SU1610489A2 - Device for playback of service information from magnetic record carrier - Google Patents

Abstract

The invention relates to magnetic recording and reduces the error in the result of reproduction of overhead information from a magnetic recording medium produced on a separate track on autonomous multichannel recording devices when exposed to significant destabilizing factors. A third additional counter 13 is inserted into the device, connected between the first output of the code information selector 3 and the first inputs of the AND elements and the first installation input of an additional trigger, the third additional trigger 15 connected by the first installation input to the first output of the selector 3, the third additional element I 16. 1 silt

Description

The invention relates to the field of agnostic recording, namely, devices for reproducing service information from a magnetic carrier.

The drawing shows a block diagram of a device for reproducing service information from a magnetic recording medium. 10

A device for reproducing service information from a magnetic recording medium comprises an amplifier 1, made in the form of an amplifier-former, which reproduces a magnetic 15 head 2, a selector 3 of code information, first elements AND 4, first counter 5, first triggers 6, digital recorder 7 , multiplexer 8, the first additional counter 9, the first additional element And 10, the waiting multivibrator 11, the first delay element 12, the third additional counter 13, the second and third additional triggers 14 and 15, the third 25 and the fourth additional power elements And 16 and 17, the third additional counter 18, the comparator 19 and the first additional delay element 20.

The operation of the device for reproducing overhead information from a magnetic recording medium is as follows.

  The reproduced signal from the magnetic recording media comes from

magnetic x-tin 2 on the amplifier 1. From the output of the amplifier 1 to the selector 3 of the code information, a pulse sequence is supplied, consisting of sync pulses and information pulses shifted relative to them by half a clock period.

Information pulses from the first output of the selector 3 of the code information arrive at the first inputs of the elements 45 and 4 and to the first installation input of the trigger 14. Sync pulses from the second output of the selector 3 are fed to the first counting input of the counter 13, which forms a frequency corresponding to the frequency Examining bits in information groups. The signal of the counter 13 in the presence of a light signal code information from the output of the trigger 14 occurs through the element And 10 on the counting vhad counter 5.. The light signal code information from the output of the trigger 14 starts the waiting multivibrator 11, which forms a short pulse synchronization counters 5 and 13. The information ends when the signal from the output of the last bit of the counter 5 arrives at the second input of the trigger 14.

The counter 5 generates switching pulses, by means of which in the elements 4 and 4 the serial code is converted into a parallel-serial code that triggers the triggers 6, which are reset by the waiting multivibrator pulses 11 transmitted through the delay element 12.

The code information from the outputs of the flip-flops 6 is fed to the input of the multiplexer 8, to the information inputs of the counter 18 and to the first information inputs of the comparator 19. In the case of forbidden code combinations, the multiplexer 8 generates a signal that triggers the trigger 15, which blocks the And 16 elements. combinations of the pulse signal from the output of the standby multivibrator 11 passes through the element 16 and directly to the first input of the element 17 and through the element 20 of the delay to the control input of the counter 18. In the counter 18 rewriting The information from the outputs of the flip-flops 6. Then, the signal arriving at the counting input of the counter 18, from the output of the delay element 12, which forms a larger delay moment than the element 20, makes an adjustment before this of the recorded or stored time code of the previous second if the reproduced signal is disabled One of the combinations.

Comparator) 9 compares the code state of the triggers 6 and the counter 18.

In the absence of destabilizing factors that distort the reproduced signal at the moment of formation of a pulse at the output of the multivibrator 11, multiplexer 8 maintains the open state of element I 16. At the same time, the comparator 19 generates a high level at the output, indicating that the codes of the current second leveled on the outputs of the flip-flops 6 with the code of the previous second, which was previously recorded in the counter 18, and then the impulse received at its counting input,

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corrected in the next second.

A high level at the output of the comparator 19 opens an element 17, through which a pulse signal passes from the output of the standby multivibrator 11 to the control input of counter 9. Therefore, the time code from the indicators of counter 18, equal to the code at the outputs of the trigger 6, is written to the signal Then the code recorded in counter 9 according to the signal received at the counting input of counter 9 from the output of delay element 12 is corrected in the next second. At the same time, the code recorded in the counter 18 is corrected.

The presence of a low level at the output of the comparator 19 signals the inequality of the codes at its information inputs and, if this inequality occurs at the time of the formation of the signal at the output of the waiting multivibrator, this means that changes occurred in the reproduced signal due to a failure or due to a deliberate change in the recorded code . In both cases, the rewriting of the reproduced information into the counter 9 is not performed, but only the correction of the previous second code is made.

If a change in the reproduced code occurred due to a deliberate change in the recorded overhead information, then, when replaying the next second, at the moment it is received04896

NIL of the next pulse from the output of the waiting multivibrator I1, the codes at the inputs of the comparator 19 will coincide and ele. The cop and 17 will issue a command to overwrite the information played from the magnetic carrier into the counter 9.

Claims (1)

Invention Formula A device for reproducing service information from a magnetic recording medium according to aut. St. No. 1458887, characterized in that, in order to reduce the reproduction error of the service information, a third additional AND element is introduced into it, through which the second additional AND element is connected to the control input of the first additional counter, the third additional i counter, through which the first additional counter is connected with information inputs to the outputs of the triggers, a comparator connected by the first information inputs to the outputs of the triggers, second information inputs to the outputs of the third additional A second counter element connected between the output of the second additional And element and the control input of the third additional counter, the counting input of which is connected to the output of the delay element.