. Therefore,
Since the refrigerant 6 passes through the adhesive made of silicone resin, which is inherently water-permeable, and evaporates over time, the effective area of the screen is set inside the surface sealed by the adhesive in anticipation of the evaporation of the conventional method. are doing. For example, in the case of a cathode ray tube with a finch outer diameter, the diameter of the sealing surface is designed to be 6 inches, and the effective area is designed to be 5 inches by subtracting 1 inch of evaporation allowance. In the case of the present invention, the bellows container 12 is mounted at a distance from the fluorescent surface panel, and the capacity of the bellows container 12 can be increased as necessary, so that evaporation does not occur as in the conventional example. There is no need to consider it.

FIG. 4 shows a second embodiment. In the figure, 13 indicates a bellows tube. The bellows tube 13 is formed into a bellows shape using a material with good thermal conductivity (for example, metal) and has a thin wall thickness. This bellows tube 13 of a desired length is bent into an arch shape on the upper surface of the frame member 11b, and both ends are fixed with adhesive.
In this embodiment, the effect is almost the same as in the first embodiment, but the connecting part with b is made by providing a hole in the frame member 11b and communicating with the refrigerant sealing part between the two panels. Refrigerant 6
It is possible to effectively generate convection caused by the temperature difference. In FIG. 6 showing the third embodiment in FIG. 5, 14 indicates a bellows tube. In this embodiment, a bellows tube 14 is fixed to the side surface of the frame member 11 (compared to the second embodiment). This effect is almost the same as the second embodiment.

〔Effect of the invention〕

As explained above, according to the present invention, a variable capacity container with good thermal conductivity is connected to a frame-like member that fixes a fluorescent surface panel and a front panel, and the inside thereof is communicated with a refrigerant sealing part. This not only absorbs the expansion or contraction of the refrigerant, but also improves the heat dissipation effect of the refrigerant. Therefore, the number of parts is reduced and manufacturing costs are reduced.

[Brief explanation of drawings]

Fig. 1 is a perspective view of the first embodiment of the present invention, Fig. 2 is a sectional view of essential parts of the first embodiment of the invention, and Fig. 3 is A of Fig. 2.
-A sectional view, FIG. 4 is a perspective view of the second embodiment of the present invention,
FIG. 5 is a perspective view of the third embodiment of the present invention, FIG.
The figure is a cutaway view of the main parts of a conventional projection type cathode ray tube. 2-・・・・・−1−−−Front panel 5−・−・−−−1−−・・−・Fluorescent surface panel 6・−・
---------- Refrigerant 11a, llb, 11c - Frame-shaped member 12 - ... Bellows container 13.14 - - Bellows pipe 1 Figure of the embodiment of the bellows pipe Figure 2 A-A cross-sectional view of Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] A transparent front panel is placed in front of the fluorescent panel at a predetermined interval, and the peripheral edges of both panels are fixed with an adhesive via a frame-shaped member, and the two panels and the frame-shaped member In a liquid-cooled projection cathode ray tube in which a transparent liquid refrigerant is sealed in an enclosed space, the frame-shaped member includes:
A projection type cathode ray tube, characterized in that a container with good thermal conductivity that follows the expansion or contraction of the liquid refrigerant and communicates with a sealed portion of the liquid refrigerant is connected and fixed.