RU1797167C - Device for coding of tv signals - Google Patents

Abstract

Usage: in television technology for masked transmission of television signals in both broadcast and subscriber television. Summary of the invention: the device comprises a signal polarity switch 1, a sampler 2, an inverter 3, a low-pass filter 4, a code generator 5, a synchronizer 6, a shift register 7, a code generator 8. An increase in the degree of masking of transmitted signals is achieved by increasing randomness generating a signal sequence with a code generator. 1 ill.

Description

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The invention relates to television technology and can be used for masked transmission of television signals in both broadcast and subscriber television.

The purpose of the invention is to increase the degree of masking of transmitted image signals.

The drawing shows a block diagram of a television signal encoding device.

The television signal encoding device comprises a signal polarity switch 1. Sampler 2, inverter 3, low pass filter (LPF) 4. code generator 5, clock generator 6, recursive shift register 7, code sample generator 8.

The television signal encoding device operates as follows: the initial video signal is input to the signal polarity switch 1, controlled by a code generator 5 connected to a clock 6. In the signal polarity switch 1

Claims (1)

SUMMARY OF THE INVENTION A television signal encoding device comprising a series-connected image signal polarity switch, the first input of which is the input of the device, a sampler, the second input of which is connected to the first output of the sync generator, an inverter and a low-pass filter, the output of which is the output of the device, a code generator rows included between the second the polarity of a certain number of lines changes in accordance with the code generated by the generator 5. From the output of switch 1, the video signal is fed to the input of sampler 2, in which samples of the video signal are taken with a frequency equal to or greater than twice the upper frp spectrum of the original signal. From the output of the sampler 2, the samples arrive at the input of the inverter 3. controlled by the code generator 8. The code generator 8 is controlled by a recursive shift register 7, which is connected to the clock 6. In the inverter 3, the samples are inverted in accordance with a code generated by a law similar to random, code generator 8. From the output inverter 3 samples of the video signal is fed to the input of the low-pass filter A with a cutoff frequency equal to the upper frp of the spectrum video signal. From the output of the low-pass filter 4, the encoded analog video signal is input to the device. Synchronizer 6 Provides synchronous operation of the code generator 5, sampler 2 and code generator 8 through a recursive shift register. the output of the sync generator and the second input of the image signal polarity switch, and a code sampler, the output of which is connected to the second input of the inverter, characterized in that, in order to increase the masking of the transmitted signals, a recursive shift register is inserted in it between the third output of the sync generator and input code generator samples.