JPH0821346B2 - Flat cathode ray tube - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat cathode ray tube used for a color television receiver, a terminal display of a computer and the like.

2. Description of the Related Art As a supporting structure of a flat-plate cathode ray tube, which is a prior art by the applicant, there is a structure shown in FIG. Front plate 1 coated with phosphor that emits light by electron beam collision
1. The vacuum envelope composed of the side wall 12 and the back plate 13 is supported by a support structure 14 so as not to be crushed by atmospheric pressure when exhausted. The support structure 14 is composed of a deflection electrode 15 for deflecting an electron beam and a needle-shaped support 17 adhered by frit attachment or the like via an insulator 16, and divides the inside of the vacuum envelope into a plurality of channels. To do. Insulator 16
Is covered by a metal cover 18 to prevent electron beam charging. The pillars 17 are made of an insulating material at predetermined intervals.
They are lined up on 16 with high precision, and a higher voltage is applied than metal back 20.

However, in the method in which the high voltage is applied only by the support 17 contacting the metal back 20 as described above, the atmospheric pressure is supported between the support 17 and the metal back 20. Considering that a considerable force is applied to the metal back 20 and the metal back 20 is easily damaged, this may lead to unstable operation of the flat panel cathode ray tube. That is, the needle-shaped support column 17 that forms a part of the support structure 14 is in contact with and supports the metal back 20 of the anode portion so that the vacuum atmosphere is not crushed by the atmospheric pressure. Experiences several heat processes in vacuum exhaust or frit sealing process, and at that time, due to the difference in the coefficient of thermal expansion or the difference in the direction of thermal expansion,
The metal back 20 may be damaged at the contact portion between the column 17 and the metal back 20.

If the metal back 20 is partially damaged and a high voltage is no longer applied to one pillar 17, that pillar
Since 17 is in a floating state as a potential, it may cause a discharge, and as a result, the trajectory of the electron beam may be greatly deviated.

The present invention solves the above problem, and an object thereof is to stably apply a high voltage to the support 17.

SUMMARY OF THE INVENTION The present invention provides a vacuum envelope with a plurality of support structures for dividing the interior into a plurality of channels and supporting the vacuum envelope against atmospheric pressure. The support structure is composed of deflection electrodes for deflecting charged particles and needle-like support columns arranged at predetermined intervals via an insulator. The insulator is made of a metal plate or a metal film to prevent the charged particles from being charged. It is separated from the charged particles by a metal cover, and the metal cover achieves the above-mentioned object by connecting the needle-shaped support with a metal piece.

Operation In the above-mentioned configuration, even if the electrical continuity between the tip of the column and the metal back is broken, a high voltage is stably applied to the needle column through the metal plate or the metal film and the metal piece.

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

FIG. 1 is a sectional view showing the structure of a support structure in one embodiment of the present invention. A vacuum envelope consisting of a front plate 11, a side wall 12 and a back plate 13 whose inner surface is coated with a fluorescent substance that emits light by collision of an electron beam is supported by a support structure 14 so as not to be crushed by atmospheric pressure when exhausted. It is supported. The support structure 14 includes a deflection electrode 15 for deflecting an electron beam.
And columns 17 adhered by frit attachment or the like via an insulator 16, and a plurality of columns 17 are provided perpendicularly to the front plate at equal intervals. The insulator 16 is covered with a metal cover 18 to prevent the electron beam from being charged. Prop 17
Are accurately arranged on the insulator 16 at desired intervals and come into contact with the metal back 20 at a predetermined position on the front plate 11.
If all the metal backs 20 and the columns 17 are in complete contact, all the columns 17 will have the same potential as the metal backs 20, but the metal backs 20 are thin metal films, and the columns 17 and the metal backs
Since atmospheric pressure is applied to the contact portion of 20, the damage of the metal back 20 must be taken into consideration. As described above, when the metal back 20 is damaged at the contact portion with the support 17, the potential of the metal back 20 is not applied through the metal back 20. Therefore, in order to prevent the inconvenience in the operation of the electron beam even if there is a contact failure between the column 17 and the metal back 20, attach the column 17 and the metal cover 18 to the metal piece 19.
The metal cover 18 and the metal back 20 are connected to a common high-voltage power supply.
The same voltage as the metal back 20 is applied to. This piece of metal 19
As a result, the pillar 17 is stably kept at the same potential as the metal back 20.

The metal piece 19 can be configured in various ways such as integrally with the metal cover 18 or separately.

FIG. 2 (a) shows that the metal cover 18 and the metal piece 19 are integrated, and star-shaped holes are formed at the same intervals as the columns 17 are lined up.
There will be 21 and pillar 17 will be there. Since the star-shaped hole 21 generally does not have much room in the short piece direction of the metal piece 19, it has an arc slightly larger than the diameter of the pillar 17, and has a star-shaped jagged shape in the long-side direction where space is available. The tip is slightly smaller than the diameter of the support 17 and always contacts the support 17. With such a star-shaped hole 21, the hole accuracy of the metal piece 19 does not require high accuracy.

FIG. 2B shows a metal piece integrated with the metal cover 18.
19 are provided at the same intervals as the columns 17, and the metal cover 18 and the columns 17 are accurately bonded to the insulator 16, and then the metal pieces 19 and the columns 17 are bonded by welding or the like. In this case, the metal pieces 19 can be attached to either side of the opposing metal covers 18, or even alternately.

In FIG. 2 (c), the metal cover 18 and the metal piece 19 are separated, and after accurately supporting the pillar 17 and the metal cover 18 to the insulator 16, the metal piece 19 is put on the pillar 17 and the end portion is covered. Is bonded to the metal cover 18 by welding or the like. In this case too, the hole 21
The star shape is the same as in Fig. 2 (a). In FIG. 1, the end of the support structure 14 on the side opposite to the column 17 is in contact with the back plate 13. However, even if various electrodes are interposed in the middle of this, the support structure 14 is If you decide to support the vacuum envelope,
The present invention can be applied.

EFFECTS OF THE INVENTION As described above, the present invention makes it possible to stably apply a high voltage to a pillar by establishing conduction between the pillar and the metal cover by using the metal piece, and the hole shape of the metal piece has a star shape. Due to this modification, the hole accuracy of the metal piece does not require high accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial sectional side view showing an embodiment of a flat cathode wire according to the present invention, and FIGS. 2 (a), (b), and (c) are flat cathode wires according to the present invention. FIG. 3 is a perspective view showing the structure of a conductive portion with respect to the column of the tube, and FIG. 3 is a partial sectional side view of a conventional flat cathode ray tube. 11 ... Front plate, 12 ... Side wall, 13 ... Rear plate, 14 ... Support structure, 15 ... Deflection electrode, 16 ... Insulator, 17 ... Pillar, 18 ...
… Metal cover, 19 …… Metal piece, 20 …… Metal back, 21
…… A star-shaped hole.

Claims (3)

[Claims] 1. A plurality of front plates, each of which is perpendicular to the front plate and arranged at equal intervals, in a vacuum envelope composed of a front plate including a phosphor and a metal back which emits light upon collision of an electron beam, a side wall and a back plate. A supporting structure, wherein the supporting structure has deflection electrodes and needle-like struts connected through an insulator, and the metal cover covering the surface of the insulator and the needle-like struts are electrically connected. A flat-plate cathode ray tube characterized by. 2. A metal cover and a needle-like support are electrically connected by a metal piece, and a high voltage is applied to the needle-like support through the metal back, and a power source common to the high voltage applied to the metal back. The flat cathode ray tube according to claim 1, wherein a high voltage having the same potential as that of the metal back is applied from the metal cover connected to the metal plate through the metal piece. 3. The metal piece has a hole into which a pillar is inserted, and the hole has an arc slightly larger than the diameter of the pillar in the short side direction of the metal piece and a star in the long side direction. The flat-type cathode ray tube according to claim 2, wherein the flat-shaped cathode-ray tube has a serrated shape, and the inner diameter of the star-shaped tip is smaller than the diameter of the support, and is formed integrally with or separately from the metal cover.