SU692113A1 - Tv signal delay arrangement - Google Patents

Description

one

The invention relates to radio engineering and can be used for the purposes of applied, broadcasting television and in sealing systems of a television channel.

A television signal delay device is known comprising a low-pass filter connected in series, a low-frequency delay block, a first adder and a first switch, a control unit connected by the first and second outputs respectively to the second input of the first switch and to the first input of the second switch, to the second input of which the input is fed signal, the first high-frequency filter, high-frequency delay unit, the second high-frequency filter, connected to the second input of the first adder 1.

However, in the known device, there are distortions of the horizontal boundaries of the focal transitions of the delayed image, the cause of which is due to the disappearance of the frequency-modulated (FM) signal read due to interpolation

signals of two adjacent rows of the aperture readout beam.

The aim of the invention is to eliminate the fallout of the video signal corresponding to the horizontal boundaries of the fast transitions.

For this, the second, third and fourth adders, two delay lines for the duration of the line, three phase inverters are introduced into the known delay device of the television signal, and the output of the second switch through the first delay line for the duration of the line is simultaneously connected to the inputs of the low-pass filter, the first high-pass filter and the first phase inverter connected to the first output

input-second adder, the second input and output of which are connected respectively to the output of the second switch and to the input of the third adder connected by input and output respectively to the output of the first high-pass filter and to the input of the high-frequency delay unit, the output of which is simultaneously connected to the inputs of the second high-pass filter second delay line for the duration of the line and the fourth adder, the second input of which and the output are connected respectively to the output of the second phase inverter connected by the input with the output second delay line for the duration of the line, and to the input of the third phase inverter, the output of which is connected to the third input of the first adder.

FIG. 1 shows the structural electrical circuit of the proposed device; in fig. 2 - diagrams at various points of the scheme.

The television signal delay device contains a low-pass filter 1 (LPF), a low-frequency delay block 2, four adders 3, 4, 5 and 6, first and second switches 7 and 8, a control unit 9, first and second filters 10 and high frequency II ( HPF), high-frequency delay unit 12, two delay lines 13 and 14 for the duration of the line, three phase inverters 15, 16 and 17.

The device works as follows

The original video signal is fed to the switch 7. At the command of the control unit 9, the switch 7 carries out the selection of the television signal (Fig. 2a). The low-frequency part of the spectrum of the original sample of the television signal is delayed by overwriting the FM signal converted in the low-frequency block of delay 2. In the latter, to eliminate distortions in the form of signal fallout at the horizontal limits of the transitions, line-by-line reading is introduced. The resultant expansion of the horizontal boundaries of the transitions is compensated by the introduction of a vertical aperture correction. It is implemented as follows.

The horizontal boundary signal is extracted in adder 4 by adding the original signal out of phase (Fig. 2a) with the delayed 13 in the delay line by the row duration (Fig. 26). Due to the high line-to-line correlation of the video signal at the output of the adder 4, a signal is obtained only from the horizontal boundaries of the high-frequency transitions (Fig. 2c). The extracted signal of the horizontal limits is delayed in the high-frequency delay unit 12-. To eliminate additive interference in the delayed signal of the horizontal boundaries, the latter is subjected to high-frequency vertical filtering by adding it in antiphase to the signal delayed in the delay line 14 for the row duration (Fig. 2d) in the adder 6. As a result, the adder 3 of the horizontal boundaries selected in this way ( Fig. 2d) with a delayed low-frequency signal in the low-frequency delay unit 2 (Fig. 2e), the width of the horizontal edges of the brightness

transitions, i.e., vertical clarity, remain unchanged in the absence of distortion in the form of signal deposition at horizontal-boundaries of the transitions (Fig. 2g).

Thus, the proposed device provides an undistorted delay of a television signal with full vertical definition for the duration of one or two fields, which degrades its functionality.

A television signal delay device containing a low-pass filter connected in series, a low-frequency delay block, a first adder and a first switch, a control unit connected by the first and second outputs, respectively, to the second input of the first switch and to the first input of the second switch, the second input of which is fed to an input signal , a first high frequency filter, a high frequency delay unit, a second high frequency filter, connected by an output to a second input of a first adder, characterized in that, In order to eliminate the video signal dropout corresponding to the horizontal boundaries of the bright transitions, the second, third and fourth adders, two delay lines for the row length, three phase inverters are entered, the output of the second switch through the first delay line for the row duration is simultaneously connected to the low-pass filter inputs of the first high-pass filter and the first phase inverter connected by an output to the first input of the second adder, the second input and output of which are connected respectively to the output of the watt switch with the input of the third adder connected by input and output respectively to the output of the first high-pass filter and to the input of the high-frequency delay unit, the output of which is simultaneously connected to the inputs of the second high-pass filter, the second delay line for the row duration and the fourth adder, the second input and the output is connected respectively to the output of the second phase inverter, connected by the input with the output of the second delay line for the duration of the line, and to the input of the third phase inverter, the output to orogo connected to the third input of the first adder.

Sources of information taken into account during the examination 1. USSR Author's Certificate No. 466623, cl. H 04 N 5/00, 1975 (prototype

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