SU1525733A1 - Device for multichannel magnetic recording and playback of signals - Google Patents

Abstract

The invention relates to a magnetic recording technique, in particular, to devices for correcting temporal distortions arising in the process of recording and reproducing, and can be used in devices for accurate magnetic recording of analog signals. The aim of the invention is to increase the fidelity of reproduction. The recording channel is formed by the 3.5 recording heads of information and reference signals coupled to the carrier 4. The playback channel consists of heads 7, amplifier 9, delay line 11, low-pass filters 12.16, analog-to-digital and digital-to-analog converters 13,15, voltage controlled oscillators 19, 30, adders, phase detectors, additional low-pass filters. 1 il.

Description

The invention relates to a magnetic recording technique, in particular, to devices for correcting temporal distortions that occur during recording and reproduction, and can be used in devices for accurate magnetic recording of analog signals.

The purpose of the invention is to increase the fidelity of reproduction.

The drawing shows a block diagram of the device.

The device contains in the recording channel input buses of information signals connected via amplifiers 2 recordings to heads 3 recording information signals on carrier 4, heads 5 recording reference signal connected to the output of generator 6 reference signal, and in the playback channel - playback rollers 7, 8 and reference signals The heads 7 are connected to the inputs of the amplifiers 9 for reproducing information signals, the outputs of which in each channel group are connected to the output bus 10 via serially connected lines 11 delays the first filter 12 is a lowpass analog-digital converter 13 (ADC) unit 14 memory 15 digital to analog converter (DAC) and a second lowpass filter 16. The input of block 14 is connected to the output of stable frequency generator 7 common to all channel groups, and the third input of memory block 14 is connected to the second input of ADC 13 and connected to the output of amplifier 18 to play the first channel through a series-connected first generator 19, controlled by the third lowpass filter 20, the adder 21, the fourth lowpass filter 22 and the first phase detector 23, the second input of which is connected to the output of the second channel playback amplifier 24 through the phase shifter 25, and the second input of the adder 21 is connected to Exit amplifier 24 via a series connection of a fifth filter 26, a lowpass second phase detector 27 and a first pulse shaper 28. The second input of the detector 27 is connected to the second input of the adder 21 through a series-connected second pulse shaper 29 and a second generator 30 controlled by voltage, and a third of the adder's input is connected to the output ne

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generator 19 through a sequence; The sixth low-pass filter 31 and the third phase detector 32, the second input connected to the output of the stable frequency generator, the first input of the detector 23 of the second and subsequent channel groups are connected to the output of the playback amplifier 24 of the previous channel group.

The device works as follows.

The magnetic signals 4 simultaneously record information signals coming through the amplifiers 2 to the heads 3, and the reference signal coming to the heads 5 from the output of the generator 6. It is advisable to use a harmonic signal as the reference signal. After reproducing in each group of channels, the information signal is read by head 7, amplified by amplifier 9, delayed by a delay line 11 that decouples the passage of signals to the inputs of the ADC 13, and through the first filter 12 is fed to the input of the ADC 13. After conversion with the sampling frequency fgW3f, where fg is the upper frequency in the spectrum of the information signal, the code is recorded in memory block 14 with the same frequency. Since the control signal of the A / D converter 13 and the recording in memory block 14 is formed from reference signals subject to the same temporal distortion as the information signal, and the match from block 14 is realized with a stable frequency Formed by generator 17 and equal to the average value frequency f, after converting the code words read from block 14 to analog voltage in the DAC 15 and filtering. On the output bus 10, an information signal is generated with a digital filter 16 with much less time distortion than in the reproduced head Box 7 of the information signal.

The ADC control signal is generated from the reference signals of the first and second reference channels as follows.

The reference signal reproduced by the heads 8 is fed to the input of the first phase detector 23 through the amplifier 18, and to its second input - through the amplifier 24 and the phase shifter 25, as a result of which its output produces a signal proportional to the inter-band.

channel temporal distortion between the first and second channels of the reference signal. The phase shifter shifts the onojpHoro phase of the signal by 90 relative to the phase of the signal from the output of amplifier 18. A signal proportional to the intrachannel time distortion in the second channel of the reference signal is generated by a phase-locked loop (PLL) consisting of a 28-pulse generator, a phase detector 27, p of the filter 26, the second generator 30, control

to increase the accuracy of time distortion correction in each channel and the fidelity of reproduction.

Claims (1)

Invention Formula A device for multichannel magnetic recording and playback of signals containing input channels of information signals in a recording channel, each of which is connected through a recording amplifier to an information signal recording head, a reference signal generator, and heads 20 voltage, and the second form of the 5 recording of the reference signal, and in each of the rotator 29 pulses. In the adder, 21, a signal is formed that is proportional to the time distortion caused by the longitudinal vibrations of the carrier and contains significantly weakened components proportional to the interchannel time distortion between the reference and information channels located between them. The output phase of the first detector 23 and the weight with which the voltages are summed up in the adder 21 are selected as a group of reproduction channels — information and reference signal reproduction heads connected to the corresponding reproduction amplifiers, a delay line connected in series to an analog-digital converter and a digital-to-analog converter, connected via an output bus to the bus, a stable frequency generator, characterized in that, in order to improve fidelity, to the channel the recordings introduced additional reference signal recording heads, connected to the output of the reference signal generator and to the recording heads of the reference signals, and the first low-pass filter was inserted into each group of playback channels, the output connected to the analog-digital converter input, and the input through the delay line the input of the information signal reproduction amplifier, a series-connected phase shifter, a first phase detector, a second low pass filter, an adder, a third low pass filter, and a generator, controlled obliquely to weaken these components. The third filter 20 filters out the components that are multiples of the frequency of the reference signal present in the signal spectrum at the output of the fifth filter 26. The output signal of the third filter 20 controls the frequency of the first generator 19, which forms the sampling frequency f. In order for the frequency of the first generator 19 to drift, the block 14 does not overflow or zero, a third phase detector is introduced — 32 and the sixth low-pass filter 31, the cut-off frequency of which is selected below the lower frequency of the device-corrected temporal distortion. When the average value of fg deviates from the output of the third detector 32, a control voltage is generated, which arrives at the third input of the adder 21 and controls the frequency of the first generator 19 so that the average value of fg becomes equal to Recording a reference signal on two tracks on either side of the track recording information signal allows you to generate a control signal ADC, containing components proportional to the intrachannel temporal distortion of the information signal channel, and therefore 0 5 records of the reference signal, and in each 0 a group of playback channels — playback heads of information and reference signals, connected to the corresponding playback amplifiers, a delay line, an A / D converter connected in series, a memory block and a D / A converter, an input connected to the output bus, a stable frequency generator, characterized by , - in order to improve fidelity of reproduction, additional recording heads of reference signals are connected to the output of the reference signal generator; and to the reference signal recording heads, and in each group of playback channels, the first low-pass filter, the output connected to the input of the analog-digital converter, and the input through the delay line - to the input of the playback amplifier of the information signal, serially connected phase shifter, the first phase detector , second low pass filter, adder, third low pass filter and voltage controlled oscillator, the output of which is connected to the second inputs of the analog-digital converter and the block memory serially connected first pulse generator, a second phase 0 a detector and a fourth low-pass filter connected by an output to the second input of the adder directly and through a second voltage controlled generator, and a second pulse shaper to the second input of the second phase detector, the third phase detector, the first input of which is connected to the output of the first generator, voltage controlled. five 0 five 715257338  low pass filter, on-input of the first phase detector, went between the output of the third phase output of the second amplifier of the reference signal of the vector and the third input of the totalizer connected to the inputs of the phase distributor, an additional head reproduced and the first pulse shaper, in the day of the reference signal and in addition with the second input of the phase money The tilt reproduction amplifier of the next group of channels of the salvo signal, with the production head, the generator output of the recording of the information signal of the reference frequency, is connected to the third between the recording heads of the reference | Q input of the memory unit and with the second signal, the output of the first amplifier of the third phase detector and The signal signal is connected to the second digital-to-analog converter.