SU777694A1 - Device for multichannel magnetic recording and reproducing - Google Patents

Description

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heHdauHK) are warped distortions due to speed fluctuations in the main channels. This makes the device YY (the number of main channels is good, and the accuracy of compensation in such analog devices is low.

In addition, due to the complexity of creating analog controlled latency with high and technical AND operational characteristics, the named device is suitable. only for use with D-modulated recording equipment. This narrows its scope.

The purpose of the invention is to improve the accuracy of the compensation of temporal distortions, simplify the device and expand the scope of its application. The goal is achieved by connecting the input of a high-pass filter parallel to the second low-pass filter to the multiplier output, to the output of which through the control unit of clock pulses the inputs of controllable delay lines are connected, and to the output of the main signals and the inputs of the first low filters in each case, the calories of the LYUNY are connected via noncontrolled lines (a delay line, an analog-code converter, a buffer memory, the second input of which is connected to the output of the common generator constant frequency and preobradrvatel kodanalog.

In addition to that, the extreme heads of the power supply unit are connected to one output of the periodic voltage generator directly and through a phase shifter.

The device has a "switch of the number of the playback heads and the mode of the scaling device".

The drawing shows a block diagram of a device for recording and playing back multi-channel information (the dotted line shows the head of the third main channel, the number of main channels can be arbitrary). . - The recording device contains a block / recording heads, including the head 2 recording reference signals and the head 3 recording the main signals. The extreme positions 2 are connected to the iK outputs of the generator 4 periodic voltages shifted by 90 °. Sources or blocks of transformations of analogs from the channels are connected to the inputs of the heads 3.

The reproduction apparatus comprises a block 5 of reproducing heads of the support base b and heads of the main signals 7. (Kaisda from ShLGLKL4 Cheoia 7): Tresan after 1 connected uncontrolled delay line 5, converter 9 analog-code. | Buffer memory 10, JJ code-anadtog converter and first low-pass filter 12. Two reproduction heads 6 signals connected to

777694

 the inputs of the phase detector 13, which is a second filter / 5 low frequency in series connected multiplier ili4ii. The output of the voltage multiplier M is connected via a high-pass filter J6 and a clock pulse shaper J7 to inputs of controlled delays / i8 delayed 1K, whose control inputs are through scalers 19

connected to the output of the phase detector /. The second inputs of all buffer memories 10 are connected in parallel to the output of the reference frequency generator 20. The dotted line shows the phase shifter 2 /.

Due to the skewing of the recording and playback heads, as well as due to the transverse oscillations of the magnetic carrier, signals from different tracks during multi-track recording are shifted into spemes during playback. These temporal distortions can be eliminated by quantizing the signals from different tracks about the shift of 1a.kt. quantization pulses from each channel taking into account the time shifts,

to introduce you, borki-in buffer memory with a variable in the general case, the frequency and non-phase, and to output from them simultaneously on all channels with a reference frequency. The required time shifts clock

quantization pulses are provided with delay lines on the control signals produced by the phase detector .13. As a result, temporal distortions due to

skewed. At the same time, since the s1G time error due to skewing is highlighted by the phase detector L by comparing the reference sipnals of the outer tracks, then the assumed change in magnitude

skewing the width of the carrier, it is necessary to change the amplitude of the control signal applied to the control inputs of the 1S delay line. This is accomplished by scaling devices 19 including voltage dividers and scale amplifiers. Static distortions, having the character of a change in the width of the carrier, other than linear, are detected during adjustment and are also taken into account by scaling devices.

The device under consideration can simultaneously perform with high accuracy knation of temporal distortions caused by fluctuations of the velocity of the nose, e, and tactile pulses. the main signals to form from the reference signals, recorded simultaneously with the main and susceptible time distortions to the same extent as

main signals. The selection of the signal obtained as a result of the multiplication of the signal doubled, the frequency of the reference signal performed by the filter with a 1/5 high-pass filter, and the formation of a clock pulse from it by the driver of the 1/7 ..

Scale devices J9 divide the amplitude of the error signal and form its necessary phases before feeding to the control inputs of the controlled delay lines J3. Passing through the delay line 18 from the generator of 17 clock pulses, the clock pulses in each cell are delayed in accordance with a bias of the heads in this and arrive at analog-code converters 9 converters 9 precisely at the moments when the first Scalgers, having passed the previously uncontrollable delay lines S. Discrete selections enter the buffer memories J unevenly, “about the addresses of the memory cells where the first and subsequent samples arrive, in all the channels coincide. The addresses of the memory cells also coincide, starting from which they start reading with the frequency of the reference oscillator 20. In the result, the analog signals received at the outputs of low-pass filters J, after converting the samples, in the L-analog converter, are completely compensated for - of sin.

The frequency of the generator 20 is equal to the average frequency of the clock pulses.

The medium speed of the carrier must be kept stable, otherwise overflow or zeroing of buffer memories may occur. If this is not done, an automatic control system is introduced (not shown in the drawing), and the control signal can be generated by the degree of filling one (any) block 10 of the buffer memory.

The delay line ./5 is a single waiting multiv1b, a rator in the formation of delays for smaller periods of clock pulses, or several series connected in series for longer delays.

The uncontrollable delay line 8 in the target of the main signal provides high accuracy in compensating temporal distortions caused by both skewing and speed fluctuations (due to the equalization of the time shifts of the main signals in relation to iK clock pulses. The same condition the main signal and clock pulses, formed from the reference signal, to the inputs of converters P analog7 code, as well as in the following circuits: high-pass filter 16 - driver / 7 clock pulses n filter 15 lower their frequencies - scale unit / 9 Instead uncontrolled proxy delay lines may be incorporated lowpass filters,...

To obtain two periodic voltages when recording with a phase shift of 90 °, a special generator is required. The recording device is greatly simplified.

if the signal is sent to one of the heads 2, the reference signals are fed directly from the generator of the single cell voltages, and to the other through the phase shifter 21 S with a phase shift of 90 °. Phaser can be, for example, lnnn delay per quarter of the reference frequency reference.

iB of those multichannel devices of magnetic recording, in which there is no need to simultaneously reproduce the main

signals on all Channels, but only on

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Large-scale device and head modes

reproduced 7 block 5. This allows

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To Any Head 7.

Such a system simplifies the device. The simplification of the device is to exclude the channel reference frequency. Introducing the high-pass filter 0 allows you to select a double reference frequency, which, after the clock generator, can be used to quantize the main signals. At the same time, the NS5 is the frequency multiplier normally required in such devices.

The expansion of the areas of prnmennn consists in the fact that this device can be used to compensate for temporal transient signals not only of frequency-modulated signals, but also on any analog signal that allows them to be quantized. This is achieved by introducing into the device of converters .9 analog-crd, buffer 5 memories 10, converters // analogue code n of generator 20.

Claims (2)

Formula of Acquired 0 I. Device for multichannel magnetic recording n reproduced, containing a block of heads, whose two heads, a driver, located on the “th block”, are connected to the generator outputs 5 .Periodic stresses shifted by phase. at 90 °, and the rest are for connecting to the main sources signals, n playback head unit, two golos yorotgb, yosprbnzvod shye 0 reference stubs, connected to two inputs of a phase detector, representing a sequentially connected multiplier is strained and is a high-pass low-pass filter, the output of which is through 5 scaled devices are connected to control inputs of controllable delay lines, the rest of the playback heads are connected to the corresponding outputs through the first low-frequency filters, 0 characterized in that, in order to improve the accuracy of the compensation of temporal distortions, simplify the device and expand its area of application, multiply voltages are parallel to the output 6 second low pass filter podklyu7; y,; An introduced high-pass filter, to the output of which, through the driver of clock pulses, are connected the inputs of controllable delay times, and between the outputs of the playback heads of the main signals and the inputs of the first low-pass filters in each channel there are consecutively connected uncontrolled delay lines, analog-code converter, a buffer memory, the second input of which is connected to the top of a common reference frequency generator and a coding converter. 2. The device according to claim 1, characterized in that the extreme heads of the block of recording heads are connected to one output of a periodic voltage generator directly and through a phase-cutter .. 3. The device according to claim 1, characterized in that a playback number switch is entered n mode device scaling. Sources of information taken into account in the examination: I. USSR Author's Certificate No. 323793, .cl. G Ы iB 5/00. 1971. 2. USSR author's certificate No. 317098, cl. G IV 5/04, 1970 (prototype). Jmr I-nr