SU1064297A1 - Device for magnetic recording of digital information - Google Patents

Abstract

A DEVICE FOR MAGNETIC RECORDING OF DIGITAL INFORMATION, containing information inputs and synchronization frequencies, connected to the g-frequency (2) signal recording generator in the form of a sequence of voltage drops of a rectangular one. Forms, as well as an output recording amplifier, connected to a magnetic recording head, characterized in that, in order to increase recording density, a rectangular-shaped recording signal converter is inserted into the sawtooth-shaped recording signal connected between the output of the p-frequency signal former rectangular shape and input recording amplifier, made of sequentially. connected to the block of the division and distribution of the time intervals of the recording signal, the control voltage driver and the sawtooth voltage generator; the control voltage driver is designed as an equalizer on the operational amplifier with resistive feedback and 2p resistors, the inverting input of the operational amplifier with resistive feedback through the first h of resistors is connected respectively to the first n outputs of the block of separation and distribution of time intervals of the signal Apis second n outputs which, respectively through the second -rezistorov g connected to the noninverting input of the operational amplifier with a resistive feedback, bond and a clock input separation and allocation of time slots of the signal recording unit is connected to the input of sync rochastoty device.

Description

The invention relates to instrumentation, in particular, to recording and reproducing digital information on moving magnetic recording media, such as magnetic tapes, discs, drums, and can be used in devices. recordings of electrical signals presented in discrete form.

Magnetic digital information recording devices are known, which form a recording signal in the form of a sequence of square-wave differential drops. These devices implement recording methods with frequency modulation (FM), phase modulation (FM), with no return to zero modified (4/5 BVNM) and other G1.

however, as the recording density of these devices increases, in order to correct the amplitude and phase distortions of the reproduction signal that occur, various pre-distortions must be introduced into the recording signal. The predistortion parameters are usually not calculated and determined experimentally, which complicates the design of such devices and makes them difficult to adjust and adjust, which does not allow for an increase in the recording density.

The closest to the present invention is a device for magnetic recording of digital information, containing information and sync frequency inputs connected to a p-frequency (n 7/2) recording signal generator in the form of a series of square voltage drops, as well as an output recording amplifier connected to magnetic

recording device. This device implements a recording method with modified phase modulation and forwards a three-frequency signal.

records in the form of a sequence of voltage drops of rectangular form, while the time intervals between differences can - have a duration of 1 T, 1, 5 T and 2 T, where T is the duration of the clock interval 2,

A disadvantage of the known device is also a low recording density.

The purpose of the invention is to increase the recording density of digital information.

The goal is achieved by the fact that. A device for magnetic recording of digital information, containing information and sync-frequency inputs, connected to the p-frequency shaper of the recording signal as a sequence of square-wave voltage drops, as well as an output recording amplifier connected to the magnetic recording head; of a square-shaped recording signal, included between the output of a square-shaped and-frequency signal generator and input of a recording amplifier, made of unit connected to the separation and distribution of the time intervals of the recording signal, the control voltage generator and the sawtooth voltage generator, while the control voltage driver is designed as a totalizer-subtractor on an operational amplifier with resistive feedback and 2p resistors, moreover, the inverting input

A Q op amp with resistive feedback through the first h of the resistors is connected respectively to the first n outputs of the time division and distribution unit.

5 intervals of the recording signal, the second n outputs of which, respectively, are connected via the second n resistors to the non-inverting input of an operational amplifier with resistive feedback, and the synchronizing input of the separation and distribution unit of the signal. The recording clock is connected to the clock input of the device.

Fig. 1 shows structures on the scheme of the device proposed, for example, in the case when the recording signal is three-frequency (3), formed by modified phase modulation, with durations of 1T, 1.5Ti2T recording time intervals; 2 - timing diagrams for the operation of the device; Fig, 3 is a block diagram of the block

5 dividing and allocating time slots of a recording signal; FIG. 4 shows timing diagrams explaining the operation of this unit.

The same elements, repeated in FIGS. 1 and 3, as well ;; (the diagrams of the same signals repeated in FIGS. 2 and 4 have the same reference numerals,

e Magnetic recorder digital. information (fig. II contains information input 1 and synchronization frequency input 2 connected to a three-frequency recording signal generator 3, output 4 of which is connected to the first input of the recording signal time distribution and time interval 5, the second input of which is connected to the synchronous frequency input 2 of the device The outputs of the block for dividing and distributing the time intervals of the recording signal are buses 6-11 connected to the inputs of the control voltage generator 12, made in the form of an adder-subtractor at the operating theater. The receiver is 13 with resistive feedback and 2p resistors, the first n outputs of which (buses 7, 9 and 11I are connected via the first P weight resistors with an inverting, and the second n outputs (tires 6jt 8 10) are connected to the non-inverting input operational amplifier with resistive feedback.

The output of the control voltage driver 12 is connected to the input of the generator 14 of a sawtooth voltage, made, for example, in the form of an integrator. The output of the sawtooth generator is connected to the input of the output recording amplifier 15, the output connected to the magnetic recording head 16.

The series-connected separation and distribution of the time intervals of the recording signal, the control voltage generator 12 and the sawtooth generator 14 form a square wave recording signal converter into the sawtooth wave recording signal.

The device works as follows.

From the input information signal and the synchronization frequency (plots a and b of Fig. 2), the p-frequency recording driver generates a three-frequency (p-3) recording signal (the plot in Fig. 2) input to the input of the division and timing distribution of the recording signal, on the other input-which pulses are synchronized. In the block-division and distribution of time intervals of the recording signal, the signal (plot in, fig. 2) is divided into separate intervals depending on their duration and polarity and distributed over separate buses {diagrams r1, r2, d1, e2, el, e2, fig. 2). .

The intervals of duration IT, 1, 5 T, and 2 T, the polarity of which is positive (for example, corresponds to a high level of voltage in the signal in, Fig. 2) go to tires 7, 9 and 11 (Fig. 1) and through the weight resistors are non-inverted. the operational input of the operational amplifier with resistive feedback, and the intervals, the polarity of which is negative (for example, corresponds to a low voltage level in the signal in, Fig. 2J goes to buses b, 8 and 10 (Fig. 1) and through such

same weight resistors on the non-inverting input. operational amplifier with resistive feedback.

The resistance values of the weight resistors are chosen in such a way that the ratio of the resistance value of the feedback resistor R 1 to the resistance value of the weight resistor corresponding to the given interval is inversely proportional to the duration of this interval. The resistance value of the resistor R2 is taken to be equal to the resistance value of the parallel-connected weight resistors connected to the non-inverted. to the operating input of the operational amplifier with resistive feedback. Thus, for time intervals with durations of 1 T, 1, 5 T

0 and 2 T and the nominal value of the feedback resistor, the ratings of the weight resistors should be R, 1.33 R and 2R, respectively.

five

At the output of the control voltage driver, a voltage of a stepped form (plot x, fig. 2) with alternating polarity in adjacent time intervals,

0, while the absolute values of the voltage amplitude at each interval are inversely proportional to the duration of these intervals. The control voltage arrives

5 to the input of a sawtooth voltage generator, at the output of which a recording signal is formed (plot and, FIG. 2) 3 as a sequence of sawtooth voltage drops, with each time

0 interval, the voltage varies linearly and in opposite directions for adjacent intervals, and at the boundaries of the intervals the absolute values of the voltage are equal for all

5 values of the duration of these intervals. .

A sawtooth recording signal (plot and, fig. 2) is fed to a floating recording amplifier, which bakes a sawtooth write current (plot to, fig. 2) of the required value in the magnetic recording head.

Block 5 of the separation and distribution of signal time intervals

5 records (Fig. 1), a block diagram of which (for the case of a three-frequency recording signal) is shown in Fig. 3, contains information input 4 and synchro-frequency 2, output buses of the recording signal inter-shaft 6-11, the first delay element 17 shifting register 18, elements one through four are EXCLUSIVE OR 19-22, sec. swarm delay element 23, two-input element OR 24, first, second

five

and the third elements NB 25-27, from the first to the sixth three-input elements I. 28-3.3, combined in pairs into three groups, the first to the sixth D triggers 34-39, unified in pairs into three groups.

In the general case, for a recording signal with the number of gradations of time intervals fi73 (n 4.5 ... |, the block of separation and distribution of time intervals of the recording signal contains a shift register with the number of bits +3, (n + 1) EXCLUSIVE OR, (n -2) two-input elements or, n elements, NOT, 2h three-input elements, And, 2p D-flip-flops and 2p output tires of intervals, and the reshaping voltage former at Etbm should have 2p weighting resistors. given without reference designators, and the additional links to them are shown dotted line.

The output 4 of the three-frequency recording signal generator is connected to the D input of the shift register 18, to the C input of which a synchro-frequency input 2 is connected via a delay element.

The first bit of the shift register 18 is connected to the first input of the first element Exclusive OR 19, the second bit of the shift register is connected to the second input of element 19, as well as to the combined first inputs of elements AND 29-31 and 33 directly, and through the first element NOT 25 - .with combined first inputs of elements AND 28, 30 and 32. The third bit of the shift register is connected to the first input of the second element Exclusive OR 20, and the fourth bit of the shift register is connected to its second input, each next bit of the shift register Istra is connected to the second input of the previous one and the first input of the subsequent XOR element, the last bit of the shift register is connected to the second input of the last element; EXCLUSIVE OR 22.

The outputs of element 20 are connected to the combined second inputs and the third inputs of elements AND 28 and 29, the outputs of the third element Exclusive OR 21 are connected to the combined second inputs And 30 and 31, the output of the fourth element Exclusive OR 22 is connected to the combined inputs of elements And 32 and 33 .

The output of element 20 is also connected to the first input OR 24 and the second element HE 26, the output of element 21 is connected to the second input OR 2, and the output of element OR 24 is connected to the input of the third element NOT 27. The outputs of the elements HE 26 and 27 are connected respectively to the combined pairs the third inputs of the three-input elements And 30 and 31, 32, -and 33. The outputs of each element And 28-33 are connected respectively to the D-input of the triggers 34-39, and the C-inputs of these triggers are combined and connected to the output of the first element EXCLUSIVE0 JUST OR 19 through the second element 23 of the delay.

The outputs of the flip-flops 34-39 are the output buses 6-11 of the separation and distribution unit of the time intervals of the recording signal, which operates as follows.

The three-frequency recording signal arrives at the f-input of the shift register, and the synchro-frequency, which is delayed in the first delay element at the time ––– 0.5 T, arrives at the C-input of the shift register (plots a and b, respectively, Fig. 4J.

In the shift register, the time delay of the recording signal was made (diagrams B1-WB, Fig. 4)

At the output of the first element, Exclusive OR 19 (Fig. 3), a signal is produced (plot l1, fig. 4),

whose front-fronts correspond to the boundaries of time intervals. Through the second delay element, this signal (plot M1, Fig. 4 enters the combined C-inputs of the trigger 34-39 (Fig. 3), and its

the leading edge is triggered by the trigger, which has a level 1 on the B-input at that moment, and the trigger on which the output had before

this level 1.

The control of the D-inputs of the flip-flops is made by: output signals of the And 28-33 elements.

In turn, the control signals are formed by AND 28-33 elements, depending on the polarity of the intervals, for which from the second bit of the shift register, a signal is received from elements 29, 31 and 33 (plot B2, Fig. 4), and elements 28 and 30 and 32 the same signal is fed in antiphase through the first element NO.

The separation of intervals according to their duration occurs when pairwise comparison of adjacent bits, starting with the third bit, shifting the register on the elements EXPRESS; SHARING OR 20-22 (plot l2-l4, fig. 4 | with

At the outputs of the second and third elements, signals (diagrams m2, c3, Fig. 4) of blocking the passage of intervals of 1.5 T and 2 T in duration are not produced in the presence of intervals of 1 T, and intervals of 2 T in the presence of intervals of 1.5 T, the blocking signals are sent to the corresponding cells And 30-33. The first pair of elements And 28 and 29 and triggers 34 and 35 allocate intervals of 1 T, corresponding to the positive and negative polarities of these intervals in the multi-frequency input signal (diagrams u1, z1 and z2, fig. 4). The second pairs of elements And 30 and 31 and triggers 35 and 36 have intervals of 1.5 T in duration of positive and negative polarity (plots P1 and P2, E1 and E2, Fig. 4). The third pairs of circuitry of the elements 32 and 33 and flip-flops 38 and 39 distinguish intervals of 2 T of positive and negative polarity of the diagrams C1 and C2, el and e2, FIG. four.). From the outputs of the flip-flops 34-39, which are also the outputs of the division and distribution of the time intervals of the recording signal, the intervals of 1 T, 1.5 T and 2 T distributed across the individual HbJM buses in the form of voltage corresponding to level 1 are input to control voltage driver. The technical advantage of the proposed device is that it provides recording density and 1.5–2 times more than the known device for recording digital information with modified phase modulation, since the recording on the carrier is carried out by a sawtooth current and non-angled current vapor, as in the known device, which reduces the phase distortion of the reproduced signals, and thus allows to increase the density. Increasing the recording density makes it possible to increase the information capacity of the magnetic recording equipment or to reduce the consumption of the carrier.

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Claims (1)

DEVICE FOR MAGNETIC RECORDING OF DIGITAL INFORMATION, containing information inputs and clock connected to the shaper of the r-frequency (>> 2) recording signal in the form of a sequence of voltage drops of a rectangular .form, as well as an output recording amplifier connected to a magnetic recording head, different the fact that, in order to increase the recording density, a rectangular-shape recording signal converter is introduced into a sawtooth-shaped recording signal, connected between the output of the shaper of the h-frequency signal, a rectangular form and the input of the recording amplifier, made of sequentially ·. connected unit separation and distribution of time intervals of the recording signal, the driver of the control voltage and the sawtooth voltage generator, while the driver of the control voltage is made in the form of a sum-calculator on an operational amplifier with resistive feedback and 2p resistors, and the inverting input of the operational amplifier with resistive feedback through the first η resistors are connected respectively to the first η outputs of the separation and distribution unit of the recording signal time intervals , the second η of the outputs of which, respectively, through the second η-resistors are connected to a non-inverting input of the operational amplifier with resistive feedback, and the synchronizing input of the unit for separation and distribution of time intervals of the recording signal is connected to the sync frequency input of the device. SU.1064297 Fig. 3