SU1660212A1 - Device for measuring coordinate distortions in focusing and deflection systems and in camera crt - Google Patents

Abstract

This invention relates to a television (TV) technique. The purpose of the invention is to improve the accuracy of measuring coordinate distortions. The device contains a TV transmitting chamber unit 1 with the focusing-deflecting system under study (FOS) and a transmitting cathode-ray tube (CRT), the optical input of which is used to design a test table. The coordinate measurement unit 2, the CRT power measurement unit 4, and the scanning parameter measurement unit 8 are connected to the corresponding outputs of block 1. The calculation and measurement registration unit 3 according to the operation algorithm, having collected data from the output of blocks 2, 4 and 8, calculates coordinate distortions the studied set of FOS and CRT, taking into account the instability of the measurement conditions (size and centering of the registry, non-linearity of the sweeps, power modes of the CRT). 6 Il.

Description

ON O O U

YU

The invention relates to a television (TV) technique and can be used in the selection of sets of focusing and deflecting systems (FOS) and transmitting cathode-ray tubes (CRT) for multi-channel color television transmitting cameras.

The purpose of the invention is to improve the accuracy of measuring coordinate distortions.

Figure 1 shows the structural electrical circuit of the device.

FIG. Figures 2-6 show the structural electrical diagrams of the first (second) measuring channel, the measuring unit for the power modes of the transmitting CRT, the gating signal generator, the amplitude normalization unit and the measuring unit for coordinates, respectively.

The device contains (Fig. 1) block 1 of a TV transmitting chamber with examined FOS and transmitting CRT, block 2 of measuring coordinates, block 3 of calculating and recording measurements, block 4 of measuring the modes of power supply of a CRT, generator 5 of a strobe signal, synchronizer 6, block 7 projections of the test table and a scanning parameter measurement unit 8 consisting of the first and second measurement channels 9 and 10.

Each of the measurement channels contains (FIG. 2) a digital-to-analog converter (D / A converter) 11, a comparator 12, an amplitude normalization unit 13, an input-output unit 14, a memory unit 15, and first and second counters 16 and 17.

The unit for measuring the power modes of a CRT contains (fig.Z) switch 18, an analog-to-digital converter (ADC) 19, memory block 20, input / output unit 21, clock pulse generator 22 (GTI), counter 23, And 24, and divide 25

The generator of the strobe signal contains (figure 4) the first, second, third and fourth counters 26-29, the first, fifth

elements And 30, ..., 34, first .... fourth

triggers 3538 and block 39 I / o.

The amplitude normalization unit contains (FIG. 5) an adder 40, the first and second ADCs 41 and 42, the inverter 43 and the first and second DACs 44 and 45.

The coordinate measurement unit contains (FIG. 6) a counter 46. An input / output slice 47, a trigger 48, first and second elements 49 and 50, a differentiation circuit 51, an inverter 52, an A / D converter 53 and a memory block 54.

The device works as follows.

Unit 7 (FIG. 1) projects a test table onto the TV camera of unit 1, which is, for example, transparent

2-3 circular dots of decomposition on the opaque background, evenly spaced in the image field. The number of rows of horizontal dots Nxn of the vertical is, for example, 15, i.e. Nx.

After starting the distortion measurement program, the unit 3 for calculating and recording the measurement sets 1 at the input

0 control of the counter 23 in block 4 of the measurement of power modes of a CRT, set it to the clock pulse counting mode. Then, unit 3 for calculating and recording measurements sets the level O at the input of the control of the counter 46 in unit 2, measuring the coordinates, putting it into installation mode, and writes zero code to the counter 46 to set the starting address for recording information in memory unit 54. After this block 3

0 calculating and registering measurements through the I / O unit 14 sets the level 1 at the control input of the counter 46, as well as the counters 16 (FIG. 2) in channels 9 and 10 of the block 8 for measuring the sweep parameters,

5 translate these counters into account mode.

At the same time, unit 4 for measuring the power modes of a CRT (Fig. 3) measures voltages on the electrodes of a CRT unit 1. For simplicity, consider the case

0 is the measurement of two voltages, the instability of which has the greatest effect on the instability of the dimensions of the raster of the anodic and ua and focusing - 1) f. These voltages are from camera power supplies.

5 unit 1 is fed to the corresponding inputs of the divider 25. Dividers are needed to match the measurement range of the measured voltages with the dynamic range of the ADC 19, the oscillator 22 clock

0 pulses generates 1 MHz pulses, which are counted by counter 23, generating a control code for switch 18. The corresponding voltage is fed to the input of ADC 19, where it converts 5 c to digital code and is written to memory block 20 using a clock pulse inverted And 24. The cell address of the memory block 20, in which the measured voltage value is written,

0 corresponds to the control input code of the switch 18.

With N-2, after 2 µs, block 4 of measuring the power modes of a CRT is ready to transmit information to block 3 for calculating and recording measurements. Therefore, after setting the operation modes of the counters 16 and 46 (Fig. 6), block 3 can immediately refer to block 4. First, block 3 sets the level O at the control input of counter 23, translation

it in the recording mode information. It `s that,

at the same time, it prohibits further recording of information in memory block 20. Then the counter 23 records the address of the 1st cell of the memory block 20, from which, through the input-output block 21, the value code Ua of the anode voltage is read into block 3, being multiplied by the factor Ka (inverse of the division factor in the divider block 25) , will give the value of Ua anode voltage. After that, the counter 23 records the address of the 2nd cell of the memory block 20, from which the code of the U f value of the focusing voltage, which is stored by the correction factor, is read into block 3 of the calculation and recording of measurements.

When measuring a lot of FOS or CRT, the measurement results of all FOS or CRT should be brought to the scale of measurements of one of the FOS or CRT. Therefore, unit 3 for calculating and recording measurements asks the operator whether to accept the conditions of the measurement data as reference ones. If so, then the reference voltages Uae, 1) φ0 are assigned the values Ua, 11f, respectively.

Then, unit 3 for calculating and registering measurements again sets level 1 at the control input of counter 23, switching unit 4 for measuring the power modes of a CRT to measurement mode until the next interrogation of unit 20 of memory.

Since the control input of the counters 16 in channels 9 and 10 of block 8 of the sweep parameters measurement was set to 1, block 8 operates in the mode of measuring the sweep parameters.

Consider the operation of channel 9. The horizontal scanning signal x (t) is fed from block 1 to the input of the ADC 42 of block 13 of the amplitude normalization (figure 5). The ADC 42 measures the value of

The x of the signal x (t) at the beginning of the forward stroke of the line, since it is triggered by the falling edge of the line quenching pulse generated by the synchronous generator 6. This value is subtracted from the original sweep signal x (t) using DAC 44 and adder 40 . Therefore, the leading edge of the horizontal damping pulse through the inverter 43 of the A / D converter 41 fixes the xy value of the horizontal scanning signal, which is fed through the DAC 45 to the reference input of the D / A converter. The zero-level sweep signal from the output of the adder 40 is fed to the input of the comparator 12, to the second input of which is fed

one of the reference levels (xi, x2XNX) is

the stresses generated by the counter 16 and the D / A converter 11; When the sweep signal coincides with the i-th reference level, the comparator 12 generates a pulse recording the response time ti, which is counted by the counter

do uro (1 +

17s from the moment of the forward stroke of the line to the memory block 15. The write address is the code of the level number at the output of the counter 16. At the same time, the write pulse from the output of the comparator 12 transfers the counter 16 to the next state, and the DAC 11 forms the (1 + 1) -th reference level with which the scan signal is compared.

Thus, the temporary positions of the intersection of the scanning signal x (t) with the reference level grid {xi} are permanently recorded in the memory unit 15. At the same time, the matching of the scale of the reference level grid at the output of the D / A converter 11 with the sweep of the sweep signal is provided automatically due to the output from the output of the DAC 45 of the magnitude Xp of the sweep of the sweep signal to the reference input of the DAC 11.

The channel 10 for measuring the parameters of a frame scan works similarly.

After entering into block 3, calculating and registering the voltage of the CRT power supply from block 4, block 3 reads the Xnach and Xp values from the A / D converters 42 and 41 of channel 9, calculates the centering value on line Cx 0.5 (Xnach + Xp), then reads the values Ynach and Yp from the outputs of ADC 42 and 41 of channel 10 and calculates the magnitude of the alignment over the frame Su 0.5 (Set + Ur), In the event that the conditions at which the measurement data is taken should be taken as the reference, reference values Chro and uro take, respectively, the values of Xp and Yp. Then block 3 calculates the equivalent raster size, depending on the instability of the power supply:

XP-XPQ, ie-aao. if-0h

2Uao2LU0

(1 + Npo

Yp-y

Ro

Y,

J- + Ua -U

ao

Po

2U

thirty

ifo

Zf - ifr 2 ifo

Thereafter, block 3 sets the level O at the control input of the counter 16 and the gating input of the comparator 12 of channel 9. At the same time, the counter 16 is set to the information recording mode from block 3, and the comparator 12 stops producing write pulses for the memory block 15. The counters 16 of channel 9 alternately write addresses from the 1st to Nx cells of the memory block 15, from which the time positions of the reference pulses ti (1 I NX) are read, after which the control inputs of the counter 16 and the comparator 12 of channel 9 are set to level 1, channel 9 is switched back to measurement mode.

Similarly, the time positions tj (1 j Ny) of the reference pulses from channel 10 are entered into block 3.

 Thereafter, an alternate measurement of the coordinates of the test table labels is performed. Unit 3 sequentially sets in the generator 5 through the block 39 I / o on the inputs of the installation reversible

counters 2629 (FIG. 4) coordinate codes

the beginning of Hock, the size of the K strobe on the line and the codes of the coordinates of the beginning of U0kna and the size L of the strobe on the frame, expressed in the number of clock pulses. The first row and frame damping pulses counters 26,..., 29 are set to a predetermined state. At the same time, the horizontal impulse sets the trigger 38, and the personnel impulse - the trigger 37 into a single state, allowing the passage of clock and horizontal pulses through the AND 3134 elements

counting inputs of reversible counters 2629. Counters 29 and 27 count to zeroing, working out the coordinates of the beginning of the gates in the row and frame, respectively. At the overflow output of the counter 29, a negative pulse appears, setting the trigger 35 to one state, which enables the counting of clock pulses to a reversible counter 26, which fulfills the specified strobe length per line. By resetting the counter 26, the trigger 35 is reset to the zero state, completing the line gate formation. Similarly, a strobe ps frame is formed at the output of flip-flop 36. Inline and frame gates, combined along AND, from the output of the AND element 30 are fed to the first input of the AND element 50 and the second input of the And element 49 in the coordinate measurement unit 2. The generated strobe should extract a signal from only one label of the test table. The video signal from the output of block 1 through ADC 53 is fed to the input of memory block 54, to the recording input of which the inverted clock pulses are fed through the element 49 ensuring the recording delay relative to the start of the ADC per poltakt. Synchronously with the ADC 53, the counter 46 generates the address of the samples of the video signal inside the strobe.

From a predetermined front of an inverted frame strobe, which is fed from the inverse output of trigger 36 in generator 5, a differentiated pulse is generated using differentiating circuit 51 and inverter 52, which sets trigger 48 to one and indicates the end of the recording of the pideosial in the first frame of the selected tags in the first half of the memory block 54.

The unit 3 for calculating and recording measurements at this point is in the state of continuous polling through the input / output unit 47 of the state of trigger 48 (polling

readiness). When a G appears at its output, block 3 sets O at the control input of the counter 46, the first input of the element 49 and the R input of the trigger 48, dropping it into

zero state. Thereafter, the counter address 46 records the cell address of the memory unit 54, from which the signal from the mark will be recorded in the second frame field. If the signal of the first field was recorded in the first (K-L / 2)

cells, then the number 46 is entered into the counter 46 (Kx xL / 2 + 1), is set at the control input of the counter 46, the first input of the element U 49 and the R input of the trigger 48, and the block 3 again switches to the polling mode of the output trigger

48.

In the next field, with the same strobe, the signal from the same label is recorded in the second half of the memory block 54. With the occurrence of 1 at the output of the trigger 48 block 3

establishes O at the control input of the counter 46, the first input of the element U 49 and the R input of the trigger 48. After this, block 3 successively enters the counter 46 of the address K-L cells of the memory block 54, of which

The amplitudes U (K, I) of the video signal samples in the selected image fragment are amplified. Then, the estimates of the coordinates X (i, j) m Y (i.j) 0,) of the test table are calculated by

calculating the average coordinates of the centers of the severity of the signal of the mark for two frame fields

five

K L / 2

.2 2 to and (Ki o

6 f,,. one ,

X (|, j) Ј; -k +

L / 2

I K 1

K L / 2

2 I u (Kii)

i

K 1 I L / 2 + 1

K U (Ki I)

i i and with about

(i I L / 2 4--1

A) Hock

, 22fu- (Kii)

 Y (i, j) 4+

 22u (Kii)

iЈ 0 L / 2) U (Ki I)

(i I L / 2 -M

i f windows

55

2 2 U (KII)

K I I ™ L / 2 + 1

and coordinate distortions with respect to the grid of reference pulses formed by the sweep parameter measurement unit 8,

taking into account changes in size and centering of the raster:

AX (l, j) X (i, j) -t ,, AY (lJ) Y (iJ) -ta- -CvValues AX (i, j) and LY (IJ) are recorded in the long-term memory of block 3, for example, specific file on a floppy disk.

After that, unit 3 proceeds to measuring the coordinate distortions at the raster point where the next label of the test table is located, and so on, until the values AX (IJ) and A Y (i, j) are measured and written to the file for all Nx Ny table labels. Thereafter, the distortion measurement procedure for the given POC or CRT ends.

After measurements of the whole batch of FOS and CRT, they are selected into triads according to the permissible values of the differential distortion between any pair of FOS or CRT that are included in the triad.

Thus, in the proposed device, the influence of instabilities of the power supply modes of the CRT, the size, alignment and non-linearity of the scans on the accuracy of measurement of the differential distortions of any two OPC or CRT, between which measurements of parameters can lie quite a long time (up to several months), is taken into account. ). In the course of sampling, such triads are removed from the general FOS or CRT batch, the data on the remaining FOS or CRT is stored until the next batch of the FOS or CRT is manufactured and can be added to the new batch for further selection of triads.

Claims (1)

Apparatus of the Invention A device for measuring the coordinate distortions of a focusing-deflection system and a transmitting cathode-ray tube, comprising a projection table of the test table, optically connected with the optical input of a television transmitting camera unit with a focusing-disconnecting system under investigation and a transmitting cathode-ray tube , the signal output of which is connected to the coordinate measurement unit, the input-output of which is connected to the first input-output of the calculation unit and the recording of measurement results, in turn is connected to the data input of the generator stro- biruyuschego signal, first and second outputs are connected to the first and second Gating inputs of the coordinate measurement unit, the clock input of which is combined with the clock input of the strobing signal generator and connected to the output of 5 clock pulses of the clock generator, the outputs of the horizontal and frame frequencies of which are connected to the corresponding inputs of the television transmitter block and the strobing signal generator, characterized in that, in order to improve the accuracy of measuring coordinate distortions, a unit for measuring the power modes of a transmitting cathode-ray tube is introduced into it and, N 5 inputs of which are connected to the corresponding N outputs of the monitored power supply voltage of the television transmitting chamber unit, the input / output of the transmitting power measurement unit 0 cathode ray tube is connected to the second input-output of the computing and recording unit of measurement results and the scanning parameters measuring unit, the first and second information inputs of which 5 are connected, respectively, with the outputs of the horizontal and vertical scanning signals of the television transmitting camera unit, the first, second and third synchronization inputs of the scanning parameters measuring unit 0 are connected, respectively, to the outputs of the pulses of the clock, line and frame frequencies of the generator, while the first and second inputs-outputs of the measuring unit of the sweep parameters are connected, respectively, with the third and fourth inputs-outputs of the calculating unit and recording results, the block for measuring the sweep parameters contains the first and second measuring channels, the inputs-outputs of which are, respectively, the first and second inputs-outputs of the measuring unit of the scanning parameters, the first and second informs The main inputs of which are, respectively, the first inputs of the first and second measuring channels, the third input of the first measuring channel, the combined second input of the first measuring channel and the third input of the second measuring channel. Channel 0 and the second input of the second measurement channel are, respectively, the first, second and third synchronization inputs of the sweep measurement unit, the first and second 5 measurement channels contain serially connected first counter, digital-to-analog converter and comparator, the output of which is connected to the counting input of the first counter, which is combined with the recording control input a memory block whose address and information inputs are connected, respectively, to the outputs of the first and second counters, the output of the memory block is connected to the first input of the I / O unit, the second and third inputs of which are connected, respectively, to the first and second outputs of the amplitude normalization block , the third and fourth outputs of which are connected, respectively, with the reference inputs of the digital-to-analog converter and the comparator, the gate input of which is combined with the input 0 control of the first counter and connected to the first output of the I / O unit, the second output of which is connected to the installation input of the first counter, and the input-output of the I / O unit is the input-output of the measuring channel, the first, second and third inputs of which are, respectively , information input of the amplitude normalization unit, the reset input of the second counter, combined with the synchronization input of the amplitude normalization unit, and the counting input of the second counter. FIG. Z Fig.Z B GLF 2120991 -H 53 Ъ-Я Ш 45 Cd 0-j WITH 50 R 5fl j  "" "..--. e- F. 6 45 47 d: blockz "but