JPS63276394A - Automatic measuring instrument for chrominance signal vector - Google Patents

Abstract

PURPOSE:To attain quick measurement with high resolution and a comparatively smallsized program by detecting two signals of an orthogonal coordinate component scanning luminescent lines on a vector scope tube surface, applying A/D conversion to the signals and processing them as data. CONSTITUTION:A vector scope 2 decomposes color components of a composite video signal inputted from a measuring object instrument 1 into two parameters such as saturation and hue and displays the result on a polar coordinate. Each deflection control voltage signal of the vector scope 2 is written in storage circuits 12, 13 via amplifier circuits 6, 8 and A/D conversion circuits 10, 11. A CPU 16 reads the stored data to apply arithmetic processing to calculate the amplitude and phase of a chrominance signal vector. The calculated result is displayed on a display device 17.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for automatically measuring color signal vectors of composite video signals.

[Conventional technology]

Conventionally, in order to measure the color component vectors, that is, the amplitude and phase of a composite video signal, "Tenvision automatic measurement of images" was used.
As stated in the document "Measurement of Analog Baseband Signals", Journal of the Televisier Society, Vol. 38, N116 (1984), data is sampled at a frequency 5 to 4 times that of the color subcarrier and A/D converted. , 6 pieces each for amplitude and phase.

The amplitude and phase were determined by computer processing using formulas that included seven trigonometric functions. However, this method is expected to increase the number of processing programs and take a long time to execute, and sufficient consideration has not been given to improving investment efficiency when applying it to inspection processes in mass-produced products and adjustment processes that require repeated measurements. It can't be said that it's a good thing.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology does not take into consideration the application to an inspection process in mass-produced product manufacturing or an adjustment process that requires repeated measurements, and there are problems in terms of processing time and equipment cost in that case.

That is, in the above-mentioned conventional technology, the color subcarrier frequency component of the composite video signal is directly sampled at a frequency 3 to 4 times that frequency, and the data obtained by A/D conversion is processed, so the processing time becomes long. The cost performance, which is evaluated based on equipment price and processing time, is not appropriate for application to the manufacture of low-cost mass-produced products such as home appliances.

Furthermore, the resolution of an element capable of A/D conversion at the above-mentioned speed is usually about 8 pits, and special 10- to 12-bit devices are expensive, so improving the resolution requires an expensive device.

SUMMARY OF THE INVENTION An object of the present invention is to provide a device for automatically measuring color component vectors of a composite video signal, which uses a relatively small program, has high execution speed, and can increase measurement resolution without significantly increasing the price. There is a thing called K.

[Means for solving intervening vertices]

The above purpose is achieved by detecting two signals of rectangular coordinate components that scan the bright line on the tube surface of the vectorscope, converting them from A/D, and processing the data. [Operation] Vectorscope In order to measure the color component vector of the composite video signal to be measured, which is displayed in polar coordinates on the tube surface, an Detects two X signals,
After amplifying the two signals so that the voltage ratio and voltage magnitude are equal to the vector displayed on the vectorscope tube surface, A/D conversion is performed and the signal is stored as digital data. Thereafter, this data is read into the central processing unit, and the magnitude and phase of the vector are processed to perform vector measurement of the color component. Here, if a signal with a small number of color changes included in the horizontal scanning period, such as a color par signal, is used as the composite video signal, the above X
Since the frequency band of each signal,
By using a converter, measurement resolution can be improved.

〔Example〕

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

FIG. 1 shows the configuration of this embodiment, in which the output of a measurement target device 1 for measuring the color component characteristics of a composite video signal is input to a vectorscope 2 and a synchronization separation circuit 6.

Output signals 4 and 5 of the vectorscope 2 are input to amplifier circuits 6 and 8, respectively. Gains of the amplifier circuits 6 and 8 can be set using variable resistors 7 and 9, respectively. The outputs of the amplifier circuits 6 and 8 are A/D
It is input to a conversion circuit 10.11.

On the other hand, the output of the synchronization separation circuit 3 is inputted to the timing signal generation circuit 15 together with the output of the clock signal generation circuit 14, and one of the outputs is inputted to the VD conversion circuit 10.11 as a sampling clock input. The outputs of the A/D conversion circuits 10.11 are sent to the storage circuits 12.11, respectively. i
3. The other output signal of the timing signal generation circuit 15 is input to the memory circuits 12 and 13 as a write control signal. Central processing unit (CPU)
) 16 reads the contents of the memory circuits 12 and 13, performs arithmetic processing, and outputs the results to the display device 17.

Next, the operation of each part will be explained. The measurement target device 1 includes an object whose electrical characteristics are to be measured, and video equipment such as a television receiver, a video tape recorder, and a video camera.

The vector scope 2 has a function of decomposing the color components of the composite video signal inputted from the measurement target device 1 into two parameters, color saturation and hue, and displaying them on a polar coordinate plane. Here, for example, if a pattern as shown in FIG. 3 is displayed when the output of the measurement target device 1 is input to the CRT, the display on the vector scope 2 will be in a state as shown in FIG. 4.

In other words, in the case of a three-color pattern of (R), G (green), and B (blue), the vector scope 2 shows the origin, burst, and vectors corresponding to R, G, and B as bright points.
, P, , Pr, , Pg, pb are observed.

Here, such a bright spot is displayed on the vector scope 2 because the electron beam irradiated from the electron gun inside the vector scope 2 (not shown) toward the cathode ray tube is
/Y orthogonal coordinate component). So, this X.

The Y deflection control voltage signals 4 and 5 are led out to the outside and input to amplifier circuits 6 and 8, respectively.

The amplifier circuits 6 and 8 have high input impedance and low capacitance input circuits so as not to give a loading effect to the signal source, and are each equipped with a variable resistor 7.9 so that the amplification factor can be adjusted. Generally, the X and Y deflection voltages of the vectorscope 2 are not equal, so the output of the amplifier circuit 6 at point PX+K in FIG. 4 is equal to the output of the amplifier circuit 8 at points P and +, and The amplification factor is set by the variable resistors 7 and 9 so that the output of the amplifier circuit 6 at the knee is equal to the output of the amplifier circuit 8 at the point PY-.

FIG. 5 shows signal waveforms obtained corresponding to FIGS. 3 and 4. In FIG. 5, the output signal of the measurement target device 1 is C
The signal waveforms obtained from the amplifier circuit 6.8 are in the states shown as X and Y, respectively, and their time axes are synchronized with the Com and V signals. The peak value of the signal is determined by each bright spot PO+ PR+ shown in Figure 4.
It can be obtained as the value of the orthogonal coordinate component corresponding to Pr+Pg*''b.

Next, the outputs of the amplifier circuits 6 and 8 are input to A/D conversion circuits 10.11, respectively, and converted into digital data, which are respectively written into storage circuits 12.13. At this time, the write control pulse to the A/D conversion and storage circuit is generated by the timing signal based on the composite synchronization signal separated from the composite video signal by the synchronization separation circuit 3 and the output signal of the clock signal generation circuit 14. It is created by the creation circuit 15.

Thereafter, the CPU 16 reads data X in the memory circuit 12 and data y in the memory circuit 13, and calculates a vector using the following equation.

, -p〒T　　　　　9. (,) Here, γ represents the absolute value of the vector, and θ represents the phase.

The r obtained in the above manner represents the hue of the composite video signal. The CPU 16 displays this result on the display device 17. Here, the display device 17 may be a monitor display device that informs the operator of the measurement results, a device that automatically determines pass or fail, or a device that displays digital data obtained as the measurement results. Alternatively, it may be a device having a function of automatically adjusting the electrical characteristics of the device 1 to be measured.

Next, the calculations of the above equations (1) and (2) are performed by the CPU 1.
Another embodiment of the present invention is shown in FIG. In this figure, the same reference numerals as in FIG. 1 indicate the same functions.

In FIG. 2, the X and Y values of the analog quantities obtained by the amplifier circuits 6 and 8 are calculated by the square sum phallic calculation circuit 18 and the arctangent calculation circuit 19, which are analog calculation elements, and the obtained vector After each analog quantity of the component is converted into a digital quantity in the A/D conversion circuit 10.11,
Written to memory circuit 12.13. After that, CPU1
6, by reading 9 the contents of the memory circuits 12 and 13 and outputting this to the display device 17, the same measurement function as in the previous embodiment can be obtained. The method of this embodiment is based on CP
Since the processing amount of U16 is reduced, it is expected that the processing time will be shortened and the execution program β memory capacity will be reduced.

According to this embodiment, the color component vector of the composite video signal is
It can be detected as a rectangular coordinate component, and this value is directly A/D converted to obtain a vector by digital calculation, or the rectangular coordinate component is converted to the absolute value of the vector by analog calculation, and then A/D converted. This allows vectors to be measured digitally. In this way, the color saturation and hue of the color components of the composite video signal can be digitally measured, and based on the results, automation of inspection and adjustment can be achieved.

As described above, in this embodiment, it is not necessary to perform interpolation calculations of trigonometric functions based on sampling data as described in the conventional example, so that the measurement processing time can be shortened. In addition, since the frequency band of the rectangular coordinate component signal can be made relatively low, it is easy to increase the number of pits in the A/D conversion circuit used for quantization, and the measurement accuracy can be improved without significantly increasing the cost of the device. can be made higher.

〔Effect of the invention〕

According to the present invention, in an automatic color signal vector measurement device, by measuring the color component vector of a composite video signal by processing information on orthogonal coordinate components, it is possible to shorten the measurement processing time, and also to reduce the measurement processing time. Since D conversion accuracy can be easily improved, measurement accuracy can be increased without a significant increase in price.

Furthermore, by using the vector digital data obtained by the device of the present invention as control data for display devices, pass/fail judgment devices, automatic adjustment devices, etc., it becomes possible to automate inspection processes and adjustment processes. It is possible to reduce the cost of products subject to inspection and adjustment.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing 18 components of an apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram of another embodiment in which a part of the system shown in FIG. 1 is different, and FIG. A diagram showing an example of a composite video signal projected on a CRT, Figure 4 is a diagram showing the screen display of a vectorscope corresponding to Figure 3, and Figure 5 is a diagram showing a composite video signal corresponding to Figures 3 and 4. FIG. 3 is a waveform diagram showing waveforms of a video signal and a rectangular coordinate component signal. 1...Measurement target device, 2...Vectorscope, 3
...Synchronization separation circuit, 6, 8...Amplification circuit, 1o, 1
1...A/D conversion circuit, 12.15...memory circuit,
14... Clock signal generation circuit, 15... Timing signal generation circuit, 16... Central processing unit (CPU)
, 17... Display device, 18... Square peace phallic calculation circuit, 19... Arctangent calculation circuit.

Claims (1)

[Claims] 1. In a device that automatically measures the color signal vector of a composite video signal to be measured, a vector scope inputs the composite video signal, and 2 detects two orthogonal coordinate components that scan a bright line on the tube surface of the vector scope. A set of detection means with variable amplification factors, two sets of A/D conversion circuits for converting the detection signals into digital signals, two sets of storage circuits for respectively storing the converted digital data, and the storage circuits for storing the converted digital data. What is claimed is: 1. An automatic color signal vector measuring device comprising: a computer that reads and arithmetic-processes the data, and calculates the magnitude and phase of the color signal vector.