JPH05299033A - Color image receiving tube - Google Patents

Abstract

PURPOSE:To obtain a stable convergence characteristic. CONSTITUTION:An electrically good conductive film 9 is arranged on the inside surface of a funnel part 8 of a glass envelope 1, and a high resistance film 10 formed by superposing one edge upon the neck part side edge of this electrically conductive film 9 is arranged on the inside surface of a neck part 2 so as to surround a high voltage electrode area of an electron gun 3. Electrically conductive tongue pieces 11 extending from a final acceleration electrode 7 of the electron gun 3 are brought into contact with the electrically conductive film 9, and an electrically conductive tongue piece 12 extending from a focusing electrode 12 is brought into contact with the other edge of the high resistance film 10, respectively. Thereby, since a micro current is flowed always to the high resistance film, an electric potential distribution can be stabilized in the inside surface of the neck part. Since a convergence characteristic is not changed with the lapse of time due to electrification, a color image hardly causing convergence error can be regenerated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-electron beam type color picture tube having a high resistance film as an antistatic means provided on the inner surface of the neck portion of a glass envelope.

[0002]

2. Description of the Related Art When high voltage charging due to floating electrons is generated on the inner surface of the neck portion of a glass envelope, the wall electric field caused by this acts on the electron beam in the electron gun through the gap between the electrodes, which changes the electron beam trajectory. , There is a risk of changing the convergence characteristics with time. Actual public Sho 41-17225
In the device disclosed in Japanese Patent Laid-Open Publication No. JP-A-2003-264, a high resistance film for preventing static electricity is provided on the inner surface of the neck portion of the glass envelope.

[0003]

In this case, one end of the high resistance film is superposed on the conductive film held at the anode potential, and the other end is placed at a position facing the focusing electrode. Therefore, even if the potential of the high resistance film on the conductive film side can be stably maintained,
The potential on the other end side changes with time due to increase / decrease of floating electrons, and there is a problem that it is difficult to satisfactorily achieve the initial purpose of stabilizing the convergence characteristic.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a final accelerating electrode (anode) potential is applied to one edge of a high resistance film while a focusing electrode is applied to the other edge. Abut the extended conductive tongue.

[0005]

With this structure, a minute current always flows through the high resistance film, and the potential on the other end edge side of the high resistance film is forcibly lowered to the focusing electrode potential. The potential distribution and the potential around it are stabilized, and stable convergence characteristics can always be obtained.

[0006]

The present invention will be described below with reference to the illustrated embodiments. As shown in FIG. 1, the neck portion 2 of the glass envelope 1
The bipotential type electron gun 3 enclosed inside is
It has a control grid electrode 4, an accelerating electrode 5, a focusing electrode 6 and a final accelerating electrode (anode) 7, and a conductive film 9 of good conductivity made of graphite is provided on the inner surface of the funnel portion 8 of the glass envelope 1. Has been. Then, the high-resistivity film 10 having one end overlapping with the end of the conductive film 9 on the neck portion side is formed on the inner surface of the neck portion 2 so as to surround the high-voltage electrode region including the final acceleration electrode 7 and the focusing electrode 6. It is provided. Further, the conductive tongue piece 11 extending from the final acceleration electrode 7 is in contact with the conductive film 9, and the conductive tongue piece 12 extending from the focusing electrode 6 is in contact with the other end edge of the high resistance film 10. .

The high resistance film 10 is mainly composed of a metal oxide such as a valve stem, and may be a uniform film or a spiral or other shape.

According to this structure, one edge of the high resistance film 10 is held at the anode potential and the other edge is held at the focusing electrode potential, so that a minute current always flows through the high resistance film 10. Since the potential distribution of the high resistance film 10 and the potential around it are stabilized, the inner surface potential of the neck portion is prevented from changing over time due to charging, and stable convergence characteristics can be obtained at all times.

[0009]

As described above, according to the present invention, it is possible to prevent the electric potential of the inner surface of the neck portion of the glass envelope from being irregularly changed by charging, and to always stabilize the electric potential distribution on the inner surface. Therefore, stable convergence characteristics can be obtained, and a color image with less color misregistration can be reproduced.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of a color picture tube embodying the present invention.

[Explanation of symbols]

 1 Glass Envelope 2 Neck Part 3 Electron Gun 6 Focusing Electrode 7 Final Accelerating Electrode 9 Conductive Film 10 High Resistor Film 11, 12 Conductive Tongue Piece

Claims (1)

[Claims] 1. A glass envelope in which an electron gun is enclosed in a neck portion has a conductive film having good conductivity on the inner surface of the funnel portion, and one edge is formed at the neck portion side edge of the conductive film. Is formed on the inner surface of the neck so as to surround the high voltage electrode region of the electron gun, and the conductive tongue extending from the final accelerating electrode of the electron gun is electrically conductive. On the membrane,
A color picture tube characterized in that the conductive tongue pieces extending from the focusing electrode of the electron gun are respectively brought into contact with the other end edges of the high resistance film.