SU1103280A1 - Device for transcribing digital information on magnetic tape for display equipment - Google Patents

Abstract

THE DIGITAL INFORMATION RECORDING DEVICE FOR A MAGNETIC TAPE FOR DISPLAY MEANS, in which the synchronous output of the multi-speed N-channel playback unit is connected to the input of the frequency multiplier unit connected in series with the first inputs of the first frequency divider for speed and second frequency divider, as well as the speed component and the unit, and the unit has a set of speed multiplication units, connected to the speed and second frequency dividers in series with the speed multiplier and second unit, and the unit has a set of frequency multiplication units, connected to the speed and second frequency dividers frequency and to the second inputs of the first frequency divider for speed and the second frequency divider, and the third input of the first frequency divider for speed is connected to the control The output of the multi-speed N-channel playback unit, and the third input of the second frequency divider is connected to the output of the control unit and to the second input of the third frequency divider, the output of which is connected to the output synchronization bus, and its third input to the output of the multiple input element OR, N inputs which through the corresponding N first pulse shapers are connected to the output buses of the device, while the clock input of the multi-speed N-channel recording unit is connected to the output of the second frequency divider , characterized in that, with col1) u reduce the error of the playback result by forming additional reassignment phasing intervals during rewriting, N write code converters are entered in it, the outputs of which are connected to the corresponding information inputs of the multi-speed N-channel recording unit, and the first inputs to the corresponding information outputs of the multi-speed N-channel playback unit, serially connected second pulse shaper and the fourth frequency divider into two, the second input Connected to the output of the second frequency divider is expensive, and its output is connected to the second inputs of the write code converters, N § play code converters, each of which contains a D-flip-flop, / RS-flip-flop, an inverter, the first and second elements, -trigger connected to the corresponding information output of the multi-speed 5th N-channel playback unit, with one input of the first element And, and through an inverter with one input of the second element And, the other inputs of the first and second elements And connected directly to the inverse and inverse outputs of the D-flip-flop, the outputs of the first and second elements I are connected respectively to the R- and S-inputs of the RS-flip-flop, the output of which is connected to the corresponding informational band of the device, while the synchronizing inputs of the D-flip-flops of the playback code converters are connected with the input of the second pulse generator and the synchronizing output of the I-turn of the multi-speed N-channel playback unit.

Description

The invention relates to instrumentation, in particular to devices for accurate magnetic recording, and can be used when rewriting digital information from one magnetic tape to another.

A recording and reproducing apparatus is known in which the information inputs of the multi-speed ZLtisi unit are connected to the corresponding outputs of the multi-speed playback unit 1.

To pair high-information playback devices with low-information display means, overwriting is used to transform the information frequency into the low-frequency range in this device. At the same time, the speed of movement of the carrier during playback of the original takes less than the speed of movement of the carrier when recording a copy. However, in this case, there is a deviation (decrease) in the recording density of the copy from the optimum for this device. So, if the speed of movement of the carrier during playback of the original Vmin, and the speed of movement of the carrier during recording; Utah copies, the copy density will be longitudinal in Vnex / Vwin times less than on the original. A decrease in recording density leads to the appearance of "pauses between the magnetization reversals on the tape, which increases the likelihood of the appearance of spurious pulses at deep formation levels, i.e., reduces the quality of copies.

Thus, this device does not allow to obtain copies of magnetic tapes with high reliability of the playback result.

Closest to the proposed technical entity is a device for rewriting digital information for display devices 2.

In this device, the transformation of the information frequency to the low frequencies is performed by overwriting when the speed of the carrier during playback is less than the speed of the carrier during recording, while the recording density on the copy and on the Original remains the same for any ratio of speeds due to transformations in the synchronization channel , which greatly improves the quality of copies of magnetic tapes.

The known device uses a modified phase modulation method, in which binary information units are coded by changing the magnetization in the middle of a bit, zeros are coded by changing the magnetization at the end of the bit, and the zeros between two units (combination 101) are not coded. Thus, binary information on a magnetic tape can be presented in the form of various combinations of magnetization drops, following with intervals T, 1, 5Т and 2Т, where T is the duration of the discharge interval.

Since, with this method of recording, the magnetization drops, the following at intervals T and 1.5 T can correspond both to units and zeroes of input information, for correct decoding, it is necessary to include in the information sequence or in the marker word the combination 101 corresponding to the phasing intervals 2T.

The main source of information distortions in the recording-reproduction process on a magnetic tape is the fallout of signals due to the destruction of the working layer, disturbance of the head-carrier contact, etc., with the loss of even one signal corresponding to an overlap of 1.5 T or 2T, can lead to incorrect decoding of all subsequent intervals T and 1.5 T, up to the appearance of the interval 2T.

In the known device due to the transformations in the synchronization channel, the information received for rewriting can be considered as recoded. Thus, with the ratio of the playback speeds of the original (V) and the recording of the copy (Vj) as V-3 2U, the unit (zero) of binary information at the output of the playback unit corresponds to two units (two zero m) of binary information at the input of the recording unit. Therefore, in the information sequence received when overwriting the input of the recording unit, the occurrence of the combination 101 is impossible, i.e. the copies will not have magnetization differences with a 2T interval between the marker words. Therefore, during reproduction of a copy, a decoding error arising due to precipitations can be corrected only by a marker word. Since the amount of useful information between marker words can be quite large (150 or more bits), the lack of combinations of 101 (phasing 2T intervals) in the information sequence received for recording increases the error during reproduction of a copy, which is a drawback of this device.

The purpose of the invention is to reduce the incidence of the playback result by forming additional phasing intervals during the rewriting.

The goal is achieved by the fact that in a digital information rewriting device on a magnetic tape, in which the synchronizing output of a multi-speed N-channel playback unit is connected to the input of a frequency multiplier unit connected in series with the first inputs of the first frequency divider and the second

the frequency divider, as well as to the first input of the third frequency divider and to the second inputs of the first frequency divider for speed and the second frequency divider, the third input of the first frequency divider for speed connected to the control output of the multi-speed N-channel playback unit, and the third input of the second divider the frequency is connected to the output of the control unit and to the second input a third. its frequency divider, the output of which is connected to the sync output bus, and its third input is connected to the output of the multi-input element OR, whose N inputs through the corresponding N first pulse drivers are connected to the device output slots, while the synchronizing input of the multi-rate N-channel recording unit is connected to the output of the second frequency divider, additionally introduced N write code converters, the outputs of which are connected to the corresponding information inputs of the multi-speed N-channel recording unit, and Pny inputs to the corresponding information outputs of the multi-speed N-channel playback unit, the second pulse shaper and the fourth frequency divider connected in series, the second input of which is connected to the output of the second frequency divider, and its output to the second inputs of the write code converters, N code converters playback, each of which contains a D-flip-flop, an RS-flip-flop, an inverter, the first and second elements AND, and the information input of the D-flip-flop is connected to the corresponding information input in the course of the multi-speed N-channel playback unit, with one input of the first element And, and through an inverter with one input of the second element And, the other inputs of the first and second elements And are connected respectively to the direct and inverse outputs D-TpHrrepai of the first and second elements And are connected respectively with the R- and S-inputs of the RS flip-flop, the output of which is connected to the corresponding device information bus, while the synchronization inputs of the D-flip-flops of the playback code converters are connected to the input of the second form pulse generator and synchronization output of the multi-speed .N-channel playback unit.

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

The device contains a multi-speed N-channel playback unit 1, the synchronization output of which is connected via frequency multiplication unit 2, the first

speed divider 3 frequencies and second frequency divider 4 to the synchronization input of the multi-speed N-channel recording unit 5, control unit 6 connected to the second input of the second frequency divider 4, fourth frequency divider 7 to two, the first input of which is connected to the output of the second divider 4 frequencies, and the phasing input through the second shaper of 8 pulses - to the synchronization output of the multi-speed N-channel playback unit 1, N converters 9 of the recording code, the first inputs of which are connected to the corresponding information ion N-outputs of the multi-channel reproduction unit 1, the second input - to the output of the fourth frequency divider 7 into two, and outputs - to the corresponding data inputs of the multi-N-KaHajjbHoro 5 recording block.

The device also contains N converters 10 of the playback code, the first inputs of each of which are connected to the corresponding information output of the playback unit I, and the second inputs of these converters 10 are connected to each other and the synchronization output of the multi-speed N-channel playback unit 1. In each converter 10 of the playback code, the first (informational) input is connected to the information input of the D-flip-flop 11, to the input of the first And 12 element and through the inverter 13 to the input of the second And 14 element. The synchronizing input of the D-flip-flop 11 is connected to the second (synchronizing) input of the 10 the playback code, and the direct and inverse outputs of the D-flip-flop are connected respectively to the second inputs of the elements 12 and 14. The outputs of the elements 12 and 14 are connected to the setup inputs of the RS-flip-flop 15. The outputs of the RS flip-flops 15 are connected to the output information ion shells and through the corresponding first formers of 16 pulses and a multi-input element OR 17 to the phasing input of the third frequency divider 18. The second input of the third frequency divider 18 is connected to the synchronization output of the multi-speed N-channel playback unit 1 and to the phase inputs of the first frequency divider 3 and the second frequency divider 4, the control input of the third frequency divider is connected to the control unit 6, and its output is to the bus device sync.

The device works as follows.

When playing the original at the speed VB, the binary information (Fig. 2a) at the output of the playback unit 1 is accompanied by synchronization signals

(Fig. 2 b), followed by a frequency fc. Synchronization signals go to frequency multiplication unit 2, at the output of which a pulse sequence with a following frequency is formed.

fv

 sn

where n is a constant number.

The pulse sequence from the output of the frequency multiplying unit 2 is fed to the input of the first frequency divider 3 at a speed with the magnitude of the division factor, at the output of which a pulse sequence with frequency is formed

 The generated pulse sequence with a frequency of 1d is fed to the input of the second divider 4 frequency, the magnitude of which is equal to n. At the output of the second divider 4 frequency, a square wave type oscillation is generated, which is fed to the clock input of the recording unit 5 with frequency

p. Un g Uz

.

 Ve vs

dep

The division factor of the second divider is selected using the control unit 6, which can be implemented, for example, as a set of switches.

If, for example, the recording speed of a copy is four times higher than the playback speed of the original (Vj 4Uv), then the frequency of the sync pulses at the input of the recording unit 5 is equal to

Ultrasound

 Gmmsn

-4fru.

Vb

FIG. 2 & shows the plot of the clock pulses supplied to the recording and to the input of the fourth divider 7 frequency into two. Phasing of the fourth frequency divider 7 by two is performed by pulses formed on the negative front (Fig. 2 g) of the playback clock by the second pulse generator 8, which can be made in the form of a single vibrator. Thus, the frequency of the sync pulses at the output of the fourth divider 7 frequency by two is always two times lower than the frequency of the sync pulses input to the recording (Fig. 2 9).

Information from the output of the multi-speed N-channel playback unit 1 (Fig. 2a) is fed to the corresponding transducers of the recording code 9, in which the synchro pulses (Fig. 2e) are output from the fourth divider

7 frequencies into two, recoding information is performed for each channel. Converters 9 write code can be made in the form of adders modulo 5 two. For the selected velocity ratio (UZ 4Uv), the unit (zero) of binary information at the input of the code converter 9 (Fig. 2a) is represented as a combination "1010 (" 0101) "on its course (Fig. 2e). Consequently, in the information sequence arriving at the inputs of block 5 of the record, the combinations "101" are always present and on the copy recorded by the modified phase modulation method there are always

tS magnetization drops at 2T intervals (Fig. 2 g), where T is the length of the bit interval of information received for recording (T) When playing a copy at a speed Vmin from the outputs of the multi-speed N-channel playback unit 1 playback information playback (Fig. 2 h) and the clock pulses (Fig. 2 and), accompanying the reproduced information with a frequency equal to f min, arrive at the corresponding inputs of the transducer code converters 10, in which the information is restored.

In each of the converters 10, the playback code information comes

Q on the L input of the trigger 11, N. and the input of the first element And 12 and through the inverter 13 to the input of the second element And 14, and the clock pulses arrive at the C input of the trigger 11, from the forward (Fig. 2k) and inverse outputs of which information shifted by time

5 1Ja11P comes respectively to the second inputs of elements 12 and 14. At the output of the first element 12, an impulse is formed (Fig. 2 l) if the information sequence meets the command 11 and an output is generated at the output of the second element 14 Fig. 2 m) if the combination "00." The pulses from the output of the element And 12 set the RS-flip-flop 15 to the state "1, and impulses from the output of the second element And 14

set it to "About

(Fig. 2 n).

Information from the outputs of converters 10 of the playback code (Fig. 2n) is fed to the output of the device and to the inputs

0 of the first formers of 1st pulses, which form narrow pulses (Fig. 2 o) for each differential information. These pulses are collected at the multiple input element OR 17 and are fed to the phasing input of the third divider 18 often, the division factor of which is VS / VB. For the selected ratio of speeds (UE 4Uv) the frequency of the sync pulses at the output of the third divider is 18 often

1 IjyiJTJlJlJTJ g

one

Claims (1)

DEVICE FOR RECORDING DIGITAL INFORMATION ON A MAGNETIC TAPE FOR DISPLAY MEANS, in which the synchronizing output of a multi-speed N-channel playback unit is connected to the input of a frequency multiplication unit connected in series with the first inputs of the first frequency divider in speed and the second frequency divider, as well as the first input of the third frequency divider frequency divider and to the second inputs of the first frequency divider in speed and the second frequency divider, and the third input of the first frequency divider in speed is connected to the control m output of a multi-speed N-channel playback unit, and the third input of the second frequency divider is connected to the output of the control unit and to the second input of the third frequency divider, the output of which is connected to the synchronization output bus, and its third input to the output of the multi-input element OR, N inputs which through the corresponding N first pulse shapers are connected to the output buses of the device, while the clock input of the multi-speed N-channel recording unit is connected to the output of the second frequency divider, distinguishing This is because, in order to reduce the error of the playback result by generating additional phasing intervals during dubbing, N transformers of the recording code are inserted into it, the outputs of which are connected to the corresponding information inputs of the multi-speed N-channel recording unit, and the first inputs to the corresponding information outputs of the multi-speed N-channel playback unit connected in series to a second pulse shaper and a fourth frequency divider into two, the second input of which is connected the output to the second frequency divider, and its output to the second _ inputs of the recording code converters, N § playback code converters, each of which contains a D-trigger, RS-trigger, inverter, the first and second elements And, and the information input D- the trigger is connected to the corresponding information output of the multi-speed N-channel playback unit, with one input of the first element And and through an inverter with one input of the second element And, the other inputs of the first and second elements And are connected respectively to direct and inverse the outputs of the D-flip-flop, the outputs of the first and second elements And are connected respectively to the R- and S-inputs of the RS-flip-flop, the output of which is connected to the corresponding information bus of the device, while the synchronizing inputs of the D-flip-flops of the transmitters of the playback code are connected to the input of the second pulse shaper and the synchronizing output of the multi-speed N-channel block playback. SU „„ 1103280