SU1182576A1 - Device for quality control of magnetic medium - Google Patents

Abstract

A DEVICE FOR MONITORING THE QUALITY OF A MAGNETIC MEDIA containing a master oscillator, a frequency divider, recording and reproducing units with magnetic heads of the same name, a register unit, a pulse counter and a register polling unit, the playback unit consists of a band-pass filter, an amplitude discriminator on a positive reproduction signal, a detector -transitions, trigger, prohibition element and amplifier, the input of which is connected to the input of the playback unit, and the output through a band-pass filter to the amplitude di to the clock output of the playback unit, to the setup input of the trigger and the input of the prohibition element, the output of which is connected to the information output of the playback unit; the master oscillator is connected to the first input of the polling register and through a divider frequencies - with the inputs of the recording units, to the outputs of which the recording heads are connected, the playback heads are connected to the inputs of the respective playback units, and the first output The register poll block is connected to the first control input of the register block, which is different from the fact that, in order to increase the reliability of the control of the multi-track information carrier, delay lines and pulse counters of the signal signals, the number of which corresponds to the number of playback blocks, are entered into it In addition, a D-trigger, an amplitude discriminator on a negative playback signal, are entered into the playback unit, (L, a signal addition unit and a driver, and fflylc ov at the extremum on each half-wave of the response of the reproduced signal, the input of which is connected to the input of the mentioned amplitude discriminators, the outputs of which through the addition unit are connected to the input Reset of the trigger, the output of which is connected to the D-input B of the trigger, to the C-input of which is connected to the output of the SG1 pulse generator on estrem 1 mu, and the output - with the second input of the inhibitor bar; the block of registers is composed of shift registers, the number of which corresponds to the number of pulse counters of the preliminary memory , the first control inputs of the shift registers are combined and connected to the first input of the register block, the second control inputs of the shift registers are combined and connected to the second input of the register block, the serial code output of the previous register is connected to the serial code input

Description

the next register, the output of the serial code of the last register is connected to the register block, and the inputs of the parallel code of the shift registers are connected to the corresponding bit inputs of the register block, the latter are connected one by one to the outputs of the corresponding pulse counters of the preliminary memory, the information inputs of the pulse counters are connected to information outputs of the playback unit, the setup inputs of the pulse counters are combined and connected via a delay line to the inputs of the block Registers and register interrogation unit and to the output of the pulse counter, the input of which is connected to the clock output of one of the reproduction units.

one

This invention relates to a magnetic recording technique, in particular, to the control of magnetic carriers.

The purpose of the invention is to increase the reliability of control of a multi-track information carrier.

The drawing shows a functional diagram of the device.

The device for quality control of Magnetic carrier 1 contains a master oscillator 2, a divider 3 frequencies, recording blocks 4 with magnetic heads 5 of the same name, a carrier transport mechanism 6, identical playback blocks 7 with identical heads 8, register block 9 composed of shift registers 10, the number of which corresponds to the number of playback blocks 7, as well as the pulse counter 11. pulses and polling block 12 are register 10. The playback block 7 consists of a band-pass filter 13, an amplitude discriminator 14 by positive sec the playback playback, the detector 15 null transitions, the trigger 16 of the prohibition element 17 and the amplifier 18, the input of which is connected to the input of the playback unit 7, and the output through the band-pass filter 13 to the amplitude discriminator 14 and through serially connected detector 15 of the zero-transition and the single-oscillator 19 - to the clock output of the playback unit 7, the setup input of the trigger 16 and the input of the inhibit element 17, the output of which is connected to the information output of the playback unit 7, while the master oscillator 2 is connected to the first input of the 12 o millet registers and through the divider 3 frequencies - with the inputs of blocks 4 records, the outputs of which are connected to the head 5 records. The playback heads 8 are connected to the inputs of the respective blocks.

7, and the first output of the polling unit 12 is connected to the first control input of the register unit 9.

8 devices also have delay lines 20 and combined into block 21

preliminary memory pulse counters 22 signals of coincidence, the number of which corresponds to the number of playback units 7.

In the latter, the converter input 23 pulses at the extremum for each half-wave of the response of the reproduced signal is connected to the input of the amplitude discriminator 14 along

positive signal of reproduction and the input of amplitude discriminator 24 through a negative signal of reproduction, the outputs of which are connected to

input Reset trigger 16, the output of which com is 1: not with U-input D of trigger 26, the C-input of which is connected to the output of the driver of 23 pulses at the extremum, and the output - with

the second input element 17 of the ban. The first control inputs of the shift registers 10 are combined and connected to the first input of the register block 9, the second control inputs of the shift registers 10 are combined and connected to the second input of the register block 9, the serial code output of each previous register 10 is connected to the serial code 3 input of the subsequent register 10 , the output of the serial code of the last register 10 is connected to the output of block 9 of registers, and the inputs of the parallel code of shift registers 10 are connected to the corresponding bit inputs of block 9 of registers after The common ones are connected in parallel to the outputs of the corresponding pulse counters 22 of the preliminary memory unit 21, the information inputs of the pulse counters 22 are randomly connected to the information outputs of the playback unit 7, the installation inputs of the pulse meters 22 are connected and connected via a delay line 20 to the second inputs of the register 9 block and the register polling unit 12, as well as to the output of the pulse counter 11, the input of which is connected to the clock output of one of the playback units 7. The recording heads 5 are installed in the path of the mechanism 6 in the direction of movement of the carrier before the reproducing heads 8. The number of channels recording-reproduction of the test signal is determined by the required resolution controlling the structure of the working layer of the magnetic carrier. The device works as follows. The high-frequency signal from master oscillator 2 is supplied to a register polling unit 12 and through a frequency divider 3 to recording blocks 4 to form a test signal representing a sequence of square pulses. The frequency of the test signal, and consequently the longitudinal density of recording pulses along each track, is determined by the requirement of providing the necessary resolution for monitoring the carrier in the longitudinal direction. The test signals recorded simultaneously over all tracks of the carrier are reproduced by magnetic heads 8 and are amplified by amplifiers 18 of the playback units 7. In the latter, the amplified signal then enters the band-pass filter 13, designed to increase the dynamic range of the playback channel when the device operates with a single-frequency test signal. From the output of the band-pass filter 13, the signal enters the amplitude discriminator inputs 14 and 24, as well as the detector input 15 of the null shaper junction 15 23. By means of the amplitude discriminator 14, rectangular pulses are generated by a positive reproduction signal when the reproducing signal exceeds a given value level ceiling elements. In a similar way, form signals by an amplitude down-mixer 24 on a negative reproduction signal when the reproduced signal is a predetermined negative level. The generated signals are then summed up in addition unit 25. By means of a detector of 15 null transitions, rectangular pulses are formed, the fronts of which correspond to zero values of the reproduction signal. The single-oscillator 19 generates narrow pulses on the front and rear edges of the output pulses of the detector 15 null transitions, which ensure the switching of the trigger 16. The latter is set to the initial state by the leading edge of the pulses coming from the adder unit 25. According to the extremum, the former 23 generates pulses from the reproduced signals corresponding to the time position of the maximum amplitude of the reproduced signal. The pulse signal from the driver 23 is fed to the input C of the trigger 26 and confirms the initial state of this trigger on the input J), and this ensures the formation of a signal dropout zone. The prohibition element 17 generates the fallout signals from both the positive and negative half-waves of the reproduced signal, arriving at the information output of the playback unit 7. The clock output of the block 7 receives pulses from the one-shot 19. Thus, at the clock output of each block of playback at -. There are clock pulses of this channel, and at the information output of each block 7 there are pulses of signals of falling out of the corresponding tracks at the moments of decreasing the amplitude of the reproduced signal of both positive and negative polarity. The dropout signals from the information output of each of the blocks 7 are fed to the information inputs of the block 21 of the preliminary memory of the fallout signals. Counters

22 of the latter carry out the counting of the number of impulses for each playback channel. The clock pulses of one of the playback units are fed to the input of the pulse counter 11, counting a predetermined number of clock pulses within the duration of the periodic quality control interval of the clock. As the counter 11 counts a predetermined number of pulses, the second input of the register block 9 receives a signal to start overwriting the number of steps in the digital code from each counter 22 to the registers 10 of block 9. The same signal after the delay line 20 serves to zero the counters 22 drop signals. the pulse counter 11 is also fed to the second input of the register polling block 12, which provides information output

about the quality of the test medium to external information recording devices via the second output of the unit

12. Information output is carried out by periodically arriving at the first input of the control unit 9 of the signal registers from the register polling unit 12. The number of dropouts in the digital code is sequentially transferred from the register to the register, while the data of the first register containing information on the number of dropsouts in the first playback unit 7 is directly sent to the output of the register block 9, which is / as the second output of the register 12 block from the external outputs of this device. Data

results and quality of magnetic media are received on the external display unit and digitally printed.

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Claims (1)

A MAGNETIC CARRIER QUALITY CONTROL DEVICE, comprising a master oscillator, a frequency divider, recording and reproducing units with the same magnetic heads, a register unit, a pulse counter and a register polling unit, the playback unit consisting of a bandpass filter, an amplitude discriminator for a positive playback signal, a detector ' zero transitions, trigger, prohibition element and amplifier, the input of which is connected to the input of the playback unit, and the output through the bandpass filter to the amplitude discrimination to the detector and through a series-connected detector of zero transitions and a single-shot to the clock output of the playback unit, to the installation input of the trigger and the input of the inhibit element, the output of which is connected to the information output of the playback unit, while the master oscillator is connected to the first input of the register polling unit and through a divider frequencies - with the inputs of the recording units, the outputs of which are connected to the recording head, the playback heads are connected to the inputs of the corresponding playback units, and the first output of the polling unit of registers is connected to the first control input of the register block, which is characterized by the fact that, in order to increase the reliability of control of a multi-track data carrier, a delay line and pulse counters of loss signals combined in the preliminary memory block are added, the number of which corresponds to the number of playback blocks, in addition , a D-trigger, an amplitude discriminator for a negative playback signal, a signal addition unit, and a pulse shaper at an extremum at I wait for the response half-wave of the reproduced signal, the input of which is connected to the input of the mentioned amplitude discriminators, the outputs of which are connected via the addition block to the Trigger reset input, the output of which is connected to the D-input of the D-trigger, the C-input of which is connected to the output of the pulse shaper by the extremum, and output - with the second input of the inhibit element, while the register block is composed of shift registers, the number of which corresponds to the number of pulse counters of the preliminary memory block, the first control inputs of the shift registers the yoke are combined and connected to the first input of the register block, the second control inputs of the shift registers are combined and connected to the second input of the register block, the serial code output of the previous register is connected to the serial code input via SU. „. 1182576 1 182576 of the following register, the output of the serial code of the last register is connected to the output of the register block, and the inputs of the parallel code of the shift registers are connected to the corresponding bit inputs of the register block, the latter are connected bitwise to the outputs of the corresponding pulse counters of the preliminary memory block, the information inputs of the pulse counters are bitwise connected to the information outputs of the playback unit, the installation inputs of the pulse counters are combined and connected through the delay line to the inputs block registers and block polling registers, as well as to the output of the pulse counter, the input of which is connected to the clock output of one of the blocks playback.