KR100188668B1 - Convergence measurement for calibration method of color picture tube - Google Patents

Abstract

The present invention discloses a calibration method for measuring the convergence of a color cathode ray tube using an optical sensor. According to a feature of the calibration method of the present invention, a reference light sensor for calibration is set among a plurality of light sensors disposed in front of a screen of a color cathode ray tube, and the actual mechanical horizontal and vertical lengths The actual length per one pixel in the horizontal and vertical directions is accurately measured according to the screen resolution as a reference for the convergence measurement of the color cathode ray tube by accurately measuring the number of pixels between the reference light sensors based on the measurement by the division method So that the accuracy of the convergence measurement result can be improved.

Description

Calibration method for convergence measurement of color cathode ray tube

FIG. 1 is a screen state diagram of a color cathode ray tube on which a crosshatch pattern before collision adjustment is displayed

FIG. 2 is a screen state diagram of a color cathode ray tube on which a crosshatch pattern after convergence adjustment is displayed

3 is a schematic diagram showing a convergence measuring system of a color cathode ray tube using an optical sensor

FIG. 4 is a reference light sensor layout diagram in the calibration method according to the present invention

FIG. 5 is a state diagram showing a screen address system of a color cathode ray tube in the method of calibrating according to the present invention

FIG. 6 is a horizontal sectional view of a color cathode ray tube according to a method of calibrating according to the present invention

FIG. 7 is a state diagram showing an optical sensor disposed on a boundary line in the horizontal split screen shown in FIG. 6

FIG. 8 is a horizontal address code generation table of the horizontal division status screen shown in FIG. 6

FIG. 9 is a vertical sectional view of a color cathode ray tube in a calibration method according to the present invention. FIG.

FIG. 10 is a vertical address code generation table of the vertical split screen shown in FIG.

DESCRIPTION OF THE REFERENCE NUMERALS

10: cathode ray tube 11: signal generator

12: optical sensor group 13: signal converter

14: Controller 15: Monitor

S1, S2, S3, S4, S5,

C1 to C9: Reference light sensor for calibration

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of measuring a color cathode ray tube. More particularly, the present invention relates to a method of calibrating a color cathode ray tube using an optical sensor.

In general, a color cathode ray tube used as a display device such as a color television receiver or a color monitor is performing convergence measurement in a manufacturing process in order to faithfully reproduce the color of a displayed image. That is, three-color electron beams (hereinafter referred to as R, R, G, and B) emitted from three electron guns (three tubes) to the entire screen area of a color cathode- G, and B beams) are focused on one pixel point on the screen of a color cathode ray tube and adjusted to be converged at mutually different incident angles, thereby enhancing the image quality.

Such convergence measurement is performed by, for example, applying a cross hatch pattern to a screen of a color cathode ray tube with a signal generator such as a pattern generator. At this time, if the convergence is not adjusted, images of R, G, and B are displayed at a predetermined interval, as shown in FIG. The R, G, and B image intervals in this pattern are measured as the amount of misconvergence.

Conventionally, in order to measure such misconvergence, a pattern is usually recognized on the screen using a camera, and the center of each color is obtained through a vision processor, Respectively. Based on the measured numerical values, the operator rotates the magnet mounted on the neck of the color cathode-ray tube while observing the pattern displayed on the screen, thereby causing the electron beam to reach the desired area of the screen so that the R, The convergence was adjusted to coincide with the state shown in FIG.

However, in the conventional method of measuring the convergence described above, the operator has to observe each color cathode ray tube set with a naked eye, resulting in a problem that accuracy, uniformity, and working efficiency of measurement are lowered. In addition, since expensive cameras are used, not only is the cost of device configuration increased, but also in the case of a large screen, it is difficult to measure misconvergence with respect to various points in the under surface, and the time required for measurement is long.

Accordingly, a method for measuring a color cathode-ray tube according to the related art has been proposed, which is a method of measuring a convergence using an optical sensor.

The method for measuring the convergence of a color cathode ray tube using the optical sensor includes measuring a misconvergence by recognizing a convergence state of an image pattern displayed on a screen through a plurality of optical sensors arranged in front of a screen of a color cathode ray tube, A current corresponding to the convergence adjustment value is applied to a coil provided around the electron gun to adjust the convergence by moving the direction of the beam by the electromagnet effect. According to the measurement using the optical sensor, it is possible to reduce the cost of the apparatus configuration by using a low-cost optical sensor instead of using an expensive camera, and it is possible to easily measure the convergence of a plurality of points on the screen It is possible to shorten the working time and increase the efficiency of the measurement.

However, in the above-described method for measuring the convergence of a color cathode ray tube using an optical sensor, there is a disadvantage in that the accuracy of measurement may deteriorate due to the accuracy of mechanical spacing between a plurality of optical sensors arranged in front of the screen of a color cathode ray tube .

In order to solve this disadvantage, it is necessary to precisely measure the actual actual length of a plurality of photosensors before the convergence measurement is performed, and to measure the actual length per one pixel in the horizontal and vertical directions according to the screen resolution of the specific color cathode- The inventor has found that there is a need to perform calibration that requires accurate measurement. The inventor of the present invention grasped that a calibration technique for a method of measuring the convergence of a color cathode ray tube using such an optical sensor has not been proposed to date.

Accordingly, it is an object of the present invention to provide a calibration method for measuring a precise measurement reference in a method of measuring a convergence of a color cathode ray tube using an optical sensor.

The calibration method provided by the present invention sets a reference light sensor for calibration among a plurality of light sensors disposed in front of a screen of a color cathode ray tube, The number of pixels between the reference light sensors is measured based on the measurement result and the actual length per one pixel in the horizontal and vertical directions is accurately measured according to the screen resolution as a reference for the convergence measurement of the color cathode ray tube The accuracy of the convergence measurement result can be improved.

According to an aspect of the present invention, there is provided a method of calibrating a color cathode ray tube,

A first step of displaying an image of a divided pattern on a screen of a color cathode ray tube and recognizing a position of a plurality of optical sensors disposed in front of the screen by a screen division method;

A second step of displaying an image of a convergence measurement pattern on a screen of the color cathode ray tube and calculating position coordinate values for the plurality of tube sensors;

A third step of calculating a pixel value between the horizontal and the vertical of the screen based on the position coordinate values of the optical sensors calculated in the second step;

A fourth step of dividing the vertical and horizontal lengths of the optical sensors by the pixel values calculated in the third step to calculate the length per pixel; And a control unit.

In particular, in the first step, the screen division is performed in the order of 2 &^lt; n > (n = natural number) And it is preferable that the screen division is completed in a state in which the plurality of optical sensors are positioned on the boundary line on which the screen is divided.

Hereinafter, a method of calibrating color cathode-ray tube convergence according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 is a cross-sectional view showing a color cathode ray tube convergence measurement system using an optical sensor, and a calibration method for measuring the color cathode ray tube according to the present invention is shown in FIG. 3 in a convergence measurement system Lt; / RTI >

Referring to FIG. 3, a convergence measurement system for a color cathode ray tube using an optical sensor will be briefly described. An image pattern for a convergence side gate, such as a cross hatch pattern, is formed on the lower surface of the color cathode ray tube 10 A plurality of optical sensor groups 12 (s1, s2, s3 ... sn) disposed in front of the screen of the color cathode ray tube 10 and a plurality of optical sensor groups 12 A signal converter 13 and a controller 14 connected to the controller 14 and a monitor 15 connected to the controller 14.

In the convergence measuring system having the above configuration, the pattern generator 11 forms a crosshatch pattern on the color cathode ray and the screen of the color cathode ray tube 10. The image light information for the image pattern is detected by the plurality of photosensor groups 12 and converted into signals through the signal converter 13 and then converted into misconvergence data by the controller 14, 14). On the basis of the misconvergence measurement data thus displayed, the direction of the electron beam is moved by a conventional method, for example, by rotating a magnet mounted on a neck portion of a color cathode ray tube or by applying a current to a coil, So that the convergence is adjusted.

In the above-described convergence measuring system for a color cathode ray tube, the signal converter 13 is usually signal-processed by a data acquisition processor (B / D), or signal amplified by an amplifier Then, it is converted into a digital signal by the A / D converter. The signal thus processed is usually analyzed and processed by the DSP processor 141 and the CPU 142 built in the controller 13 and calculated as a miss convergence measurement value. In FIG. 3, reference numeral 16 denotes a robot for supporting and transporting a color cathode ray tube to be measured for convergence, and reference numeral 17 denotes a robot controller for controlling the robot 16.

The present invention provides a calibration method for measuring and setting a precise measurement reference in a method and apparatus for measuring the convergence of a color cathode ray tube using an optical sensor as described above, In the case of the 14 to 20 color cathode ray tube, as shown in Fig. 4, nine photosensors c1 to c9 of the central part among the photosensors s1 to sN arranged at 25 places in front of the screen are mechanically And set it as the reference light sensor for calibration.

On the other hand, the other sixteen optical sensors are arranged to be movable in order to correct the outer dimensions according to the type of the color cathode ray tube. Since the light sensors moved in this manner may be spaced apart, they are not suitable for the calibration, and only the nine fixed optical sensors c1 to c9 are used for calibration. In addition, the lengths of the intervals between the fixed nine optical sensors c1 to c9 should be mechanically and precisely measured, and the length thereof must be measured in advance. In addition, at least three optical sensors among the nine optical sensors c1 to c9 are selected to find the number of pixels between the horizontal and the vertical, and the actual spacing between the optical sensors is divided to obtain the actual length .

In the above state, the color cathode ray and the address system of the screen 101 shown in FIG. 5 are divided into two halves of black and white on the screen of the color cathode ray tube as illustrated in FIG. 6 proceeding the image 2 in the pattern ⁿ (n = integer) equal parts of the black, the screen is divided into sequential back-divided image patterns to recognize the position of the optical sensor S1 to S5. Here, it is assumed that a certain light sensor is present in the white image pattern, and is assumed to be 0 in the case of being present in the black image pattern. Since the upper left position of the screen is the reference point when recognizing the position of the optical sensor, the screen division is gradually decreased from the maximum division.

That is, an image of a divided pattern divided into two halves at first is displayed, and the controller 14 reads the position coordinates of the optical sensors S1 to S5. At this time, since the light sensors S1 to S4 detect the black pattern, they are recognized as being present in the black pattern among the black and white patterns having little luminance value, and are input as 1. The photosensor S5 detects the white pattern, It is recognized as being present in the white pattern among the black and white patterns and input as 0.

Subsequently, the screen in the divided pattern state divided into black and white as described above is divided into quarters again to display quadrisected black and white divided patterns, and the controller 14 controls the position coordinates of the optical sensors S1 to S5 Read. At this time, since the optical sensors S1 and S5 exist in the black pattern, they are input as 1, and the optical sensors S2 and S3 exist in the white pattern and are input as 0.

However, since the optical sensor S4 is present on the boundary line of the black and white divided patterns as shown in FIG. 6, the process is difficult. In this case, the processing continues every time a subsequent screen division is performed. In this case, special processing is performed. That is, if an arbitrary optical sensor appears first on the boundary line of the black and white divided patterns, the first case is input as 1, and the subsequent cases are all processed as 0 (or vice versa) have). Accordingly, the optical sensor S4 is input as 1 according to this criterion, and is input as 0 unconditionally in the subsequent screen division.

As described above, when the screen division is progressed in a black and white divided image pattern of 2 ⁿ (n = natural number) equally, all the photosensors are displayed on the boundary line of the black and white divided patterns as shown in FIG. 7 The state in which the user exists is displayed. After this state, there is no need to further divide the screen. FIG. 8 is a horizontal address code table of each optical sensor obtained at this time, which is data on the position coordinates of the own color cathode ray tube image.

Next, as illustrated in FIG. 9, on the screen of the color cathode-ray tube, a black and white divided image pattern of 2 ⁿ (n = natural number) And proceeds to division to recognize the positions of the optical sensors S1 to S5. Here, the screen vertical division method is also the same as the above-described horizontal division method, and a detailed description thereof will be omitted.

The horizontal and vertical address codes of each optical sensor obtained by the screen division method as described above are data on the coordinates of the position of each optical sensor on the screen of the color cathode ray tube. Using this data, the distance between the optical sensors in the horizontal and vertical directions is calculated as a pixel value, and the actual mechanical horizontal and vertical lengths between the optical sensors are divided by the pixel (water) value to calculate the length per pixel do.

For example, when the horizontal and vertical lengths of the optical sensors are represented by Hm and Vm, and the horizontal and vertical pixel numbers of the optical sensors calculated by the screen division method are represented by Hp and Vp, respectively, (1) and (2).

In other words,

Horizontal Calibration Length = Hm / Hp [mm / pixel] ------- (1)

Vertical Calibration Length = Vm / Vp [mm / pixel] ------- (2)

The data obtained by the above equations (1) and (2) are used to check the presence or absence of each optical sensor on the screen of the color cathode-ray tube through the control operation of the program built in the controller () (), The operator can perform the convergence measurement more precisely based on the display.

As described above, the calibration method for measuring the convergence of a color cathode ray tube according to the present invention sets a reference light sensor for calibration among a plurality of light sensors disposed in front of a screen of a color cathode ray tube, And the number of pixels between the reference light sensors is accurately measured on the basis of the measured horizontal and vertical polarizations, and the horizontal and vertical polarizations according to the screen resolution, which is a reference for the convergence measurement of the color cathode- It is possible to improve the accuracy of the result of the measurement of the convergence of the color cathode ray tube by accurately measuring the actual length per pixel. The technique of the present invention can be applied not only to the calibration for the measurement of the convergence of the color cathode ray tube, various systems using geometry measurement and optical sensors In the calibration technique of the equipment it can be obtained an effect that can be widely applied width.

Claims (8)

A first step of displaying an image of a divided pattern on a screen of a color cathode ray tube and recognizing a position of a plurality of optical sensors arranged on the screen front by screen division; A second step of displaying an image of a convergence measurement pattern on a screen of the color cathode ray tube to calculate position coordinate values for the plurality of optical sensors; A third step of calculating a pixel value between the horizontal and the vertical of the screen based on the position coordinate values of the optical sensors calculated in the second step; And a fourth step of calculating a length per pixel by dividing the vertical and horizontal lengths of the respective photosensors by the pixel values calculated in the third step, and calculating a length per pixel by using the calibration method for convergence measurement of the color cathode ray tube 2. The color cathode ray tube according to claim 1, wherein the screen division in the first step is performed sequentially from 2 ⁿ (n = natural number) Calibration method. 2. The method according to claim 1, wherein the screen division in the first step is performed in such a manner that the plurality of optical sensors are sequentially positioned on a boundary line on which a screen is divided while sequentially progressing in an image pattern of 2n (n = natural number) And the screen division is completed in a state in which the screen is divided into a plurality of regions. The method of claim 1, 2 or 3, wherein the screen division in the first step includes a horizontal division step and a vertical division step. The method according to any one of claims 1 to 3, wherein the image pattern divided in the first step is displayed in an image pattern in which black and white colors are alternated. The method as claimed in claim 1, wherein, in the first step, optical sensors corresponding to the number of the optical sensors within a range of 30 to 40% of the plurality of optical sensors located at the center of the screen are mechanically fixed and set as reference optical sensors for calibration A calibration method for measuring the coarsness of a color cathode ray tube. The method of claim 1 or claim 6, wherein in the first step, at least three photosensors among the reference photosensors are selected and calibrated. 2. The method of claim 1, wherein the horizontal and vertical calibration lengths calculated in the fourth step are calculated by the following equations (a) and (b). Horizontal Calibration Length = Hm / Hp [mm / pixel] ------- (a) Vertical Calibration Length = Vm / Vp [mm / pixel pixel] ------- (b) {Hm: actual mechanical horizontal length between optical sensors} {Vm: actual mechanical vertical length between optical sensors} {Hp: Number of horizontal pixels between optical sensors calculated for screen division} {Vp: Number of horizontal pixels between optical sensors calculated by the screen division method}