SU1288939A1 - Device for processing signals in magnetic recording and playback - Google Patents

Abstract

The invention relates to radio engineering and provides an increase in the accuracy of information reproduction by reducing the interference from defects in magnetic media. The device contains a recording channel 1 consisting of a unit for stretching a signal over time, a frequency converter 3, an amplifier 4 and a block of 5 magnetic heads. and a playback channel 6 consisting of a block of 7 magnetic heads, a frequency demodulator 8, a delay line (LZ) 9 per line, a detector of 10 fallouts, a block AND compression of the signal over time, a block 12 of combining, an interpolation unit 13 and adders 14 and 15. The combination unit 12 comprises a clock pulse generator 16, a control pulse generation block 17, a LZ 18 per line, a control block 19, a switch 20, a fall out signal extraction unit 21 and a LZ 22 with taps. Interpolation unit 13 comprises level storage units 23,24, voltage subtraction unit 25 and replacement signal generation units 26-28. In order to increase the accuracy of information reproduction, a combination block 12, an interpolation block 13, and adders 14 and 15 are entered into the reproduction channel. S sla cx 00 (SAE SO (Rig.1

Description

i

The invention relates to radio engineering and can be used in analog and digital recording and reproducing signals to improve the accuracy of the reproduced information.

The purpose of the invention is to improve the accuracy of information reproduction by reducing interference from magnetic carrier defects.

FIG. Figure 1 shows a structural electrical circuit of a signal processing device for magnetic recording and reproduction; in fig. 2 - epures, for aus, the device operation.

A signal processing device for a magma signal, for example, in amplitude, as a result of which it is possible to separate them in block 2 of the fallout signal extraction unit. From the adder 14, the signal through the line 9 delay per line enters the combining unit 12, where it is additionally delayed (in block 22), and after the fallout signal is extracted from it (block 21), is fed to the 4th input of the second adder 15 (FIG 2H), on the 1st, 2nd and 3rd inputs of which, in the presence of precipitations, substitution signals are also given (Fig. 2, p, p.). In the adder 15, all the replacement signals are summed to form a complete replacement signal (Fig. 2c), which is added to the reproduced signal, recorded recording and playback contains

channel 1 of the recording, consisting of a sequence of t5 by the supervising unit 12 combining (Fig. 2n). Ultimately connected to the block 2 stretching the signal received in the adder 15 (Fig. 2t)

the signal in time, the frequency transducer through the I 1 compression unit of the signal during the driver 3, the amplifier 4 and the magnet 5 unit is fed to the output of the b channel of the playback heads, and the input of the stretch reduction unit 2. In the absence of fallout signals

signaling in time is the substitution by interpolation unit 13 of not vykanal 1 record, the output of which is 20, and the signal from block 12 is output of block 5 of magnetic heads, passing through the second adder 15 through and playback channel 6, consisting of block 7 magnetic heads, frequency demodulator 8, first line 9 delay per line, detector 10 fallouts, block 11 25 compressing the signal in time, block 12 combining, block 13 interpolation and the first 14 and second 15 adders.

The combining unit 12 comprises series-connected generator 16 tacto-bits without changes.

The registration unit 12 operates as follows.

Two signals arrive at the control pulse generation unit 17: at the second input - a fallout signal from the detector of 10 depositions (Fig. 2c), and at the first input - clock pulses from a generator of 16 clocks (Fig. 2a), which starts pulses, block 17, the output is controlled with the beginning of the line by the signal, the positating pulses, the delay line 18 per line, the control unit 19, the switch 20, the fallout signal extraction unit 21 and the delay line 22 with taps.

The interpolation block 13 contains the first

from the frequency demodulator 8, and outputs for the line an integer number of pulses .N, following with an interval. DT is selected from the condition MI11 / 2, where 1min is the minimum duration of depositions. AT

23 and a second 24 level memory storing unit 35 of a control pulse generation unit n, a voltage subtraction unit 25 and three auxiliary pulses, the second and the third replacement signal generation units 26-28, are transformed.

The signal processing device for magnetic recording and playback works as follows.

When recording, the input signal is fed to the input of the signal stretching unit 2 over time and after the frequency converter 3, through the amplifier 4, is fed to the block 5, mag40

ca: from the leading edge of the fallout signal and the first clock pulse following it - pulse I (Fig. 2d), from the falling edge of the fallout signal and the first clock pulse following it - pulse II (Fig. 2d), the falling edges of the auxiliary pulses 1 and II a pulse III is formed with a duration of ta equal to an integer n of DT intervals. t, e

filament heads. Reproducible FM-sig- (Fig. 2e). This impulse arrives (flg. 26) after the second block 7 is mag- nized to the (Y + th input of the switch 20. The control heads go to the frequency section.) In the initial state, the demodulator 8 and the detector 10 are output the beginning of the line and during playback, in which when the line drops out, when the signal is out of a signal, the dropout signal is outlined (Fig. 2c), the switch switches to the drop-through unit that passes through the own (. O-and interpolation to control their operation, bypassing delay delay line 22 After the end of the row, the switch 20 also switches to the initial state and, under the action of pulse III, also connects to the first input of the first adder 14.

The second input of the adder 14 from the frequency demodulator 8 is supplied with a reproducible signal (Fig. 2h) and both signals are tapped off line 22

la fold. The dropout signal (Fig. 2c) has a difference from the replay delay, delaying the signal by a time t.t.-j equal to the HI pulse duration.

for example, in amplitude, as a result of which it is possible to separate them in block 2 of the precipitation signal extraction unit. From the adder 14, the signal through the line 9 delay per line enters the combining unit 12, where it is additionally delayed (in block 22), and after the fallout signal is extracted from it (block 21), is fed to the 4th input of the second adder 15 (FIG 2H), on the 1st, 2nd and 3rd inputs of which, in the presence of precipitations, substitution signals are also given (Fig. 2, p, p.). In the adder 15, all the substitution signals are summed to form a complete substitution signal (Fig. 2c), which is added to the reproduced signal, passing through the combining unit 12 (Fig. 2n). Signal received in adder 15 (fig. 2t)

The signal from the combining unit 12 through the second adder 15 is also processed.

dit unchanged.

The registration unit 12 operates as follows.

Two signals arrive at the control pulse generation unit 17: at the second input, a dropout signal from the detector 10 drops out (Fig. 2c), and at the first input — clock pulses from the generator 16 clock pulses (Fig. 2a), which starts at the beginning of the line signal coming from the frequency demodulator 8, and gives for the line an integer number of pulses .N, following with an interval. DT is selected from the condition MI11 / 2, where 1min is the minimum duration of depositions. AT

watches tap line 22

delays, delaying the signal by a time t.t.-j equal to the pulse duration HI.

Therefore, the signal containing both the reproduced signal and the fallout signal from the switch 20 to the fallout signal extraction unit 21 is delayed by time ty, equal to the total delay time of blocks 9 and 22, i.e. ty tcTp-f-t3 . The precipitation signal extraction unit 2 separates the deposition signal and the reproduced signal, for example, by isolating the deposition signal itself and restoring the original reproduced signal (Fig. 2h) in the deposition interval. The signal of deposition selected by block 21 is fed to the second input of control block 19 (Fig. 2i). Separated from the fallout signal, the reproduced signal (Fig. 2n) from the second output of the fallout extraction block 21 is fed through the fifth output of the superposition block 12 to the fourth input of the second adder 15. The fallout selection of the fallout signal I can be ocyniecTBJieHO, for example, from the threshold element or comparator. To restore the signal to the dropout area corresponding to its original. at the output of the frequency demodulator 8 (fig. 2h), it is possible, for example, for the duration of the fallout signal (fig. 2i) to turn off the second output of block 2 (by heating, by controlling the fallout signal highlighted in block 21 by block the second output b; 1ka 21 of the precipitation signal extraction). At the same time, during the interval of fallout, the signal from block 2 of combining to the second adder 15 does not arrive and, therefore, in this area we have, as in the original signal (Fig. 2h), a zero level of the reproduced signal (Fig. 2n).

In block 17, the generation of control pulses from the first, next z., And the leading edge of pulse III, clock im.p,:; and the falling edge of pulse lil produces an auxiliary pulse IV (Fig. 2e) of duration ti (n-1) -Lt from the back front of which a pulse V of duration is produced (Fig. 2g), which from the fourth output of the combining unit 12 is fed to the fifth input of the interpolation unit 13 and through the second delay line 18 per line to the control unit 19 - impulse 2 (Fig. 2m) , the second input of which receives the fallout signal (Fig. 2i), delayed by delay lines 9 and 22 by the time ttcTp-fti and 1 allocated by the fallout signal extraction unit 21. The control block 9 of the incoming pulses forms three control pulses: the 1st, generated by the leading edge of the impulse and the falling edge of the pulse 2 (Fig. 2k); 2nd impulse 2 itself (Fig. 2m J; 3rd, formed by the falling edges of impulse 2 and impulse

0

0

five

five

fallout (fig. 2l). The control pulses are fed to the first, second, and third inputs of the interpolation unit 13 for controlling, respectively, the generating signals 26-28 for the offset signals. In the absence of a fallout signal from the detector of 10 fallouts, the reproduced signal is not subjected to a delay in the combining unit 12, control pulses are not generated and are not transmitted to the interpolation unit 13. B.LOCK 13 interpolation works as follows: P1IM image.

The first 23 and second 24 level memorization units are received: on the first inputs from the frequency demodulator 8 (Fig. 2h); on the second, a dropout signal from the detector is 10 dropouts (Fig. 2c). When a dropout signal arrives, 6.10K 23 remembers the signal-, level;: 1.1. the correlation of the following: the start of the attack: .-:;::, and the block of the 24th level U 2, corresponding to the general KOiiuy В1 1 pad (fng. 2h). Za-: e nU) iO ypoHiin Ui and Ug are applied to lirafniH voltages, which gives the difference in voltages and, respectively, to the first 26 6. iOKi produce a signal when they are (access to their second, respectively, control pulses ( f |, g. 2k, h) from block 12 joint replacement of a replacement: a block of replacement signal LJjs

. 2o) with aMiJ.iiiT) is equal to Ui and length. DIFFERENT DURATION OF THE 1ST IMC, depicted in 2K: the third block 28 is the measurement signal of Clause 5 (Fig. 2p) with amplitude equal to I. :). And for a length equal to the duration; ; Vro control pulse. Directly and with D.iOKa 25 subtracting the voltages to the second sig substitution unit 27. to the third entrance of which .n.avT. V duration t. 2.J) from the fourth unit output of 12 o; iic-i: n i. The second block 27 of generating signals, containing, for example,:, iipeMCHHoro interval in us; multiply and integrator,) C V into the voltage Us, d, -1 of the strength t- ,, and the expression .iHiOiuee voltage Uyo

n 11 in filing

 produces a line 1 and 11 r women not reaching,. amplitudes of 6U.

iia is the second input of the second replacement signal of the 2nd (Fig. 2m) block 27 al replacement of U.i (Fig. 2n). P .: Replacing 1 U: (U.i, .Gor I 5, where i are folded; -cash. Before the start of the 23 26 and 28 null-out signals

L4, iL - ts

no substitutions are produced and the voltages at the outputs of blocks 26-28 are zero

Claims (3)

1. A signal processing device for magnetic recording and playback, comprising a recording channel consisting of a series-connected time stretcher, a frequency converter, an amplifier and a magnetic head unit, the input of the time stretching unit being a recording channel, the output of which is the output of the magnetic heads unit, and the playback channel, consisting of series-connected magnetic heads unit and frequency demodulator, as well as from the delay line per line, detek Oia of fallouts and signal compression unit in time, while the input of the deposition detector is connected to the output of the magnetic heads unit, the input of which is the input of the playback channel, the output of which is the output of the signal compression unit in time, characterized in that information by reducing the interference from defects of the magnetic carrier; a combination unit, an interpolation unit and the first and second adders are entered into the playback channel; the first, second and third inputs of the second adder are connected The first, second and third outputs of the interpolation block, respectively, the first, second and third inputs of which are connected respectively to the first, second and third outputs of the combining unit, the first and second inputs of which are connected respectively to the output of the first delay line per line and to the output of the detector dropout connected to the first input of the first adder, the output of which is connected to the input of the first delay line per line, the output of the frequency demodulator is connected to the second input of the first adder, to the third input of the block combination to the fourth input of the interpolation block, the fifth input of which is connected to the fourth output of the combination block, the fifth output of which is connected to the fourth input of the second adder, the output of which is connected to the input of the signal compression block in time, and the sixth input of the interpolation block to the output of the fallout detector. 2. The device according to claim 1, different the fact that the combination block contains after- level connected clock generator, control pulse generation unit, line delay line and control unit, a switch connected in series and a fallout selection unit, as well as delay lines with taps, the first N outputs of which are connected respectively to the first N inputs of the switch, (N - | -1) -th input of the switch is connected to the input of the delay line with taps and is the first input of the combining unit, (M + 2) -th input of the switch is connected to the second output of the control pulse generation unit, the second The input of which is the second input of the combining unit, the first, second and third outputs of which are respectively the first, second and third WHE inputs of the control unit, the second input of which is connected to the first output of the allocation unit of the fallout, the first output of the control pulse generation unit the quarters output of the combining unit, the third input of which is the input of the clock generator, the second output of the precipitation signal extracting unit is the output of the combination unit. 3. The device according to claim 1, characterized in that the interpolation block comprises the first and second level memory blocks, the voltage subtraction block., The first, second and third replacement signal generation blocks, the outputs of which IB: 1 are first, second and third, respectively the outputs of the interpolation unit, the output of the first level storage unit is connected to the first inputs of the first block of generating the signal of the mixing of the voltage subtracting unit, the output of which is connected to the first input of the second block of the replacement signal, the output of the second In addition, the level is connected to the second input of the voltage subtraction unit and to the first input of the third replacement signal generation unit, the second inputs iiepeoi o, the second and third replacement signal generation units are the first second and third inputs of the interpolation unit, respectively the fourth input of which is the combined i.v. inputs of the first and second level memory blocks, the fifth input of the interpolation block is the third input of the second replacement signal generation unit, the central input of the interpolation block is common second inputs of the first and second blocks of memory I I I I I I I I I I I I .g