KR0158464B1 - Electron gun for color cathode ray tube - Google Patents

Abstract

The present invention discloses an electron gun for a color cathode ray tube.

The present invention is a color cathode ray tube comprising a cathode, a control electrode and a screen electrode forming an anterior triode, and a first, second, three, four, five, six, seven focus electrode and a final acceleration electrode forming an auxiliary and main lens system. An electron gun, wherein a constant voltage is applied to the screen electrode and the first focus electrode, a focus voltage higher than a constant voltage is applied to the 3,7 focus electrodes, and the first focus electrode is deflected when the focus voltage is a base voltage. A dynamic focus voltage synchronized with the signal is applied, and the first focus electrode is characterized in that an elongated electron beam through hole is formed, which has the advantage of obtaining a uniform electron beam cross section in the typical fluorescent film.

Description

Electron gun for colored cathode ray tube

1 is a sectional view showing a conventional electron gun for a cathode ray tube, showing a method of applying a voltage to each electrode.

2 is a sectional view showing the electron gun for the color cathode ray tube according to the present invention, showing a voltage application method.

FIG. 3 is a perspective view showing an extract of an electrode forming the quadrupole lens shown in FIG.

4 is a sectional view showing another embodiment of the electron gun for color cathode ray tube according to the present invention, showing a voltage application method.

FIG. 5 is a perspective view showing an extract of an electrode forming the quadrupole lens shown in FIG.

* Explanation of symbols for main parts of the drawings

21: cathode 22: control electrode

23: screen electrode 24: first focus electrode

25: second focus electrode VD: dynamic focus voltage

VS: Constant voltage VF: Focus voltage

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron gun for color cathode ray tubes, and more particularly to an electron gun for inline type cathode ray tube improved in a voltage application method for applying a predetermined potential to each electrode constituting the electron gun.

In general, a cathode ray tube forms an pixel by electron beams emitted from an electron gun enclosed in a neck portion of which are selectively deflected according to a deflection yoke and landed on a fluorescent film formed on an inner surface of the panel. Gather together to form an image. Therefore, in order to form a clearer image, it is important to ensure that the electron beam emitted from the electron gun is accurately landed on the fluorescent point of the fluorescent film. In the cathode ray tube, when the electron beam emitted from the electron gun is deflected by the deflection yoke and is deflected toward the periphery of the fluorescent film, the uneven deflection magnetic field of the deflection yoke is affected, and the inner surface of the panel is fluorescence due to the geometric curvature. The spots landing on the film were distorted, so that the fluorescent point of the fluorescent film could not be landed correctly.

In order to solve such a problem, conventionally, the cross section of the electron beam emitted from the electron gun is distorted in the reverse direction of the nonuniform magnetic field effect of the deflection yoke, and the focal length of the electron beam is scanned to the center part of the fluorescent film and to be scanned to the periphery part. Attempts have been made to change the time.

Figure 1 shows an embodiment of a conventional electron gun for color cathode ray tube to solve the above problems.

This forms the cathode 11, the control electrode 12, and the screen electrode 13, which form the anterior tripolar portion, and the auxiliary, main lens system. The first, second, and third focus electrodes 14, which form a unipotential electrostatic lens, are formed. And a final accelerating electrode 17 disposed adjacent to the third focusing electrode 16 to form a bi-potential electrostatic lens including a quadrupole lens.

A predetermined potential is applied to each of the electrodes, and a constant voltage VS is applied to the screen electrode 13 and the second focus electrode 15, and the first and third focus electrodes 14 and 16 are respectively applied to the screen electrode 13 and the second focus electrode. The focus voltage VF higher than the constant voltage VS is applied, and the anode voltage VE of higher voltage than the voltages is applied to the final acceleration electrode 17.

A conventional cathode ray tube electron gun 10 configured as described above is formed between the first, second and third focus electrodes 14, 15 and 16 when the electron beam emitted from the cathode 11 is scanned into the center portion of the fluorescent film. The cross section of the electron beam is pre-focused and accelerated by a unipotential focus electrostatic lens, and is formed between the third focusing electrode 16 and the final acceleration electrode 17 and has a quadrupole effect. By distorting in a direction opposite to the distortion direction caused by the non-uniform magnetic field and landing on the fluorescent film, distortion of the electron beam due to the non-uniform magnetic field of the deflection yoke is compensated.

However, as described above, correcting the cross section of the electron beam by the four-lens action of the main lens and correcting the distortion of the cross section of the electron beam due to the non-uniform magnetic field of the deflection yoke is expected to have satisfactory effects due to the weak effect of the quadrupole lens. There was a problem that the cross section of the electron beam was distorted at the center of the fluorescent film.

The present invention has been made to solve the above problems, it is possible to uniformly form the cross section of the electron beam landing on the entire fluorescent film and to improve the focus characteristic of the electron beam for cathode ray tube can be improved The purpose is to provide an electron gun.

In order to achieve the above object, the present invention, the cathode, the control electrode and the screen electrode forming the pre-triode, the first, second, 3, 4, 5, 6, 7 focus electrode and the final acceleration electrode forming the auxiliary and main lens system In the electron gun for color cathode ray tube provided with,

A constant voltage is applied to the screen electrode and the first focus electrode, a focus voltage higher than a constant voltage is applied to the 3 and 7 focus electrodes, and the focus voltage is set to the first focus electrode to be a base voltage, thereby synchronizing with a deflection signal. A focus voltage is applied,

The first focus electrode is characterized in that the elongated electron beam through hole is formed.

In addition, another feature of the present invention for achieving the above object, the first, second, third, fourth, fifth, sixth, seventh and seventh focus electrodes forming a cathode, a control electrode and a screen electrode and an auxiliary and main lens In the electron gun for color cathode ray tube provided with the final acceleration electrode,

A constant voltage is applied to the screen electrode and the first focus electrode, a focus voltage higher than a constant voltage is applied to the first and third focus electrodes, and a dynamic voltage synchronized with a deflection signal when the focus voltage is a base voltage to the seventh focus electrode. A focus voltage is applied, and an elongated electron beam through hole is formed in the seventh focus electrode.

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

2 shows a cathode for a color cathode ray tube according to the present invention, which comprises a cathode 21, a control electrode 22, and a screen electrode 23, which form an anterior triode, and a unipotential electrostatic lens as an auxiliary lens. First, second, third, fourth, fifth, sixth, seventh focus electrodes 24, 25, 26, 27, 28, 29, 31 and adjacent to the seventh focus electrode 31 And a final accelerating electrode 32 provided to form a bi-potential quadrupole electrostatic lens.

Here, as shown in FIG. 3, the screen electrode 23 and the first focus electrode 25 are formed with the electron beam passing holes 23H and 25H having a horizontal shape, and the first focus electrode 24 has an elongated shape. An electron beam through hole 24H is formed.

A predetermined voltage is applied to each of the electrodes, which will be described below.

A constant voltage VS is applied to the screen electrode 23 and the second focus electrode 25, and a focus voltage VF higher than the constant voltage is applied to the third and seven focus electrodes 24 and 26 and 31. The first focus electrode 24 is applied with a dynamic focus voltage VD that is the base voltage and is synchronized with a deflection signal.

A high voltage anode voltage VE is applied to the sixth focus electrode 29 and the final acceleration electrode 32.

As another embodiment of the electron gun according to the present invention, as shown in FIG. 4, the cathode 41, the control electrode 42, and the screen electrode 43, which form an anterior tripolar portion, and a unipotential electrostatic lens as an auxiliary lens. The first, second, third, fourth, fifth, sixth, seventh focus electrodes 44, 45, 46, 47, 48, 49, 51, and the seventh focus electrode 51 And a final acceleration electrode 52 which is installed adjacent to form a bi-potential quadrupole electrostatic lens.

Here, the sixth focusing electrode 49 and the final accelerating electrode 52 have a horizontal electron beam through hole 49H, 52H, as shown in FIG. 3, and the seventh focusing electrode 51 has a vertical shape. A long electron beam through hole 51H is formed.

A predetermined voltage is applied to each of the electrodes, which will be described below.

A constant voltage VS is applied to the screen electrode 43 and the second focus electrode 45, and a focus voltage VF higher than the constant voltage VS is applied to the first and third focus electrodes 44 and 46. When the focus voltage VF is set as the base voltage, the dynamic focus voltage VD synchronized with the deflection signal is applied to the seventh focus electrode 51.

In addition, a high-pressure enowood voltage VE is applied to the sixth focus electrode 49 and the final acceleration electrode 52. A predetermined voltage lower than the focus voltage VF is applied to the fourth and fifth focus electrodes 47 and 48.

Referring to the operation of the electron gun for the color cathode ray tube according to the present invention configured as described above are as follows.

In the electron gun for the color cathode ray tube according to the present invention, if a predetermined voltage is applied to each of the electrodes as described above, whether the dynamic focus voltage VF is applied between the screen electrode 23 and the second focus electrode 25. A quadrupole lens is selectively formed, and a unipotential electrostatic lens is formed between the third, fourth, fifth and sixth focus electrodes 26, 27, 28, and 29, and the sixth focus electrode 29) and a unipotential main electrostatic lens is formed between the final acceleration electrode (32).

Therefore, the electron beam emitted from the cathode 21 of the electron gun passes through each of the electrostatic lenses and lands at each fluorescent point of the fluorescent film. This landing process is scanned when the electron beam is scanned at the center of the fluorescent film and at the periphery. When divided into times as follows.

First, when the electron beam emitted from the cathode 21 is scanned to the center portion of the fluorescent film, the dynamic focus voltage VD in synchronization with the deflection signal is not applied to the first focus electrode 24. The quadrupole lens formed between the first and second focus electrodes 24 and 25 is not formed. Accordingly, the electron beam emitted from the cathode 21 is preliminarily focused and accelerated by an electrostatic lens formed between the third, fourth, fifth and sixth focus electrodes 26, 27, 28 and 29. After refocusing and accelerating by the unipotential main electrostatic lens formed between the 6 and 7 focus electrodes 29 and 31, the circular electron beam is landed in the best state at the center of the fluorescent film. When the electron beam emitted from the cathode 21 of the electron gun is scanned to the periphery of the fluorescent film, the dynamic focus voltage VD is applied to the first focus electrode 26 in synchronization with the deflection signal. ) And the first and second focus electrodes 24 and 25 form a unipotential type electrostatic lens including a quadrupole lens. That is, in the screen electrode 23 and the second focus electrode 25, horizontally-shaped electron beam through holes 23H and 25H are formed, and the first focus electrode 24 has an elongated electron beam through hole 24H. Is formed, an electrostatic lens including a quadrupole lens is formed therebetween. Accordingly, the electron beam emitted from the cathode 21 is diverged to receive the diverging force in the vertical direction and the focusing force in the horizontal direction by the quadrupole lens to be lengthened, and the third, fourth, fifth and sixth focus electrodes 26 are formed. (27) (28) and (29) are pre-focused and accelerated by the electrostatic lens formed between the six, seven focus electrodes (29) and the re-focused by the unipotential main electrostatic lens formed between the 31 and After being accelerated, it is deflected by deflection yoke and landed at the periphery of the fluorescent film.

The cross section of the electron beam landing on the fluorescent film is compensated by the nonuniform magnetic field of the deflection yoke having the focusing force and the diverging force in the vertical direction and the horizontal direction when the longitudinally shaped electron beam cross section of the quadrupole lens is deflected. Will have an electron beam cross section. In addition, the electron gun according to the present invention compensates for the distortion of the non-uniform deflection magnetic field of the deflection yoke by making the electron beam longitudinally adjacent to the cathode 21, thereby doubling the effect of the quadrupole lens.

And another embodiment of the electron gun as shown in FIG. 4 has the same effect as described above.

As described above, the electron gun for the color cathode ray tube according to the present invention can reduce spherical aberration in each electrostatic lens by focusing and accelerating the electron beam emitted from the cathode. Furthermore, the focus characteristic is improved to obtain a uniform electron beam cross section in all fluorescent films. As a result, the resolution of the cathode ray tube employing the same can be improved.

Claims (5)

An electron gun for a color cathode ray tube, comprising a cathode, a control electrode, and a screen electrode forming a transposition triode, and a first, second, third, four, five, five, seven focus electrode and a final acceleration electrode forming an auxiliary and main lens system. A constant voltage is applied to the screen electrode and the first focus electrode, a focus voltage higher than the constant voltage is applied to the 3 and 7 focus electrodes, and the focus voltage is synchronized to the deflection signal when the focus voltage is set to the base voltage. An electron gun for a color cathode ray tube, wherein a dynamic focus voltage is applied, and an elongated electron beam through hole is formed in the first focus electrode. The electron gun for a color cathode ray tube according to claim 1, wherein the electron beam passing holes formed in the screen electrode and the second focus electrode are horizontal. The electron gun for a color cathode ray tube according to claim 1, wherein the sixth focus electrode and the final acceleration electrode are applied on a coin. An electron gun for a color cathode ray tube comprising a cathode, a control electrode, and a screen electrode forming an anterior triode, and a first, second, third, four, five, six, seven focus electrode and an final acceleration electrode forming an auxiliary and main lens system. A constant voltage is applied to the screen electrode and the first focus electrode, a focus voltage higher than the constant voltage is applied to the first and third focus electrodes, and the focus voltage is set to the seventh focus electrode to synchronize with a deflection signal. A dynamic focus voltage is applied, a high-pressure enowood voltage is applied to the sixth focus electrode and the final acceleration electrode, and the seventh focus electrode has an elongated electron beam through hole formed therein. The electron gun for a color cathode ray tube according to claim 3, wherein the electron beam passing holes formed in the six focus electrodes and the final acceleration electrodes are horizontal.