JPS6323873Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to improvement of cathode ray tubes used in display devices and the like.

Conventionally, it has been considered to form a display device by combining a large number of cathode ray tubes that emit red, blue, and green light, and Figures 1 and 2 show the main components of such cathode ray tubes. ing.

In the figure, 1 is a cylindrical glass container with a diameter of about 29 mm, 2 is a luminescent screen formed by coating the inner wall of one end of the glass container 1 with a monochromatic phosphor, 3 is an aluminum backing film deposited on the luminescent screen 2,
4 is a luminescent screen 2 via an aluminum backing film 3
5 is an electron gun assembly disposed opposite to the luminescent screen 2, which is composed of a cathode 6 for emitting electrons, a first grid 7, a second grid 8, and an anode 9. and is held in a predetermined positional relationship by a stem lead 10 and bead glass (not shown). 11 and 12 are spacers and getters fixed to the anode 9, and the spacer 11 is in elastic contact with the inner wall of the glass container 1 and electrically connected to the internal conductive film 4.

Further, the getter 12 is formed by inserting a barium compound into an annular metal container, and is supported toward the inner wall of the adjacent glass container 1 at a position that does not block the electron beam.

Under such a configuration, the electron beam is spread over the entire surface of the luminescent screen 2 as shown by the dashed line, and exhibits a predetermined luminescent color.

However, in order to spread the electron beam over the entire surface of the luminescent screen 2, it is necessary to make the electron beam passing hole of the anode 9 large. Therefore, when the getter 12 is scattered, the getter particles are scattered in the glass container. It collides with the inner wall of the second grid 8, is reflected, passes through this hole, and is deposited on the anode 9 side of the second grid 8. As a result, when the cathode ray tube is operated, approximately
Since a potential difference of 10KV is applied, the second grit 8
Cold emission is emitted from the tube, causing the phosphor to glow and inducing discharge in the tube.
This was supposed to deteriorate the withstand voltage characteristics.

This idea was made to eliminate the above-mentioned drawbacks, and a getter shield was added to improve the withstand voltage characteristics.

Hereinafter, this invention will be explained as an example in Figs. 3 and 4.
The diagram will be explained.

In the figure, reference numeral 13 is a getter shield, which is the main part of this invention.
2 and is formed by welding to the flange portion of the anode 9.

When getter particles are scattered by high-frequency heating of getter 12 by forming such getter shield 13, getter particles reflected from the inner wall of glass container 1 will be blocked by getter shield 13. , the fear of vapor deposition on the second grit 8 can be eliminated.

Figure 5 shows another embodiment of this invention.
The getter shield 13 is formed in a size large enough to cover the center of the getter 12 and the support 12a. By minimizing the size of the getter shield 13 in this manner, it is possible to suppress the adverse effects caused by high frequency heating during getter flushing. Further, as shown in FIG. 6, by folding back the upper part of the getter shield 13 and welding and fixing the getter 12 to this folded-back portion, it is possible to reduce the number of parts and improve workability.

In the above embodiment, a cathode ray tube used as a light source of a display device was described, but the same method can be applied to a cathode ray tube that is attached to an electron gun and has a getter disposed toward the inner wall of a glass container. be able to.

As explained above, according to this invention, it is possible to prevent the occurrence of cold emission from the grit electrode, and it is possible to eliminate the disadvantages of unnecessary light emission and deterioration of withstand voltage characteristics.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views showing the main structure of a conventional cathode ray tube, FIGS. 3 and 4 are cross-sectional views showing the structure of a cathode ray tube that is an embodiment of this invention, and FIG.
FIG. 6 is a block diagram of main parts showing another embodiment of this invention. In the figure, 1 is a glass container, 2 is a luminescent screen,
5 is an electron gun, 8 is a second grit, 9 is an anode, 11
is a spacer, 12 is a getter, and 13 is a getter shield. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims for Utility Model Registration] (1) A glass container, a luminescent screen and an electron gun formed opposite to each other on both sides of the glass container, and a light-emitting screen and an electron gun attached to the electron gun and directed toward the adjacent inner wall of the glass container. and a getter shield arranged substantially parallel to the getter between the electron beam passage hole of the anode of the electron gun and the getter to prevent getter particles from entering the electron beam passage hole. A cathode ray tube characterized by: (2) The cathode ray tube according to claim 1, wherein the getter and the getter shield are fixed by welding to the anode of an electron gun. (3) The cathode ray tube according to claim 1, wherein the getter shield is bent and the getter is attached to the bent portion.