SU898498A1 - Device for shapping synch pulses at reproducing from magnetic record carrier - Google Patents

Description

(54) DEVICE FOR THE FORMATION OF SYNCHRONIZATION PULS DURING PLAYBACK FROM MEDIA

I

The invention relates to magnetic recording, in particular, to devices for forming synchronization pulses during playback from a magnetic recording medium.

A device dp of forming synchronous pulses during playback from a magnetic recording medium is known, which comprises an input bus of a reproduced signal connected via a driver to a synchronization signal with an output bus of synchronization pulses G1.

This device has a relatively simple design, however, it does not allow for the formation of pulses from a reproduction signal recorded on a magnetic recording medium with a sufficiently high density.

It is also known a device for generating synchronization pulses during reproduction from a magnetic recording medium, comprising an input bus of a reproduced signal connected to the input of a demodulator, a pulse generator, and a MAGNETIC RECORDING

the stroke of which is connected to the first input of the error signal shaping unit and to the input of the controlled counter connected to the output bus of the synchronization pulses, a trigger, a delay unit, an analog inverter, an OR element to the element I. This device allows the formation of synchro-pulse during playback of the signal recorded on a magnetic recording medium with a sufficiently high density of C 2.

The disadvantage of this device consists in a significant error in the formation of synchronization pulses during reproduction with noto: magnetic recording.

The purpose of the invention is to reduce the error in the formation of synchronization pulses when extracting from magnetic recording media.

Claims (2)

The goal is achieved in that the device for generating synchronization pulses during reproduction from the magnetic recording medium introduces amplitude and humble detectives, the outputs of which are connected via the OR element to the first inputs of the trigger and the AND element, and a series of digital signal installation unit and switching unit, inputs which are connected to the outputs of the block of the formation of the error signal and the trigger, and the outputs to the controlled counter. At the same time, the demodulator output is connected via a delay unit to the second trigger input and to the second input element I, the output of which is connected to a controllable counter connected by output to the second input of the error signal generation unit and the input bus of the reproduced signal is connected to the input of one amplitude discriminator via analogue inverter k: Connected to the input of another amplitude discriminator. An apparatus is shown for generating synchronization pulses from playback of a magnetic recording medium. The device contains our input 1 reproduced signal, connected “about the input of demodulator 2, g agora 3 pulses. The output of the pulse generator 3 is connected to the first input of the error signal generating unit 4 and to the input of the controlled counter 5 connected to the output bus 6 of the synchronization pulses by the output. The proposed device also includes amplitude discriminators 7, the outputs of which are connected through the element OR 8 to the first inputs of the trigger 9 and the digital signal setup unit II connected in series and the switching unit 12. The inputs of the switching unit 12 are connected to the outputs of the error signal generating unit 4 and the trigger 9, and the outputs to the controlled counter 5. The output of the demodulator 2 is connected to the output bus 13 of the reproduced signal and connected through the block 14 to the second input of the trigger 9 and the second input element Y o, the output of which is connected to the controlled counter 5. At the same time, the output of the controlled counter 5 is connected to the main input of the 4 unit forks the signal of the mismatch, and the input bus I of the reproduced signal is connected to the input of one amplitude specific discriminator 7 through an analog inverter 15. Moreover, the 89 4 input uirtHo 1 reproducing the valid signal is also connected to the input of the second amplitude discriminator 7. The proposed device generates synchronization pulses during playback from the reproduced signal. In the case of the loss of the reproduced signal, it generates reproduction pulses, the frequency of which is equal to its frequency before the beginning of this fallout. The use of the invention makes it possible to significantly reduce the error in the formation of synchronization pulses when playing back from a magnetic recording medium. The invention The device for generating a pulse gg during playback from a magnetic recording medium, contains an input bus of a reproduced signal connected to the input of the demodulator, a pulse generator, the output of which is connected to the first input of the error signal generating unit and to the input of the mapped counter a connected an output to the input bus of synchronization pulses, a trigger, a delay unit, an analog inverter, an OR element, and an AND element, that is, an e-ec-cell, which, in order to reduce the error spines of synaptic pulse shaping, amplitude discriminators are entered into it, the outputs of which are connected via the OR element to the first inputs of the trigger and the AND element, and a digital signal installation unit and a switching unit connected in series, the inputs of which are connected to the outputs of the error shaping signal and trigger, and the outputs to the controlled counter, and the demodulator output is connected via a delay unit to the second trigger input and to the second input of the And element, the output of which is connected to the controlled account iku, connected to the output vgortm input signal generating unit mismatch, and the input bus of the reproduced signal is connected to one input of an amplitude discriminator via an analog inverter and the other input is connected to an amplitude discriminator. Sources of information taken into account in the examination s 1. Hoagland A. S. Digital magnetic recording, Moscow, Soviet radio, 1967, p. 162-164. 2. Japanese patent No. 53-4OO85, class, 102 E 333, 25,10,78 (prototype).