JP2765102B2 - Convergence measurement device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a convergence measuring device for measuring a convergence state of a color CRT of a television receiver.

[Summary of the Invention] The present invention projects bright lines of each primary color on the surface of a color CRT,
In a convergence measuring device for detecting the light intensity data of each primary color and measuring the amount of misconvergence, the tube surface is divided into a measurement region showing the bright line and a non-measurement region showing the other two colors which are not measured. By setting the total area of the bright lines reflected in the measurement area and the image area of each color reflected in the non-measurement area to be almost the same, the current value of each primary color supplied to the color CRT is almost constant during the measurement section. Therefore, it is possible to prevent a measurement error due to a high voltage fluctuation due to a difference in current value of each primary color.

[Prior Art] The present applicant has previously proposed a phase detection type convergence measuring device (see Japanese Patent Application No. 63-310670).

This convergence measuring device has a pattern generator that outputs a video signal to a color CRT to be measured. This pattern generator creates a video signal that gradually shifts the bright lines (vertical or horizontal) of each primary color in a part of the area of the color CRT's screen, and displays a white pattern in other areas. I do. An optical sensor is disposed at a position facing the tube surface, and the optical sensor has a directional sensitivity characteristic of a single peak characteristic. The detection output of the optical sensor is supplied to a calculating means, which calculates the amount of misconvergence from the light intensity data of each primary color.

Thus, the optical sensor is arranged at an arbitrary position on the surface of the color CRT, and the pattern generator projects a bright line for each primary color on the surface of the color CRT. The calculation means creates an envelope curve for each primary color from the detection output of each primary color of the optical sensor, finds the position of the peak value of this envelope curve, and compares the position of the peak value for each primary color to obtain the misconvergence amount. Is calculated. Then, the misconvergence amount is measured at a plurality of locations on the surface of the color CRT by changing the position of the optical sensor on the surface of the tube.

In the above measurement, a white area is generated on the tube surface. When green, red, and blue bright lines are independently projected on the tube surface, the beam current of the color CRT changes and the high voltage changes. In this manner, when the high voltage changes, the position of the color electron peak shifts. Therefore, a white region is provided in a part of the tube surface to improve the instability of the high voltage.

[Problems to be Solved by the Invention] However, even if the white area is provided as described above, the current value of the current bright line color is larger than the current values of the other colors. The current value fluctuates. There is a drawback that the displacement of the bright line is caused by the change of the high voltage due to the change of the current value, specifically, the manner of dropping the high voltage, which causes a measurement error. In order to prevent this, it is generally conceivable to reduce the difference between the current values of the primary colors by narrowing the width of the bright line.
Cannot be adopted due to problems such as S / N deterioration.

Accordingly, it is an object of the present invention to provide a convergence measuring apparatus which prevents a high voltage fluctuation due to a difference in current value of each primary color and eliminates a measurement error caused by a high voltage fluctuation.

[Means for Solving the Problems] A convergence measuring apparatus according to the present invention for achieving the above object is provided at a position facing a tube surface of a color CRT and having an optical sensor having a unimodal directional sensitivity characteristic. Misconvergence amount calculating means for comparing and calculating light intensity data for each primary color from the detection output of the optical sensor to calculate a misconvergence amount; dividing the tube surface into a measurement region and a non-measurement region; A pattern in which bright lines of primary colors are arranged at regular intervals and moved in the vertical direction is projected, and the other two colors that are not measured are projected in the non-measurement area, and the total area of the bright lines reflected in the measurement area and the non-measurement area And a pattern generator for outputting, to the color CRT, a video signal for setting substantially the same image area of each color reflected on the color CRT.

[Operation] When, for example, a red bright line pattern is projected on the measurement area on the tube surface, green and blue images are projected on the non-measurement area.
For example, if a green bright line pattern is projected on the measurement area, the bright line pattern is changed such that red and blue are projected on the non-measurement area, the light intensity data of each primary color is detected, and the misconvergence amount is calculated. You. In this measurement, since the total area of the bright lines and the image areas of the other two colors in the non-measurement area are almost always the same in the measurement section, the color CRT
The current value of each primary color that is energized is substantially constant, high-voltage fluctuation does not occur, and the bright line position does not shift due to high-voltage fluctuation.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows a measurement state of the convergence measuring device A. In FIG. 2, a color CRT (color cathode ray tube) 1 to be measured is built in a television receiver B, and a tube surface 2 of the color CRT 1 is exposed to the front. The signal cable 3 of the convergence measuring device A is connected to the video signal input terminal of the television receiver B, and the convergence measuring device A outputs a color signal.
An image is projected on the screen 2 of the CRT1. The convergence measuring device A has an optical sensor 4 connected by a cable, and the optical sensor 4 is arranged at a contact position of the tube surface 2 so as to face the tube surface 2.

FIG. 3 is a cross-sectional view showing a positional relationship between the tube surface 2 and the optical sensor 4. In FIG. 3, the tube surface 2 has a fluorescent portion 2b disposed on an inner surface of a panel glass 2a.
It emits light when the electron beam is irradiated on 2b. The optical sensor 4 is provided with a microswitch SW. When the optical sensor 4 is brought into contact with the tube surface 2, the microswitch SW is turned on. The measurement is started by the ON signal of the microswitch SW and the
The flowchart shown in FIG. 11 is executed.

FIG. 4 shows a directional sensitivity characteristic diagram of the optical sensor 4. In FIG. 4, the horizontal axis indicates the incident angle (degree) of light incident on the optical sensor 4 from the tube surface 2 of the color CRT 1, and the vertical axis indicates the intensity (incident angle) of the incident light on the optical sensor 4 at each incident angle. Are relative light intensities when the light intensity is 0% and the light intensity is 100%. The directional sensitivity characteristic of the optical sensor 4 is maximum when the incident angle is 0 °, the light intensity decreases as the absolute value of the incident angle increases, and the absolute value of the incident angle becomes approximately 20 °.
It exhibits a so-called unimodal characteristic of 0% at about °.

FIG. 1 shows a circuit block diagram of the convergence measuring device A. In FIG. 1, the detection output (light intensity data) of the optical sensor 4 is transmitted via an amplifier 5 to an A / D converter 6.
And digitized by the A / D converter 6. The digitized light intensity data is written to the measurement data memory 7 based on a write signal of the CPU 8. The CPU 8 controls reading and writing of the operation memory 9 and the program memory 10 in addition to the measurement data memory 7. The calculation memory 9 stores calculation data necessary for performing calculation processing on various data. The program memory 10 stores data for executing a measurement program, a modulation factor calculation program, a non-measurement area change program, a bright line interval automatic correction program, a misconvergence amount calculation program, and a display program. The contents of each program will be described together with the following operations. The CPU 8 has a modulation factor calculating means driven according to a modulation factor calculating program and a misconvergence amount calculating device driven according to a measuring program. The modulation factor calculating means first lists the maximum value MAX and the minimum value MIN of the light intensity data of the primary colors to be measured, and calculates the modulation factor F by executing the formula of (MAX−MIN) / (MAX + MIN) = F. I do. The value of this modulation factor is 0.2-0.6
If it is within the range, it is determined to be appropriate, and if it is outside this range, it is determined to be inappropriate. If it is determined to be inappropriate, the modulation degree data is sent to the bright line interval calculation unit 11. If the value of the degree of modulation is almost zero, a non-measurement area change command is sent to the non-measurement area setting unit 12. In this embodiment, the modulation degree calculating means determines the modulation degree from the difference between the maximum value and the minimum value of the light intensity data. However, the state of the envelope curve of the light intensity data (for example, the difference between the maximum value and the minimum value of the curve, (Inclination angle). The misconvergence amount calculating means interpolates the discrete light intensity data (shown in FIG. 5) read out from the measurement data memory into light intensity data (envelope curve) that changes finely as shown by a broken line in FIG. After the conversion, the time point (position) at which the peak value of the light intensity data (envelope curve) for each primary color is obtained is detected. For example, the red and blue colors are compared with the time point (position) at which the peak value of the green light intensity data is obtained. The difference from the time (position) at which the peak value of the light intensity data is obtained, that is, the amount of misconvergence is calculated. In addition, the CPU 8 controls the bright line interval calculation unit 1 according to each program.
1. The drive of the non-measurement area setting unit 12 and the display unit 13 is controlled. The bright line interval setting unit 11 outputs bright line interval data that determines the interval δ between bright lines projected on the display screen 2. If the value of the modulation factor output from the CPU 8 is a value other than 0.2 to 0.6, the modulation factor Outputs the bright line interval data according to the value. Unmeasured region setting section 12 is intended to designate a non-measurement area S ₂ of the screen, 1/4 1/4 space or left of the right tube surface 2 in this embodiment
Is configured to set one of a space in the non-measurement area S _2. When the non-measurement area change command is sent from the CPU 8, and outputs the non-measurement area data to ever opposite region and the non-measurement area S _2. The display unit 13 displays the amount of misconvergence and the like, and displays the value of the degree of modulation in order to manually correct the interval between the bright lines when the automatic correction program for the interval between the bright lines is not provided. Further, a signal of the keyboard unit 14 is input to the CPU 8. By inputting data from the keyboard unit 14, data in the arithmetic memory 9, the program memory 10, and the like can be updated. When the distance between the bright lines is manually corrected, the data is input from the keyboard unit 14 and corrected.

Bright line interval data and non-measurement area data are input to the pattern generator 15 via the CPU 8. The pattern generator 15 generates a video signal for displaying a video as shown in FIG. 7 and outputs the video signal to the color CRT 1. That is, the area designated the tube surface 2 in a non-measurement area data and non-measurement area S _2, and partition the remaining ones as measurement area S _1, red measurement area S _1, green or predetermined intervals δ blue 1 / N of the interval δ every frame in the vertical direction.
(N is an integer equal to or greater than 2 and is 4 in this embodiment)
It reflects the bright line pattern to be shifted by, the non-measurement area S ₂
The other two colors that have not been measured are projected solidly.
Then, set substantially the same in so as the respective total area and the color image area of the non-measurement area S ₂ of the plurality of emission lines of the measuring area S _1. Here, the image area of each color refers to the area irradiated with the electron beam of the color, and the area of the composite color is calculated as the image area of each color. When the shift amount of the bright line is 1 / N of the bright line interval δ, as shown in FIG. 7, the ratio of the measurement region S ₁ to the non-measurement region S ₂ is N: 1, and the ratio of the bright line width to the bright line interval δ. Is 1 / N.
With this setting, assuming that the vertical dimension of the tube face 2 is H and the horizontal dimension is L, each area is B = G = 1 / (N + 1) · H, R = N /
(N + 1) · 1 / N · H = 1 / (N + 1) · H, which is the same. For this embodiment in the example N = 4, the measurement area S ₁ and the non-measurement area S ₂ ratio 4: 1, which is the ratio of the emission line width to the bright line interval δ 1/4.

Also, as shown in FIG. 8, the arrangement of the bright line changes as the position of the solid line → the position of the one-dot chain line → the position of the two-dot chain line → the position of the three-dot chain line every time the frame progresses, and this arrangement is repeated. When such a bright line is generated on the tube surface 2, the detection output of the optical sensor 4 becomes, as shown in FIG. 5, the time points A, B, C, D, a, b, c, d, at the frame switching time intervals. The light intensity at α,... becomes discrete light intensity data exhibiting a characteristic that changes in an alternating manner. Therefore, the optical sensor 4 is set to the color CRT1
May be located at an arbitrary position with respect to the tube surface 2 and the measurement period may be 4 frame periods in principle. In addition, the pattern generator 15 is configured to generate the direction of the bright line in the vertical direction shown in FIG. 7 and the horizontal direction perpendicular thereto.

Hereinafter, the operation of the above configuration will be described with reference to the flowchart of FIG.

When the optical sensor 4 is brought into a contact state at an arbitrary position on the tube surface 2 of the color CRT 1, the micro switch SW is turned on. The CPU 8 first executes a modulation degree calculation program in response to the ON signal of the micro switch SW. That is, the bright line interval data of the bright line interval calculating unit 11 and the white area data of the white area setting unit 12 are sent to the pattern generator 15 by the control signal of the CPU 8. Pattern generator 15 creates an image signal on the basis of this data, the tube surface 2 is arranged, a red emission line in the measurement area S ₁ shown in FIG. 7 for example, blue and green in the non-measurement area S ₂ An image of the composite color is displayed. Then, the bright line shifts for each frame, and the light intensity data (calculated in FIG. 5) for each shift is taken into the measurement data memory 7. When the red light intensity data is captured, the modulation degree of the light intensity data is calculated by the modulation degree calculation means. When the value of the modulation degree is almost zero, the non-measurement area change program interrupts and the non-measurement area is changed. If it is changed, and the value of the modulation factor is out of the range of 0.2 to 0.6, the bright line interval automatic correction program interrupts and corrects the bright line interval δ.

That is, when the optical sensor 4 is arranged on the non-measurement area as shown in FIG. 12, the light intensity data shows almost the same value for all data values as shown in FIG. It is almost zero. Then, a non-measurement area change command is sent from the modulation factor calculation means to the non-measurement area setting unit 12. The non-measurement area setting unit 12 sends non-measurement area data different from the conventional one to the pattern generator 15, and the image state of the screen 2 is switched as shown in FIG. Further, when the light sensor 4 is in the measurement area S ₁ as shown in FIG. 7, the value of the modulation factor becomes as the light intensity data is shown in FIG. 9 is 0.2 or less when emission line interval δ is smaller than the optimum value Conversely, when the bright line interval δ is wider than the optimum value, the light intensity data becomes as shown in FIG. 10, and the value of the modulation factor becomes 0.6 or more. Then, the value of the modulation factor is sent to the bright line interval calculation unit 11, and the bright line interval calculation unit 11 calculates an appropriate bright line interval δ from the value of the modulation factor and sends it to the pattern generator 15.

After the non-measurement area change program and the bright line interval automatic correction program are finished, if the value of the modulation factor is in the range of 0.2 to 0.6, the program shifts to the measurement program without interruption. In this measurement program, red, green, and blue bright lines are projected on the tube surface 2 in order, and light intensity data as shown in FIG.
It is stored for each of green and blue. If the value of the modulation degree in the modulation degree calculation program is in the range of 0.2 to 0.6, the red light intensity data at that time is employed as it is, and only the green and blue measurements are performed in the measurement program.

Next, the misconvergence amount calculation program is executed, and the misconvergence amount calculation means obtains the peak value of the red and blue light intensity data with respect to the time (position) at which the peak value of the green light intensity data is obtained ( Position, that is, the amount of misconvergence is calculated.

Finally, the display program is executed, and the display unit 13 displays the misconvergence amount. The misconvergence amount may be displayed on the color CRT 1 to be measured. Thus, the vertical and horizontal misconvergence amounts can be measured by measuring the vertical and horizontal bright line states while changing the position of the optical sensor 4 on the tube surface 2.

In the above measurement, the total area of the bright line and the non-measurement area S ₂
Since the image area of each of the other two colors is always the same during the measurement section, the current value of each primary color that is supplied to the color CRT1 is constant, so that high-voltage fluctuation does not occur. Therefore, the displacement of the bright line due to the high-voltage fluctuation does not occur, and a highly accurate measurement result can be obtained.

In this embodiment, the _two uncolored composite colors are projected in the non-measurement area S2 in a solid pattern. However, if the area of each primary color is the same, each primary color can be separated into separate parts or partially. It may overlap and be projected. Further, in this embodiment, the image areas of the respective primary colors are set to be completely the same, but the respective areas may be made different as long as the high-voltage fluctuation does not occur.

[Effects of the Invention] As described above, according to the present invention, there is provided a convergence measuring apparatus for projecting a bright line of each primary color on a tube surface of a color CRT, detecting light intensity data of each primary color and measuring a misconvergence amount. And dividing the tube surface into a measurement area that reflects the bright line and a non-measurement area that reflects the other two colors that are not measured,
Since the total area of the bright line reflected in the measurement area and the image area of each color transferred to the non-measurement area were set to be almost the same, the current value of each primary color supplied to the color CRT is almost constant during the measurement section, This has the effect of preventing measurement errors due to high voltage fluctuations caused by different current values of the primary colors.

Since the red, green, and blue current values are almost constant during the measurement, the frequency characteristics of the red, green, and blue drive circuits of the color CRT and the rising characteristics of the cathode of the color CRT (low frequency characteristics). This has the effect of eliminating the adverse effects of

[Brief description of the drawings]

1 to 13 show an embodiment of the present invention, FIG. 1 is a circuit block diagram of a convergence measuring device, FIG. 2 is a perspective view showing a measuring state, and FIG. 3 is a position of a tube surface and an optical sensor. FIG. 4 is a cross-sectional view showing the relationship, FIG.
FIG. 5 is a diagram showing light intensity data, FIG. 6 is a diagram showing light intensity data having an appropriate modulation factor, FIG. 7 is a diagram showing a bright line generation state, FIG. 8 is a diagram showing an arrangement of bright lines, FIG. 9 is a diagram showing light intensity data when the value of the modulation is small, FIG. 10 is a diagram showing light intensity data when the value of the modulation is large, FIG. 11 is a flowchart, and FIG. FIG. 13 is a front view of the John receiver, and FIG. 13 is a diagram showing light intensity data when an optical sensor is arranged on a non-measurement area. A: Convergence measuring device, 1: Color CRT, 2
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Claims (1)

(57) [Claims] An optical sensor having a directional sensitivity characteristic of a single peak characteristic, which is disposed at a position facing a tube surface of a color CRT, and comparing light intensity data of each primary color from a detection output of the optical sensor to calculate an error. A misconvergence amount calculation means for calculating a convergence amount; and a pattern in which the tube surface is divided into a measurement region and a non-measurement region, and the measurement regions are arranged such that bright lines of each primary color are arranged at regular intervals and moved in the vertical direction. And the other two colors that are not measured in the non-measurement area, and the image signal for setting the total area of the bright lines reflected in the measurement area and the image area of each color reflected in the non-measurement area to be substantially the same. A convergence measuring device comprising a pattern generator for outputting to a color CRT.