JPH05219516A - Landing correcting device - Google Patents

Abstract

PURPOSE:To correct mis-landing due to the effect of the earth magnetism being present ununiformly in a cathode ray tube with high accuracy. CONSTITUTION:A station correction coil 9 is arranged to the neck part of a cathode ray tube to apply static correction to the magnetic field. Furthermore, two correction coils whose correction magnetic axes are intersected orthogonally with each other are used as a pair, and x-axis correction coils 1-4 and y-axis correction coils 5-8 are arranged to four corners around the cathode ray tube so that the direction of the magnetic field generated by the two coils are coincident with the directions of X and Y axes and partial correction is implemented by the combined vector in the directions of X and Y axes.

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 a decrease in color purity caused by the influence of the earth's magnetism.

[0002]

2. Description of the Related Art Generally, in a color television receiver which produces a display image by deflecting an electron beam to scan a phosphor, the landing position of the electron beam is changed by the influence of the earth's magnetism, and the brightness on the display image is Chromaticity changes occur. This mislanding is corrected by using a correction coil and applying an appropriate correction current to it to cancel the influence of the geomagnetism.

As a conventional landing correction device, there is, for example, a structure shown in FIGS. In FIG. 5, 42 is a correction coil for correcting the x-direction component of the geomagnetism, 43 is a correction coil for correcting the y-direction component of the geomagnetism,
A correction coil 44 corrects the z-direction component of the earth's magnetism. In FIG. 6, reference numerals 45, 46, 47 and 48 are correction coils for partially correcting the mislanding in the peripheral portion of the cathode ray tube.

In the conventional landing correction coil constructed as shown in FIGS. 5 and 6 above, while confirming the display image of the color television receiver, it is possible to display the image at 42, 43, 44 or 45, 46, 47, 48. Mislanding is corrected by passing an appropriate correction current and visually determining the optimum correction current.

A conventional automatic landing correction device is disclosed, for example, in JP-A-52-40921, "Automatic landing correction device for color television receiver". The mislanding correction method of the automatic landing correction device of this conventional example is based on the assumption that the mislanding amount is as shown in FIG. 7 depending on the direction in which the screen surface of the color television receiver is peeled off. Is supplied to the landing correction coil provided at the neck portion of the cathode ray tube to correct the hypothetical mislanding amount shown in FIG.

The correction current is supplied to the landing correction coil as follows. That is, a first detecting means (not shown) for detecting a magnetic field in the tube axis direction of the color cathode ray tube and a second magnetic field detecting means (not shown) for detecting a magnetic field in a direction orthogonal to the tube axis direction on a horizontal plane. And) so as to obtain the first and second sawtooth wave signals of the vertical scanning period having the polarities and the magnitudes according to the outputs of the first and second magnetic field detecting means, and the second sawtooth wave. A signal obtained by modulating a sawtooth wave signal having a horizontal scanning period with the signal and the first sawtooth wave signal are superimposed and supplied to the dynamic landing correction coil.

[0007]

However, the above-mentioned FIG.
With such a configuration, the actual distribution of the earth's magnetism in the cathode ray tube is concentrated in the peripheral area due to the influence of the frame (ferromagnetic material) that supports the cathode ray tube, making it non-uniform, so accurate correction is required. It had a problem that it could not be done.
Further, in the configuration as shown in FIG. 6, it is possible to partially correct, but static correction cannot be performed, and since the direction of the correction magnetic field is fixed, the influence of geomagnetism in the peripheral portion of the cathode ray tube. However, there is a problem in that it cannot be accurately corrected. Further, in the configurations shown in FIGS. 5 and 6, since the landing correction is visually performed by the person performing the adjustment while visually observing the display image of the color television receiver, the adjustment takes a long time, and the adjustment is accurate and quantitative. However, there was a problem in that it was not possible to correct the problem.

Further, in the conventional example, the apparatus described in Japanese Patent Application Laid-Open No. 52-40921, "Automatic Landing Correction Device for Color Television Receiver", the amount of mislanding is as shown in FIG. It is determined assuming that they are uniformly distributed. However, as described above, the distribution of the geomagnetism in the cathode ray tube is concentrated around the cathode ray tube due to the influence of the frame that supports the cathode ray tube and the like, and is not evenly distributed. As you can see from the above,
In the above-mentioned conventional example, even if the mislanding amount is assumed as shown in FIG. 7 and a correction current commensurate with the mislanding amount is applied to the correction coil, the landing correction cannot be performed accurately.

In view of the above, the present invention provides an x-axis direction correction coil and a y-axis correction coil as one correction coil pair at the four corners of the peripheral portion of the cathode ray tube.
The combined vector of the correction magnetic field generated by the y-axis correction coil accurately corrects the influence of geomagnetism that becomes uneven in the cathode ray tube, especially in the peripheral portion of the cathode ray tube, and the correction coil is arranged at the neck portion of the cathode ray tube. It is an object of the present invention to provide a landing correction device capable of performing highly accurate correction by performing static correction. Further, the amount of mislanding is obtained by detecting the luminance and chromaticity information on the screen, and a correction current corresponding to the amount is applied to the correction means to perform automatic correction, which is accurate and quantitative in a short time. An object of the present invention is to provide a landing correction device capable of correction.

[0010]

According to a first aspect of the present invention, an x-axis correction coil and a y-axis correction coil are used as one correction coil pair.
Landing correction means arranged at the four corners of the peripheral portion of the cathode ray tube to perform partial correction, second landing correction means arranged to the neck portion of the cathode ray tube to perform static correction, and correction signals to these landing correction means are provided. A landing correction apparatus comprising: a driving unit that supplies the driving unit and a control unit that controls the driving unit. Further, it has magnetic field detection means for detecting the direction of the earth's magnetism and the magnetic field strength at a predetermined position of the color television receiver,
The landing correction device is characterized in that the control means and the driving means generate a landing correction signal in accordance with an output from the magnetic field detection means.

According to a second aspect of the present invention, display means for displaying image receiving information of a color television receiver, landing correcting means for correcting mislanding, driving means for supplying a correction signal to the landing correcting means, and this driving means. Means for controlling the means, a photoelectric conversion element provided at a predetermined position of the display means, and an error due to the luminance and chromaticity distribution in the two-dimensional area on the display image as well as output by the photoelectric conversion element. The landing correction device is characterized by comprising landing error detection means for obtaining a landing amount, and the control means controlling the drive means in accordance with an output from the landing error detection means.

[0012]

According to the first aspect of the invention, a static correction coil is provided in the neck portion of the cathode ray tube to perform static correction, and in order to perform partial correction, an x-axis correction coil, y
By arranging the axial correction coils as correction coil pairs at the four corners of the peripheral portion of the cathode ray tube, the combined vector in the x-axis direction and the y-axis direction produced by these correction coils causes unevenness in the cathode-ray tube, especially the peripheral portion of the cathode-ray tube. It is possible to accurately correct the influence of the geomagnetism, which becomes stronger with. Further, the landing correction can be automated by detecting the direction of the geomagnetism and the magnetic field strength and applying a correction current corresponding thereto to the correction means.

According to the second aspect of the present invention, the luminance and chromaticity distributions in the two-dimensional area on the display image are detected by the photoelectric conversion element, the amount of mislanding is obtained based on the detected amount, and the correction signal corresponding to the amount is obtained. By supplying the correction means, the landing correction can be automated, and accurate and quantitative correction can be performed in a short time.

[0014]

1 (a) is a block diagram of a landing correction device according to a first embodiment of the present invention, and FIG. 1 (b) is a layout view of partial correction coils. In FIG.
Reference numerals 1 to 8 are landing correction coils for partial correction, which are arranged around the cathode ray tube, 1 to 4 are x-axis direction correction coils, and 5 to 8 are y-axis direction correction coils. Further, 9 is a landing correction coil for static correction arranged at the neck portion of the cathode ray tube, 10 is a drive unit that supplies a correction signal to these correction coils, 11 is a control unit that controls the drive unit 10, and 12 is an image on the cathode ray tube. Is a display unit for displaying.

The operation of the landing correction apparatus of this embodiment having the above-described structure will be described below. According to this embodiment, the partial correction coils are the x-axis direction correction coils 1 to 4, and the y-axis direction correction coils 5 to 8 are one correction coil pair, and are provided at the four corners of the cathode ray tube peripheral portion.
It is possible to accurately correct the mislanding caused by the concentration of the earth's magnetism in the peripheral portion of the cathode ray tube due to the influence of the frame supporting the cathode ray tube by the combined correction magnetic field in the x and y directions. The above description will be described in detail with reference to FIG.

In FIG. 4, reference numeral 40 denotes a geomagnetic vector causing mislanding, and 41 denotes an electron beam vector. Mislanding occurs when a Lorentz force is applied to the electron beam to change the landing position of the electron beam. To eliminate mislanding, set the geomagnetic vector to 0 or
Or geomagnetic vector 40 and electron beam vector 41
There are two possible ways to match the directions of. The latter method is explained in more detail as follows.

The magnitude of the Lorentz force that causes mislanding depends on the geomagnetic vector 40 and the electron beam vector 4.
When the angle formed by 1 is θ, it depends on sin θ. That is, if the directions of the geomagnetism and the electron beam coincide with each other, the Lorentz force becomes 0, and the mislanding due to the geomagnetism will not occur. To perform the former of the two methods of canceling mislanding described above, x, y,
Correction coils in the z and 3 directions must be used. However, it is difficult to provide the z-direction correction coil due to the configuration of the color television receiver, and the latter method is more practical.

From the above, in order to accurately correct the influence of the earth's magnetism, a correction coil capable of generating a magnetic field in the x and y directions is required, and the xy plane component of the geomagnetic vector is a composite vector in the x and y directions. To change the direction of the geomagnetism to match the direction of the electron beam. To summarize the above, the mislanding due to the geomagnetism causes the direction of the geomagnetism to be the electron beam direction even if the direction of the magnetic field generated by the correction coil is fixed and only the magnitude thereof is changed as shown in FIG. It is impossible to make them coincide with each other, and the direction of geomagnetism is changed by changing the magnitude and direction of the correction magnetic field vector created by the x-direction correction coil and the y-direction correction coil. It is possible to correct with high accuracy.

Further, by providing the partial correction coils 1 to 8 as in the present embodiment, the correlation at the position on the color television display screen, that is, even if the correction is applied to one part, the error is made to the other part. Phenomena that increase the landing amount are reduced. In this embodiment, a static correction coil 9 is further provided at the neck portion of the cathode ray tube to enable static correction.

It is also possible to perform landing correction as follows. FIG. 2 shows the method. In FIG. 2, 13 to 20 are landing correction coils for partial correction similar to those of the first embodiment, 21 is a static correction coil similar to that of the first embodiment, and 22 is a correction current to the correction coils. A drive unit, 23 is a magnetic field detection unit that detects the intensity and direction of the geomagnetism, 24 is a control unit that generates a control signal according to the output from the magnetic field detection unit 23, and controls the drive unit 22, and 25 is an image on the cathode ray tube. Is a display unit, and 26 is a setting unit for manually setting the direction.

The operation of the landing correction device constructed as above will be described below. This behavior is
The magnetic field detector 23 for the geomagnetism is provided to detect the intensity and direction of the geomagnetism, the control unit 24 generates a control signal according to the detection output, and the drive unit 22 for supplying the correction current to the correction coils 13 to 20 and 21. By controlling, the landing correction is automated. It should be noted that the control unit 24 previously stores correction data according to the intensity and direction of the geomagnetism. It is also possible to manually set the direction using the setting unit 26.

FIG. 3A is a block diagram of a landing correction device according to the second embodiment of the present invention, and FIG. 3B is a layout diagram of partial correction coils. In FIG. 3, 27 to 34 are landing correction coils for partial correction similar to those of the first embodiment, 35 is a static correction coil similar to that of the first embodiment, and 36 is a correction current to the correction coils. The drive unit 37 detects the luminance and chromaticity on the color television display screen and detects the mislanding error. The mislanding error detection unit 38 outputs a control signal corresponding to the output from the mislanding error detection unit 37. A control unit 39 is generated and controls the drive unit 36, and a display unit 39 displays an image on the cathode ray tube.

The operation of the landing correction apparatus of the present embodiment constructed as above will be described below. The mislanding error detection unit 37 is arranged in the correction portion, and the brightness and chromaticity in the correction portion are captured by the photoelectric conversion element,
The mislanding error is detected by the data.
The control unit 38 generates a control signal according to the output from the mislanding error detection unit 37 to control the drive unit 36, thereby automating the landing correction. As described above, according to the present embodiment, the landing correction can be automated, and accurate and quantitative correction can be performed in a short time.

Here, the control unit 38 will be described in detail. In the present embodiment, the evaluation amounts of mislanding are taken to be luminance and chromaticity. However, when proceeding with automatic correction, it is necessary to determine the convergence condition of what should be the convergence. Therefore, the mislanding error is obtained by the following (Equation 2).

[0025]

[Equation 2]

The mislanding error at the correction point is obtained by the above (Equation 2), and the control unit 38 controls the correction currents to the correction coils 27 to 34 and 35 so that the mislanding evaluation amount of the correction unit approaches the reference value. Shed. In this case, the convergence condition is determined by emphasizing chromaticity, that is, r in (Equation 2). Because at the point of maximum brightness, chromaticity does not always come closest to the reference value as well,
If the uniformity on the display screen of a color television receiver is important, the convergence condition must be determined by weighting the chromaticity. The specific convergence conditions are as follows. That is, this is a method in which the chromaticity r is within a certain allowable range and the point where the luminance is maximum within that range is set as the convergence point.
Here, it is appropriate that the above-mentioned permissible range is a permissible range in which the distance on the chromaticity diagram from r, that is, the reference value, is 0.01 or less as a result of visual image quality evaluation experiments.

As described above, the mislanding error on the color television display screen to be corrected by the control unit 38 is obtained, and a correction signal corresponding to the mislanding error is sent to the correction coils 27 to 34 and 35 to obtain the optimum value. Correct the mislanding by determining the convergence point. As a procedure for the correction, first, static landing correction is performed on the center of the screen of the color television receiver, and then partial correction is performed in the peripheral portion of the screen. The first
In the above embodiment, the partial correction coils 1-8 and 13-2
Although the shape of 0 is a rectangle, it goes without saying that other shapes are also effective. The same applies to the partial correction coils 27 to 34 of the second embodiment.

[0028]

As described above, according to the first aspect of the invention, the x-axis direction correction coil and the y-axis direction correction coil are used as a partial correction coil to form one correction coil pair, and the correction coil pairs are provided at the four corners around the cathode ray tube. It is possible to accurately correct the mislanding due to the concentration of the geomagnetism in the peripheral part of the cathode ray tube due to the influence of the frame supporting the cathode ray tube, etc., by arranging and arranging these x-axis and y-axis direction correction coils. It will be possible. Further, it has a magnetic field detecting means for detecting the direction of the earth's magnetism and the magnetic field strength at a predetermined position of the color television receiver, and the control means and the driving means output the landing correction signal in accordance with the output from the magnetic field detecting means. According to the configuration for generating, the landing correction can be automated by detecting the magnetic field strength and direction of the earth's magnetism and generating a correction signal corresponding to the detected magnetic field strength and direction.

According to the second aspect of the invention, the luminance and chromaticity on the color television display image are detected, the mislanding error is obtained, the correction coil is driven by the correction signal according to the error amount, and the landing correction is performed. By automating
Accurate and quantitative landing correction can be realized in a short time, and its practical effect is great.

[Brief description of drawings]

FIG. 1A is a block diagram of a landing correction device according to a first embodiment of the present invention, and FIG. 1B is a layout diagram of the partial correction coil.

FIG. 2A is a block diagram of a landing correction device having a magnetic field detection unit, and FIG. 2B is a layout diagram of the partial correction coil.

FIG. 3A is a block diagram of a landing correction device according to a second embodiment of the present invention, and FIG. 3B is a layout diagram of the partial correction coil.

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

FIG. 5 is a configuration diagram of a conventional landing correction coil.

FIG. 6 is a configuration diagram of a conventional landing correction coil.

FIG. 7 is a diagram showing a conventional assumed mislanding state.

[Explanation of symbols]

 1 to 4 x-axis direction correction coil 5 to 8 y-axis direction correction coil 9 static correction coil 10 correction coil drive unit 11 control unit for drive unit 12 display unit 13 to 16 x-axis direction correction coil 17 to 20 y-axis direction correction coil 21 static correction coil 22 correction coil drive unit 23 magnetic field detection unit 24 control unit of drive unit 25 display unit 26 manual setting unit 27 to 30 x-axis direction correction coil 31 to 34 y-axis direction correction coil 35 static correction coil 36 correction coil drive Part 37 Mislanding error detection part 38 Control part of drive part 39 Display part

Claims (5)

[Claims] 1. A pair of two correction coils whose correction magnetic field axes are orthogonal to each other, and a magnetic field direction created by the two coils is a horizontal direction on the cathode ray tube surface and a vertical direction on the cathode ray tube surface. The landing correction means having at least a plurality of coil pairs arranged at the four corners of the cathode ray tube peripheral portion so as to coincide with each other, the driving means for supplying a correction signal to the landing correction means, and the driving means. A landing correction device comprising control means for controlling. 2. The landing correction device according to claim 1, wherein the landing correction means has a static correction coil arranged at a neck portion of the cathode ray tube. 3. The landing correction means comprises magnetic field detection means for detecting the direction of the earth's magnetism and the magnetic field strength at a predetermined position of the color television receiver, and according to the output from the magnetic field detection means. A control means and a drive means generate a landing correction signal.
The landing correction device described. 4. A display means for displaying image reception information of a color television receiver, a landing correction means for correcting mislanding, a drive means for supplying a correction signal to the landing correction means, and a control means for the drive means. Control means, a photoelectric conversion element provided at a predetermined position of the display means, and an error based on the luminance and chromaticity distribution in the two-dimensional area on the display screen of the display means as well as the output from the photoelectric conversion element. A landing correction device comprising landing error detection means for obtaining a landing amount, wherein the control means controls the drive means in accordance with an output from the landing error detection means. 5. The landing error detecting means calculates (Equation 1) from the luminance and chromaticity information, finds an error with respect to a reference value of luminance and chromaticity due to mislanding, and supplies it to the control means as a landing error signal. The landing correction device according to claim 4, wherein [Equation 1]