JPS62273610A - Multi-track type digital magnetic recording circuit - Google Patents

Abstract

PURPOSE:To reduce number of circuit connections and the circuit scale by using one constant current source and making a pulse required for pulse train recording the same as a signal driving and controlling a recording head. CONSTITUTION:n-Set of series circuits each comprising switching elements SK1, SL1-SKn, SLn are connected between a constant current source CI and ground and a series circuit comprising elements SKC, SLC is connected. One end of recording heads H1, H2-Hn is connected to a connecting point of the elements SK1 and SL1 and the other end is connected to a connecting point of the elements SKC and SLC. In turning on the elements SK1, SLC, a recording current +I flows and in turning on the elements SL1, SKC, a current -I flows. In controlling the elements SK1-SKn, SL1-SLn and SKC, SLC, a panel current flows to heads H1-Hn. In this case, a phase difference is given between the heads and the current I does not simultaneously to the head by controlling the switching element source group, then a magnetic pattern (pulse train recording) by a consecutive magnetization region on each track of a magnetic tape medium is obtained, power consumption is reduced to reduce the temperature rise due to heating and crosstalk is reduced.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (Field of Industrial Application) The present invention is directed to a digital magnetic recording/reproducing device, particularly a multi-trunk type digital magnetic recording/reproducing device having a finite plurality of tracks. This relates to a multi-track digital magnetic recording circuit that performs multi-track recording. A device has been developed that generates a clockable digital signal, records it on a magnetic recording medium such as magnetic tape, and plays it back.1) When an analog signal is converted to a digital signal,
Digital magnetic recording and reproducing devices require a much wider frequency band than conventional analog magnetic recording and reproducing devices.

A multi-track digital magnetic recording/reproducing device is designed to reduce the recording density per track by distributing digital signals to a plurality of tracks.

In conventional digital magnetic recording, a model of a magnetization pattern as shown in FIG. 4(b) is created on a magnetic tape medium by passing a rectangular wave alternating current as shown in FIG. 4(a) through a recording head. Record. A circuit for performing such recording is, for example, composed of a magnetic recording circuit using positive and negative power supplies as shown in FIG. 6. In FIG. CI211 ”' * CI n
l is a positive constant current source, C112, CI22 . ...,
cr□ is a negative constant current source, 5lll S21@ ”'*
Snt is a switching element for flowing a recording current to the recording head H; Sun82□,...+Sn
2 is a switching element for causing a recording current to flow through the recording head H.

When multi-tracked as shown in Figure 6,
Two constant current sources are required for each recording head, which also increases power consumption.

Furthermore, problems such as complicated wiring arise in connection between the recording head and the drive circuit.

On the other hand, instead of using a rectangular wave current as shown in FIG. 4(a) above, a current as shown in FIG. 5(a) with a pulse width necessary for magnetically reversing the magnetic tape medium is used. By passing a pulsed current through the recording head, the magnetic pattern on the magnetic tape medium is created such that the magnetized area is continuous, as shown in FIG. 5(b), and is approximately equal to the magnetized pattern in FIG. 4(b). Become. This method is called pulse train recording.
Power consumption is reduced, temperature rise due to heat generation is reduced, and crosstalk is reduced.

<Problems to be Solved by the Invention> However, even when performing pulse train recording, a current source and drive circuit are required for each recording head, and a recording pulse signal is required separately from the signals that control each switching element. However, the circuit scale becomes larger when multi-track is used.

The present invention was devised in view of the above points, and an object of the present invention is to provide a multi-track digital magnetic recording circuit that performs pulse train recording with a simple circuit configuration.

Means and operation for solving the above problems In order to achieve the above object, the present invention provides a multi-track digital magnetic recording and reproducing device that records digital signals on a finite plurality of tracks. Each of a plurality of switch circuits formed by connecting two switching elements in series is connected in parallel between a power supply and a reference potential, and each of the first and second switching elements of each switch circuit is connected in parallel. Connect one end of each of the plurality of recording heads to the third
and a fourth switching element connected in series is connected between the power supply and the reference potential, and the connection point of the third and fourth switching elements is connected to the plurality of recording heads as well as the plurality of recording heads. The ends of the switching element are connected in common, and the first switching element is turned on, and the fourth switching element is turned on.
or the second switching element described above is turned on.
The above-mentioned switching elements are controlled to turn on the above-mentioned switching element and the above-mentioned third switching element is also turned on, so that a recording current is caused to flow in one direction or the opposite direction to each of the above-mentioned recording heads. are doing.

Further, as an embodiment of the present invention, the means for controlling each of the switching elements described above to cause a recording current to flow through the recording head is the same as the signal that operates the means for latching and controlling digital data recorded by the recording head. It is configured to operate with the following signals.

That is, the present invention uses one constant current source, and furthermore, in an embodiment, uses the same signal for the pulses necessary for pulse train recording and the signal for controlling and driving the recording head. Embodiment 1 An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram showing the basic configuration of a multi-track digital magnetic recording circuit according to an embodiment of the present invention.

In FIG. 1, CI is a constant current source, and switching elements SKI, SLl, and S
K□ and S L 21-+ S K n (!: S L n
n series circuits, that is, a series circuit of a first switching element and a second switching element, are connected, and a third
switching elements. and a fourth switching element S,
c series circuit is connected, one end of each of the plurality of recording heads H, IH2+, Hn is connected to each connection point of the first switching element O and the second switching element S, and 3 switching elements. A plurality of recording heads H are connected to the connection point between the switching element SLo and the fourth switching element SLo.
The other ends of 1 to Hn are commonly connected.

In the above configuration, for example, the switching element S
By turning on KI and switching element SLc, a recording current flows through the recording head H1 as indicated by the solid arrow. Further, by turning on the switching element SL1 and the switching element SKc, a recording current flows through the recording head H1 as indicated by a dotted arrow. Recording head H
The same applies to 2 to H. Moreover, the switching elements SKI to 5Knl SL1 to SLn and the switching elements SKI to 5Knl and SL1 to SLn. , Wang. is controlled, and a pulse current is applied to the recording heads H1 to Hn, for example, as shown in FIG. 5(a). This pulse current gives a phase difference between the recording heads H1-Hn, and the recording heads H1-Hn
By controlling the switching elements so that the recording currents do not flow simultaneously, it is possible to record a magnetization pattern as shown in FIG. 5(b) in each trunk Vc on the magnetic tape medium.

FIG. 2 is a circuit diagram showing details of the main parts of a multi-track digital magnetic recording circuit according to an embodiment of the present invention.
FIG. 3 is a timing chart showing the signal flow in FIG. 2, just in case it corresponds to the recording head of FIG.

In FIG. 2, CI is a constant current source, H1 to H4 are recording heads, QKI to QK41, QL1 to QL4, and QKoIQ.
I...! are the first switching element group, the second switching element group, and the third switching element group in FIG. 1, respectively. Fourth
The switching element corresponds to the switching element of , and is composed of a transistor. 1.2 and 3 are D-type flip-flops 70, respectively. Data to be recorded given to the terminal is inputted to the D-type flip-flop 1, and is clocked by the clock signal CK. The address signals A and B of the recording heads applied to the terminals A and B correspond to the input 0 address signals A and Bi' to the recording heads H8 to H4,
For example, recording head H1 (B=0°A-0), H2 (B=
O, A=1), H3(B=1, A-0), H
a (B=1, A=1).

The output of the D type flip 70 tube 2 is N A N D game.
) 5.7, the output of the NAND gate 4.6, and the output of the D-type flip-flop 3 is added to the NAND gate 4.6.
The outputs are applied to NAND gates 6 and 6, and the mutual outputs are applied to NAND gates 4 and 5, and signals T1 to T4 are output from NAND gates 4 to 7, respectively. The signals T0 to T correspond to the recording heads H1 to H4, respectively. For example, when the recording head H1 records recording data D corresponding to the recording head H1, the signal T1 becomes L#. T, is input to one input terminal of NOR gates 9-12, respectively, and K, which is the output of 10 D-type flip-flops, is input to the other input terminal of NOR gates 9-12.

A signal is input, and signals 1 to 4 are output from NOR gates 9 to 12, respectively. The signal Kl- becomes mHa when the signals T1 to T4 are respectively 1L" and the ζ output of the D-type flip-flop 1 is 1L#. That is, in each of the recording heads H1 to H4, When the data D to be recorded is 1H'', the signals 1 to 4 are 1H#, and the transistors QKI to QK4 are turned on and operate.

On the other hand, the output signal of the NOR gate 18. is clock C
It is obtained as a NOR output signal of K and signal K, and when clock CK is L' and signal Kc is L#, signal L
0 becomes H. That is, the data D to be recorded is s Ha,
When the clock CK is at L#, the signal L is at "H1" and the transistor QLo is turned on.

Therefore, in the recording heads H1 to H4, when the recording data D is 1H#, the respective transistors QKI to
When QK4 is on and the clock CK is V''L'', the transistor L0 is turned on and a recording current flows through each of the recording heads H1 to H1.

Next, the signals RI and ~L4 are each connected to the signal T at one input terminal.
1 to T4 are input, and NAN is input to the other input line.
NOR gates 14 to 1 to which the output of the D gate 13 is input
The signals L1 to L4 are obtained as the outputs of the gate 13 when the signals T1 to T4 are %L', the signal K is 1H#, and the clock CK is 1L# (that is, the output of the gate 13 is 1L#). ), it becomes 'H#. That is, in each of the recording heads H1 to H4, the data D to be recorded is %
When the signal is L# and the clock CK is 1L#, the signals L1 to L4 are 1H#, and the transistors QLI to QL
4 operates when turned on. On the other hand, when the recording data D is 1L#, the signal K is set to H1, and the transistor QKc is turned on.

Therefore, in the recording heads H1 to H4, when the recording data D is II La, the transistor QK.

is on, and when CK is %LII, each transistor QLI~QH4id is on,
A recording current -■ flows through each of the recording heads Ht-H4.

As described above, by inputting the address signals A and B of the recording head to be recorded, the data D to be recorded, and the clock CK, the recording current engineer corresponding to the recording data D to the recording heads H8 to H4 can output the clock CK. flows for a pulse width of 1 L'', and a magnetization pattern as shown in FIG. 4(b) is recorded on each track on the magnetic tape medium.

As described above, in the embodiment of the present invention, a digital magnetic recording circuit that uses pulse train recording of a multi-track digital magnetic recording and reproducing apparatus that records digital signals on a finite plurality of tracks performs pulse train recording. By using the same signal for the pulses needed to control and drive the recording head, and by using one constant current source, it is possible to reduce the circuit connections and circuit size, making it easier to integrate into LSI. <Effects of the Invention> As described above, according to the present invention, the number of wires between the head and switching elements can be reduced, and the circuit scale can therefore be reduced, making it easier to implement into LSI. be suitable.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the basic configuration of a multi-track digital magnetic recording circuit according to an embodiment of the present invention, and FIG. 2 is a diagram showing details of essential parts of a multi-track digital magnetic recording circuit according to an embodiment of the present invention. Circuit diagram, Figure 3 is a timing chart showing the signal flow in Figure 2, Figure 4 (a) is a diagram showing the recording current waveform, Figure 4 (b)
is a diagram of the magnetization pattern of the magnetic tape medium, FIG. 5(b) is a model diagram of the magnetization pattern of the magnetic tape medium during pulse train recording, and FIG. 6 is a diagram showing a conventional magnetic recording circuit. OCI・
...constant current source, SKI~SKn...first switching element, SL, ~S0. n...second switching element, sKc...third switching element, Hl-H...recording head, QK1 to QK
4゜QL! ~QL41 QKO'QLc...Transistor, A, B...Address signal, D...Record data, CK...Clock signal. Agent Patent attorney Itaru Sugiyama Mata (1 other person) ζ, C Figure 2 (bJ Figure 5

Claims (1)

[Claims] 1. In a multi-track digital magnetic recording and reproducing device that records digital signals on a finite plurality of tracks, each of a plurality of switch circuits each comprising a first and a second switching element connected in series. the first and second switching elements of each switch circuit are connected in parallel between the power supply and the reference potential, and one end of each of the plurality of recording heads is connected to each connection point of the first and second switching elements of each switch circuit; A switch circuit formed by connecting switching elements in series is connected between a power source and a reference potential, and the other ends of the plurality of recording heads are commonly connected to the connection point of the third and fourth switching elements. The first switching element is turned on and the fourth switching element is turned on, or the second switching element is turned on.
Each of the switching elements is controlled so that the third switching element is turned on and the third switching element is turned on, so that a recording current flows through each of the recording heads in one direction or the opposite direction. A multi-track digital magnetic recording circuit. 2. The means for controlling each of the switching elements to flow a recording current to the recording head is operated by the same signal as the signal for operating the means for latching and controlling digital data to be recorded by the recording head. A multi-track digital magnetic recording circuit according to claim 1, characterized in that: