JP2811710B2 - 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]

According to the present invention, a bright line of each primary color is projected on a tube surface of a color CRT so as to be gradually shifted, and the light intensity of each primary color is detected by an optical sensor arranged at a position opposite to the tube surface, and a convergence state is obtained from the light intensity data. For a convergence measuring device that measures the emission line of each primary color, the emission line pattern that gradually shifts the emission line of each primary color is repeatedly projected in a certain order, and a misconvergence amount is created for each emission line pattern, and the latest error of each phase is created. By calculating the average misconvergence amount by adding and averaging the convergence amounts, highly accurate measurement can be performed without extending the measurement time.

(Prior art)

The present applicant has previously proposed a convergence measuring device of the phase detection type (see Patent Application (5) dated December 8, 1988).

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 bright line pattern video signal that gradually shifts a bright line (vertical direction or horizontal direction) of each primary color by a constant value in the vertical direction on the surface of a color CRT. 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.

The optical sensor is arranged at an arbitrary position on the surface of the color CRT, and the pattern generator projects a bright line pattern 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, such a measurement is performed a plurality of times, a plurality of misconvergence amounts are calculated, and the convergence state is known.

[Problems to be solved by the invention]

In the above measurement, the following measurement time is required to calculate one misconvergence amount. That is, assuming that the number of samplings required to create any of the green, red and blue envelope curves is S and the unit shift time of the bright line is t, light intensity data is sampled for each of the green, red and blue bright lines. Therefore, T (measurement time) = 3 (three colors) × S (sampling number) × t (unit shift time) for measuring the misconvergence amount in one of the vertical and horizontal directions.

Here, to improve the measurement accuracy, it is sufficient to increase the number of samplings (S). However, if the number of samplings is increased, the measurement time becomes longer as can be seen from the above equation, and the relationship between the measurement accuracy and the measurement time is contradictory. It is in. It should be noted that the unit shift time (t) cannot be made any faster from the viewpoint of the function of the apparatus.

Therefore, an object of the present invention is to provide a convergence measurement device capable of performing high-accuracy measurement without extending the measurement time.

[Means for solving the problem]

In order to achieve the above object, a convergence measuring apparatus according to the present invention generates a video signal representing a bright line pattern composed of a plurality of bright lines separated from each other by a predetermined interval δ to generate a color CRT.
, And all the bright lines in the first bright line pattern periodically have a predetermined width δ / N (N is an integer of 2 or more).
A first phase mode in which the video signal is generated so as to be shifted by a predetermined amount, and all the bright lines in the first bright line pattern are periodically shifted from a second bright line pattern shifted by a width smaller than the predetermined width δ / N. A pattern generator having a second phase mode for generating the video signal so as to shift by the predetermined width δ / N, and a directional sensitivity characteristic having a single peak characteristic, which is disposed at a position opposite to a tube surface of the color CRT. An optical sensor having: In each of the first and second phase modes, a misconvergence amount is calculated from a detection output of the optical sensor,
A misconvergence amount calculating means for calculating an average misconvergence amount by adding and averaging the misconvergence amounts calculated in each of the first and second phase modes.

[Action]

When the phase of the bright line pattern is A, B,..., The pattern generator is driven to repeatedly display an A-phase bright line pattern, a B-phase bright line pattern,. The calculation means calculates the amount of misconvergence of each phase from the detection output of the optical sensor. or,
The calculation means calculates the average misconvergence amount by adding and averaging the most recent misconvergence amount of each phase measured for each measurement. Since this average misconvergence amount is output every time each phase is measured, a predetermined number of data can be obtained in a short time, and the accuracy is good because it includes the measurement results of all phases.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 shows a measurement state of the convergence measuring device A. In FIG. 2, a television C has a built-in color CRT (color cathode ray sensation) 1 to be measured, 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 position A outputs a color signal.
An image is projected on the screen 2 of the CRT1. The convergence measurement position 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. 10 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 100% when the light intensity is 0 °. 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 single peak characteristic of 0% at about 呈.

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 degree calculation program, a white area change program, an emission 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. CPU8
Has a modulation degree calculating means driven according to a modulation degree calculating program and a misconvergence amount calculating means driven according to a measuring program. The modulation factor calculating means first lists the maximum value MAX and the minimum value MIN among the light intensity data of the primary colors to be measured, and calculates the modulation factor F by executing the equation of MIN / MAX = F. If the value of the degree of modulation is in the range of 0.2 to 0.6, 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 white area change command is sent to the white 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 FIGS. 5 and 6) read out from the measurement data memory to change finely as shown by broken lines in FIGS. 5 and 6. Light intensity data (envelope curve)
, And detects the time (position) at which the peak value of the light intensity data (envelope curve) for each primary color is obtained. For example, red and blue with respect to the time (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. The misconvergence amount calculating means calculates the average misconvergence amount by adding and averaging the latest misconvergence amounts of the respective phases. In this embodiment, since the bright line pattern is composed of two phases, the A phase and the B phase, as described below, the misconvergence amount in the case of the A phase or the B phase of the current measurement and the misconvergence amount in the case of the B phase or the A phase of the previous measurement. The average misconvergence amount is calculated by adding and averaging the convergence amount. The CPU 8 has a bright line interval calculation unit 11 and a white area setting unit 12 according to each program.
And the display unit 13 is drive-controlled. The bright line interval calculation unit 11 outputs bright line interval data that determines the interval δ between bright lines projected on the display screen 2, and the value of the modulation factor output from the CPU 8 is 0.
If the value is other than 2 to 0.6, bright line interval data is output according to the value of the modulation factor. The white area setting unit 12 designates a white area of the screen. In this embodiment, one of the right half and the left half of the screen 2 is set as a white area. When a white area change command is sent from the CPU 8, white area data is output in which an area opposite to the previous area is set as a white area. 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, the operation memory 9,
Data in the program memory 10 and the like can be updated. If you want to manually adjust the line spacing,
Enter more data and correct.

Bright line interval data and white area data are input to the pattern generator 15 via the CPU 8. As shown in FIG. 7, the pattern generator 15 generates and outputs a video signal that makes the area specified by the white area data white and makes the other area a bright line pattern. The bright line pattern is obtained by dividing a plurality of bright lines arranged at regular intervals δ of red, green or blue into 1 / N (N is an integer of 2 or more) of the interval δ for each frame in the vertical direction. In this case, as shown in FIG. 8, the arrangement of the bright line changes from the position of the solid line to the position of the solid line every time the frame advances.
This arrangement is changed from the position of the dashed line to the position of the two-dot chain line to the position of the three-dot chain line. In addition, such a bright line pattern can create two phases of A phase and B phase having different bright line positions,
The bright line position of one phase is arranged at an intermediate position with respect to the other. Specifically, for example, assuming that the bright line position shown in FIG. 8 has the A phase, the intermediate position (the broken line position in FIG. 8) of each bright line becomes the B phase bright line position. When the pattern generator 15 sends an A-phase bright line pattern for each primary color (red, green, and blue), it then sends a B-phase bright line pattern for each primary color, and repeatedly outputs in this order.
When such a bright line is generated on the tube surface 2, the detection output of the optical sensor 4 becomes, as shown in FIGS. 5 and 6, the time points A, B, C, D, a, b, at frame switching times. The light intensity at c, d, α,... becomes discrete light intensity data exhibiting a characteristic that changes in an alternating manner. Therefore, the optical sensor 4 may be located at an arbitrary position with respect to the tube surface 2 of the color CRT 1, and the measurement period may be, in principle, four frame periods (four samplings). or,
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. The pattern generator 15 creates an image signal based on this data, and an image on which a green bright line of the A phase is arranged besides the white area as shown in FIG. The bright line shifts for each frame, and the light intensity data for each shift (see FIG. 5).
Is taken into the measurement data memory 7. When the green light intensity data is captured, the modulation degree of the light intensity data is calculated by the modulation degree calculating means. If the value of the modulation degree is almost zero, the white area change program interrupts and the white area is changed. If 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 the bright line interval δ is corrected.

After the white 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, green, red, 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 red 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 green light intensity data at that time is adopted as it is, and only the measurement of red and blue is performed by 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 (a ₁ ) is calculated.
When the misconvergence amount (a ₁ ) of the first measurement is calculated, the display program is executed, and the misconvergence amount is displayed on the display unit 13.

When the first measurement is completed, the pattern generator 15 displays the B-phase bright line pattern, and the light intensity data (see FIG. 6) is loaded into the measurement data memory 7 in the same manner as described above, and the misconvergence amount based on the light intensity data is obtained. (B ₁ ) is calculated. The misconvergence amount calculating means calculates the average misconvergence amount by calculating the formula of (a ₁ + b ₁ ) / 2, and the average misconvergence amount is displayed on the display unit.
Appears on 13.

By performing the third measurement (the bright line pattern of the A phase), the fourth measurement (the bright line pattern of the B phase), and so on, the measurement results as shown in the following <Table> are displayed on the display unit.
Appears on 13.

From the above <Table>, the average misconvergence amount is output for each phase measurement, so that a predetermined number of data can be obtained in a short time, and only the first measurement can be obtained from the A-phase bright line pattern (4 sampling numbers). The convergence amount, but after that, the bright line patterns (8
Since the average misconvergence amount is obtained from the (number of samplings), the result is almost the same as the case where the number of samplings is doubled as shown in FIG. 9, and accurate data can be obtained.

In this embodiment, the pattern generator 15 is configured to generate the two-phase bright line pattern of the A phase and the B phase. However, three or more phases (A phase, B phase, C phase,
...) may be configured to generate the bright line pattern. In this case, the average misconvergence amount is (A + B + C +
...) / 2 is calculated.

In addition, in this embodiment, the white area setting unit
Although 12 is configured to set either the right half or the left half of the tube surface 2 to a white region, a range sufficient to suppress the high-voltage fluctuation of the color CRT 1 other than where the optical sensor 4 is disposed. May be set as a white area, and the size and position of the white area are not limited.

Further, in this embodiment, the pattern generator 15 is configured to arrange a plurality of bright lines at a fixed interval. However, only one bright line is projected, and this one bright line is gradually shifted by a predetermined amount. May be configured.

〔The invention's effect〕

As described above, according to the present invention, the bright line of each primary color is projected on the tube surface of the color CRT so as to be gradually shifted, and the light intensity of each primary color is detected by an optical sensor arranged at a position facing the tube surface, For a convergence measuring device that measures a convergence state from this light intensity data, a plurality of phases of bright line patterns are repeatedly projected in a fixed order for bright line patterns that gradually shift bright lines of each primary color, and a misconvergence amount is created for each bright line pattern. In addition, since the average misconvergence amount is calculated by adding and averaging the latest misconvergence amount of each phase of the measured data, it is possible to perform high-precision measurement without extending the measurement time. .

That is, in the conventional case, it is sufficient to increase the number of samplings in order to perform high-accuracy measurement. However, the measurement time for calculating one misconvergence amount increases in proportion to the number of samplings. I can't do much.

However, according to the present invention, the number of samplings used in calculating one misconvergence amount is not increased, and the misconvergence amounts are calculated and averaged in a plurality of phase states in which sampling points are shifted from each other. Therefore, the same effect as in the case where the number of samplings is increased can be obtained without increasing the measurement time for calculating one misconvergence amount, so that highly accurate measurement can be performed.

[Brief description of the drawings]

1 to 9 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 of A phase, FIG. 6 is a diagram showing light intensity data of B phase, FIG. 7 is a front view of a television receiver, and FIG. 8 is a diagram showing arrangement of bright lines. And FIG. 9 shows 2
FIG. 10 shows light intensity data when the number of samplings is doubled, and FIG. 10 is a flowchart. A: Convergence measuring device, 1: Color CRT, 2
···································································································· 15

Claims (1)

(57) [Claims] An image signal representing a bright line pattern composed of a plurality of bright lines separated from each other by a predetermined interval δ is generated to generate a color CR.
T, wherein the video signal is generated such that all bright lines in the first bright line pattern are periodically shifted by a predetermined width δ / N (N is an integer of 2 or more).
And a second mode in which all bright lines in the first bright line pattern are shifted by a width smaller than the predetermined width δ / N.
A pattern generator having a second phase mode for generating the video signal so as to be periodically shifted by the predetermined width δ / N from the bright line pattern of the color CRT; An optical sensor having a directional sensitivity characteristic of a peak characteristic; and a misconvergence amount is calculated from a detection output of the optical sensor in each of the first and second phase modes, and is calculated in each of the first and second phase modes. And a misconvergence amount calculating means for calculating an average misconvergence amount by adding and averaging the obtained misconvergence amounts.