RU1775873C - Tv signal transmission-reception system - Google Patents

Abstract

The invention relates to color television broadcasting and applied television and can be used to increase the clarity of television images in television sets and video control devices without expanding the spectrum of the signal transmitted to the receiving devices. An object of the invention is to reduce the bandwidth of a television signal. The system comprises a filter unit 1, a transmitting tube 2, an encoder 3, a spectrum compression unit 4, a decoder 5, and a spectrum recovery unit 6. A method for transmitting a video signal with a width of 9 MHz allows the transmission of such a video signal over an existing network of radio transmitters and long-distance communication lines, providing an increase the image clarity in the receiver is 1.5 times. Zil.

Description

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The invention relates to color television broadcasting and applied television, and can be used to improve the quality (clarity) of a television image in televisions and video monitoring devices (video monitors) without expanding the spectrum of the signal transmitted to the receiving devices.

The closest in technical essence is a color television signal conditioning apparatus comprising, on the transmitting side, a series of light filters, a transmitting television tube and an encoder, and a decoder on the receiving side.

This device has a significant drawback - low horizontal image clarity, since the components of the spectrum of the luminance video signal with frequencies above 6 MHz are not transmitted to the receiver.

An object of the invention is to reduce the bandwidth of a television signal.

In order to achieve this goal, a vehicle transmission and reception system, comprising, on the transmitting side, a block of optical filters, a transmitting television tube and an encoder, and on the receiving side, a decoder, a spectrum compression unit, the input of which is connected to the encoder output, is inserted on the transmitting stdron and the output is the output of the transmitting side, and a spectrum reconstruction unit is introduced at the receiving side, the input of which is the input of the receiving side, and the output is connected to the input of the decoder, while the spectrum compression unit holding in series the first bandpass filter, the input of which is the input of the spectrum compaction unit, the first amplitude modulator, the second input of which is connected to the output of the first oscillator of the subcarrier frequency, the first low-pass filter and the first adder, the second input of which is connected to the input of the compaction unit, spectrum through the second low-pass filter, and the output of the first adder is the output of the spectrum compression unit, and the spectrum recovery unit contains a second bandpass connected in series the first filter, the input of which is the input of the spectrum recovery unit, the first comb filter, the second amplitude modulator, the second input of which is connected to the output of the second oscillator of the subcarrier frequency, the third bandpass filter and the second adder, the output of which is the output of the spectrum recovery unit and sequentially connected by a second comb filter, the input of which is connected to the output of the second band-pass filter and a third adder, the second input of which is connected to the input of the second band-pass filter

through a notch filter, and the output of the third adder is connected to the second input of the second adder.

In FIG. 1 shows a system for transmitting and receiving a TC signal, where 1 is a block of light filters, 2 is a transmitting tube, 3 is an encoder, 4 is a spectrum compression unit, 5 is a decoder, 6 is a spectrum reconstruction unit; in FIG. 2 is a diagram of a spectrum compression unit; in FIG. 3 - block diagram is presented

5 spectrum reconstruction.

The device operates as follows. In the filter block, the incoming luminous flux from the transmitted scene is divided into three luminous fluxes - red, green and blue, which focus on the photosensitive surfaces of the three PT light emitting electron tubes (instead of tubes, charge-coupled devices or other types of tubes can be used5 Py converters of light to signal). At the outputs of these tubes, respectively, video signals ER, Eg, Ev are supplied to the inputs of the encoder, where they undergo the necessary processing, including receiving

0 of them are a brightness signal with a spectral width of 9 MHz (for SECAM or PAL systems with 625 lines) and two color-difference signals Е кгу и. Color difference signals modulate color fluctuations

5 subcarrier, forming an 11c color signal, which is added to the luminance signal and at the output of the encoder, a full color television signal is created, which differs from the standard signal only

0 in that the luminance signal has a spectrum width of 9 MHz instead of 6 MHz. This signal arrives at the input of the video signal spectrum compaction unit — BU, in which the components of its spectrum are extracted from the luminance signal in the frequency range from b to 9 MHz, which modulate in amplitude the carrier oscillation with a frequency of 9.5 MHz and the lower side a modulated oscillation band with a spectrum of 0.5-3.5 MHz is added to the BC to a luminance signal having a spectrum of 6 MHz width (after removing the components of 6.0-9.0 MHz). Thus, at the output of the control unit, the spectrum of the full signal consists of the spectrum of the luminance signal 0-6.0 MHz, an additional 5th spectrum of the luminance signal 0.5-3.5 MHz in the form of a lower sideband of modulated oscillations and a color signal Уц with a spectrum of 3.5 6.0 MHz This signal is transmitted to the receiver via a standard communication channel with a 0-6.0 MHz video band. AT

from the output of the video detector, the signal is fed to the input of the BV spectrum reconstruction unit, in which an additional spectrum of 0.5-3.5 MHz is allocated using the band and comb filters and, using the 9.5 MHz carrier wave, this additional spectrum is transferred as a lower side bands of amplitude-modulated oscillation in the frequency range 6.0-9.0 MHz and in this form is added to the brightness signal, as a result of which a brightness signal with a spectrum width of 0-0.9 MHz and a standard color signal Uz are generated at the output of the BV.

The sum of these signals is supplied to a decoder, the output of which produces primary color signals E g, E d, E b with a spectral width of 0-0.9 MHz, modulating the electron beams of a color picture tube.

In FIG. 2, in the spectrum compression unit, the input of the first bandpass filter receives from the encoder output a full color television signal in which the luminance signal has a spectrum of 0-9 MHz. From the output of this filter, a signal with a spectrum of 6-9 MHz is fed to the first amplitude modulator, to which a vibrational subcarrier with a frequency of 9.5 MHz is supplied from the first oscillator subcarrier. equal to the odd harmonic of half the line frequency (e.g. 1215th or 1217th). From the output of the first amplitude modulator, the signal enters the first low-pass filter, which passes the lower side frequency band 0.5-3.5 MHz, which is then fed to the first input of the first adder. From the input of the first bandpass filter, the full video signal is supplied to the second low-pass filter, from the output of which a video signal with a spectrum of 0-6 MHz is supplied to the second input of the first adder, at the output of which the video signal has a spectrum of 0-6 MHz. This spectrum consists of a spectrum of a luminance signal of 0–6 MHz, in which the full spectrum of a color signal is 3.5–6 MHz and an additional spectrum of a luminance signal in the frequency range 0.5–3.5 MHz.

From the output of the first adder of the spectrum compression unit, the full video signal is fed to the receiver at the input of the second band-pass filter of the spectrum recovery unit (Fig. 3). From the output of this band-pass filter, a signal with a spectrum of 0.5-3.5 MHz, consisting of the inverse spectrum of the brightness signal (lower sideband 0.5-3.5 MHz) and the lower part of the spectrum of 0.5-3.5 MHz of the brightness signal, arrives at the first comb filter, in which this lower part of the spectrum of the luminance signal of 0.5-3.5 MHz is removed from this signal.

From the output of the first comb filter, the inverted spectrum of the luminance signal of 0.5-3.5 MHz is supplied to the second amplitude modulator, to which from the second generator

subcarrier is supplied with a carrier oscillation with the same frequency as the first subcarrier generator in the spectrum compaction unit generates. From the output of the second amplitude modulator, the signal is fed to

a third band-pass filter, at the output of which a lower side frequency band with a spectrum of 6-9 MHz is supplied to the first input of the second adder. From the input of the first comb filter, the signal is also fed to the input of the second comb filter, the output of which forms the lower part of the spectrum of the luminance signal 0.5-3.5 MHz, fed to the first input of the third adder, to the second input of this

The adder provides a signal from the output of the notch filter, which removes part of the 0.5-3.5 MHz spectrum from the full signal with a 0-6 MHz spectrum. coming from the spectrum compaction unit.

From the output of the third adder, a brightness signal with a spectrum of 0-6 MHz, which includes the spectrum of a color signal of 3.5-6 MHz, is fed to the second input of the second adder, the output of which is the spectrum of the brightness signal

has a width of 0-9 MHz and contains a color signal. This signal is then fed to a decoder (SECAM, PAL, T C), the output of which produces primary color signals E R, E d, E in with a spectrum width of 0-9 MHz

each.

The proposed method for transmitting a spectrum of a video signal with a width of 9 MHz allows the transmission of such a video signal over an existing network of radio transmitters and long-distance communication lines, providing an increase in the clarity of the image in the receiver by 1.5 times in comparison with the existing standard television system by 625 lines and 2 times in systems

MASINDTU.

Claims (1)

SUMMARY OF THE INVENTION A system for transmitting and receiving a television signal, comprising, on a transmitting side, a series of light filters, a transmitting television tube and an encoder, and a decoder on the receiving side, characterized in that a compression unit is introduced on the transmitting side to reduce the band of the television signal spectrum, the input of which is connected to the output of the encoder, and the output is the t-output of the transmitting side, and a spectrum reconstruction unit, the input of which is the input, is introduced at the receiving side the input side of the receiving side, and the output is connected to the input of the decoder, while the spectrum compaction unit contains a first-pass filter in series, the input of which is the input of the spectrum compaction unit, a first amplitude modulator, the second input of which is connected to the output of the first oscillator of the subcarrier frequency, the first a low-pass filter and a first adder, the second input of which is connected to the input of the spectrum compaction unit through a second low-pass filter, and the output of the first adder is the output of the compaction unit pektra and spectrum reconstructing unit comprises a second bandpass sequentially soedinenyye 0 5 a filter, the input of which is the input of the spectrum recovery unit, a first comb filter, a second amplitude modulator, the second input of which is connected to the output of the second subcarrier oscillation generator, a third bandpass filter and a second adder, the output of which is the output of the spectrum recovery unit, and sequentially connected by a second comb filter, the input of which is connected to the output of the second band-pass filter, and a third adder, the second input of which is connected to the input of the second band-pass filter through a filter, and the output of the third adder is connected to the second input of the second adder. Fig.Z