SU1070706A2 - Video signal reproduction device - Google Patents

Abstract

DEVICE FOR PLAYING VIDEOSIGNAGES on aut. St. 919160, characterized in that, in order to increase the video signal reproduction accuracy by eliminating gaps of the video signal with a slow level change, a counting trigger and an adder are introduced, the first output of the display area line estimator is connected to the first through the digital-to-analog converter. the selector output and the second input of the syagmltor, while the counting input of the trigger counter is connected to the third output of the synchronizer. S About chg about 1 About: 0)

Description

The invention relates to television devices for monitoring and measurement, in particular, to devices for displaying oscillograms of the voltage of a television or other signal on the screen of a video monitor unit.

According to the main auth. No. 919160 is known a device comprising a series-connected selector, whose input is intended to supply an input video signal, a row counter, an installation input of which is connected to the second output of the selector and to the first synchronizer input, and a code comparison unit, the second input of which is connected to the output of the selection block. the output of the counter of the lines, the output of the selection block of the beginning of the display zone is connected to its second input, and the first output of the selector It is connected to the second input of the synchronizer, and the switch, as well as series connected rows counter of the display area, the installation input of which is connected to the first output of the synchronizer, a digital-to-analog converter, a comparator, the second input of which is connected to the input of the selector, And the code comparison unit and the counting input of the row counter of the display zone, the storage unit, the control input of which is connected to the second output of the synchronizer and the control input of the switch, the first The address input is the switch output, and the information output of the storage unit is connected to the input of the video monitoring unit, in addition, the counter of raster elements, the counting input of which is connected to the third output of the synchronizer, the setup input is connected to the first output of the selector, and the output is connected to the second address input of the memory unit, the first information input of the switch is connected to the second output of the line counter of the display zone, and the second information input is connected to the output of the subtractor G. 1J.

The disadvantage of this device is inaccurate reproduction of the video signal in the presence of a constant or slowly varying level in the last sections, as well as in case of a significant excess of one gradation of the selected quantization scale over the noise dispersion of the video signal.

In these cases, there will be no intersection with the quantization level in the signal areas with a constant value, and nothing will be written into the memory block. horizontal waveform waveforms will not be played.

The purpose of the invention is to improve the accuracy of video playback.

The goal is achieved by the fact that in a device for reproducing a video signal containing a series-connected selector, the input of which is intended to supply an input video signal, a line counter, the setup input of which is connected to the second output of the selector and the first input of the synchronizer, and a code comparison unit, the second input which is connected to the output of the block of choice of the analyzed line, while the output of the row counter is connected to the first input of the subtractor, the output of the block of selection is connected to the second input signal the start of the display area, and the first output of the selector is connected to the second input of the synchronizer, and the switch, as well as the series connected rows counter of the display area, the installation input of which is connected to the first output of the synchronizer, digital-analog converter, comparator, the second input of which is connected to the selector input. And, the second input of which is connected to the output of the comparison unit KoJiOB and the counting input of the row counter of the display area, the storage unit, the control input of which is connected to the second output b the synchronizer and the control input of the switch, the first address input to the switch output, and the information output of the memory block dego is connected to the input of the video control unit, in addition, the counter of raster elements, the counting input of which is connected to the third e. synchronizer output, the setup input is connected to The first output of the selector, and the output is connected to the second address input of the storage unit, with the first information input of the switch. connected to the second output of the display zone row counter, and the second information input connected to the subtraction output, a counting trigger and an adder are entered, the first output of the row counter of the display is connected to the input of a digital-analog converter through an adder, and the counting trigger is connected between the first output of the selector and the second input of the adder, while the counting input of the counting trigger is soin-in with the third output of the synchronizer.

The introduction of these blocks and connections allows changing the quantization levels by the amount of one gradation in each raster element and thereby ensuring the crossing of the comparator threshold with the sections of a constant level in the analyzed signal. Figure 1 shows the structural electrical circuit of the device; Fig. 2.3 shows voltage diagrams at some points of the device. The device contains a block 1 for selecting the analyzed line, block 2 for selecting the signal of the beginning of the display zone, block 3 for subtraction, switch 4, video control block 5, synchronizer 6, selector 7, counter 8 lines, block 9 comparing code counter 10 lines of display zone, digital-analog converter ( C 11, comparator 12, element 13.I, storage unit 14, counter 15 of raster elements, counting trigger 16, adder 17. The device works as follows: Directly converting the analyzed signal into a digital code in the proposed device The amplitude information is obtained by a comparator 12c controlled threshold and a storage unit 14 arranged in a matrix form. The matrix dimensions are determined as follows: the number of rows is equal to the N-number of graphs that the analyzed signal quantizes; the number of columns equal to the number of raster elements in the line of the television signal, i.e. the number of samples by which the signal will be represented in the display device. The number of rows of the matrix of the storage unit 14 is in turn uniquely related to the number of threshold values for the comparator 12: each threshold value of the comparator 12 corresponds to its own row of the RAM matrix 14. The total threshold value of the comparator 12 operates the entire dynamic range of the signal with N gradations. The comparator threshold is controlled by a digital-analog converter 11, the output voltage of which is determined by the state of the counter 10 lines of the display zone, and also the state of the counting trigger 16. In the recording mode, the code of the counter is 10 lines of the zone. display through the adder 17 is fed to the input of the digital-to-analog converter 11, thereby setting the corresponding level of the poro I of the comparator 12. The inverse counter code 10 lines of the display zone through the switch 4 is connected to the first address input of the storage unit 14, and thus records. Prepare the matrix of the storage unit 14 corresponding to a given threshold level of the comparator 12. Changing the threshold of the comparator 12 in the recording mode occurs tio an impulse, which arrives at the counting input of the counter 10 rows of They are displayed from the output of block 9 comparison codes. This pulse is generated at the output of block 9 of the comparison of codes at the moment when the second input of the comparator 12 enters the signal of the selected line, the code of which is set at the output of block 1 of the choice of the analyzed line. -The recording process lasts N frames. During this time, the comparator threshold will successively pass through all possible values of the video signal: from N-ro, corresponding to the maximum value, to zero, corresponding to the minimum value. The pulses from the output of the comparator 12 at the moments of coincidence of the signal level in this raster element with the threshold level pass through the element 13 AND, and in the corresponding cells of the storage array, block 14 in -. signals are being written. In the remaining cells of the matrix, O are saved. Thus, the recorded units on the zero field of the matrix form an oscillogram of the video signal. In the read mode, it is displayed on the screen of the video monitor unit 5. In this case, the output of the subtraction unit 3 is connected to the first address input of the memory unit 14 using the switch 4. The code at the output of subtraction unit 3 is determined by the difference of the code of the current line, which is fed to the first input of subtraction unit 3 from the counter output of 8 lines, and the code fed to its second input from the output of block 2 of the display zone signal start selection. With the aid of the block 2 for selecting the signal of the beginning of the display zone and block 3 for the subtraction, the waveform of the video signal is set to any convenient place of the frame. The synchronizer b and the selector 7 generate the appropriate clocking and control signals. The video signal from the output of the storage unit 14 can be fed to the input of the video monitor unit 5 in parallel with the main signal, and then on the same screen you can observe both the analyzed image and the video signal of the analyzed line, which is especially convenient when taking photographs. The unit 1 for selecting the analyzed line and unit 2 for selecting the signal of the beginning of the display zone can be executed included in the device,

for example, in the form of a set of switches, with the help of which they form binary codes of the corresponding size

In the device according to the main copyright certificate in the recording mode during one frame, the code from the output of the counter 10 rows of the display zone remains unchanged, the comparator threshold level does not change, and the input signal parts with the same value do not intersect with the comparator threshold levels 12 (as shown in Fig. 2) . This leads to the fact that on the reproduced waveform of the signal these sections are lost (Fig. 3) In the proposed device, the output code of the counter 10 lines of the display zone in the recording mode per unit of the least significant bit in each raster element is changed through the second input of the adder 17. Accordingly the magnitude of one gradation changes the threshold levels of the comparator 12, thereby providing an intersection with the signal areas of a constant value. The specified change in the input code of the DAP 11 is performed using a counting trigger 16, which The variable frequency pulses of the raster elements, which are removed from the third output of the synchronizer 6. The output signal of the counting trigger 16 is fed to the second input of the adder 17, and at the beginning of each line, this trigger is reset to the lower clock sync pulses from the first output of the selector 7.

Thus, the introduction of additional elements into the device makes it possible to increase the accuracy of the video signal display by clearly displaying the horizon; and weakly changing parts of the Formed waveform of the selected line.

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Claims (1)

A DEVICE FOR PLAYING A VIDEO BY AUT. St. No. 919160, which is related to the fact that, in order to improve the accuracy of video signal reproduction by eliminating omissions · sections of the video signal with a slow level change, a counting trigger and an adder are introduced, the first output of the line sketcher of the display eons being connected to the input of the digital-analog converter via an adder, and a counting trigger is connected between the first output of the selector and the second input of the adder, while the counting input of the trigger counter is connected to the third output of the synchronizer.