SU1654851A1 - Device for selecting synchronizing pulses of object image lines - Google Patents

Abstract

The invention relates to automation, in particular, to a device for selecting clock pulses of rows of object images. The purpose of the invention is to improve the noise immunity of the device. The goal is achieved by introducing the element HE, the fourth decoder, and the second trig-1-ger. 3 il.

Description

The invention relates to automation, in particular to devices for selecting clock pulses when receiving images of objects.

The purpose of the invention is to improve the noise immunity of the device.

FIG. 1 is a block diagram of the device; in fig. 2 and 3 - time diagrams of his work.

The device contains a pulse generator 1, analog-to-digital converter (ADC) 2, peak detector 3, first 4, second 5 and third 6 counters, first 7, second 8, third 9 and fourth 10 decoders, first 11, second 12 and third And elements, elements NOT 14, element OR 15, first 16 and second 17 triggers, and, moreover, input 18 and outputs 19 and 20.

The device works as follows.

The video signal in the form of amplitude-modulated oscillation from the input 18 is fed to the PEAK detector 3

and controlled pulse generator 1, which produces two parallel pulse sequences, phased in phase with the carrier oscillation of the input video signal and controlling the operation of the analog-digital converter 2 and the decoder 7. In this case, the converter 2 outputs digital samples of the input video signal with a frequency multiple of the carrier oscillation , to the output information bus 19 of the device and the decoder 7, which sends pulses to its separate outputs corresponding to high and low values of the input video signal. These parallel pulse sequences are used to detect the elements of the line sync pulse signal, which is characterized by alternating high and low values of the video signal (Fig. 2a).

During the search for the clock pulse element And 12 open

X

SP 00 SL

the potential of the trigger 16S is therefore the output pulses of the generator 1 are counted by the counter 4, which is reset to the initial state by the output pulse from the first output of the decoder 7, which gives a pulse when a high value of the video signal arrives at its input. The decoder 8 generates a pulse to the first element 11 and in the presence of a high number of samples of the input video signal corresponding to the element of the synchronization series (Fig, 26). The next low pulse after the high value of the video signal from the other output of the decoder 7 gates the element AND whose output signal arrives at the counting input of the counter 6. Thus, the decision about the arrival of one synchronization element is recorded.

Counter 6 similarly accumulates the threshold value of such decisions, in the presence of which the decoder 10 is triggered (FIG. 2d). At this, the element NOT 14 closes the element 11 and opens the element AND 13. The second input of element II 13 receives a signal from another output of the second decoder 8S issued when accumulating in the counter 4 a predetermined number of low values of the video signal reference. The output pulse of the second element AND 13 (Fig. 2b) sets the initial state of the counter 6, overturns the triggers 16 and 17, and returns the initial state of the counter 5 through the OR 15 element. This detects the timing pulse of the specified channel and generates the output phase device signal

The phasing of the output signal of the clock pulses is performed as follows.

By the structure of the line (Fig. 3e), it can be seen that the full line consists of two channels, each of which contains its own synchronizing pulse (SA or CB), the result of the sounding of space (KA or KB), the information part (A or B) and telemetry information (TA or TV). When the device is running, the counter 15 is continuously under 1654851d

momentum when the counter reaches 5

ten

15

20

25

thirty

35

a code corresponding to the number of digital samples for half the length of the video signal line. The output pulse of the decoder 9 overturns the trigger 16 (Fig. Z), than prepares the device for detecting the synchronizing pulse of the line in this manner, produces the source clock of the counter 5 through the electrode OR 15 and tilts the output trigger 17, the pulse of the synchronizing signal rows from the output of the element 13 (fig. 3k) sets the counter 5 to the initial state (fig. 3) and thus phases the generation of the output signal of the device to the phase of the true synchronizing pulses of the lines (fig. 3). a latch state 17, if it wa ustroyst when entering into the phase is opposite (FIG. Zl and g), the last of the sequence shown koto ryh uc muddy clock pulses of the channel rows.

When the noise of the useful signal is distorted, the device continues to output sync pulses of rows at output 20 with the phase that was before distortion. At the first correctly detected synchronizing pulse, the necessary phase adjustment in the input signal of the device is performed.

Claims (1)

Invention Formula 40 A device for selecting synchronizing pulses of rows of the image of objects, containing a peak detector, whose input is the information input of the device, and the output is connected to information input 4 of the analog-digital converter, the synchronization input of which is connected to the first output of the pulse generator, and the output is information output of the device, the first decoder, the information input of which is connected to the output of the analog-digital converter, and the synchronization input is connected to the second output of the gene Ator pulses, whose input is connected to the information input device, the first counter, the counting input of which is connected to the ne vym output of the first decoder, and an output connected to the information 50 55 reads the conversion cycle pulses from the output of the generator 4 (fig. 3), the decoder 9 outputs to its output five 0 five 0 five a code corresponding to the number of digital samples for half the length of a video signal line. The output pulse of the decoder 9 overturns the trigger 16 (Fig. Zi), which prepares the device for detecting the line clock pulse in the manner described, sets the initial state of the counter 5 through the OR 15 element, and overturns the output trigger 17 of the line output element And 13 (Fig. W) sets the counter 5 to the initial state (Fig. W), and thus phases the generation of the output signal of the device to the phase of the true clock pulses of the rows (Fig. W). The same n the pulse changes the state of trigger 17 if it is opposite when the device enters the phase (Fig. W and W), the last of which shows the sequence of true clock pulses of a given channel of lines. When the noise is distorted by the useful signal, the device continues to output a sync pulse signal to the output 20 with a phase that was distorted. The first correctly detected synchronizing pulse produces the necessary phase adjustment of the output signal of the device. Invention Formula A device for selecting clock pulses of object image lines, which contains a peak detector, whose input is the information input of the device, and the output is connected to the information input of the analog-digital converter, the synchronization input of which is connected to the first output of the pulse generator, and the output is the information output of the device, the first decoder, the information input of which is connected to the output of the analog-digital converter, and the synchronization input is connected to the second output of the gene Ator pulses, whose input is connected to the information input device, the first counter, the counting input of which is connected to the first output of the first decoder, and an output connected to the information the input of the second decoder, the first output of which is connected to one input of the first element I, the second counter, installation, the input of which is connected to the output of the element OR, and the output connected to the information input of the third decoder, the first trigger, the direct output of which is connected to one input of the second element And, the third counter and the third element AND, characterized in that, in order to improve the noise immunity of the device, it contains an element NOT, the output of which is connected to the second input of the first element AND, the third input of which is connected to toromu input of the first decoder, and an output connected to the counting input of the third counter whose input is connected installation o16548516 to the output of the third element And, the fourth decoder, the information input of which is connected to the output of the third { the output is connected to the input of the NOT element and to one input of the third element I, the other input of which is connected to the second output of the second decoder, and the output connected to the inverse input of the first trigger, the direct input of which is connected to the output of the third decoder, and the second trigger, whose counting input is connected to the output of the third decoder, the setup input is connected to the output of the third AND element, and the output is the synchronizing output of the device, while the inputs of the OR element are connected to the outputs of the third AND element and the third decoder. 1  nineteen one P FIG. 2 well P P and to l P one g