JPS58225547A - Projection picture tube with liquid cooling structure - Google Patents

Abstract

PURPOSE:To not only reduce the leak of X ray emitted from the electron gun to about 1/10 but also reduce the plate thickness to about 1/2 and absorb the electron beam emitted from the electron gun thereby improving brightness by forming a blanket with a zinc dicast and by executing the baked painting of black conductive coating to the internal circumference of zinc dicast. CONSTITUTION:A blanket 5 is made of a zinc dicast. Thereby, in calculation of X ray absorbing coefficient for the wavelength of 0.06nm (20.6keV), the zinc shows the X ray absorbing coefficient as high as 35.3(cm<-1>) which is 9.5 times of 3.7(cm<-1>) of aluminium. Therefore, the X ray absorbing coefficient becomes high, plate thickness can be reduced and the interval between face of CRT and glass face plate can be shortened. The baked painting of black conductive coating is executed to the both sides of CRT face and metal shield tightening side, namely to the entire part of internal circumference of blanket. Thereby, thermal conductivity and light absorbing coefficient of electron beam can be enhanced drastically.

Description

[Detailed description of the invention] The present invention relates to a cathode ray tube having a liquid-cooled structure.

As shown in Figures 1 and 2, a liquid-cooled cathode ray tube has the following features:
An adhesive tape 2 is wrapped around the outer circumference of the maximum outer diameter of a cathode ray tube 1 whose interior is evacuated to a high vacuum, and a metal shield bandage 3 heated and expanded is wrapped around the outer circumference of the cathode ray tube. The maximum outer diameter part of No. 1 is tightly tightened to shield X-rays. Furthermore, in order to fix the top surface of the cathode ray tube face and the glass face plate 4, a blanket 5 is attached to the outer periphery of the metal shield bandage 3, and a silicone adhesive layer 6 is applied.
The refrigerant 7 is inserted into the hollow space between the glass face plate 4 and the glass face plate 4 through a small hole in the side surface of the blanket 6 for the purpose of suppressing the temperature rise on the face of the cathode ray tube. Note that 5a indicates a mounting lug formed integrally with the blanket 5.

FIGS. 3 and 4 show other examples in which the corner portions of the blanket 10 are flat plate-shaped, and the lug 11 is attached to a metal shield bandage 3.
It is welded and fixed to.

In this way, the metal shield bandage 3 is wrapped around the maximum outer diameter of the Plow tube, which has the effect of shielding X-ray leakage from the outer circumferential surface of the Plow tube. However, since an aluminum blanket is used around the cathode ray tube face,
It had drawbacks such as a low X-ray absorption coefficient and almost no shielding effect against X-ray leakage.

The present invention has been made in view of the above-mentioned drawbacks of the conventional art, and it is an object of the present invention to provide a projection type picture tube having a liquid-cooled structure that has a high effect of shielding X-ray leakage and high light absorption efficiency of electron beams.

Embodiments of the present invention will be described below with reference to the drawings.

In the present invention, the blanket 5, 1O is processed by zinc die casting. By processing blanket 5, 1O by zinc die-casting, the X-ray absorption coefficient is reduced to 0.06 wavelength.
Calculated for X-rays of nm (20,6 key), aluminum is 3.7 (cm-1) and zinc is 35.3 (cm-').
It has an X-ray absorption coefficient of 9.5 times. This increases the X-ray absorption coefficient and allows the plate thickness to be made thinner, so that the distance between the cathode ray tube face and the glass face plate can be shortened. In addition, a black conductive coating is applied to the cathode ray tube face side and the metal shield side, that is, the entire inner peripheral surface of the blanket, to greatly increase thermal conductivity and electron beam light absorption efficiency, improving performance. can be achieved.

As is clear from the above explanation, according to the liquid-cooled structure projection picture tube of the unexploded BAC, by using zinc die-casting, not only can the leakage of X-rays emitted from the electron gun be reduced to about 1/10, but also the plate thickness The thickness of the blanket has been reduced to approximately 1/2 to improve its functionality as a product, and the entire inner peripheral surface of the blanket is coated with a black conductive coating, which absorbs the beam light emitted from the electron gun and makes it brighter. Effects such as improved performance were also obtained.

[Brief explanation of the drawing]

Figure 1 is an explanatory longitudinal cross-sectional view of the main parts of a projection picture tube with a liquid-cooled structure;
2 is an explanatory plan view of the vicinity of the corner in FIG. 1, FIG. 3 is an explanatory longitudinal cross-sectional view of a main part of the corner showing another example, and FIG. 4 is an explanatory plan view of the vicinity of the corner of FIG. 3. 1... Braun tube, 2... Adhesive tape, 3
...Metal shield bandage, 4...Glass face] plate, 5...Blanket, 7...Refrigerant, 10...Blanket. Figure 1 Figure 3 Seki Figure 2 Figure 4v! J1

Claims (1)

[Claims] Adhesive tape is wrapped around the maximum outer diameter of the cathode ray tube, and a metal shield bandage is wrapped around the outer circumference of the adhesive tape to shield the X-rays emitted from the electron gun, and is also placed on the fluorescent surface side of the cathode ray tube. A projection type picture tube having a liquid cooling structure, in which a refrigerant having a transmittance equivalent to that of cathode ray tube glass is injected into a hollow part between the glass face plate and a blanket for fixing the face plate and the cathode ray tube. In the projection type picture tube having a liquid-cooled structure, the blanket is formed from aluminum die-casting to zinc die-casting, and the inner peripheral surface of the zinc die-casting is coated with a black conductive coating.