KR20020073994A - Electron gun for color picuture tube - Google Patents

Abstract

PURPOSE: An electron gun for color CRT is provided to reduce dispersion of the voltage applied to the electrode by forming a connecting portion to the pattern resistance, while preventing distortion of electronic lens. CONSTITUTION: An electron gun(40) comprises a cathode assembly(41); a plurality of electrodes(42,43) sequentially aligned from the cathode assembly; bead glasses(51,52) where the cathode assembly and electrodes are fixed; an arc preventing metal band(70) having both ends fixed to one of electrodes, and which is wound around the bead glass; and a voltage reducing unit(60) arranged in a lengthwise direction of the bead glass, at the position corresponding to the arc preventing metal band, and which has a pattern resistance(62) having a connecting portion(64) having a relatively lower resistance per unit length.

Description

Electron gun for color picuture tube

The present invention relates to a color cathode ray tube, and more particularly, to a color cathode ray tube having an electron gun having an improved voltage drop structure for dropping a voltage applied to an electrode constituting an electron gun and applying it to an adjacent electrode.

A typical color cathode ray tube is a panel 12 in which a fluorescent film 11 is formed, a shadow mask frame assembly 13 mounted on an inner surface of the panel 12, and a neck portion that is sealed to the panel 12. A funnel 15 having 14). An electron gun 20 for emitting an electron beam for exciting a fluorescent film is fixed to the neck portion 14, and a plurality of ends for supplying a predetermined voltage to each electrode constituting the electron gun are attached to an end portion of the neck portion 14. Lead pins 16 are installed.

The electron gun includes a cathode assembly that is an emission source of an electron beam and a plurality of electrodes sequentially installed from the cathode assembly, wherein the cathode assembly and each of the electrodes are fixed by a pair of bead glass. In addition, a predetermined voltage is applied to the cathode assembly constituting the electron gun and the respective electrodes by a lead pin and a connector fixed to the stem of the neck portion.

On the other hand, when the number of electrodes constituting the electron gun increases for the multi-stage focusing of the electron beam, the number of the lead pins also increases, resulting in poor insulation and breakdown voltage characteristics between the lead pin or the connector and electrode connecting the lead pin and the electrode. There is this. In order to solve such a problem, conventionally, a voltage applied to an electrode of one side is dropped by using a resistor and then applied to an electrode of an adjacent electron gun. One of the electrodes constituting the electron gun, for example, an electrode suppressing bead glass and an arc suppressor having both ends fixed to the electrode are installed at an electrode at a boundary of the electrodes to which high pressure and low pressure are applied. The leakage current flowing through the inner circumferential surface of the neck portion or the bead glass is cut off from the inner conductive film of the cathode ray tube.

2 shows an example of a cathode ray tube electron gun (disclosed in US Pat. No. 4,945,284) in which a voltage is dropped between electrodes using a resistor.

As shown, the electron gun has a plurality of electrodes 21-28 _ and some of these electrodes 21-28 supply a predetermined voltage to the electrode on one side by means of lead pins or are located at the end of the electron gun 28. ; The final accelerating electrode is supplied to the resistor 30 by depressurizing the enowood voltage.

The resistor 30 is provided with a pattern resistor 32 wrapped by an insulator (not shown) on the upper surface of the ceramic substrate 31 fixed to the bead glass 29. It is connected to the ends of the metal tapes 33 connected to the electrodes for applying a voltage. A portion of the bead glass 27 provided with the pattern resistor 32 is wrapped by the arc-proof metal band 35 described above.

Since the portion of the pattern resistor 32 as described above corresponds to the anti-arc metal band 35, there is a problem in that the capacitance of the pattern resistor 32 is changed by increasing the capacitance therebetween.

When the portion corresponding to the arc protection metal band 35 is not a linear pattern, metal is separated from the pattern resistance in the metal band during the deposition by high frequency, thereby affecting the resistance value of the pattern resistance.

Since the change of the resistance value as described above causes the voltage applied to the electrode to be varied, the magnification of the electron lens may be varied so that the electron beam cannot be accurately landed on the fluorescent film.

The present invention has been made to solve the above problems, and an object thereof is to provide an electron gun for a color cathode ray tube having an electron gun capable of reducing the resistance change of the pattern resistance for applying a reduced voltage to the electrodes constituting the electron gun.

1 is a cross-sectional view of a typical cathode ray tube,

2 is a perspective view of a conventional electron gun,

3 is a perspective view of an electron gun for a CARAL cathode ray tube according to the present invention;

4 and 5 are perspective views showing another embodiment of the electron gun for the color cathode ray tube according to the present invention.

In order to achieve the above object, the electron gun for the color cathode ray tube of the present invention,

A cathode assembly, a plurality of electrodes sequentially installed from the cathode assembly, bead glasses to which the cathode assembly and the electrodes are fixed, and both ends of the cathode assembly are fixed to the bead glass And a voltage drop means provided with an anti-arc metal band and at least one connection portion formed in the longitudinal direction of the bead glass at a position corresponding to the arc-proof metal band and having a relatively low resistance per unit length. It is characterized by that.

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

As shown in FIG. 1, the color cathode ray tube includes a panel 12 having a fluorescent film 11 formed on an inner surface thereof, a shadow mask frame assembly 13 mounted on an inner surface of the panel 12, and sealed to the panel. A deflection of the funnel 15 having the neck portion 14, the electron gun 40 provided on the neck portion 14, the neck portion and the cone portion of the pennula 15, and the electron beam emitted from the electron gun. A deflection yoke 17 and a plurality of lead pins 16 are provided at the end of the neck portion 14 to supply a predetermined voltage to the electrodes constituting the electron gun 40. Here, the electron gun 40 has both ends fixed to the electrode, and bead glass 51 and 52 and a metal band 70 is wound around the substrate of the voltage drop means to be described later.

Meanwhile, as shown in FIG. 3, the electron gun 40 includes a cathode assembly 41 that forms an emission source of an electron beam, a control electrode 42 that is sequentially installed from the cathode assembly 41, and forms a tripolar portion; First, second, third, fourth and fifth focus electrodes 44, 45, 46, 47 and 48 which are sequentially installed from the screen electrode 43 and the screen electrode 43 to form an auxiliary lens. And a final acceleration electrode 49 disposed adjacent to the fifth focus electrode 48 to form a main lens. The cathode assembly 41, the electrodes 42-48, and the final acceleration electrodes 49 are fixed in position by a pair of bead glasses 51 and 52. The number of the focus electrodes is not limited by the above-described embodiments, and can be added or subtracted depending on the characteristics of the electron gun.

The bead glass 51 on one side is provided with a voltage drop means 60 for dropping the voltage applied to at least one electrode constituting the electrode of the electron gun and applying it to the other electrode.

The voltage drop means 60 is provided on the bead glass 51, the substrate 61 made of a thin ceramic plate, a pattern resistor 62 formed in a predetermined pattern in the longitudinal direction of the substrate 61, and the substrate Connectors 63 for electrically connecting the pattern resistor 62 and the electrodes forming the electron lens, and an insulating layer (not shown) formed on the substrate 61. Here, the pattern resistor 62 is formed in a waveform or sawtooth wave shape, the portion corresponding to the arc-resistant metal band 70 is relatively lower than the pattern resistor 62 to minimize the area corresponding to the resistor. At least one connection portion 64 is formed to be straight to have a.

The connecting portion 64 is formed to form a straight line with respect to the longitudinal direction of the bead glass 51, as shown in Figure 3, or as shown in Figure 4 formed of two waveforms in the parallel direction of the bead glass Can be. In addition, as shown in FIG. 5, the connection part is formed in a direction parallel to the bead glass 51, but its width W1 is wider than the line width W2 of the pattern resistor. Here, the shape of the connecting portion 64 is not limited to the above-described embodiment, and may be any structure that can reduce the capacitance between the vapor deposition film and the straight portion by the connecting portion and the preventive metal band.

Meanwhile, an end portion of one side of the pattern resistance of the voltage drop means 60 is connected by the final acceleration electrode 49 and the first connectors 63a, and the electrodes to drop the voltage are formed of the pattern resistor 62 and the first resistor. It is connected by two connectors 63b.

The electron gun for the color cathode ray tube configured as described above is supplied with a high voltage to the pattern resistor 62 through the final acceleration electrode 49 connected to the internal conductive film to reduce the pressure, and the reduced voltage is applied to the second connector 63b. It is supplied to the selected focus electrodes of the electron gun 40 through. In this process, the connecting portion 64 formed at the portion corresponding to the anti-arc metal band 70 is formed straight in the longitudinal direction of the bead glass 51 or two or more are installed in parallel (see FIG. 4). It is possible to prevent the resistance value of the pattern resistor 62 from being changed by the capacitance between the arc preventing metal band 70 and the connecting portion 64. That is, since the corresponding area of the connecting portion 64 and the arc protection metal band 70 can be minimized, the influence of capacitance between them can be minimized.

As described above, the cathode ray tube having the electron gun of the present invention can reduce the dispersion of the voltage applied to the electrode forming the electron lens by the voltage drop of the pattern resistance by forming a connection portion in the pattern resistance, and furthermore the electron lens Can prevent distortion.

The invention has been described with reference to the embodiments shown in the drawings. This is merely exemplary, and it will be understood by those skilled in the art that various modifications and embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (3)

A cathode assembly, a plurality of electrodes sequentially installed from the cathode assembly, bead glasses to which the cathode assembly and the electrodes are fixed, and both ends of the cathode assembly are fixed to the bead glass And a voltage drop means provided with an anti-arc metal band and at least one connection portion formed in the longitudinal direction of the bead glass at a position corresponding to the arc-proof metal band and having a relatively low resistance per unit length. Electron gun for color cathode ray tube, characterized in that. The method of claim 1, The connection part of the electron gun for a color cathode ray tube, characterized in that formed in the straight direction of the bead glass. The method of claim 1, The connection part is a color cathode ray tube electron gun, characterized in that the line width is formed wider than the line width of the pattern resistance.