JPH03119892A - Convergence measuring device - Google Patents

Abstract

PURPOSE:To enable inspection by a measuring device itself without using a special equipment for inspection by providing a self-inspecting means to inspect it by projecting luminescent lines with patterns wholly in the same color on a tube surface according to data obtained by the pattern in the same color whether the measuring device is normal or not. CONSTITUTION:A convergence measuring device A is equipped with a pattern generator 15, optical sensor and CPU 8. The pattern generator 15 is provided to output the video signal of the pattern to a color CRT 1 so that the luminescent line is each primary color can be projected at a position to be shifted at fixed intervals in a vertical direction, and the optical sensor is arranged at a position faced to a tube surface 2 of the color CRT 1 and equipped with a directional sensitivity property of unit-model property. The CPU 8 executes arithmetic for comparing light intensity data for each primary color to be detected by the optical sensor 4 and calculates the amount of miss convergence. Then, the pattern generator 15 is controlled and the patterns of video signals to be outputted to the color CRT 1 are wholly set in the same color. According to the respective light intensity data to be obtained from the respective patterns in the same color, it is inspected whether the measuring device is normal or not.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a convergence measuring device for measuring the convergence state of a color CRT of a television receiver.

U Overview of the Invention] The present invention projects the bright lines of each primary color on the tube surface of a color CRT at positions shifted by a fixed interval in the vertical direction, and uses an optical sensor with a single peak directivity characteristic to +i? j) A convergence measurement device that is placed opposite to the tube surface and calculates the amount of misconvergence from the detection output of the sensor, projects bright lines on the tube surface in patterns of the same color, and is obtained from each pattern of the same color. By providing a self-detection means to check whether the measuring device is normal or not based on the data, it is possible to test under almost the same conditions as the measurement conditions without using special testing equipment.

"Prior Art" The present applicant previously proposed a phase detection type convergence measurement device (see Japanese Patent Application No. 63-310670). This convergence measuring device projects a plurality of bright lines located at regular intervals on the screen of a color CRT to be measured, by shifting them in the vertical direction by I/N of the interval (N is an integer of 2 or more). A misconvergence amount calculation that calculates the amount of misconvergence from the detection output of the pattern generator, the optical sensor that is placed opposite the screen surface of the color CRT and has a single-peak directional sensitivity characteristic, and the sensor for each primary color. and means.

Then, the pattern generator projects bright lines for each primary color on the screen of the color CRT, and the misconvergence calculation means creates an envelope curve for each primary color from the detection output of each primary color from the optical sensor. The amount of misconvergence is calculated by calculating the position of the peak value and comparing the position of the peak value for each primary color.

As described above, the measuring device described above can easily measure the convergence state of a color CRT, but if the measuring device itself does not operate normally, accurate measurement results cannot be obtained. For this reason, checks have conventionally been carried out by means of standard CRTs or by means of simulated signal generators.

The former method involves preparing a standard CRT whose amount of misconvergence is known in advance, measuring the amount of misconvergence on this standard CRT, and checking by comparing the measured data with accurate data.

The latter method is carried out by causing a simulated signal generator to output a signal simulating the light emission of a color CRT, and manually inputting this simulated signal to the measuring device as an optical sensor output to check the measured data.

[Problems to be Solved by the Invention] However, the former method requires a standard CRT, and the latter method requires a simulated signal generator, posing problems in terms of management and the like. Furthermore, since these items had to be prepared at the time of the inspection, the inspection itself was not easy to perform.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, it is an object of the present invention to provide a convergence measurement device that can perform self-inspection without using any special inspection equipment.

[Means for Solving the Problems] A convergence measuring device of the present invention to achieve the above object includes a pattern that projects the bright lines of each primary color on the screen of a color CRT at positions shifted by a fixed interval in the vertical direction. a pattern generator that outputs a video signal to the color CRT; a light sensor that is placed opposite the screen surface of the color CRT and has a single-peak directional sensitivity characteristic; and a light intensity of each primary color to be detected by the sensor. a misconvergence amount calculation means for calculating a misconvergence amount by comparing and calculating data; and a misconvergence amount calculation means that controls the pattern generator to
All of the video signal patterns outputted to the apparatus are of the same color, and a self-test means is provided for checking whether the measuring device is normal or not based on each light intensity data obtained from each pattern of the same color.

[Similar to the measurement process, when the color CRT to be measured and the convergence measuring device are set and the test mode is selected, the same color pattern is repeated on the screen and the self-test means compares the light intensity data of each pattern. If it is normal, the light intensity data of each pattern will match, and if it is abnormal, the light intensity data of each pattern will be different, so the measuring device itself can be inspected. Therefore, the test can be performed using the measuring device itself without using any special test equipment.

〔Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows the measurement state of the convergence measuring device A. In FIG. 2, television receiver B has a built-in color CRT (color cathode ray tube) l to be measured, and this color CRT! The tube surface 2 of is exposed to the front. The signal cable 3 of the convergence measurement device A is connected to the video signal input terminal of the TV Noyon receiver B,
Color CI? An image is projected on the screen 2 of the TI. or,
The convergence measuring device A has an optical sensor 4 connected by a cable, and the sensor 4 is disposed opposite the tube surface 2 at a contact position with the tube surface 2 .

FIG. 3 shows a cross-sectional view showing the positional relationship between the tube surface 2 and the optical sensor 4. In FIG. 3, the tube surface 2 is made up of a fluorescent section 2b arranged on the inner surface of a panel glass 2a, and when the fluorescent section 2b is irradiated with an electron beam, it emits light. Further, the optical sensor 4 is provided with a microswitch SW, and when the optical sensor 4 is brought into contact with the tube surface 2, the microswitch SW is turned on.

Measurement is started by the ON signal of this microswitch SW, and 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 (degrees) 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 (in degrees) of the incident light on the optical sensor 4 at each incident angle.
Relative light intensity when the light intensity when the incident angle is Oo is taken as 100%) is shown. The directional sensitivity characteristics of the optical sensor 4 are maximum when the angle of incidence is 0°, and as the absolute value of the angle of incidence increases, the light intensity decreases and becomes 0% when the absolute value of the angle of incidence is approximately 20°, which is a so-called simple type. exhibits peak characteristics.

FIG. 1 shows a circuit block diagram of a convergence measuring device A. In FIG. In FIG. 1, the detection output (light intensity data) of the optical sensor 4 is sent to an A/D converter 6 via an amplifier 5
and is digitized by the A/D converter 6. The digitized light intensity data is written into the measurement data memory 7 based on a write signal from the CPU 8. C.P.
In addition to the measurement data memory 7, U8 controls reading and writing of the calculation memory 9 and the program memory 0. The calculation memory 9 stores calculation data necessary for processing various data. The program memory 10 stores data for executing a measurement program, a modulation degree 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 explained together with the following operations. The CPU 8 has a modulation degree calculation means that is driven according to a modulation degree calculation program, a misconvergence amount calculation means that is driven according to a measurement program, and a self-inspection means that is driven according to a test program. The modulation degree calculation means first restores the maximum value M A,
7) Calculate the modulation degree F by executing the formula. If the value of this modulation degree 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 that it is inappropriate, the modulation degree data is sent to the bright line interval calculation unit 11.

Further, if the value of the modulation degree is approximately 0, a white area change superimposition is sent to the white area setting section 12. In this embodiment, the modulation degree calculation means discriminates the modulation degree from the difference between the maximum value and the minimum value of the light intensity data, but it also determines the modulation degree from the difference between the maximum value and the minimum value of the light intensity data. It may also be determined based on the angle of inclination). The misconvergence calculation means performs interpolation processing on the discrete light intensity data (shown in Fig. 5) read from the measurement data memory, and converts it into light intensity data (envelope curve) that changes finely as shown by the broken line in Fig. 6. Then, the time point (position) at which the peak value of the light intensity data (envelope curve) for each primary color is obtained is detected. The difference between the peak value of the intensity data and the time point (position) at which it is obtained, that is, the amount of misconvergence, is calculated. The self-inspection means controls the pattern generator 15 described below to check the pattern generator 1.
5 to output bright line patterns of the same color, for example, red, and execute a measurement program, calculation program, and 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 limited to outputting an inspection mode signal to the pattern generator 15, and the existing program is used for other purposes, so self-inspection is possible with only a slight software change. be. In addition, the CPU 8 operates the bright line interval calculation unit 11 . The white area setting section 12 and the display section 13 are driven and controlled. The bright line interval setting unit 11 outputs bright line interval data that determines the interval δ between bright lines projected on the screen 2, and the value of the modulation degree output from the CPU 8 is 0.2 to 0.6.
If the value is other than that, bright line interval data corresponding to the value of the modulation degree is output. The white area setting section 12 specifies the white area of the screen, and in this embodiment, it is configured to set either the right half or the left half of the tube surface 2 as the white area.

When a white area change command is sent from the CPU 8,
Output white area data with the opposite area as the white area. The display unit 13 displays the amount of misconvergence, etc., and also displays the value of the modulation degree in order to manually correct the bright line spacing if the automatic bright line spacing correction program is not available. Furthermore, signals from the keyboard section 14 are input to the CPU 8. By inputting data manually from the keyboard section 14, the calculation memory 9. In addition to being able to update data in the program memory 10 and the like, the keyboard section 14 is provided with a self-test key, and when this key is selected, a test program is executed. In addition, when manually correcting the bright line interval, data is inputted from the keyboard unit 14 and corrected.

Pattern generator! 5 receives bright line interval data and white area data via the CPU 8. As shown in FIG. 7, the pattern generator 15 makes the area specified by the white area data white and the other areas red.

A plurality of green or blue bright lines arranged at regular intervals δ are arranged in the vertical direction for each frame at 1/N of the interval δ (N is an integer of 2 or more, and in this example it is 4). It generates and outputs a video signal with a pattern that shifts in steps, but when a test mode signal is output from the self-test means, only a pattern of bright lines of the same color, for example, red, is generated and output. That is, as shown in FIG. 8, the arrangement of the bright lines changes from the solid line position to the one-dot chain line position to the two-dot chain line position to the three-dot chain line position as each frame advances, 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 is detected at time points A, B, C, and D at intervals of frame switching time, as shown in FIG.

The light intensities at ab, c, d, α, . . . become discrete light intensity data exhibiting characteristics that change in alternating current. Therefore, the optical sensor 4 may be placed at any position with respect to the tube surface 2 of the color CRT 1, and the measurement period may be, in principle, a period of four frames. Further, the pattern generator 15 is configured to generate bright lines in the vertical direction shown in FIG. 7 and in the horizontal direction perpendicular to this direction.

Hereinafter, the operation of the above configuration will be explained according to the flowchart of FIG. 9.

When the optical sensor 4 is brought into contact with any part of the tube surface 2 of the color CRTI, the microswitch SW is turned on. The CPU 8 first executes a modulation degree calculation program in response to an on signal from the microswitch SW. That is, the bright line interval data from the bright line interval calculation section 11 and the white area data from the white area setting section 12 are sent to the pattern generator I5 in response to a control signal from the CPU 8. The pattern generator 15 creates a video signal based on this data, and an image of a pattern in which green bright lines are arranged in areas other than the white area is displayed on the screen 2, for example, as shown in FIG.

Then, this bright line shifts every 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 imported, the modulation degree of the light intensity data is calculated by the modulation degree calculation means, and if the value of this modulation degree is almost zero, the white area change program interrupts and changes the white area. Also, if the value of the modulation degree is outside the range of 0.2 to 0.6, the bright line spacing automatic correction program interrupts and corrects the bright line spacing δ.

When this white area change program and bright line spacing automatic correction program are finished, the modulation degree value will be 0.2 to 0.
If it is within the range of 6, it is determined whether or not an inspection program is selected without these programs interrupting.

If the inspection program is not selected, the process moves to the measurement program. In this measurement program, green, red, and blue bright lines are sequentially projected on the tube surface 2, 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 within the range of 0°2 to 0.6, the green light intensity data at that time is used as is, and only red and blue measurements are performed in the measurement program. Next, the misconvergence m calculation program is executed, and the misconvergence amount calculation means calculates the time point (position) at which the peak value of the red and blue light intensity data is obtained relative to the time point (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 amount of misconvergence is displayed on the display section 13.

Further, if an inspection program is selected, the process moves to the inspection program. In this inspection program, only the red bright line pattern is displayed repeatedly, and the same color (
Each light intensity data of the red) pattern is processed by the above-mentioned measurement program, misconvergence amount calculation program, and display program. i.e. the same color (red)
The peak value of each light intensity data is calculated, and the difference between the respective peak values is calculated and displayed on the display unit 13. If the measuring device is operating normally, the light intensity data for the same color will naturally have the same value, so it is normal when the difference in the L route peak (＾) is zero, and the difference in the above R peak values is other than zero. It is determined that there is an abnormality when .

In this example, the bright line positions of the patterns of the same color (red) are all at the same position, or the bright line positions are also placed in the middle of the bright line positions shown in FIG. 8 (positions shifted by 1/8 of the bright line interval δ). If this position is placed, it is thought that the error will be maximum at this position, so more accurate inspection can be performed. In addition, in order to perform a more accurate inspection, a bright line may be placed at a further intermediate position.

In addition, -field period (16.7 m s at 60 MHz
) The amount of afterglow is the smallest in the red color among common phosphors for televisions, so it is preferable to use a red pattern as in this example because the influence of the afterglow can be prevented as much as possible. - If the afterglow characteristic of a color other than red becomes smaller due to changes in the field period or phosphor, use that color.

[Effect of the Invention 1] As described above, according to the present invention, the bright lines of each primary color are projected on the screen of a color CRT at positions shifted by a fixed interval in the vertical direction, and the directional sensitivity characteristic is In a convergence measuring device, an optical sensor is arranged opposite to the tube surface, and the amount of misconvergence can be calculated from the detection output of the sensor. Since a self-testing means for testing whether the measuring device is normal or not based on data obtained from the pattern is provided, it is possible to test the measuring device itself without using special testing equipment.

Further, since the test can be performed in substantially the same state as the measurement state, there is an effect that test equipment is not required and the test can be carried out easily.

Further, according to the present invention, it is possible to measure the degree of error (fluctuation) in measured values due to the influence of external light and unnecessary magnetic fields.

[Brief explanation of drawings]

1 to 9 show embodiments of the present invention, FIG. 1 is a circuit block diagram of the convergence measuring device, FIG. 2 is a perspective view showing the measurement state, and FIG. 3 is the position of the tube surface and the optical sensor. A cross-sectional view showing the relationship, Figure 4 is a directional sensitivity characteristic diagram of the optical sensor,
Fig. 5 is a diagram showing light intensity data, Fig. 6 is a diagram showing light intensity data with appropriate modulation degree, Fig. 7 is a front view of a television receiver, and Fig. 8 is a diagram showing the arrangement of bright lines. , FIG. 9 is a flowchart diagram. A...Convergence measuring device, 1...Color CRT,
2...Tube surface, 4...Optical sensor, 8...CPU (
misconvergence amount calculation means, self-inspection means), 15
...Pattern generator. 421 room 3 square frame 8 years old painted soil and holidays 2nd picture tube surface and Yusen qn 71! -15- (0-5054015 A degree- 尤Pump's pilgrimage to Rokusho) sweat l1 button 1 figure 4 ABCDabcdα strength level 1 figure 1 figure 6

Claims (1)

[Claims] (1) A pattern generator that outputs to the color CRT a video signal of a pattern that projects bright lines of each primary color at positions shifted by a fixed interval in the vertical direction on the screen of the color CRT; a misconvergence amount calculation means that calculates a misconvergence amount by comparing and calculating a light intensity data for each primary color detected by an optical sensor arranged at a position and having a single-peak directional sensitivity characteristic; controlling the pattern generator to generate the color CRT
The convergence measurement method is characterized in that the patterns of the video signals outputted to the device are all the same color, and the device is equipped with self-testing means for checking whether the measuring device is normal or not based on each light intensity data obtained from each pattern of the same color. Device.