JPS63261654A - Cathode-ray tube - Google Patents

Abstract

PURPOSE:To improve the withstand voltage characteristic by branching an inner lead from a connector crossing the surface near the surface facing the neck inner wall of an insulating support bar and arranging this inner lead toward a stem pin along almost the center of the surface. CONSTITUTION:A connector 10 is bent and arranged along the surface facing the inner wall of the neck tube 1 of a bead glass 9 so that the middle section is extended in the tube axis direction at the center section of the bead glass surface. An inner lead 11 is branched from the connector crossing the surface facing the inner wall of the neck tube of the bead glass and arranged toward a stem pin along the surface at the center section of the surface of the bead glass. The distances between the connector 10 and the fourth grid electrode 6 and between the inner lead 11 and the second grid electrode 4 and the first grid electrode 3 are wide, and the electric discharge between them is thereby suppressed. The electric discharge is prevented from reaching the second grid electrode, the first grid electrode, a cathode, and a heater.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a cathode ray tube with improved voltage resistance characteristics.

[Conventional technology]

Conventionally, in order to improve the withstand voltage characteristics of cathode ray tubes, a voltage that exceeds the maximum rated voltage of each part is applied to the cathode ray tube after the exhaust process to remove dust, internal graphite powder, etc. that has adhered to the surface of the component. Foreign matter, such as getter scattered outside the desired area, or a contaminant film on the surface of an insulator (becomes a conductive film, becomes an electron emission source under a high electric field, or sometimes becomes a secondary electron emission surface and becomes positively charged) (It may even become a region)
So-called spot knocking has been carried out in which the particles are removed by incineration and evaporation, mainly due to the heat generated during discharge due to the application of high voltage. Ideally, when spot knocking occurs, only the target foreign matter or contaminant is removed and no other side effects occur, but in reality, too strong sparks and creeping discharges are generated, causing damage to the electron gun. The insertion point of the electrode support member into the insulating support rod called bead glass or multiform glass, which supports each electrode insulated from each other, may be damaged, or in extreme cases, cracks may occur in the glass neck tube wall. there were.

In order to make spot knocking more effective, in order to make it easier to apply voltage to the fifth and third grid electrodes, which were conventionally left floating without applying a specific potential during spot knocking, the connectors of these electrodes were changed. , Patent Application No. 62-1 discloses that the surface of the bead glass facing the inner wall of the neck tube is bent and extended until it reaches approximately the center of the surface.
It is proposed in No. 2412. Also, Jikko 61-16
No. 596 discloses an inner lead whose one end is connected to the third grid electrode in order to protect the first grid electrode, the second grid electrode, the cathode, or the heater from creeping discharge that travels through the bead glass. is placed in the space where the bead glass and the inner wall of the neck tube directly face each other without contacting the inner wall of the neck tube, and is also used as a conductive lead to prevent creeping discharge that occurs along the surface of the bead glass between the cathode and anode. It is stated that

In the above-mentioned conventional technology, the conductive lead does not cross the surface of the bead glass facing the inner wall of the neck tube, but is folded back at the center. Therefore, as the potential of the bead glass increases, the conductive lead between the cathode, heater, and anode increases. There was a problem that it was weak against creeping discharge.

Furthermore, a conductive conductor is placed in a space where the vinyl glass and the inner wall of the neck tube directly face each other, across the bead glass without contacting the inner wall of the neck tube, in the third grid inner lead whose one end is connected to the third grid electrode. When used as a lead, no consideration was given to the gap length between the conductive lead and the electrode, and there was a problem in that discharge was likely to occur between the conductive lead and the electrode.

[Problem that the invention seeks to solve]

The present invention can prevent creeping discharge from the anode to the grid electrode, electrode, or heater through the inner wall of the neck tube, bead glass, etc. as described above, and also provides a conductive lead and a grid provided for preventing creeping discharge. An object of the present invention is to provide a cathode ray tube that can prevent discharge between electrodes.

[Means for solving problems]

In order to solve the above problems, in the present invention, a connector connecting between a plurality of different grid electrodes (for example, the fifth grid electrode and the third grid electrode) of the electron gun is connected to the electron gun electrode at a predetermined relative position. The surface facing the inner wall of the neck tube of the insulating support rod for insulating support is placed approximately at the center of the surface in the axial direction of the tube.
Both ends are bent at right angles and placed close to and across the surface, and both ends are connected to another or the same grid electrode (e.g. of a third grid) and are placed facing the inner wall of the neck tube of the insulating support rod. from a connector that traverses this surface in close proximity to the surface that
The inner lead was branched, and the inner lead was arranged along the approximate center of the surface toward the stem bin.

[Effect]

Almost all color cathode ray tubes in recent years use in-line electron guns, but the grid electrode assembly for three parallel electron beams in one plane of this electron gun is arranged in a plane perpendicular to the tube axis. The bead glass, which is long in the direction parallel to the electron beams and short in the direction perpendicular to it, supports this elongated grid electrode on the outside in the narrow direction, so the surface of the bead glass facing the inner wall of the neck tube and the inside of the neck tube The distance from the wall surface is relatively wide. If you take the above measures, the connectors that interconnect multiple separate grid electrodes, and the inner lead that connects the grid electrodes and the stem bin, will be connected to the inner wall of the bead glass neck tube. The gap between the electrode and the electrode is wide, and there is a bead glass in between, so sparks between the electrode and the electrode are difficult to occur. The length of the connector and inner lead arranged on the side surface is longer than the conventional one, so creeping discharge on the inner wall of the neck tube and bead glass is more likely to occur than in the case of the conventional structure. This increases the probability that creeping discharge from the anode reaches the grid electrode, cathode, or heater can be prevented.

[Embodiment] Figure 1 is a cross-sectional view of a multi-stage focused electron gun according to an embodiment of the present invention, taken along a plane including the tube axis and in which three electron beams are parallel (the left side of the figure is the phosphor screen side, the right side is the stem side). ), 21st J! 1 is a cross-sectional view of the same part of the same example taken along a plane perpendicular to the plane including the tube axis and on which the three electron beams are parallel. Cathode, 3 to 8 are first to sixth grid electrodes, 9 is bead glass,
10 is a connector that connects the fifth grid electrode 7 and the third grid electrode 5 and holds them at the same potential; 11 is a central connector whose both ends are connected to the third grid electrode 5 and which traverses the bead glass along the surface of the bead glass 9; This is an inner lead that branches from the inner lead and runs on the surface toward a stem pin (not shown). In this electron gun, a high voltage of about V is applied only to the sixth grid electrode 8 from an anode (not shown) to the fifth grid electrode 7 and the third grid electrode 30.
The grid electrode 5 is connected by a connector 10, and a medium voltage of several volts is applied from the stem pin via the inner lead 11, and the other electrodes are connected to the fourth grid electrode 6, which has the highest potential among them, and the second grid electrode. Since only a few hundred volts at most are applied to the grid electrode 4, this method is commonly called the unipotential-bipotential focusing method.

Focusing is relatively good over the entire screen.

As described above, the connector 10 is bent along the surface of the bead glass 9 on the side facing the inner wall of the neck tube 1 so that the intermediate portion runs along the center portion of the surface of the bead glass in the tube axis direction. Further, the inner lead 11 is branched from a connector that crosses the surface of the bead glass facing the inner wall of the neck tube, and is wired along the central part of the surface of the bead glass toward the stem pin. With this configuration, the distances between the connector 10 and the fourth grid electrode 6, and between the inner lead 11 and the second grid electrode 4 and the first grid electrode 3 are wide, so that discharge between them is suppressed. Furthermore, with respect to creeping discharge via the inner wall of the neck tube 1 and the bead glass 9, since the connector 10 and the inner lead ↓1 are located close to the inner wall of the neck tube 1 and for a long time, discharge will not occur between them. This can prevent discharge from reaching the second grid electrode, the first grid electrode, the cathode, and the heater.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to widen the distance between the connector and inner lead and the grid electrode, cathode, and heater whose potentials are different from these, and furthermore, the connector and inner lead face the inner wall of the neck tube. sparks between the connector and the grid electrode, cathode and heater during spot knocking (or during practical operation), as well as the bead glass and/or the heater.
Alternatively, since the generation of sparks and neck light emission through the inner wall of the neck tube can be suppressed, the withstand voltage characteristics of the cathode ray tube are improved.

[Brief explanation of drawings]

Figure 1 shows a tube axis of a multi-stage focused electron gun according to an embodiment of the present invention.
FIG. 2 is a sectional view taken along a plane in which the electron beams of the book are arranged in parallel, and FIG. 2 is a sectional view taken in a plane perpendicular to the plane in which three electron beams are arranged in parallel, including the tube axis at the same point in the same embodiment. 1...Neck tube, 2...Cathode, 3~8...1st~
6 Grid electrode, 9... Bead glass, 10... Connector, 11... Inner lead.躬1巳IO: Connector 11;

Claims (1)

[Claims] 1. A connector that connects multiple different grid electrodes of the electron gun housed in the neck tube of the cathode ray tube glass bulb,
The surface of the insulating support rod that insulates and supports the electron gun electrode at a predetermined relative position, facing the inner wall of the neck tube, is bent approximately at the center of the surface in the direction of the tube axis at the intermediate portion, and at right angles at both ends, so that the surface faces the inner wall of the neck tube. An inner lead from a connector disposed adjacent to and across, further connected at both ends to another or the same grid electrode, proximate to and across the surface facing the inner wall of the neck tube of the insulated support rod. A cathode ray tube characterized in that the inner lead is arranged along the approximate center of the surface toward the stem pin.