JPS60261004A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To increase a reproducing voltage by providing an adder adding outputs of plural reproducing amplifiers connected respectively to plural windings interlinking with a magnetic circuit in a magnetic head. CONSTITUTION:A reproducing voltage is generated in windings 11, 12 to a reproduced magnetic flux of a magnetic head core, and since the plural windings 11, 12 and the reproducing amplifiers 13, 14 are provided in the same magnetic circuit, then a reproduced output becomes a voltage corresponding to the entire winding number 2N (N is the winding number of each winding). A resonance frequency deciding the operating possible band as a magnetic head depends on the product between the inductance and the stray capacitance of each winding, even when plural winding groups are provided, the resonance frequency is the same as the case with a single winding. As a result, while the reproduced output is increased to a value corresponding to the total winding number 2N, the resonance value is kept to a high value of the each split winding.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to magnetic recording and reproducing devices such as fixed magnetic disk drives, flexible magnetic disk drives, and magnetic tape devices.

Structure of a conventional example and its problems FIG. 1 shows a conventional magnetic recording/reproducing apparatus. The configuration of this conventional example will be explained below with reference to FIG. 1.

In FIG. 1, 1 is a magnetic head, and this magnetic head 1 detects changes in magnetic flux of a magnetic recording medium. Reference numeral 2 denotes an amplifier for amplifying the reproduction voltage of the magnetic helad 1, and the output of the amplifier 2 is guided to a signal processing circuit 3 for demodulation.
Obtain the desired signal.

On the other hand, a write circuit 4 is also connected to the magnetic head 1 and applies a write current to the magnetic head 1 as required.

Next, the operation of the conventional example No. 1 will be explained.

The reproduction voltage EP detected by the magnetic head 1 is
For the magnetic flux ψ in the magnetic circuit interlinked with the windings (number of turns N), Bp = N * (& ψ/”) ・----・(t
) is given in a time differential form proportional to the number of windings.

On the other hand, the winding of the magnetic head 1 has an inductance L, and the inductance has the relationship L - N2 (2) with respect to the number of windings N. . Furthermore, the inductance forms a resonant system due to the stray capacitance C, and the resonant frequency f of the resonant system. is, fo = 1/2πvL - ・・・・・・・・・・・・(3
). The operating area of the magnetic head 1 is the above (3)
) is given by the formula. Limited to the following frequency ranges.

In the above conventional example, if the number of windings N is increased in order to increase the reproduction voltage based on the above equation (1), the above (21
, (as is clear from Equation 31, the resonant frequency was lowered and the upper limit of the usable frequency range was lowered. In other words, in order to secure the usable frequency range of the magnetic head 1, In this case, the number of windings must be kept below a certain value, and therefore, the upper limit of the reproduction voltage has also been determined.From equation (3), reducing the stray capacitance C is effective in increasing the resonant frequency. However, it is not necessarily easy to reduce the stray capacitance in reality.

Purpose of the Invention The present invention eliminates the drawbacks of the conventional example described above, and aims to increase the number of windings and increase the reproduction voltage without reducing the usable frequency range as a magnetic head. It is something to do.

Structure of the Invention In order to achieve the above object, the present invention provides a plurality of windings provided in the same magnetic circuit of a magnetic head and a plurality of windings configured to connect each of the winding groups to one amplifier. It is equipped with a group of regenerative amplifiers, and has the effect of increasing the reproducing voltage while keeping the resonant frequency of the magnetic head constant.

DESCRIPTION OF EMBODIMENTS The configuration of an embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2, reference numeral 10 denotes a core forming a magnetic path of the magnetic head, and a plurality of windings 11 and 12 are provided so as to interlink with the magnetic flux flowing into the core 10. The above winding 11.
12 are each connected to a lead wire 15.1 to a regenerative amplifier 13.14.
6. The regenerative amplifier group is connected to an adder 17 to finally obtain a single regenerative output. (2) 8 is a write circuit.

Note that in this embodiment, for simplicity, two windings and a regenerative amplifier are illustrated, but the number is not limited to two. or,
In the above embodiment, recording is performed using one of the plurality of windings, but a plurality of windings may also be used. Furthermore, as a method of configuring the windings, it is not necessarily necessary to form a plurality of independent windings, and it is also possible to provide an intermediate tap and operate the windings equimetrically as a plurality of windings.

Next, the operation of the above conventional example will be explained.

In FIG. 2, the number of turns of each winding is N. In response to the reproducing magnetic flux of the magnetic helad core, a reproducing voltage expressed by equation (1) is generated in the winding, but in this embodiment, the same magnetic circuit includes a plurality of windings 11, 12 and regenerative amplifiers 13. 1
4, the final playback output E, tot
al is E, total = N"' + N"'-13
It is possible to set t δ to −(N+N)−9− t and obtain a voltage corresponding to the total number of turns. On the other hand, the resonant frequency that determines the usable band as a magnetic head depends on the product of the inductance and stray capacitance of each individual winding. Therefore, even if it has a plurality of winding groups, its resonant frequency is the same as in the case of a single winding.

As a result, while increasing the reproduction output to a value corresponding to the total number of windings, it is possible to maintain the resonant frequency at the high value of each divided winding.

Furthermore, by operating the regenerative amplifier and the adder as a differential amplifier, the common-mode noise removal ability can be improved by making it the product of the regenerative amplifier and the adder, compared to the conventional regenerative amplifier alone. It is.

Note that with multiple windings, there is a concern about the influence of mutual inductance, but since the windings are terminated with high impedance, this influence is small.

Effects of the Invention The present invention has the above-described configuration, and provides the following effects.

(a) Since it is possible to provide a magnetic head system with a high resonance frequency and a large reproduction output, the S/N of the reproduction signal is improved.

(b) Since the above effects can be obtained depending on various structural parameters of the magnetic recording medium and the magnetic head, the resolution does not deteriorate.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional magnetic recording and reproducing device, and FIG. 2 is a block diagram of a magnetic recording and reproducing device according to an embodiment of the present invention.
This is a diagram. 10...Core, 11.12...Winding, 13.14.
Regenerative amplifier, 15.16... Lead wire, 17... Adder. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2

Claims (1)

[Claims] A plurality of windings interlinked with the same magnetic circuit in the magnetic head,
A magnetic recording/reproducing device comprising a plurality of reproducing amplifiers connected to each of the windings, and an adder for adding the outputs of the plurality of reproducing amplifiers.