KR0177132B1 - 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 relates to an electron gun for a color cathode ray tube comprising a cathode, a control electrode, and a screen electrode forming an anterior triode, and first, second, third, and four focus electrodes and an final acceleration electrode forming an auxiliary and main lens system. The electron beam distortion compensation means for preventing the distortion of the electron beam cross-section due to the rotational distortion of the electron beam when the electron beam is deflected on the exit side of the second focus electrode and the incident side of the third focus electrode is provided, which is caused by deflection aberration It has the advantage of compensating for the distortion of the electron beam.

Description

Electron gun for colored cathode ray tube

1 is a view showing the state in which the electron beam is landing on the fluorescent film.

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

FIG. 3 is a sectional view showing an electron gun for a color cathode ray tube according to the present invention, showing a voltage application method.

4 is a perspective view showing an exit side of a second focus electrode.

5 is a perspective view showing the incidence side of the third focus electrode.

6 through 8 illustrate dynamic voltages.

9 is a perspective view showing another embodiment of the electron gun according to the present invention.

10 and 11 show cross sections of an electron beam emitted by an electron gun.

* 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 26: third focus electrode

27: fourth focus electrode 28: final acceleration electrode

VDI: First Half Dynamic Focus Voltage VF: Focus Voltage

VD2: Second Half Dynamic Focus Voltage VD3: Third Focus Voltage

The present invention relates to an electron gun for a color cathode ray tube, and more particularly, to an electron gun for a color cathode ray tube that can compensate for the distortion of an electron beam due to an uneven magnetic field caused by a deflection yoke.

In general, a cathode ray tube forms an image by electron beams emitted from an electron gun enclosed in its neck portion, selectively deflected by deflection yokes according to dice, and landing on a fluorescent film formed on an inner surface of a panel, and these pixels are collected. An image is formed. Therefore, in order to form a brighter picture, it is important to make the electron beam emitted from the electron gun accurately land 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 electron beam spot landing on the film is distorted as shown in FIG. 1, which causes a problem that a uniform electron beam spot cannot be obtained in the entire fluorescent film.

In order to solve such a problem, conventionally, the cross section of the electron beam emitted from the electron gun is distorted in the opposite direction of the influence of the nonuniform magnetic field of the deflection yoke, and the focal length of the electron beam is scanned when the electron beam is scanned to the center of the fluorescent film and to the periphery. The dynamic focusing method which makes it variable to have been sought.

2 shows an example of such a dynamic focus electron gun.

This is because the cathode 11, the control electrode 12, and the screen electrode 13, which form an anterior triode, form an auxiliary and main lens system. The first and second focus electrodes 14, 15 and the second And a final acceleration electrode 16 provided adjacent to the focus electrode 15. Here, the elongated electron beam through hole 14H and the elongated electron beam through hole 15H are respectively formed in the exit side surface 14a of the first focus electrode 14 and the incident side surface 15b of the second focus electrode 15, respectively. ) Are formed respectively.

A predetermined potential is applied to each of the electrodes, and a focus voltage VF is applied to the first focus electrode 14, and the focus voltage VF is applied to the second focus electrode 15 as a base voltage. In addition, a dynamic focus voltage VD is applied in synchronization with the deflection signal, and the final acceleration electrode 16 is applied with a high-voltage anode voltage VE higher than the voltages.

In the conventional cathode ray tube electron gun 10 configured as described above, the dynamic focus voltage VD is not applied to the second focus electrode 15 when the electron beam emitted from the cathode 11 is scanned to the center portion of the fluorescent film. Final focusing and acceleration by an electron lens formed between the electrode 13 and the first focusing electrode 14 and final focusing by a main lens formed between the second focusing electrode 15 and the final acceleration electrode 16. And accelerated to land in the central portion of the fluorescent film.

In addition, when the electron beam emitted from the cathode 11 of the electron gun is deflected to the periphery of the fluorescent film, a dynamic focus voltage VD is applied to the second focus electrode 15, thereby providing first and second focus electrodes 14 and 15. The electron beam is lengthened by the quadrupole lens formed between the first and second electrodes, and the dynamic voltage VD is applied to the second focusing electrode 15, thereby finally focusing and accelerating by the main lens, which is relatively weakened. As described above, the elongated and accelerated electron beam passes through a non-uniform magnetic field of the yaw that has a large divergence in the transverse direction, and the distortion is compensated for and landed at the periphery of the fluorescent film.

However, the electron gun 10 may form a quadrupole lens when landing on the periphery of the fluorescent film to reduce the overall spherical aberration and improve the focus characteristic, but the dynamic focus voltage VD may be applied to the second focus electrode 15. When applied, the main lens formed between the second focusing electrode 15 and the final accelerating electrode 16 is weakened, so that a convergence drift phenomenon of the electron beam may occur. In addition, as the intensity of the main lens is weakened, the cross-sectional compensation of the electron beam due to the nonuniform magnetic field of the deflection yoke is not completely achieved, and the top or bottom of the cross-section of the electron beam landing at the periphery of the fluorescent film is inclined toward the corner of the fluorescent film. There is a problem inherent in that a uniform electron beam cross section cannot be obtained in all fluorescent films.

The present invention was created in order 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 characteristics of the electron beam color cathode ray which can improve the resolution of the cathode ray tube employing it The purpose is to provide a conventional gun.

In order to achieve the above object, the present invention is a color cathode ray comprising a cathode, a control electrode and a screen electrode constituting the pre-triode, the first, second, three, four focus electrode and the final acceleration electrode constituting the auxiliary and main lens system In the conventional electron gun, the electron beam distortion compensation means for preventing the distortion of the electron beam cross-section due to the rotational distortion of the electron beam when the electron beam is deflected on the exit side of the second focus electrode and the incident side of the third focus electrode is characterized in that provided do.

Another feature of 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 focus electrode and a final acceleration electrode forming an auxiliary and main lens system. In the electron gun, an electron ratio distortion compensating means is provided on the exit side of the first focus electrode and the exit side of the third focus electrode to prevent distortion of the electron beam cross section due to rotational distortion of the electron beam when the electron beam is deflected.

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

3 shows the electron gun for the color cathode ray tube according to the present invention, which comprises the cathode 21, the control electrode 22 and the screen electrode 23 forming the pre-triode, and the first, second, and second auxiliary lenses. 3, 4 focus electrodes 24, 25, 26, 27, and a final acceleration electrode 28 disposed adjacent to the fourth focus electrode 27 to form a bipotential main electrostatic lens. It is composed. An electron beam for compensating cross-sectional distortion of the electron beam due to rotational distortion of the electron beam when the electron beam is deflected according to the feature of the present invention on the exit side surface 25a of the second focus electrode 25 and the entrance side surface of the third focus electrode 26a. Distortion compensation means is provided.

The electron beam distortion compensating means is a first longitudinal electron beam passing hole inclined at a predetermined angle to the right direction with respect to the traveling direction of the electron beam as shown in FIG. 4 on the emission side surface 25a of the second focus electrode 25. 25H is formed and the inclined side 26a of the third focusing electrode 26 is inclined in the opposite direction to the first electron-shaped electron ratio passing hole 25H as shown in FIG. The two-shaped electron beam through hole 26H is formed. Here, the inclination angles of the first and second type electron beam passing holes 25H and 26H are preferably 15 degrees to 45 degrees with respect to the vertical side perpendicular to the traveling direction of the electron beam. In addition, a predetermined voltage is applied to each of the electrodes, a focus voltage VF is applied to the first focus electrode 24, and the focus voltage is applied to the second focus electrode 25 as a base voltage. As shown in FIG. 7, the first half dynamic voltage VD1 is applied to the third focus electrode 26, and a second half dynamic voltage having a phase difference with respect to the first half dynamic voltage VD1 is shown in FIG. 7. VD2) is applied. The fourth focus electrode 27 is applied with a third full dynamic focus voltage VD3 as shown in FIG. 8, and the final acceleration electrode 28 has a high-voltage enowood voltage VE higher than the voltage. ) Is applied.

In another embodiment of the present invention, as shown in FIG. 9, the cathode 31, the control electrode 32, and the screen electrode 33 forming the anterior triode are formed of the first, second, third, and second lenses. 4, 5 focus electrodes 34, 35, 36, 37, 38, and the final acceleration electrode 39 disposed adjacent to the fifth focus electrode 38 to form a bipotential main electron lens. It is configured to include. The emission side surface 34a of the first focusing electrode 34 and the emission side surface 36a of the third focusing electrode 36 exhibit cross-sectional distortion of the electron beam due to rotational distortion of the electron beam during deflection of the electron beam according to the feature of the present invention. Compensating electron beam distortion compensating means is provided. The electron beam distortion compensating means has a first longitudinal electron beam through hole 34H which is inclined at a predetermined angle to a right direction with respect to the traveling direction of the electron beam on the exit side 34a of the first focus electrode 34 and is formed. The second longitudinal electron beam passing hole 36H inclined in the opposite direction to the first longitudinal electron beam passing hole 34H is formed in the emission side 36a of the three focus electrode 36.

Here, the inclination angles of the first and second elongated electron beam through holes 34H and 36H are preferably 15 degrees to 45 degrees with respect to the vertical axis perpendicular to the traveling direction of the electron beam. The long electron beam through hole is preferably formed in a rectangular or elliptical shape. A predetermined voltage is applied to each of the electrodes, and a focus voltage VF is applied to the first and third focus electrodes 34 and 36, and the focus voltage is applied to the second focus electrode 35 as a base voltage. The first half dynamic voltage VD1 as shown in FIG. 6 is applied and the fourth focus electrode 37 has a phase difference with respect to the first half dynamic voltage VD1 as shown in FIG. A two half dynamic voltage VD2 is applied. The fifth focus electrode 38 is applied with a complete third dynamic focus voltage VD3 as shown in FIG. 8, and the final acceleration electrode 39 has a high-voltage enowood voltage VE higher than the voltage. ) Is applied.

The operation of the electron gun for the color cathode ray tube according to the present invention configured as described above will be described as an embodiment shown in FIG.

In the electron gun 20 for the color cathode ray tube according to the present invention, when a predetermined voltage is applied to each of the electrodes as described above, a prefocus lens is formed between the screen electrode 23 and the first focus electrode 24. The first, second and third dynamic focus voltages are between the first, second and third focus electrodes 24 and 25 and 26 and between the second and third and fourth focus electrodes 25 and 26 and 27. The quadrupole lens is formed according to whether (VD1), (VD2), and VD3 are applied, and a main electron lens is formed between the fourth focus electrode 27 and the final acceleration electrode 28.

Therefore, the electron beam emitted from the cathode 21 of the electron gun 20 passes through each electron lens and lands at each fluorescent point of the fluorescent film. This landing process is performed when the electron beam is scanned at the center of the fluorescent film. When divided into the upper right and lower left, the upper left and lower right of the fluorescent film is described as follows.

First, when the electron beam emitted from the cathode 21 is scanned into the center portion of the fluorescent film, the dynamic focus voltage synchronized with the deflection signal is not applied to the second, third and fourth focus electrodes 25, 26, 27. Therefore, a potential difference does not occur between the first and second focus electrodes 24 and 25 and the third and fourth focus electrodes 26 and 27, so that the quadrupole lens is not formed. Therefore, the electron beam emitted from the cathode 21 is preliminarily connected and accelerated by a prefocus lens formed between the screen electrode 23 and the first focus electrode 24, and finally the fourth beam electrode 27 and the fourth focus electrode 27. Final connection and acceleration are made by the kettle lens formed between the acceleration electrodes 28 so that the circular electron beam is landing in the best state in the center of the fluorescent film.

When the electron beam emitted from the cathode 21 of the electron gun 20 is scanned to the upper right side and the lower left side of the fluorescent film, a first half dynamic voltage VD1 is applied to the second focus electrode 25 and a third The second half dynamic voltage VD2 is not applied to the focus electrode 26, and the complete third dynamic focus voltage VD3 is applied to the fourth focus electrode 27. Therefore, between the second and third focus electrodes 25 and 26, the first longitudinal electron beam passing hole 25H formed on the emission side of the second focus electrode 25 is leftward with respect to the electron beam traveling direction. An inclined quadrupole lens is formed, and between the fourth focus electrode 27 and the final acceleration electrode 28, a dynamic focus voltage VD is applied to the fourth focus electrode 27 so that the main lens is weakened relatively. Is formed.

Accordingly, the electron beam emitted from the cathode 21 forms an elongated longitudinal shape as shown in FIG. 10 by the quadrupole lens, and the elongated longitudinal electron beam is accelerated by the main lens. Afterwards, the divergence force in the horizontal shape due to the influence of the non-uniform magnetic field caused by the deflection yoke and the rotational distortion force in the right direction are compensated to form a cross section of the electron beam scanned on the upper right and lower left.

When the electron beam emitted from the electron gun is scanned to the upper left and the lower right, the first half dynamic voltage VD1 is not applied to the second focus electrode 25, and the second half is applied to the third focus electrode 26. The dynamic voltage VD2 is applied, and the third dynamic focus voltage VD3 is applied to the fourth focus electrode 27.

Therefore, between the second and third focus electrodes 25 and 26, the second longitudinal type electron beam through hole 26H formed on the incident side of the third focus electrode 26 is moved to the right direction with respect to the electron beam traveling direction. An inclined quadrupole lens is formed, and a main lens that is relatively weakened by applying a dynamic focus voltage VD to the fourth focus electrode 27 is applied between the fourth focus electrode 27 and the final acceleration electrode 28. Is formed.

Accordingly, the electron beam emitted from the cathode 21 forms an elongated longitudinal shape inclined in the right direction as shown in FIG. 11 by the quadrupole lens, and the elongated longitudinal electron beam is accelerated by the main lens. Afterwards, the divergence force in the horizontal shape due to the influence of the non-uniform magnetic field by the deflection yoke and the rotational distortion force in the left direction are compensated to form a circular cross section of the upper and lower left beams.

The quadrupole lens action of the electron gun of another embodiment according to the present invention shown in FIG. 9 is also the same as the present invention. As described above, the electron gun for the color cathode ray tube of the present invention emits an electron beam caused by deflection aberration by rotating the axis of the electron beam emitted from the cathode and elongated by the quadrupole lens in the opposite direction of the axis rotated by the nonuniform magnetic field of the deflection yoke. Compensation of deterioration has the advantage of improving the image resolution of the cathode ray tube employing it.

Claims (8)

A cathode, a control electrode, and a screen electrode forming the pre-triode, the first, second, third, and fourth focus electrodes forming the auxiliary and main lens systems and the final accelerating electrode; and an emission side and the third focus of the second focus electrode. In the electron gun for a color cathode ray tube provided with an electron beam distortion compensation means for preventing the distortion of the electron beam cross-section caused by the rotational distortion of the electron beam when the electron beam is deflected on the incident side of the electrode, the electron beam distortion compensation means and the emission side of the second focus electrode A first longitudinal electron beam through hole and a second longitudinal electron beam through hole which are inclined at a predetermined angle with respect to the vertical direction of the traveling direction of the electron beam are formed on the incident side of the third focus electrode, and a focus voltage is applied to the first focus electrode. Wherein the first and second half dynamic focus voltages are applied and selectively applied to the second and third focus electrodes, respectively, in synchronization with a deflection signal. Electron gun for color cathode ray tube made with gong. The electron gun for color cathode ray tubes according to claim 1, wherein the first and second elongated electron beam through holes are rectangular. The electron gun for a color cathode ray tube according to claim 1, wherein the first and second elongated electron beam passing holes are inclined in opposite directions. The color cathode ray tube according to any one of claims 1 to 3, wherein the inclination angles of the first and second elongated electron beam passing holes are 15 to 45 degrees with respect to the vertical axis perpendicular to the electron beam traveling direction, respectively. Electron gun. An electron gun for a color cathode ray tube comprising a cathode, a control electrode, and a screen electrode forming an anterior triode, and first, second, third, fourth, and fifth focus electrodes forming an auxiliary and main lens system and a final accelerating electrode. And an electron beam distortion compensation means for preventing distortion of the electron beam cross section due to rotational distortion of the electron beam when the electron beam is deflected on the emission side of the focus electrode and the emission side of the third focus electrode. The first type electron beam according to claim 5, wherein the electron beam distortion compensating means is inclined at a predetermined angle with respect to the vertical direction of the traveling direction of the electron beam on the emission side surface of the first focus electrode and the emission side surface of the third focus electrode. A through hole and a second longitudinal electron beam through hole are formed, and a dynamic focus voltage is applied to the first and third focus electrodes, and the first and second half dynamic focus voltages are synchronized to the second and fourth focus electrodes, respectively, in synchronization with a deflection signal. Electron gun for color cathode ray tube, characterized in that applied to the configuration. The electron gun for a color cathode ray tube according to claim 6, wherein the first and second elongated electron beam passing holes are inclined in opposite directions to each other. The color cathode ray according to any one of claims 6 to 7, wherein the inclination angles of the first and second elongated electron beam passing holes are 15 degrees to 45 degrees with respect to the vertical side which is perpendicular to the electron beam traveling direction, respectively. Tolerance gun.