JP2811809B2 - 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] In the present invention, bright lines of each primary color are projected on the surface of a color CRT at a position shifted by a predetermined interval in the vertical direction, and an optical sensor having a directional sensitivity characteristic of a single peak characteristic is arranged opposite to the surface of the tube. In the convergence measuring device for calculating the amount of misconvergence from the detection output of the optical sensor, bright lines are projected in the same color pattern on the tube surface, and the measuring device is normally operated based on data obtained from each of the same color patterns. By providing a self-inspection means for inspecting whether or not the inspection is performed, the inspection can be performed in almost the same state as the measurement state without using any special inspection equipment.

[Prior Art] The present applicant has previously proposed a convergence measuring apparatus of the phase detection type (see Japanese Patent Application No. 63-310670). This convergence measuring device uses the color CR
A pattern generator for projecting a plurality of bright lines located at regular intervals on the tube surface of T by shifting the bright lines by 1 / N (N is an integer of 2 or more) of the interval in the vertical direction;
An optical sensor having a directional sensitivity characteristic of a single peak characteristic and a misconvergence amount calculating means for calculating a misconvergence amount from a detection output of the optical sensor for each primary color, which is disposed at a position facing the tube surface of T. I have.

Thus, the pattern generator projects a bright line for each primary color on the surface of the color CRT, and the misconvergence amount calculating means creates an envelope curve for each primary color from the detection output of each primary color of the optical sensor, and generates an envelope curve for this primary curve. The position of the peak value is determined, and the misconvergence amount is calculated by comparing the position of the peak value for each primary color.

As described above, the measuring device can easily measure the convergence state of the color CRT, but if the measuring device itself does not operate normally, an accurate measurement result cannot be obtained. Therefore, conventionally, the check was performed by means of a standard CRT or by means of a simulated signal generator.

The former means prepares a standard CRT whose misconvergence amount is known in advance, measures the misconvergence amount of the standard CRT, and compares the measured data with accurate data for checking.

The latter means is performed by causing a simulation signal generator to output a signal simulating light emission of a color CRT, inputting the simulation signal as an optical sensor output to a measuring device, and checking measurement data.

[Problem to be solved by the invention] However, in the former method, the standard CRT is
Also, the latter means requires a simulated signal generator, and has a problem in management and the like. In addition, since these must be prepared at the time of inspection, the inspection itself cannot be easily performed.

Therefore, an object of the present invention is to provide a convergence measuring device capable of performing its own inspection without using a special inspection device in order to solve the above-mentioned problems.

[Means for Solving the Problems] A convergence measuring apparatus according to the present invention for achieving the above object provides a convergence measuring device for displaying a video signal of a pattern for projecting a bright line of a desired color at a position shifted by a constant interval on a tube surface of a color CRT. A pattern generator that outputs to the color CRT; a control unit that controls the pattern generator to output a video signal of the pattern of a desired color bright line to the color CRT; An optical sensor having a directional sensitivity characteristic of a single peak characteristic, and controlling the pattern generator by the control means, causing the color CRT to output a video signal of the pattern of each primary color, and detecting each of the optical sensors. First calculating means for comparing the light intensity data for each primary color to calculate the amount of misconvergence; A second calculator that controls the color CRT to output a video signal of the pattern of the same color, and compares and calculates peaks of respective light intensity data obtained from the patterns of the same color; And self-inspection means for inspecting whether or not the measurement device is normal based on the result of the comparison operation of the peaks from the calculation means.

[Operation] When the color CRT to be measured and the convergence measuring device are set as in the measurement and the inspection mode is selected, the pattern of the same color is repeated on the tube surface by the second calculating means and the self-inspection means. The light intensity data of each pattern is compared and examined. If the light intensity data is normal, the light intensity data of each pattern matches. If the light intensity data is abnormal, the light intensity data of each pattern is different. Therefore, the inspection can be performed by the measuring device itself without using a special inspection device.

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 flowchart shown in FIG. 9 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 factor calculation program, a white area change program, a bright line interval automatic correction program, a misconvergence amount calculation program, an inspection program, and a display program. The contents of each program will be described together with the following operations. The CPU 8 has a modulation degree calculating means driven according to the modulation degree calculating program, a misconvergence amount calculating means (first calculating means) driven according to the measuring program, a second calculating means driven according to the inspection program, and a self-inspection means. 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 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 calculating means converts the discrete light intensity data (shown in FIG. 5) read from the measurement data memory into light intensity data (envelope curve) which changes finely as shown by a broken line in FIG. 6 by interpolation processing. Then, the time point (position) at which the peak value of the light intensity data (envelope curve) for each primary color is obtained, for example, the red and blue light with respect to 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 intensity data is obtained, that is, the amount of misconvergence is calculated. The second calculating means and the self-inspection means control the pattern generator 15 described below to
And outputs a pattern of bright lines of the same color, for example, red, and executes a measurement program, an arithmetic program, and a display program for each pattern in the same manner as in the measurement. That is, in this embodiment, the contents of the inspection program are output only to the pattern generator 15 by outputting the inspection mode signal, and the other programs are referred to, so that the self-inspection can be performed with only a slight software change.
Further, the CPU 8 controls the driving of the bright line interval calculation unit 11, the white area setting unit 12, and the display unit 13 according to each program. 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. 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,
If there is no automatic bright line interval correction program, the value of the degree of modulation is displayed in order to manually correct the bright line interval. Further, a signal of the keyboard unit 14 is input to the CPU 8. By inputting data from the keyboard unit 14, the data in the operation memory 9, the program memory 10, etc. can be updated, and the keyboard unit 14 is provided with a self-inspection key, and when this key is selected, the inspection program is executed. You. 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 white area data are input to the pattern generator 15 via the CPU 8. As shown in FIG. 7, when the area specified by the white area data is set to white, the pattern generator 15 sets a plurality of bright lines arranged at regular intervals δ of red, green or blue in other areas. In the vertical direction at every frame δ
1 / N (N is an integer of 2 or more; in this embodiment, it is 4) generates and outputs a video signal of a pattern that is shifted by one unit. However, when the inspection mode signal is output from the self-inspection unit, all are the same. Only a pattern of a color, for example, a red bright line is generated and output. That is, as shown in FIG. 8, every time the frame progresses, the arrangement of the bright line changes from a solid line position → a dashed line position → a two-dot chain line position → a three-dot chain line position, 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 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 basically four frame periods. Also, pattern generator 15
Are configured so that the direction of the bright line is generated in the vertical direction shown in FIG. 7 and the horizontal direction perpendicular to the vertical direction.

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 of a pattern in which a green bright line is arranged in addition to the white area as shown in FIG. Then, the bright line shifts for each frame, and the light intensity data (see FIG. 5) for each shift 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.

When the white area change program and the bright line interval automatic correction program are finished, and if the value of the modulation factor is in the range of 0.2 to 0.6, these programs do not interrupt,
It is determined whether the inspection program has been selected.

If the inspection program has not been selected, the operation moves to the measurement program. 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. 5 is stored in the measurement data memory 7 for each of green, 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 is calculated. Finally, the display program is executed, and the display unit 13 displays the misconvergence amount.

If the inspection program has been selected, the process proceeds to the inspection program. In this inspection program, only the red bright line pattern is sequentially and repeatedly projected, and each light intensity data of the same color (red) pattern is processed by the above-described measurement program, misconvergence amount calculation program, and display program. That is, the peak value of each light intensity data of the same color (red) is obtained, the difference between each peak value is calculated, and this is displayed on the display unit 13. If the measuring device is operating normally, the light intensity data of the same color is of course the same value, so it is normal when the difference between the peak values is zero, and when the difference between the peak values is other than zero. It is determined that it is abnormal.

In this embodiment, the bright line positions of the pattern of the same color (red) are all the same position. However, the bright line is also located at an intermediate position (a position shifted by 1/8 of the bright line interval δ) of the bright line positions shown in FIG. If it is arranged, this position is considered to have the maximum error, so that more accurate inspection can be performed. In the case of performing a more precise inspection, a bright line may be arranged at a further intermediate position.

The residual light quantity after one field period (16.7 ms at 60 MHz) is the smallest for a general phosphor for television, so using a red pattern as in this embodiment minimizes the effect of the afterglow. It is preferable. If the afterglow characteristic of a color other than red decreases due to a change in one field cycle or a phosphor, that color is used.

[Effects of the Invention] As described above, according to the present invention, an optical sensor in which a bright line is projected to each primary color at a position shifted by a certain interval in the vertical direction on the tube surface of a color CRT, and the directional sensitivity characteristic is a single peak characteristic. In a convergence measuring device which is arranged opposite to the tube surface and calculates the amount of misconvergence from the detection output of this optical sensor, wherein bright lines are projected on the tube surface in the same color pattern, and obtained from the same color pattern. Since the self-inspection means for inspecting whether or not the measuring device is normal based on the obtained data is provided, there is an effect that the measuring device itself can be inspected without using a special inspection device. Further, since the inspection can be performed in substantially the same state as the measurement state, there is an effect that the inspection can be easily performed in combination with the fact that the inspection equipment is unnecessary. Furthermore, according to the present invention, there is an effect that it is possible to measure how much an error (wobble) of a measured value is caused by the influence of external light or an unnecessary magnetic field.

[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, FIG. 6 is a diagram showing light intensity data having an appropriate modulation factor, FIG. 7 is a front view of a television receiver, and FIG. 8 is a diagram showing arrangement of bright lines. FIG. 9 is a flowchart. A: Convergence measuring device, 1: Color CRT, 2
... Tube surface, 4... Optical sensor, 8... CPU (misconvergence amount calculating means (first calculating means, second calculating means,
Self-inspecting means), 15 ... pattern generator.

Claims (1)

(57) [Claims] 1. A pattern generator for outputting, to the color CRT, a video signal of a pattern showing a position at which a bright line of a desired color is shifted by a constant interval on the surface of a color CRT; Control means for outputting an image signal of the pattern of the bright line of the color to the color CRT; an optical sensor arranged at a position facing the tube face of the color CRT, having a directional sensitivity characteristic of a single peak characteristic; and the control means Controlling the pattern generator to output a video signal of the pattern of each primary color to the color CRT, and comparing and calculating light intensity data for each primary color detected by the optical sensor to calculate a misconvergence amount. Controlling the pattern generator by the control means, and causing the color CRT to output a video signal of the pattern of the same color. Second calculating means for comparing and calculating the peaks of the respective light intensity data obtained from the patterns of the same color, and determining whether the measuring device is normal based on the result of the comparison of the peaks from the second calculating means. A convergence measuring device, comprising: