JPS63181244A - Cathode-ray tube - Google Patents

Abstract

PURPOSE:To make the electrode knocking to be easily applied to a control electrode and prevent the occurrence of sparks while a CRT is installed by providing a conductive lead folded at the center of a bead glass on an inner lead connected to a focusing electrode at one end. CONSTITUTION:A U-shaped conductive lead 11a folded at the center (about W/2) of the width W of a bead glass is provided on an inner lead 11 connected to the third grid electrode 5. The lead 11a and a connector 10 are arranged in a space where the first inner wall of a neck section and the bead glass 9 are faced to each other so as not to be brought into contact with the inner wall and the bead glass 9. The high voltage by the electrode knocking during the production of a cathode-ray tube is applied to the sixth grid 8 and conducted through a region other than the region surrounded by the connector 10 and the lead 11, spot and float knocking is performed, and lugs of the first and second grid electrodes 3, 4 are removed. The bead glass 9 is kept at a low potential by the presence of the connector 10 and the lead 11a, and sparks across electrodes are absorbed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cathode ray tube with improved voltage resistance characteristics.

[Conventional technology]

In general, a cathode ray tube consists of a fluorescent surface for obtaining an image and an electron gun assembly that generates and impinges an electron beam on the fluorescent surface, which are placed opposite each other in a glass pulp evacuated to a high degree of vacuum. In order to obtain clear images, many improvements have been made to the focus electrode of the electron gun structure. Also,
In order to obtain very clear images, it is common practice to apply a high voltage to the electron gun assembly and the fluorescent surface.

However, when a high voltage is applied, discharge phenomena related to the electron gun assembly increase, resulting in a decrease in the productivity of the cathode ray tube. There have been problems that degrade the quality of cathode ray tubes, such as vacuum breakdown due to damage to the neck tube accompanied by sparks that do not result in sparks and neck emission (brown spots) that do not result in sparks, and X-ray emission from within the neck tube.

To improve this problem, for example, as disclosed in Japanese Utility Model Publication No. 16596/1982, bead glass is added to the third grid inner lead, one end of which is connected to the third grid electrode of the electron gun assembly. A cathode ray tube has been proposed in which a conductive lead is provided in a space where the conductive lead and the inner wall of the neck directly face each other without contacting the inner wall of the neck.

[Problem that the invention seeks to solve]

A cathode ray tube constructed in this way can prevent creeping discharge that occurs along the bead glass surface between the cathode, heater, and anode by providing conductive leads; It is impossible to perform spot knocking on electrodes below the third grid electrode during tube manufacturing,
As a result, during the operation of the cathode ray tube, strays occur in the second grid electrode system, and in extreme cases, sparks occur, and the above-mentioned problems have not been sufficiently improved.

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and its purpose is to prevent electrode knocking during cathode ray tube manufacturing, which is likely to occur on the second grid electrode, and to ensure that sparks are not generated during mounting. The object of the present invention is to provide a cathode ray tube that can prevent the above problems.

[Means for solving problems]

In the cathode ray tube according to the present invention, the third grid inner lead, one end of which is connected to the third grid electrode of the electron gun assembly, is provided with a bead in a space where the bead glass and the neck inner wall directly face each other without contacting the neck inner wall. A conductive lead is provided that is folded back approximately at the center of the glass.

[Effect]

Since the conductive lead in the present invention does not cross over the bead glass and is folded back at the center, electrode knocking does not occur on the electrodes below the third grid electrode, and the second grid electrode
Projections such as the first grid electrode are removed.

〔Example〕

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

FIG. 1 is a plan view of an electron gun assembly with a unipotential-bipotential focusing structure showing an embodiment of a cathode ray tube according to the present invention, and FIG. 2 is a plan view of FIG. 1 viewed from the lateral direction. . In these figures, 1 is the neck part that constitutes the glass pulp of the cathode ray tube, 2 is the cathode held and housed in the neck part 1 by a cathode sabot (2 m),
Reference numerals 3 to 8 designate first to sixth grid electrodes that are similarly arranged in the neck portion 1 in sequence along the tube axis direction. The cathode 2 and each of the grid electrodes 3 to 8 are held at regular intervals by bead glass 9.

10 is a connector connected between the third grid electrode 5 and the fifth grid electrode T to hold both electrodes 5.7 at the same potential; 11 is a connector connected at one end to the third grid electrode 5 and connected to the other end; This is a third grid inner lead that is connected to a stem bin (not shown) and supplies a predetermined voltage to the third grid electrode 5 from outside the cathode ray tube. This inner lead 11 has an approximately U-shaped shape that is folded back at the center, which is approximately half (v2) of the width W of the bead glass 90, where the width of the bead glass 9 is W, at the portion connected to the third grid electrode 5. A letter-shaped conductive lead 11a is provided and connected to the third grid electrode 5.

And these conductive leads 11 & and connector 1
0 is arranged in a space where the inner wall of the neck part 1 and the bead glass 9 directly face each other, as shown in cross section in FIGS. 3 and 4, respectively, without contacting the inner wall of the neck part 1 and the bead glass 9. There is.

In such a configuration, high voltage due to electrode knocking during cathode ray tube manufacturing is applied to the sixth grid electrode 8, and the area on the bead glass 9 other than the area A surrounded by the connector 10 and the area B surrounded by the conductive lead 11m is applied to the sixth grid electrode 8. is conducted to perform spot non-king and float knocking, and the protrusions of the second grid electrode 4 and the first grid electrode 3 are removed.

Further, during the mounting of the cathode ray tube, the bead glass 9 is at a low potential due to the presence of the connector 10 and the conductive lead tta, so that sparks between the electrodes can be absorbed. In this case, the bead glass 9 of the conductive lead 11m
The upper length was set to approximately 12 times the width W of the bead glass 9, but if this length is made shorter, sparks between the electrodes will easily occur during mounting, and if it is made longer, knocking may occur on the lower electrode. It will no longer take. Therefore, it is desirable to set this length to at least W/2 of the width W of the bead glass 9. Moreover, since the conductive lead 11#L is formed in a substantially U-shape by being folded back at the center without crossing the bead glass 9, deformation is extremely small even when heat is applied. , has the function of a damper, so the third grid electrode 5 and the fifth grid electrode 7
There is no stress caused by thermal deformation at all.

〔Effect of the invention〕

As explained above, according to the present invention, the inner lead, one end of which is connected to the electron beam focusing electrode of the electron gun assembly, comes into contact with the inner wall of the neck portion in the space where the bead glass and the inner wall of the neck portion directly oppose each other. By providing a conductive lead that folds back almost at the center of the bead glass, electrode knocking can be applied to the control electrode, thereby eliminating protrusions and preventing sparks between the electrodes during mounting. Extremely excellent effects such as reliable prevention and improved withstand voltage characteristics can be obtained.

[Brief explanation of the drawing]

1 and 2 are a plan view and a side view of an electron gun assembly showing an embodiment of a cathode ray tube according to the present invention, and FIGS. 3 and 4 are main parts of FIGS. 1 and 2, respectively. FIG. 1... 6. Neck part, 2''... Electrode) 2a0Φ... Cathode support, 3... First grid electrode, 4...
2nd grid electrode, 5...3rd grid electrode, 6...4th grid electrode, 7...5th grid electrode, 8...6th grid electrode
Grid electrode, 9...Bead glass, 10...Connector, 11.Fist...Third grid inner lead, 11a
・・Conductive lead.

Claims (1)

[Claims] 1. The inner lead, which has one end connected to the focusing electrode and the other end connected to the stem lead, is provided with a conductive lead that is folded at approximately the center of the bead glass in a space where the bead glass and the inner wall of the neck directly face each other. A cathode ray tube characterized by: