JPH0748361B2 - Cathode ray tube - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a cathode ray tube, and more particularly to an improved coating of a conductive coating on a funnel.

[Conventional technology]

3 and 4 are a cross-sectional view and a perspective view showing a getter mounting structure of a conventional cathode ray tube disclosed in, for example, Japanese Patent Laid-Open No. 60-221941. In FIG. 3, 9 is a conductive coating 8 on the inner surface.
Is a funnel portion having an anode button terminal 10 embedded in the funnel portion 9, and 11 is a nipple portion protruding from the anode button terminal 10 to the inside of the tube. Further, 12 is a getter-supporting metal plate, which has a getter 13 at its tip and is attached to the nipple portion 11.

A partial side sectional view of FIG. 2 shows a detailed adhered state of the above-mentioned conductive coating film 8. The conventional conductive coating film 2 has an anode button terminal 4
It can be seen that the inner portion and the nipple portion 5 are also coated.

Next, the operation will be described with reference to FIG.

In order for the cathode ray tube to operate, a high voltage must be supplied from the anode button terminal 10 to either the electron gun or the fluorescent screen, and a high voltage is applied to the conductive film 8 in order to supply a high voltage. In the prior art, the high voltage applied from the anode button terminal 10 has been conducted to the entire coating by the conductive coating 8 applied to the inner portion of the anode button terminal 10 and the nipple portion 11.

[Problems to be Solved by the Invention]

In the conventional conductive coating treatment on the inner wall surface of the funnel of the cathode ray tube, since the coating is applied to the entire inner wall surface, the contact between the nipple portion 5 and the getter supporting metal plate 6 and the vibration of the anode button cause The conductive coating applied to the inner part of the funnel of the terminal 4 and the nipple part is peeled off, causing problems such as sparking and electrical leakage in the finished anode wire tube during operation.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a cathode ray tube having excellent high voltage characteristics without peeling off the conductive coating applied on the inner wall surface of the funnel. To do.

[Means for Solving the Problems]

In the present invention, a conductive coating is applied on the inner wall surface of the funnel of the cathode ray tube except for the exposed surface inside the funnel of the anode button terminal, the nipple portion, and the vicinity of the exposed portion of the anode button terminal.

[Action]

In the present invention, on the inner wall surface of the funnel of the cathode ray tube, the exposed surface inside the funnel of the anode button terminal, the nipple portion,
Since the conductive coating is applied except on the exposed portion of the anode button terminal, the conductive coating is not peeled off due to contact with the getter supporting metal plate.

〔Example〕

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

FIG. 1 is a partial configuration diagram of a cathode ray tube according to an embodiment of the present invention.

In the figure, the same reference numerals as in the conventional example indicate the same parts, and the conductive coating 2 is not applied to the inner portion of the anode button terminal 4, the nipple portion 5, and the inner portion of the anode button terminal 4. .

The high voltage applied to the anode button terminal 4 is conducted by the contact between the getter supporting metal plate 6 protruding from the nipple portion 5 and the conductive coating 2, and is supplied to the entire conductive coating 2.

As described above, in this embodiment, the coating is not performed near the anode button terminal 4, the nipple portion 5, and the inner portion of the anode button terminal 4, so that the joining point between the nipple portion 5 and the getter supporting metal plate 6 is not changed. The conductive coating film 2 does not peel off due to contact, vibration, or the like. Further, the conduction of the high voltage applied from the anode button terminal 4 is also prevented from the inside of the anode button terminal 4 and the nipple portion 5 in the past.
Whereas it was done by the conductive coating 2 applied to
Contact between the getter supporting metal plate 6 connected to the nipple portion 5 of the anode button terminal 4 and the conductive film 2 brings about conduction, and a stable high voltage is conducted to the electron gun and the fluorescent screen, whereby the cathode ray tube High pressure stability can be maintained.

〔The invention's effect〕

As described above, according to the cathode ray tube according to the present invention, on the funnel inner wall surface of the cathode ray tube, except for the exposed portion on the funnel inner wall surface side of the anode button terminal, the nipple portion, and the vicinity of the exposed portion of the anode button terminal. Since a conductive coating is applied, even if there is contact or vibration at the junction between the nipple and getter support plate,
The conductive coating is not peeled off, and therefore, there is an effect that a stable image can be obtained without causing sparks or electric leakage of the electron gun.

[Brief description of drawings]

FIG. 1 is a partial configuration diagram of a cathode ray tube according to an embodiment of the present invention, FIG. 2 is a diagram showing a coating state of a conventional conductive coating, and FIGS. 3 and 4 are sectional views of a conventional getter mounting structure. It is a figure and a perspective view. In the figure, 1 is a funnel portion, 2 is a conductive film, 3 is a getter, 4 is an anode button terminal, 5 is a nipple, 6 is a getter supporting metal plate, and 7 is a getter supporting metal plate extension. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A funnel portion, an anode button terminal exposed on the inner wall surface of the funnel portion and embedded in the funnel portion, and a nipple portion projecting on a portion of the anode button terminal exposed on the inner wall surface of the funnel. A conductive coating applied to the inner wall surface of the funnel portion except for the exposed portion of the anode button terminal on the inner wall surface side of the funnel, the nipple portion and the inner wall surface of the funnel portion near the exposed portion of the anode button terminal; A getter supporting metal plate attached to and abutting on the conductive film, and a high voltage applied from the anode button terminal is supplied to the conductive film via the getter supporting metal plate. Is a cathode ray tube.