JPH05316525A - Landing correction device - Google Patents

Abstract

PURPOSE:To provide an automatic landing correction device by which deterioration in color purity caused by deformation of a shadow mask or an effect of an undesired magnetic field or the like is corrected with high accuracy in a color television receiver. CONSTITUTION:A cylindrical X axis direction correction coil 7 and a cylindrical Y axis direction correction coil 8 whose correction magnetic field axes are orthogonal to each other being components of the landing correction means are used as a pair, and they are arranged to a cathode ray tube neck section so that the directions of the magnetic fields generated by the said two coils are coincident with directions of the X and Y axes and the landing correction means is provided with a drive section 3 to apply a correction signal to the landing correction means and a control section 4 controlling the drive section 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a landing correction device for a color television receiver, which prevents deterioration of color purity caused by deformation of a shadow mask, an influence of an unnecessary magnetic field and the like.

[0002]

2. Description of the Related Art Generally, in a color television receiver that deflects an electron beam to scan a phosphor to produce a display image, the landing position of the electron beam is changed due to deformation of a shadow mask, influence of an unnecessary magnetic field, and the like. Changes in brightness and chromaticity occur on the displayed image. This mislanding is corrected by using a correction coil and applying an appropriate correction current to the beam to cancel the change in the beam landing due to the deformation of the shadow mask, the influence of the unnecessary magnetic field, and the like.

A conventional landing correction device is disclosed, for example, in Japanese Patent Laid-Open No. 3-149733, "Pility correction device". The mislanding correction method of this conventional landing correction apparatus is shown in FIGS.
This is as shown in (b) and FIG. 5 (c). The operation will be described below.

In FIG. 5A, 14 is a coil for generating a Y-axis direction landing correction magnetic field, and 21 is an X-axis.
A coil for generating an axial landing correction magnetic field. Further, 9 is a green beam, 10 is a red beam, and 11 is a blue beam. In the following figures, the same parts are designated by the same reference numerals and the description thereof will be omitted. In the landing correction coil shown in FIG. 5A, a correction current for realizing a desired landing adjustment amount is supplied to the coils 14 and 21 to correct mislanding.

In FIG. 5B, reference numeral 22 is a coil for generating a landing correction magnetic field in the X-axis direction. In the landing correction coil shown in FIG. 5B, a correction current for realizing a desired landing adjustment amount is supplied to the coils 14 and 22 to correct mislanding.

In FIG. 5 (c), numeral 23 is a coil for generating a Y-axis horizontal landing correction magnetic field.
In the landing correction coil shown in FIG. 5C, a correction current for realizing a desired landing adjustment amount is supplied to the coils 23 and 21 to correct mislanding.

Another example is Japanese Patent Laid-Open No. 3-1255.
No. 91 publication, “Purity / Convergence Adjustment Device”. The mislanding correction method of this conventional landing correction apparatus is as shown in FIGS. 6A and 6B, and will be described in detail below.

FIG. 6A is a block diagram of the landing adjusting device. In FIG. 6A, 1 is a CRT, 24
Is a deflection yoke, 25 is a landing miss / convergence miss detector, 26 is a landing miss / convergence miss calculator, 27 is a landing miss / convergence miss input, 28 is a current value calculator, 29 is a digital /
An analog converter, 30 is an amplifier, and 31 is a landing miss / convergence smith correction coil.

FIG. 6B shows a landing adjusting device. In FIG. 6B, reference numeral 32 is a coil for generating a Y-axis direction landing correction magnetic field, and 33 is a coil for generating an X-axis direction landing correction magnetic field.
It is arranged so as to surround the green beam 9, the red beam 10, and the blue beam 11.

In FIG. 6 (a), a landing error detector detects a landing error with its detection surface facing the CRT screen, and an optimum correction current is generated by a calculator, an arithmetic unit, and an amplifier based on the detection signal. Let the coils 32, 3
Run to 3 to correct mislanding.

[0011]

However, the above-mentioned FIG.
In such a configuration, the X-axis direction landing correction magnetic field is not a uniform magnetic field, and there is a problem that accurate correction cannot be performed. Further, in the configuration as shown in FIG.
The structure of the purity adjustment coil becomes complicated. Furthermore, FIG.
In the configuration as shown in (b), the landing correction has a problem that the adjustment is complicated and time-consuming because the landing error detection unit outside the color television apparatus is used.

In view of the above, the present invention provides an X-axis direction cylindrical correction coil and a Y-axis direction cylindrical correction coil as one correction coil pair at the neck portion of the cathode ray tube. It is an object of the present invention to accurately correct landing mistakes due to the deformation of the shadow mask and the influence of the unnecessary magnetic field, by the combined vector of the correction magnetic fields generated by the axial direction cylindrical correction coil.

Furthermore, the mislanding amount is obtained by detecting the beam incident angle information on the shadow mask, and the correction current corresponding to the mislanding amount is supplied to the correcting means to perform automatic correction, which is accurate in a short time. It is also an object of the present invention to provide a landing correction device that can perform quantitative correction.

[0014]

A first aspect of the present invention is a cylindrical type X
The axis correction coil and the cylindrical Y-axis correction coil are arranged as one correction coil pair at the neck portion of the cathode ray tube, and the landing correction means for performing correction at each position on the CRT display screen and the correction signal to this landing correction means are provided. It is a landing correction device characterized in that it is provided with a drive means for supplying and a control means for controlling the drive means.

Further, in the landing correction means, the X-axis correction coil is a two-pole coil radially provided with respect to the neck tube of the CRT.

A second aspect of the present invention comprises a landing correction means for correcting mislanding, a fluorescent substance provided in the display area of the display means and having directivity with respect to an incident angle of an electron beam, and the display area. Detecting means for detecting an incident angle of the electron beam on the shadow mask in synchronization with the scanning electron beam; driving means for supplying a correction signal to the landing correcting means; control means for controlling the driving means; And a landing error detection unit that outputs the detection unit and obtains a mislanding amount on the display screen, and the control unit controls the drive unit according to the output from the landing error detection unit. Is a landing correction device.

[0017]

According to the first invention, a cylindrical X-axis correction coil,
By arranging the cylindrical Y-axis correction coil as a correction coil pair in the neck portion of the cathode ray tube, the combined vector in the X-axis direction and the Y-axis direction generated by these correction coils causes deformation of the shadow mask, influence of an unnecessary magnetic field, etc. Mislanding can be corrected easily and accurately.

According to the second aspect of the invention, the landing correction is performed by detecting the incident angle of the electron beam on the shadow mask, finding the mislanding amount based on it, and supplying a correction signal corresponding to the mislanding amount to the correction means. It realizes the automation of and enables accurate and quantitative correction in a short time.

[0019]

1 (a) is a block diagram of a landing correction device in a first embodiment of the present invention, FIG. 1 (b) is a layout diagram of landing correction coils, and FIG. 1 (c) is a CRT of the landing correction coil. It is a sectional view in the tube axis direction.

In FIG. 1 (a), 1 is a CRT, 2 is a cylindrical landing correction coil for correction arranged at the neck of a cathode ray tube, 3 is a drive unit for supplying a correction signal to these correction coils, and 4 is a drive unit. A control unit 5 for controlling the drive unit 3 is a display unit for displaying an image on the cathode ray tube.

In FIG. 1B, 6 is a neck portion of the CRT, 7 is a cylindrical X-axis direction correction coil, and 8 is a cylindrical Y-axis direction correction coil. The Z axis indicates the tube axis direction of the CRT, and the positive Z direction indicates the tube surface direction of the CRT. θ is X
The winding angle of the X-axis direction correction coil with respect to the axis, and φ is the winding angle of the Y-axis direction correction coil with respect to the Y axis. Also, 9 is a green beam, 10 is a red beam, 11 is a blue beam,
l is the distance between the green beam 9 and the red beam 10 and between the green beam 9 and the blue beam 11. Reference numeral 12 is an X-axis direction correction magnetic field, and 13 is a Y-axis direction correction magnetic field.

In the landing correction apparatus of this embodiment constructed as described above, by adjusting θ according to the distance l, the blue beam separated from the magnetic field acting on the green beam 9 by the distance l on the X-axis. 11. The magnetic field acting on the red beam 10 can be made to have the same direction and the same magnitude parallel to the Y axis. That is, the same correction amount can be applied to the green beam 9, the blue beam 11, and the red beam 10 in the X-axis direction.

Further, by adjusting φ according to the distance l, the magnetic field acting on the green beam 9 and the magnetic field acting on the blue beam 11 and the red beam 10 separated by the distance l on the X axis are set on the X axis. It is possible to have the same direction and the same size in parallel. That is, green beam 9, blue beam 11, red beam 10
The same correction amount can be applied to the Y-axis direction.

By supplying a correction signal corresponding to the scanning position from the drive unit 3 to the above correction coil, mislanding can be corrected in the entire area of the display screen.

As described above, according to this embodiment, the correction coil is the cylindrical X-axis direction correction coil 7, and the cylindrical Y-axis direction correction coil 8 is one correction coil pair, and the cathode ray tube neck portion 6 is provided. By providing the above, it is possible to accurately correct the mislanding caused by the deformation of the shadow mask, the influence of the unnecessary magnetic field, etc. by the combined correction magnetic field in the X and Y directions.

FIG. 2 is a layout view of the landing correction coil. In FIG. 2, 7 is a cylindrical X-axis direction correction coil,
Reference numeral 14 is a Y-axis direction correction coil.

In the landing correction apparatus of the present embodiment constructed as described above, by adjusting θ according to the distance l, the blue beam separated from the magnetic field acting on the green beam 9 by the distance l on the X axis is adjusted. 11. The magnetic field acting on the red beam 10 can be made to have the same direction and the same magnitude parallel to the Y axis. That is, the same correction amount can be applied to the green beam 9, the blue beam 11, and the red beam 10 in the X-axis direction.

Further, the coils 14 can make the magnetic fields acting on the green beam 9, the blue beam 11 and the red beam 10 have the same direction and the same magnitude parallel to the Y axis. That is, the green beam 9, the blue beam 11, and the red beam 10 can be given the same correction amount in the Y-axis direction. By supplying a correction signal corresponding to the scanning position to the above correction coil from the drive section, mislanding can be corrected in the entire area of the display screen.

As described above, according to this embodiment, the correction coil is the cylindrical X-axis direction correction coil 7 and the cylindrical Y-axis direction correction coil 14 is one correction coil pair, and the cathode ray tube neck portion 6 is provided. By providing the above, it is possible to accurately correct the mislanding caused by the deformation of the shadow mask, the influence of the unnecessary magnetic field, etc. by the combined correction magnetic field in the X and Y directions.

FIG. 3 is a block diagram of a landing correction device according to the second embodiment of the present invention. In FIG.
Reference numeral 1 is a CRT, 2 is a cylindrical landing correction coil for correction arranged in the neck portion of the cathode ray tube, 3 is a drive unit that supplies a correction signal to these correction coils, 4 is a control unit that controls the drive unit 3, 5 Is a display unit for displaying an image on the cathode ray tube. Reference numeral 15 is a landing error detector, 16 is a shadow mask, and 17 is a fluorescent substance having directivity with respect to the incident angle of the electron beam.

The operation of the landing correction device configured as described above will be described with reference to FIG. Figure 4
In the above, 18 is an electron beam, 19 is the light emitted from the 17 phosphors on the shadow mask, and 20 is the phosphor on the tube surface.

First, the display screen is divided into a plurality of parts so that the 17 phosphors are included one by one. The divided one
In order to display only one portion, the drive unit 3 supplies a current to the display unit 5 to display an image, and at the same time, the drive unit 3 supplies the correction current to the correction coil 2 to sequentially change the amount. At this time, the phosphor 17 emits light only when the incident angle of the beam matches its directivity. This light is detected by the detector 15
The amount of correction current flowing through the correction coil, which is obtained by the above, is fed back to the control unit 4. The controller 4 calculates the mislanding amount from the correction current amount and determines the correction current amount required for the correction. This operation is performed for each of the divided display screens, the correction current amount in each part is determined, and the drive unit 3 is controlled by the information of the current amount. In this way, the mislanding correction is automated in the entire display screen.

As described above, according to this embodiment, the landing correction can be automated, and accurate and quantitative correction can be performed in a short time.

In the first embodiment, the method of controlling the magnetic field directions of the X-axis and the Y-axis has been described by arranging the coil in the neck portion of the cathode ray tube for the correction, but in the other portions. It may be provided.

Further, in the second embodiment, a case where a fluorescent substance having directivity with respect to the incident angle of the electron beam is provided to detect the incident angle of the electron beam to the shadow mask to perform the landing correction. As described above, the detection signal may be used to correct the convergence or geometric distortion.

[0036]

As described above, according to the first invention, the correction coil is a cylindrical X-axis direction correction coil, and the cylindrical Y-axis direction correction coil is one correction coil pair, and the cathode ray tube neck portion is provided. The shadow mask deformation, which is the combined vector of the magnetic fields created by these X-axis and Y-axis direction correction coils,
It becomes possible to accurately correct the mislanding due to the influence of the unnecessary magnetic field.

According to the second invention, the incident angle of the electron beam on the shadow mask is detected, the mislanding error is obtained, and the correction coil is driven by the correction signal according to the error amount to automate the landing correction. As a result, accurate and quantitative landing correction can be realized in a short time, and its practical effect is great.

[Brief description of drawings]

1A is a block diagram of a landing correction device according to a first embodiment of the present invention, FIG. 1B is a layout diagram of a landing correction coil, and FIG. 1C is a cross-sectional view of the landing correction coil in the CRT tube axis direction.

FIG. 2 is a cross-sectional view of the landing correction coil according to the first embodiment in the CRT tube axis direction.

FIG. 3 is a block diagram of a landing correction device according to a second embodiment of the present invention.

FIG. 4 is a diagram for explaining the operation of the embodiment.

FIG. 5A is a CR of a conventional landing correction coil.
(B) is a sectional view of another conventional landing correction coil in the CRT tube axial direction. (C) is a sectional view of another conventional landing correction coil in the CRT tube axial direction.
Cross section of RT tube axis

6A is a block diagram of a conventional landing correction device, and FIG. 6B is a cross-sectional view of a correction coil in the CRT tube axis direction.

[Explanation of symbols]

 1 CRT 2 Landing correction coil 3 Drive part 4 Control part 5 Display part 6 CRT neck part 7 Cylindrical X-axis direction correction coil 8 Cylindrical Y-axis direction correction coil 9 Green beam 10 Red beam 11 Blue beam 12 X-axis direction correction coil Magnetic field 13 Y-axis direction correction magnetic field 14 Y-axis direction correction coil 15 Landing error detection unit 16 Shadow mask 17 Phosphor having directivity 18 Electron beam 19 Light emitted by phosphor 20 Phosphor on tube surface 21 X-axis direction correction coil 22 X-axis direction correction coil 23 Y-axis direction correction coil

Claims (3)

[Claims] 1. A pair of two cylindrical correction coils whose correction magnetic field axes are orthogonal to each other in a plane perpendicular to the tube axis of the cathode ray tube, and the magnetic field direction created by the two coils is the X-axis direction (cathode ray tube). (A horizontal direction on the tube surface), and a landing correction means having at least a coil pair arranged in the neck portion of the cathode ray tube so as to match the Y-axis direction (the vertical direction on the tube surface of the cathode ray tube), A landing correction apparatus comprising: a driving unit that supplies a correction signal to the landing correction unit; and a control unit that controls the driving unit. 2. A coil for generating a magnetic field in the X-axis direction is a CRT.
2. The landing correction device according to claim 1, wherein the landing correction device comprises a two-pole magnetic field radially provided to the neck tube. 3. A display means for displaying image reception information of a color television receiver, a landing correction means for correcting mislanding, and a display area of the display means, the directivity for an incident angle of an electron beam. A fluorescent material having: a detection means for detecting an incident angle of the electron beam on the shadow mask in synchronization with an electron beam scanning the display area; and a driving means for supplying a correction signal to the landing correction means, It has a control means for controlling the driving means, and a landing error detection means for obtaining the mislanding amount on the display screen while outputting the detection means, and according to the output from the landing error detection means. A landing correction device characterized in that the control means controls the drive means.