KR950003459B1 - Crt - Google Patents

Abstract

The leakage current flowing through inner layer of a neck is prevented by a leakage current protector so that the distortion of the electron beam is prevented. The cathode ray tube includes an inner conduction layer (15), a neck unit (16a), and a leakage current protector (20) placed between an inner conduction layer (15) and the neck unit. The leakage current protector is formed by spraying the silicon which protects the layer of a the neck unit charged by high voltage which is applied to the inner conduction layer.

Description

Cathode ray tube prevents current flow into the neck

1 is a partial cross-sectional view of a conventional cathode ray tube.

2 is an enlarged cross-sectional view showing an A portion shown in FIG.

3 is a partially enlarged cross-sectional view of a cathode ray tube in which current flow to an inner surface of a neck portion is prevented according to the present invention.

* Explanation of symbols for main parts of the drawings

11: fluorescent film 12: panel

13: shadow mask frame assembly 14: electron gun

15: inner conductive film 16: funnel

20: current blocking means

The present invention relates to a cathode ray tube, and more particularly, to prevent leakage of an electrostatic lens formed between electrodes of an electron gun by preventing a leak current flowing from the inner conductive film applied to the inside of the funnel to the inner wall of the neck portion. The present invention relates to a cathode ray tube in which current flow to an inner surface of a neck portion is prevented.

A typical cathode ray tube is fixedly installed such that the shadow mask frame assembly 3 is spaced apart from the fluorescent film 2a by a predetermined distance inside the panel 2 having the fluorescent film 2a formed therein, as shown in FIG. The panel 2 is sealed with a funnel 5 coated with an inner conductive film 5a on an inner surface thereof, and an electron gun 6 is fixedly installed inside the neck portion 5b of the funnel 5. A deflection yoke 7 for deflecting the electron beam emitted from the electron gun 6 is fixed to the outside of the neck portion 5b. Here, the inner conductive film 5a may be in contact with the bulb spacer 6b of the shield cup 6a of the electron gun 6 fixed to the neck portion 5b, as shown in FIG. It is applied to the part corresponding to the lower end of the outer circumferential surface.

In the cathode ray tube 1 configured as described above, the electron beam emitted from the electron gun 6 is deflected by the deflection yoke 7 so as to be scanned in the entire fluorescent film. The inner conductive film 5a is the shield cup 6a. Since it is applied to the inner circumferential surface of the neck portion 5b opposite to the outer circumferential surface of the circumferential surface, a leakage current flowing along the inner surface of the neck portion 5b is generated by a high voltage applied to the inner conductive film 5a. Therefore, the electrostatic lens formed between the electrodes of the electron gun 6 is distorted by the leakage current, so that a convergence error occurs in the electron beam, and further, the resolution of the cathode ray tube is deteriorated. It was. In more detail, quantum is filled in the neck portion 5b of the funnel 5 by a high-pressure anode applied to the inner conductive film 5a, and the electron beam causes the chargeable drift phenomenon of the electron beam. As a result, the electron beam emitted from the electron gun 6 cannot be landed at each fluorescent point, and the resolution of the cathode ray tube is lowered.

Therefore, the present invention was created in order to solve the above problems, it is possible to completely block the leakage current flowing through the funnel from the inner conductive film to the neck portion can prevent the distortion of the electron beam trajectory, and further, the neck portion that can improve the resolution The purpose is to provide a cathode ray tube which is prevented from flowing current to the inner surface.

In order to achieve the above object, the present invention, the inner conductive film is sealed to the panel, the inner conductive film is applied to the inner surface and the neck portion of the cathode ray tube in which the current flow to the inner surface of the neck portion is sealed, the electron gun is sealed, the inner conductive film And a current blocking means for blocking the flow of current at a boundary portion between the neck and the inner circumferential surface thereof.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 shows a cathode ray tube 10 according to the present invention, in which a fluorescent film 11 is formed on an inner surface thereof, and a panel 12 fixed to be spaced apart from the fluorescent film 11 by a predetermined distance, and It is sealed with the panel 12, and the electron gun 14 is enclosed in the neck part 16a and the inner surface is equipped with the funnel 16 in which the internal conductive film 15 of graphite was formed. At the boundary forming the boundary between the 15 and the neck portion 16a, a current blocking means 20 is provided in accordance with the features of the present invention. Here, the current blocking means 20 may be any insulating member capable of blocking a current flowing along the inner surface of the neck portion 16a from the inner conductive film 15. However, the inner conductive film 15 and the neck portion 16a may be used. It is preferable to use silicone which can be easily applied to the boundary of the inner circumferential surface.

Referring to the operation of the cathode ray tube 10, the current flow to the inner surface of the neck portion according to the present invention configured as described above is as follows.

First, in the cathode ray tube 10, a predetermined voltage is applied to the electron gun 14 and the internal conductive film 15, respectively, so that an electrostatic lens is formed between the electrodes constituting the electron gun 14. In this state, the electron beam emitted from the cathode of the electron gun is focused and accelerated by the electrostatic lens and landed on the fluorescent film 11 formed on the inner surface of the panel to form one pixel, and these pixels gather to form one screen. Is achieved. In this case, since the high voltage is applied to the internal conductive film 15, a leakage current is generated due to a voltage difference between the internal conductive film 15 and the inner surface of the neck portion 16a and the electrode constituting the electron gun, but the internal conductive film Since silicon, which is the current interrupting means 20, is coated on the inner surface of the neck portion 16a and 15, the leakage current does not flow along the neck portion 16a. Therefore, the electrically charged protons of the inner wall of the neck portion 16a are not filled, thereby preventing distortion of the electron beam trajectory generated by the filling of the quantum on the inner circumferential surface of the neck portion 16a, as well as unnecessary. Arc discharge can be prevented.

In more detail, since the silicon is coated at the boundary between the inner surface of the inner conductive film 15 and the net portion 16a to partition them, the neck portion 16a is formed by a high voltage positive potential applied to the inner conductive film 15. It is possible to prevent the filling of both in the inner surface of the C), and further, it is possible to prevent the electrostatic lens formed between the electrodes of the electron gun 14 from being distorted, thereby preventing the trajectory of the electron beam from being deformed. Therefore, the electron beam emitted from the electron gun can be accurately landed on the fluorescent film, thereby improving the resolution of the cathode ray tube.

As described above, the cathode ray tube of which the current flow to the inner surface of the neck portion is prevented can prevent leakage current from flowing from the inner conductive film along the inner wall of the neck portion, and further, the merits of the cathode ray tube can be improved. There is this.

Claims (2)

A cathode ray tube in which a current flow is prevented from flowing to an inner surface of a neck portion provided with an inner conductive film coated on an inner surface of the panel and having a funnel in which an electron gun is enclosed in the neck portion, wherein the inner conductive film 15 and the neck portion are prevented. (16a) A cathode ray tube which prevents current flow to an inner surface of a neck portion, characterized in that a current blocking means for interrupting current flow is provided at a boundary with the inner surface. The cathode ray tube of claim 1, wherein the current interruption means 20 is silicon coated on the boundary between the inner conductive film 15 and the inner surface of the neck portion 16a. .