SU649027A1 - Device for reproducing digital information from magnetic carrier - Google Patents

Description

The invention relates to the field of instrumentation and can be used in storage devices with movable information carriers.

It is known that an increase in the resolution of the recording-reproduction channel or a decrease in recording density (on the internal and external tracks of a magnetic disk, the information recording density is different) causes the appearance of "shelves" in the playback signal.

After the differentiation of such a signal, in places of the shelves there are spurious outbursts, from which, during the formation of the pulse sequence of the reproduction signal, false pulses are generated, leading to the loss of unambiguity of the reproduced information.

Devices are known in which amplitude limiting schemes or thresholds of signal 1, 2 are used to eliminate spurious emissions in the reproduction signal.

However, with an increase in the recording-reproduction channel resolution, spurious emissions reach values that make it impossible to use amplitude limiting schemes.

The closest in technical essence to the present invention is a device for reproducing digital information from magnetic media, comprising a differentiation circuit, an amplifier-limiter, a pulse shaper and a delay circuit connected in series, and a second pulse shaper 3.

This device also provides suppression of false emissions. However, the presence of filters complicates it.

The purpose of the invention is to simplify the device and increase its reliability.

For this purpose, a trigger is additionally introduced into the proposed device, one input of which is connected to the output of the amplifier-limiter, the synchronization input — to the output of the delay circuit, and the output — to the input of the second pulse generator, the output of which is connected to the output of the device.

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

Device for reproducing digital information from magnetic media

contains a magnetic head, ira; iK, iioi: e ii to the output of the counting trigger-usi; it; 1 ziisn 2, differential1a. . li, amplifier-limit: 4, impulse generator o, delay circuit 6, i JHrrep 7, and forma-tree impulses 8.

The device works as follows.

Recording information 9 is supplied by a counting trigger recording amplifier 2, the output signal 10 of which is behind P1C by magnetic head 1 to the information carrier. The playback signal II from the output of the magnetic head is amplified by a differential amplifier 3, the output signal 12 of which enters the limiting amplifier 4. The signal 13 from the output of the limiting amplifier is fed to the inputs of the trigger 7 and the driver 5, the signal 14 of which is delayed by circuit 6 for the time f, signal 15 is applied to the synchronized input of this trigger.

Elimination of false pulses in the c, playback playback is carried out by the interaction of signals 13 and 15 but to the inputs of the trigger 7. The output signal 16 by the driver 8 generates the output signal 17, since the trigger 7 switches from the reproduction signal pulses 15.

Introduction to the trigger device and its appropriate connection does not allow

TOL (, K (, 1 yii K; -T; iT, STR (; Ye1; iO. N i iliJBljUHTb

robustness and ipfirmaii ;;, since with non-key reasons (lower frequencies and lower frequencies, temporary distortions that narrow the strobe interval are excluded).

Claims (3)

1. US Patent No. 3715738, cl. 340-174, H, 1973. 2. US patent number 3735372, cl. 340-174, IH, 1973. 3. US patent number 3810232, cl. 340--174, 1H, 1974.