JPH08180814A - Color cathode-ray tube apparatus - Google Patents

Abstract

PURPOSE: To provide just focusing property throughout the whole area of a screen by applying optinum focusing voltage corresponding to the scanning position of an electron beam to a dynamic focusing electrode of an electron gun. CONSTITUTION: Regarding a color cathode-ray tube apparatus composed of a color cathode-ray tube having an electron gun provided with a dynamic focusing electrode and a deflecting apparatus attached to a color cathode-ray tube, the following means are used; a ROM 11 in which a focusing voltage correcting value data is written and a focusing electric power source 15 to apply focusing voltage corresponding to the scanning position of an electron geam based on the data to the dynamic focusing electrode of the electron gun are provided. The focusing electric power source is composed of an address producing circuit 10 to determine the scanning position of an electron beam based on a horizontally synchronous signal and a vertically synchronous signal and a voltage generating circuit (output circuit 14) which reads out the focusing voltage correcting value data at that position from the ROM 11, carries out D/A conversion 12, and amplifies 13 the data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube device, and more particularly to a color cathode ray tube device having a structure in which just focus can be obtained over the entire screen of a color cathode ray tube having a dynamic focus electron gun.

[0002]

2. Description of the Related Art In a color cathode ray tube having an in-line type electron gun, a deflection yoke causes a horizontal deflection magnetic field component to have a pincushion type magnetic field distribution and a vertical deflection magnetic field component has a barrel type magnetic field distribution. A self-convergence method can be realized by giving a non-uniform magnetic field of (barrel type). However,
In general, the self-convergence non-uniform deflection magnetic field acts as a magnetic lens on the electron beam by exerting a diverging force in the horizontal direction and a converging force in the vertical direction to produce astigmatism. The amount of the distortion, and further, the horizontal diverging force and the vertical focusing force described above dynamically change depending on the deflection position (the position of the beam spot on the screen).

Conventionally, as a method for solving the above problems, a method using a dynamic drive quadrupole lens described below has been adopted. That is, as shown in FIG. 3, the electron gun having the dynamic drive quadrupole lens has a cathode 1, a first grid 2 as a control grid,
The second grid 3 as the first acceleration grid, and the -1 grid 4 as the convergence-1 grid, the 3rd-2 grid 5 as the convergence-2 grid, and the fourth grid as the second acceleration grid that configure the quadrupole lens 7. It is composed of 6. Then, a constant focus voltage EC3S is applied to the 3-1 grid 4, and a dynamic voltage EC3D as shown in FIG. 4, which changes according to the position on the screen where the electron beam reaches the 3-2 grid 5, is applied. Apply. Then
As shown in FIG. 5, the quadrupole lens 7 exerts a diverging force 8 in the vertical direction and a converging force 9 in the horizontal direction with respect to the electron beam, and the quadrupole lens 7 causes electrons to be generated by the non-uniform deflection magnetic field of the deflection yoke. The effects of horizontally distorting the beam are canceled out, and an undistorted beam spot is obtained over the entire screen.

[0004]

However, in the above-mentioned dynamic focus drive, the characteristics of the electron gun of the cathode ray tube and the fluorescence of the shadow mask and the inner surface of the panel can be obtained only by macroscopically adjusting the shape of the electron beam spot over the entire screen. It is not possible to deal with partial focus adjustments that occur due to design factors such as the relationship with the surface, and assembly factors such as the combination with the deflection yoke, and just focus on the entire screen as high definition progresses. The problem that is not obtained is becoming more prominent. In order to solve the above problems, an object of the present invention is to write a focus correction value, which has been converted into data over the entire screen, into a ROM, and synchronize the optimum focus voltage with the scanning of an electron beam based on the ROM data. Let me
It is an object of the present invention to provide a color cathode ray tube device in which just focus can be obtained over the entire screen by applying to a dynamic focus electrode.

[0005]

According to the present invention, there is provided an electron beam mounted on a panel having an inner surface on which a fluorescent surface for emitting light by an electron beam is formed and a neck connected to the panel via a funnel. In a color cathode-ray tube device including an electron gun equipped with a dynamic focus electrode for emitting light and a deflection device mounted on the outer wall of the funnel, a ROM in which focus voltage correction value data is written
And a focus power supply for applying a focus voltage corresponding to a scanning position of an electron beam to the dynamic focus electrode of the electron gun according to the data, to provide a color cathode ray tube device. An address generating circuit for the focus power source to determine the scanning position of the electron beam from the horizontal synchronizing signal and the vertical synchronizing signal, and a voltage generating circuit for reading the focus voltage correction value data at the position from the ROM, performing D / A conversion and amplifying the read data. It is preferable that the focus voltage correction value data written in the ROM is at least the correction value data determined by the design of the color cathode ray tube.

[0006]

According to the above structure, since the optimum focus voltage corresponding to the scanning position of the electron beam can be applied to the dynamic focus electrode of the electron gun, just focus can be obtained over the entire screen. Therefore, even in a high-definition color cathode ray tube, the brightness and color purity do not decrease. Also,
An address generation circuit that determines the scanning position of the electron beam from the focus power source from the horizontal synchronizing signal and the vertical synchronizing signal, and R
A focus power supply having a simple configuration can be obtained by configuring the focus power supply circuit to generate an optimum focus voltage based on the OM data. In addition, since the ROM data is the correction value data determined by the design of the color cathode ray tube, misfocus, which is a practical problem, does not occur, but the color cathode ray tube, the deflection yoke, and the purity convergence magnet are individually combined. Even better just focus can be obtained by adding the data (hereinafter referred to as ITC data) at the time of the ITC test to be adjusted.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. The same parts as those of the conventional example are designated by the same reference numerals and the description thereof will be omitted. A color cathode ray tube device according to an embodiment of the present invention is
Similar to the conventional example, the cathode 1, the first grid 2, the second grid 3, and the 3-1 grid 4, the 3-2 grid 5, and the fourth grid 6 that configure the quadrupole lens 7 as in the conventional example. 1, an address generating circuit 10 for determining the position on the screen where the electron beam reaches from the horizontal synchronizing signal and the vertical synchronizing signal, and the design of the color cathode ray tube, as shown in FIG. ROM 11 in which correction value data to be determined is written, a D / A converter 12 that generates an analog voltage based on the ROM data at the position of the address generation circuit, a voltage amplifier 13 that amplifies the analog voltage to an optimum focus voltage, and a static voltage EC3
It is characterized by comprising a focus power supply 15 composed of an output circuit 14 which superimposes on S to generate a dynamic voltage EC3D. And this dynamic voltage EC3
D is applied to the 3rd-2 grid 5 and the 3rd-1 grid 4
When a constant focus voltage EC3S is applied to the quadrupole lens 7, the quadrupole lens 7 exerts an optimum diverging force in the vertical direction and an optimum focusing force in the horizontal direction with respect to the scanning position of the electron beam,
A just-focused beam spot can be obtained over the entire screen.

As a second embodiment of the present invention, as shown in FIG. 2, the basic grid structure and the focus power source are:
Similar to the first embodiment, the ROM 16 in which, in addition to the correction value data determined by the design of the color cathode ray tube, the individual correction data at the time of the combination inspection (ITC) with the deflection yoke of each color cathode ray tube is written. Use focus power supply 1
7 is set. According to this embodiment, since the distortion of the beam spot in each color cathode ray tube device due to the combination of the deflection yoke and the color cathode ray tube can also be corrected, just focus with further improved accuracy can be obtained. Although the example in which the G3 grid is divided to form the quadrupole lens has been described above, the present invention is not limited to this embodiment. For example, an electron gun in which the G4 electrode is divided to form the quadrupole lens is used. Needless to say, the same effect can be obtained even when applied.

[0009]

According to the present invention, since the optimum focus voltage corresponding to the scanning position of the electron beam can be applied to the dynamic focus electrode of the electron gun, just focus can be obtained over the entire screen. Therefore, even in a high-definition color cathode ray tube, the brightness and color purity do not decrease. In addition, the focus power source is composed of an address generation circuit that determines the scanning position of the electron beam from the horizontal synchronization signal and the vertical synchronization signal and a voltage generation circuit that generates an optimum focus voltage based on the ROM data. Power is available. Further, by using the ROM data as the correction value data determined by the design of the color cathode ray tube, the misfocus, which is a practical problem, does not occur.
Even better just focus can be obtained by adding ITC data to be tested in combination with the deflection yoke.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a dynamic focus power supply of a color cathode ray tube device which is an embodiment of the present invention.

FIG. 2 is a configuration diagram of a dynamic focus power supply of a color cathode ray tube device which is another embodiment of the present invention.

FIG. 3 is a block diagram of an electron gun having a conventional general quadrupole lens.

FIG. 4 is a voltage waveform diagram of dynamic focus drive.

FIG. 5 is a configuration diagram of a quadrupole lens for explaining dynamic driving.

[Explanation of symbols]

 10 address creation circuit 11, 16 ROM 12 D / A converter 13 voltage amplifier 14 output circuit 15, 17 focus power supply

Claims (3)

[Claims] 1. A panel having an inner surface on which a fluorescent surface for emitting light by electron beam bombardment is formed, and a dynamic focus electrode for emitting an electron beam mounted in a neck connected to the panel via a funnel. In the color cathode-ray tube device including the electron gun and the deflection device mounted on the outer wall of the funnel, the ROM in which the focus voltage correction value data is written and the focus voltage corresponding to the scanning position of the electron beam by the data A color cathode ray tube device comprising a focus power supply applied to a dynamic focus electrode of a gun. 2. An address creating circuit for the focus power source to determine a scanning position of an electron beam from a horizontal synchronizing signal and a vertical synchronizing signal, and a voltage for D / A converting and amplifying focus voltage correction value data at the position read from the ROM. The color cathode ray tube device according to claim 1, comprising a generating circuit. 3. The color cathode ray tube device according to claim 1, wherein the focus voltage correction value data written in the ROM is correction value data determined at least by design of the color cathode ray tube.