SU1450137A1 - Transceiver of stereo/color television signal - Google Patents

Abstract

The invention relates to a television technique. The purpose of the invention is to ensure full compatibility with the color television system NIIR and increase the noise immunity of the device operation in the event of phase distortions in the communication channel. A second adder, a third low-pass filter, an inverter, an amplitude modulator, a second delay element, and a nonlinear element are entered into the device on the transmitting side, and two amplifiers, a third delay element, an amplitude detector, and an inverter are input at the receiving side. In the transmission and reception of a stereo color television signal, due to quadrature modulation of the subcarrier frequency, the color difference signals of the left frame of the stereo pair in the nth row and the AM subcarrier frequency are provided by the narrowband luminance signal of the right frame of the stereo pair in (n + "1) th reference line full compatibility of the device with the color television system. The device provides insensitivity of the quadrature modulated oscillation to the phase distortions in the communication channel, thereby increasing the noise immunity of the color channel of the device. 2 Il. with $ (L

Description

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The invention relates to a technique of television and can be used to create systems of applied and broadcast stereo color television.

The purpose of the invention is to ensure full compatibility with the color television system NIIR and to increase the noise immunity of the device operation in the event of the occurrence of phase distortions in the communication channel.

Figures 1 and 2 show the structural electrical diagrams of the transmitting and receiving sides of the transmission and reception device of the stereo color television signal, respectively.

The device for transmitting and receiving a stereo color television signal on the transmitting side contains the first 1 and second 2 matrix transducers, the first delay element 3, the first adder 4, the first 5 and second 6 low-pass filters, the first 7 and second 8 balanced modulators, the second adder 9, subcarrier generator 10, phase shifting element 11, third filter 12 lower clock, inverter 13, amplitude modulator 14, second delay element 15, switch 16 and nonlinear element 17, and on the receiving side - band pass: filter 18, first element 19 delay , the first amplifier 20, the switch 21, the second delay element 22, the second amplifier 23, the first synchronous detector 24, the phase-shifting element 25, the second synchronous detector 26. the matrix converter 27, the amplitude detector 28, the inverter 29, the cutting filter 30 and the third element 31 delay.

The device works as follows

The color-separated video signals from the left color transmitting television camera, corrected by gamma correctors, arrive at the first. matrix converter 1, where they are converted into a luminance signal and Jud and color difference signals U () and Ufe-Y) j "Then the color difference signal U (iy) from the second output of the first matrix converter 1 is fed to the first low-pass filter 5, where the width is limited its spectrum is up to 1.5 kHz. From the first filter 5 low-pass narrowband color difference signal UjR-r)

arrives at the first input of the first balanced modulator 7, the second input of which receives the signal of the frequency carrier from the generator 10 of the carrier. In the first balanced modulator 7, the balance of the subcarrier signal is balanced by the signal U (RY) A From the third output of the first matrix converter 1, the color difference signal 1ЧV-y) l enters the second low-pass filter 6, where it is limited by spectrum to 1, 5 MHz. From the output of the second filter of 6 low frequencies, a narrowband color signal is an azno signal and (V1L is fed to the first input of the second balanced modulator 8, the second input of which receives a signal, the color subcarrier frequency from the output of the phase-shifting element 11, where 90 of the phase of the subcarrier signal coming from the subcarrier generator 10. In the second balanced modulator B, a balanced modulation of the signal of the subcarrier frequency shifted by 90 phase occurs with the color difference signal ll (3) j

 From the outputs

The first 7 and second 8 balanced modulators of the balanced modulated subcarrier signals are fed to the respective inputs of the second adder 9, where they are added together and form a quadrature modulated oscillation.

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The color-separated video signals received from the right television camera, corrected by gamma correctors, are fed to the second matrix converter 2. In the second matrix converter 2, the flat video signal of the right frame of the stereo pair Uyj, is formed. This signal is fed to the third low-pass filter 12, where its spectrum is limited to 1.5 MHz. From the third low-pass filter output 12, the narrow-band luminous signal Uyn is fed to the inverter 13, which inverts the video signal UYH From the inverter's 13 output, the negative compressed narrow-band signal UYH arrives at the first input of the amplitude modulator 14, the second input of which receives the subcarrier frequency signal from the subcarrier generator 10; In the amplitude modulator 14, amplitude modulation of the signal occurs The operating frequency of the signal Um. With ampli

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The amplitude modulated signal of the subcarrier frequency is fed to the second delay element 15, which provides the time agreement of the signals. The subcarrier frequency signal, amplitude modulated by the signal Uy, from the output of the second delay element 15 is fed to the second input of the switch 16, to the first input of which a signal is sent to the subcarrier frequency, the quadrature modulated color difference signals and (y-y) l (the switch 16 operates from switching pulses with a horizontal frequency. It commutes line by line the subcarrier frequency signal, quadrature modulated by the color difference signals U {R-YJA and (c) l the subcarrier frequency signal is amplitude-modulated by a pulsed signal Pu the output of the switch 16, these subcarrier signals arrive at a nonlinear element 17, which serves to create an unmodulated signal of the subcarrier frequency — pedestal, with a level of Uf, 0.1 A. that is necessary to ensure the normal operation of synchronous detectors on the receiving side at low levels subcarrier signal.

From the first output of the first matrix converter 1, the received luminance signal of the left frame of the stereo pair Uyj enters the first element

3 delay, which coordinates the signals of the right and left frames of the stereo pair in time. The first input of the first adder 4 receives the video signal Jud from the output of the first element 3 of the delay, and the second input receives the signal of the subcarrier frequency, quadrature modulated by color-difference narrowband signals) and U (a-y) x

in the nth row and amplitude-modulated narrowband negative compressed luminous signal Uy, in (n + 1) -th row. In the first adder

4the addition of these signals occurs. In summary, the output of the first adder 4 is the total video signal of the stereo color image.

The resulting full video signal, IL, formed on the transmitting side, is transmitted over the communication channel. If phase distortions appear in the communication channel, they also act on the reference subcarrier frequency signal with the same magnitude

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the tautly modulated signal ui ", and the subcarrier frequency signal, quadrature modulated by the color difference signals Uy) and b (.v. due to this, the phase shift of these signals relative to each other does not change, therefore with further synchronous detection of the color difference No color distortion signals occur.

The video signal U., from the communication channel is fed in parallel to the input of the rejector filter 30 and to the input of the band-pass filter 18. The band-pass filter 18. only passes the modulated subcarrier spectrum. After the band-pass filter 18, the modulated signal of the subcarrier frequency is fed in parallel to the second input of the switch 21 and to the input of the second delay element 22, where it is delayed by the duration of one line. The first amplifier 20 serves to compensate for the attenuation of the modulated subcarrier frequency that occurred in the second delay element 22. It is necessary that the span of the delayed and forward signals of the modulated subcarrier frequency at both inputs of the switch 21 is the same, which in turn is necessary for the subsequent correct amplitude detection of the signal Uy in the amplitude detector 28.

; In switch 21, the forward and delayed signals of the subcarrier frequency are switched, and the forward signal is switched line by line

40 to the third delay element 31 and to the second amplifier 23, and the delayed signal is switched line by line, but, conversely, to the second amplifier 23 and the third delay element 31. Switch 45 is switched by using horizontal line pulses, and the switch is phased in such a way that during each line, the second amplifier 23 posts 50 a reference signal of the subcarrier frequency amplitude-modulated by the signal Uy, and the third delay element 31 receives a signal of the frequency carrier, quadrature modulated 55 ignalami U (R.y) j and u (8-y) q third delay element 31 is a delay subcarrier frequency signal, the quadrature modulated color difference signal .5. .14

  And U (3.yj, for the time by which the signal of the reference subcarrier frequency amplitude-modulated by the signal Uy is delayed in the second amplifier 23; In the second amplifier 23, the signal of the reference subcarrier frequency amplified by the signal Uy is amplified by ten times This is done so that the synchronous detectors 24 and 26 would only respond to the amplitude of the subcarrier frequency quadrature modulated color difference signals (-vU (Bv) and not react to the amplitude of the reference subcarrier frequency amplitude-modulated signal ohm Uyp. In the first synchronous detector 24 the detection and selection of the color difference signal .yy takes place, which then goes to the second input of the matrix converter 27. The first input of the second synchronous detector 26 receives a subcarrier frequency signal which is square-modulated signals UfR.y; and Ufg.y, and the second input receives the reference signal of the subcarrier frequency amplified ten times by the second amplifier 23, amplitude modulated by the signal Uy, but shifted out of phase by 90 phase-shifting elements 25 by 90 In synchronous detector 26, synchronous detection and separation of the color difference signal U (which is then fed to the third input of the matrix converter 27 takes place,

From the output of the second amplifier 23, the reference subcarrier frequency signal, amplitude-modulated by the signal UY, is fed to the input of the amplitude detector 28, where the narrow-band negative compressed signal Uy repeats for two adjacent rows. Further, this signal arrives at the input of the inverter 29, where the inversion and amplification of the luminance signal of the right stereopair frame, t, e, occurs. Inverter 29 restores the original signal Uy,.

The full video signal CD in parallel with the bandpass filter 18 is fed to the input of the notch filter 30, which is tuned to the subcarrier frequency and cuts it out of the spectrum of the wideband

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the left-focal length video signal of the left frame of the stereo-Uy to reduce the visibility of interference from the subcarrier frequency on the screen of the television receiver. Next, from the output of the notch filter 30, the capacitive video signal Uy is fed to the input of the first delay element 19, the delay time of which is equal to the delay time that the color difference signals tR-YU undergo. The signal And goes to the first input of the matrix converter 27, where the signal Uy, U (Ry ) and U (B-YU U-split signals of the left frame of the stereo pair, corrected by Kbbl (T then color-separated video signals of the left frame of the stereo pair and the speaker signal of the right frame of the stereo pair are converted into a visible image object.

Claims (1)

Invention Formula A stereo television signal transmission and reception device containing, on the transmitting side, the first matrix converter, the first delay element and the first adder, the second matrix converter, the first low pass filter and the first balanced modulator, the subcarrier generator, which are serially connected; connected to the second input of the first balanced modulator and through the phase-shifting element to the second input of the second balanced modulator, and on the receiving side - tally filter and the first delay element, the series-connected band-pass filter and the second delay element, the switch, the first and second synchronous detectors, the phase-shifting element and the matrix converter, and the input of the notch filter is connected to the input of the band-pass filter, characterized in that the goal of ensuring full compatibility with the NIIR color television system and improving the noise immunity of the device’s operation in the event of a phase distortion in the communication channel on the transmitting side f introduced a second adder, the third lowpass filter, an inverter, an amplitude modulator, the second delay element and nonlinear element, wherein the third. 714 low pass filter, inverter, amplitude modulator, second delay element, switch and nonlinear element are connected in series between the output of the second matrix converter and the second input of the first adder, the second and third outputs of the first matrix converter are connected to the inputs of the first and second low-pass filters, respectively the first and second balanced modulators are connected respectively to the first and second inputs of the second adder, the output of which is connected to the second input of the switch, l yuschy input of which is input to the switching signal line frequency, subcarrier oscillator output is connected to the second input of the amplitude modulator, the first and second amplifiers are introduced on the reception side, the third element of o one five 0 37-8 holders, amplitude detector and inverter, the first, second and third inputs of the matrix converter are connected to the outputs of the first delay element, the first and second synchronous detectors, respectively, the first amplifier is connected between the output of the second delay element and the first input of the switch, the second input of which is connected to the output bandwidth filter, and the first and second outputs are connected to the inputs of the third delay element and the second amplifier, respectively, whose output is connected to the input of the amplitude detector, to the first the input of the first synchronous detector and the input of the phase-shifting element, the output of the third delay element is connected to the second inputs of the first and second synchronous detectors, and the output of the amplitude detector is connected to the input of the inverter. 1 Compiled by A.Prozorovsky Editor G. Volkov-Tehred L. Serdyukova Proofreader E. Lonchakova Order 6978/56 Circulation 660 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5 Production and printing company, Uzhgorod, st. Project, 4 Subscription