SU593234A1 - Device for reading information off magnetic carrier - Google Patents

Description

one

The invention relates to computing and is intended for use in systems for reproducing digital soundtracks from parallel magnetic tracks.

carrier.

A known device for reading information recorded by a method without returning to zero is characterized by sensitivity to carrier bias, the presence of which leads to erroneous reproduction of information. It is also known a device for reproducing digital signals with self-synchronization. It contains a serially connected playback amplifier and a detector, the outputs of which are connected to the outputs of the device through the pulse shapers and elements AND. The second inputs of the AND elements are connected to a trigger, one input connected to the device outputs via the OR element. The second input of this trigger through another OR element is connected to decoders connected with € 0 pulse counters. The device also contains a second trigger, the counting input connected to the outputs of the first OR element, and the outputs to the decoders directly and through the pulse shapers to the counters, the counting inputs of which are connected to the clock generator. This device has a relatively low recording density.

information, which is two times lower than the recording density by a method without returning to zero, which is closest to isooretition on technical sushi, is a device for reading information from a magnetic carrier, containing: ash, its counters, the counting inputs of which are connected to the generator clock pulses, a trigger, one of the inputs of which is connected to the primary-1 input of the device and the element And, one input of which is connected to the output of the trigger, and the output to the output of the device. the device cannot be used with sufficient reliability for reproducing signals without self-synchronization, ensuring their higher linear recording density. The aim of the invention is to increase reliability. In the described device, this is achieved by the fact that it contains comparison blocks, a register and an OR element whose inputs are connected to the first input of the device and the output of the first comparison block, the output of the 1 and 1И element is connected to the control input of the first counter whose output is connected to the first inputs of the blocks comparison, the second inputs of which are connected to the outputs of the register connected by one of its input with the output of the second counter, and the other with the second input of the device and the input of the second counter, and the output of the second comparison block n with a different output device and the second

the input of the element is And, and the output of the first block of the comparison with another input of the trigger.

FIG. 1 shows a block diagram of the described device; in fig. 2 - time diagrams of his work.

The device contains a clock pulse generator 1, an OR 2 element, impulse counters 3 to 4, comparison blocks 5 and 6, a register 7, a trigger 8 and an AND 9 element. A signal from the information track of the carrier is fed to the input bus 10 of the device 11 - with sync, her tracks; output code pulses are output to bus 12, and clock pulses to output bus 13.

When the input bus 11 receives signals from the sync track (see Fig. 2, diagram b), pulse counter 4 is reset. The counting input of counter 4 receives pulses from generator 1 (see Fig. 2, diagram b), the frequency of which is much higher than the frequency of the input reproduction signal.

Thus, the counter 4 is drying, measuring the duration of the sync signal period.

When signals are received from the sync track, the counter code 4 is transferred to register 7. The contents of register 7 are compared with the counter 3 reading, which is reset to the initial state by the signals of the OR 2 element and counts the pulse of the generator 1. In this case, two comparison blocks 5 and 6 are used, the second of which compares the register-shifted code. When the codes of the counter 3 and register 7 coincide, the comparison unit 5 generates a pulse, which triggers the trigger 8, passes the OR element 2, and sets the counter 3 to the initial state; In the initial state, the counter 3 is also set by the sigals from the information track (see Fig. 2, diagram a).

In this way, the signals of the information track are synchronized with the signals of the superhighway.

Sync pulses (see Fig. 2, diagram e), the incoming and output device bus, are generated by a block of comparison 6 in the middle of the period of the information signal.

The selection of pulses of binary units is carried out with the help of trigger 8 and element AND 9. When a signal arrives on the input bus 10, trigger 8 produces a signal (see

FIG. 2, diagram g), passing a sync pulse through the element I 9 to the output bus 12 of the device (see FIG. 2, diagram h).

In the initial state, the trigger 8 is set by a pulse coming from the comparison unit 5.

Using the described device to reproduce the signals recorded by the non-zero method can significantly increase the reliability of the reproduction. This is ensured by the fact that the device monitors the change in the speed of movement of the carrier and corrects the data to be reproduced when the information signals are shifted relatively synchronizing within dz50% of the moment clock period.

Claims (1)

Invention Formula A device for reading information from a magnetic carrier containing counters, the counting inputs of which are connected to a clock generator, a trigger, one of whose inputs are connected to the first input of the device, and an element, one input of which is connected to the trigger output, and an output to the device output, characterized in that, in order to increase the reliability of the device, it contains comparison blocks, a register and an OR element, whose inputs connected to the first input of the device and the output of the first comparison unit, the output of the OR element is connected to the control input of the first counter, the output of which is connected to the first inputs of the comparison units, the second inputs of which are connected to the outputs of the register connected by one input to the output of the second counter, and the other to the second input of the device and the input of the second counter, and the output of the second comparison unit is connected to another output of the device and the second input of the element is And, and the output of the first block is compared to another input of the trigger. --T V " Ih h V one one. one  " fus.l  V. , - H S 593234 FIG. 2