SU1270786A1 - Device for correcting time distortions - Google Patents

Abstract

The invention relates to magnetic recording and allows improving the accuracy of the correction of the time scale of the reproduced signal. The pulse control input signal to the buffer store 5 is formed from the reference signal by selecting it with filter 8 and amplifying with an adjustable amplifier 10, re-allocating with a band filter 11 and multiplying the frequency in the multiplier 17. Frequency equalizer 14 allows changing the control law of the amplifier 10 and filter 11 dependence on the spectrum of temporal distortion. The voltage of the frequency equalizer 14 is subtracted from the voltage of the source 13 of the reference voltage in the subtractor 12; Line 9 of the delay and the element 26 of the delay are used to equalize (L of the temporal position of the signals. 1 Il. N9 O CX) 05

Description

The invention relates to techniques for magnetic recording, and in particular to devices for reproducing signals with time-scale correction.

The purpose of the invention ~ improving the accuracy of the correction of the time scale of the reproduced signal.

The drawing shows a structural diagram of the device.

The device comprises a unit 1 for reproducing information and reference signals recorded on one track, a reproducer 2 of the reproduced signal, a shaper 3 of the control signals, a converter 4 analog-code, a buffer storage 5, a converter 6 code-analog, low-pass filter 7.

The driver signal generator 3 comprises a band-pass filter 8, a delay line 9, a controlled amplifier 10, a band-pass filter 11, a voltage subtractor 12, a reference voltage source 13, a frequency corrector 14, a low-pass filter 15, a quadratic detector 16, a frequency multiplier 17, an AND element 18, a voltage comparator 19, a reference voltage source 20, an OR element 21, an AND element 22, a clock pulse generator 22 and an inverter 24.

The reproduced signal generator 2 comprises a filter 25 and a delay element 26.

The device operates as follows.

The information and reference signals reproduced by the reproducing unit 1 are separated by filters 25 and 8, respectively. The information signal is converted to a digital code in the converter. 4. Each code word is written to the buffer storage 5 synchronously with the formation of the code and the reference signal, and reading from the buffer storage 5 is performed with the clock frequency of the generator 23. After the converter 6 and filter 7, the analog signal with the corrected time scale is fed to the output bus of the device.

The pulse input control signal to the buffer storage device 5 is formed from the reference signal by isolating it with a filter 8 and amplifying it with an adjustable amplifier 10, re-isolating it with a band-pass filter 11 and multiplying the frequency in the multiplier 17.

The gain of the adjustable 'amplifier 10 and the passband of the filter 11 vary in proportion to the depth of spurious amplitude modulation, and the greater the depth of spurious amplitude modulation, the greater the gain and the narrower the passband of amplifier 10 and filter 11, respectively. The law of variation in spurious amplitude modulation is formed by isolating the envelope in a quadratic detector 16 and a low-pass filter 15. The frequency corrector 14 allows you to change the control law of the amplifier 10 and the filter 11 depending on the nature of the spectrum of temporary distortions. Voltage corrector voltage. 14 is subtracted from the voltage of the source 13 in the subtractor 12. In the absence of spurious amplitude modulation, the voltage at the output of the subtractor 12 is set to zero. With a shallow depth of parasitic amplitude modulation, a voltage is generated at the output of the comparator 19, which allows signals to pass through the And 18 element and the OR 21 element to the input of the converter 6. At the same time, a potential is formed at the output of the inverter 24, which prohibits the passage of pulses from the generator 23 to the second input of the converter 6. When a large depth of spurious modulation allows the passage of pulses from the output of the generator 23.

The delay line 9 and the delay element 26 serve to align the temporal position of the signals.

Claims (2)

The invention relates to a magnetic recording technique, in particular, to the ycTpofits of signal reproduction with a time scale correction. The purpose of the invention is to improve the accuracy of the correction of the reproduced signal. The drawing shows a block diagram of the device. The device contains a unit 1 for reproducing informational and reference signals recorded on a single track, shaper 2 of the reproduced signal, shaper 3 of directing signals J analog-to-code converter 4, buffer storage 5, analog-to-code converter 6, low-pass filter 7. Shaper 3 control signals contains a band-pass filter 8; 9 delays S spravh e-shy amplifier 10, band-pass filter II, subtractor 12 voltages, reference voltage source 13, frequency corrector 14, low-pass filter 15, quadratic detector 16, frequency multiplier 17, And 8s element comparator 19 voltage, source 20 of the reference voltage, the element .OR 21 element AND 22, the oscillator 22 of clock pulses and the inverter 24. The generator 2 of the reproduced signal contains a filter 25 and a delay element 26. The device works as follows. The playback information and the support signals reproduced by playback unit 1 are separated by filters 25 and 8, respectively. The information signal is converted into a digital code in the converter .4, Each code word is written to the buffer storage 5 synchronously with the formation of the code and the reference signal, and the reading from the buffer storage 5 is performed at the clock frequency of the generator 23. After the converter 6 and filter 7, the analog signal with the time-corrected signal is fed to the output bus of the device by the Pb pulse input control signal, is formed into the buffer storage 5 from the reference signal by selecting it with feed 8 and amplifying amplifying amplifier 10, re-allocating the bandpass filter 11 and multiplying the frequency in the multiplier 17 1 62 The gain of the adjustable amplifier 10 and the passband of the filter 11 change in proportion to the depth of the parasitic amplitude modulation, and the greater the depth of the parasitic amplitude modulation, the greater the gain and the narrower the bandwidth of amplifier 10 and filter 11, respectively. The law of variation of the parasitic amplitude modulation is formed by highlighting the envelope in the quadratic detector 16 and low pass filter 15, Frequency Corrector 14 allows you to change the control law of amplifier 10 and filter 11, depending on the nature of the temporal distortion spectrum. Frequency corrector voltage. 14 is subtracted from the voltage of source 13 in the subtractor. 2. In the absence of parasitic amplitude modulation, the voltage at the output of the subtractor 12 is set to zero. When the parasitic amplitude modulation depth is shallow, a voltage is generated at the output of the comparator 19, allowing signals to pass through AND 18 and the OR element 21 to the input of converter 6. At the same time, a potential is formed at the output of inverter 24 that prevents the passage of pulses from generator 23 to the second input of converter 6 When a parasitic module ufiH is deep enough, the passage of pulses from the output of the generator 23 is permitted. Line 9 delay and delay element 26 serve to equalize the temporal position of the signals. Apparatus of the Invention A device for correcting temporal distortions, comprising a driver of control signals, a clock pulse generator and a driver of the reproduced signals sequentially connected to the reproduction head, a converter analog-code converter, a buffer accumulator and a code analog converter, with output clock generator of the clock pulse connected to output buffer control bus, characterized in that, in order to improve the accuracy of the correction of the time scale of the reproduced signal la shaper control sig31 The cable is made in the form of a delay line controlled by an amplifier, the first and second AND elements, the OR element whose inputs are connected to the outputs of the AND elements, and the output to the control bus of the input of the buffer accumulator, the first and second reference voltage sources, the comparator, the first input connected to the first source of the reference voltage, and direct and inverse. The outputs are connected respectively to the first input of the first element And-and to the first input of the second element And, the second input of which is connected to the clock pulse generator in, first bandpass filter, whose output is connected to a multiplier via 707864 the second input of the first element And the second bandpass filter and successively connected to the output of the second bandpass filter of the quadratic detector, low pass filter and frequency corrector connected to the first input of the subtractor, while the output of the second source of the reference voltage is connected to the second input of the subtractor, the output the second band-pass filter through a delay line and a controlled amplifier connected to the input of the first band-pass filter, the control input of which 15 is connected to the control input of the controllable amplifier and the output of the subtractor, and the second input of the comparator is connected to the output of the low-pass filter.