SU1515199A1 - Device for marking and searching for information with variable speed of magnetic tape - Google Patents

Abstract

The invention relates to the accumulation of information, namely, devices for marking and searching information on a magnetic tape, and makes it possible to increase the efficiency of using a magnetic tape in the start-stop mode by allowing recording and reproduction of marker signals during acceleration and deceleration periods of the magnetic tape. When recording, the markup code is obtained from the pulse sequence, which is formed at the output of the tape speed sensor and is proportional to the speed of the magnetic tape. Thus, the recording is carried out with a constant density, and when searching for reproducible information, it is synchronized with the same pulse sequence from the output of the tape speed sensor and a marking code is extracted from it. 1 hp f-ly, 2 ill.

Description

The invention relates to the accumulation of information, namely, devices for marking and searching information on a magnetic tape.

The purpose of the invention is to increase the efficiency of use of a magnetic tape in the start-stop mode by providing recording and playback of marker signals at the moments of acceleration and deceleration of a magnetic tape.

Fig. 1 is a functional block diagram of a recording / playback device; on - signal plots, in accordance with the principle of operation of the proposed device.

The device comprises a magnetic recording-reproducing apparatus 1 with a tape speed sensor 2. The output of the speed sensor 2 is connected to the input of the first trigger 3, the first output of which is connected to the input of the first differentiation unit 4 and to the input of the second differentiation unit 5 of the first and second differentiation units 4 and 5, respectively, connected to the first and second input of the former

6 markers, the output of which is connected to the first input of the magnetic recording-reproduction apparatus 1. Block output

A coordinate input 7 is connected to the first input of the comparator unit 8, the output of which is connected to the second input of the magnetic recording-reproduction apparatus 1. The first inputs of the frequency and phase comparators 0 and 11, which are the first and second inputs of the synchronization unit 9, are connected to each other.

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responsibly with the output of the magnetic recording-reproducing apparatus 1 and the tape speed sensor 2. The output of the frequency comparator 10 is connected to the first input of the adder 2, and the output of the phase comparator 11 to the second input of the adder 12 "The output of the adder 12 is connected to the input of the voltage controlled oscillator 13 The output of the voltage controlled oscillator 13 is connected to the second frequency inputs and phase comparators 10 and 1.1, the first inputs of the second 15 and third 16 shift register and the first input of the second trigger 20, the input of the third differentiation unit 14 is connected to the input of the phase comparator 11 and the second inputs of the second and third registers 15 and 16 shifts, and the output to the first, input of the second element And 2 n outputs of the second and third registers 15 and 16 of the shift are connected to n inputs of the third and fourth elements 17 and 18 "The output of the OR element 19 is connected to the second input of the second trigger 20 and the first input of the distributor 22 is a pulser, and the first and second inputs are connected respectively with the third and fourth elements 17 and 18 ,. The output of the second trigger 20 is connected to the second input of the second element And 21,. the second input of the distributor.l .: 22 pulses and the first input of the first shift register 24 The output of the distributor 22 pulses is connected to the first input of the first element And 23, the second input of which is connected to the output of the second element And 21. The output of the first element And 13 is connected to the second input of the first shift register 24, the output of which is connected to the second input of the comparison unit 8

The device works as follows

Since the beginning of the tape movement in the magnetic recording-reproduction apparatus 1, pulses are formed at the output of the tape speed sensor 2 (Fig 2a), the frequency of which is directly proportional to the speed of the magnetic tape movement. The pulse sequence is fed to the input of the first trigger 3, where two sequences are formed from it (fig. 2b, c) arriving at the inputs of differentiation blocks 4 and 5 from the output

5 0 5 0 5 0

five

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Yes, which narrow pulses arrive at the marker marker (fig. 2d, d), in which one of the sequences is divided into zones of n pulses, for example, eight pulses, markers defining the beginning and end of the marking zone are formed with the appearance of every eighth pulse, and a binary markup code is written between them (Fig. 2e), with the markup code being generated through one zone. Thereafter, the markup signal is added to another sequence (Fig. 2g). The resulting pulse sequence markup code is recorded on a magnetic tape. In the form of magnetization drops (fig.2z). Before starting the search in the comparison unit 8 from the coordinate input unit 6, the binary code of the desired marking zone is entered. When playing at the output of magnetic recording-reproduction apparatus 1, a pulse sequence is formed (FIG. 2), which, together with the motion speed sensor 2 signal, is fed to the inputs of the phase and frequency comparators, respectively. 2k), equal in frequency to the tape speed sensor signal and phased with the informational playback signal. The resulting synchronization signal, together with the information the signal is fed to the inputs of the shift registers 15 and 16, designed to select areas of the information signal free from marking. The binary pulse sequence of these zones is known in advance and allows identifying marker pulses of the end of these zones in schemes AND 17 and 18. These pulses are added in the OR circuit 18 (FIG. 2L) into a sequence phasing the second trigger 20 and the pulse distributor 22. At the output of the blind trigger, pulses are generated that allow the output marker pulses and the marking code (figm, n, o, p). Information) 1a sequence enters the second scheme And. 1 in the form of narrow pulses received at the output of block 14 of differential flow. At the outlet of the distributor, impul1) СОВ по51

An impulse sequence allowing the output of the first circuit AND 23 of the marking code (FIG. 2p) is obtained, and the first shift register 24 converts the narrow impulses of the marking code into a binary code (FIG. 2, t.), which is compared with the preset in block 8 comparison, and in the case of a match in the block, the Stop command is generated.

Claims (1)

Invention Formula 1, A device for marking and searching information at a variable speed of a magnetic tape containing a magnetic recording-reproducing apparatus with a tape speed sensor, a first trigger, a first differentiation unit, a marker generator, the output of which is connected to the first input of a magnetic recording apparatus playback, the comparison unit, the output of which is connected to the second input of the magnetic recording-playback apparatus, and the coordinate input unit, the output of which is connected to the first input of the comparison unit, the output sensor the tape speeds are connected to the input of the first trigger, the first output of which through the first differentiation unit is connected to the first input of the marker maker, characterized in that, in order to increase the efficiency of the use of the magnetic tape in the start-stop mode, by ensuring recording and reproducing marker signals in moments of acceleration and deceleration of the magnetic tape, the second and third differentiation units are introduced into it, the first, second and third shift registers, the first - fourth elements AND, the pulse distributor owl, the second trigger, the OR element, the synchronization unit, the first and second inputs of which are connected respectively to the outputs of the tape speed sensor and the magnetic-recording apparatus 996 and the output is connected to the first inputs of the second and third shift registers and the first input of the second trigger, the second output of the first trigger is connected through the second differentiation unit to the second input of the marker maker, the second inputs of the second and third shift registers are connected to the second input of the synchronization unit and the input of the third differentiation unit, the output of which is connected to the first input of the second And element, the outputs of the second and third., shift registers are connected to the inputs of the third and fourth And elements, the left and second inputs of the OR element are connected respectively to the outputs of the third and fourth elements AND, and the output of the element OR is connected to the second input of the second trigger and the first input of the pulse distributor, the second input of which is connected to the second input of the second element AND, the first input of the first shift register and the output the second trigger, while the output of the pulse distributor is connected to the first input of the first element And the second input of the first element And is connected to the output of the second element And, and the output is connected to the second input of the first shift register, whose output is connected to the second input of the comparator 2 A device according to 1, in which the synchronization unit contains a frequency comparator, the first input of which is the first input of the unit, a phase comparator, the first input of which is the second input of the unit, the adder, the first and second inputs of which are connected with the outputs of the frequency comparator and the phase comparator, respectively, and the output is connected to the generator input of the controlled voltage, the output of which is connected to the output of the block and connected to the second inputs of the frequency and phase comparators aftplnlnLLLLJ JShnLLLLLLSShlShlrShJShflShlPLI s J J J J JlJtlJTGlLJ J JlJTLJtr in (jnji.r ( I I I J I . fi shshshshlpshishllllllllllshshlp pplpsh / 7 M and ijTJTjajTJTJ-UTJTJTJTJTjnjTJ / 7 rI I I 1 I Ml I I III III III I / 7 p. I I I 1 I L J 1 I I and I I il