JPH04103004A - Reading/writing circuit - Google Patents

Abstract

PURPOSE:To reduce the write-station of other track than a target track by grounding one end of at least one write/read coil in two write/read coils through a resistor. CONSTITUTION:As for one write/read coil 11 in two write/read coils 11, 12, one end thereof is grounded through a resistor. To the center taps of these two read/write coils 11, 12, a DC voltage is always applied. Also, to one end of the write/read coil 11 wound round to a magnetic core 9 of narrow track width, a ground resistance 1 for minute current electric conduction is attached. That is, to the magnetic core 9 of narrow track width, a minute DC current magnetic flux is always flowing, and its direction is set to the direction for negating DC magnetic field receiving from a step-motor, etc., of a floppy disk device. In such a way, a write-station of a magnetic recording medium caused by an inflow of a magnetic flux is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a read/write circuit, and particularly to a read/write circuit suitable for use in a floppy disk device.

(Prior art) In recent years, with the increase in the capacity of floppy disk devices, floppy disk devices have narrower track widths than conventional floppy disk devices.
High T P I (Tracks Per Inch
) has been published.

On the other hand, if a magnetic head with a narrow track width is used, read/write compatibility with software assets used in conventional floppy disk drives cannot be obtained.

For this reason, recently, a magnetic head assembly having two magnetic cores with different track widths as shown in FIG. 3 has been devised. This has a structure in which a magnetic core 9 with a narrow track width and a magnetic core 10 with a conventional track width are mounted adjacent to each other on the same slider 8.

FIG. 2 shows a write/read circuit for driving this magnetic head assembly. In the conventional example shown in FIG. 2, there is a write/read coil 11 for a magnetic core with a narrow track width, and a read/write coil 12 for a magnetic core with a conventional track width.
and the side erase coil 13 are connected to the write/read circuit section 20, and each is selectively used.

[Problem to be solved by the invention]

In this conventional example, when the write/read circuit unit 20 and the magnetic head assembly 8 drive the magnetic core 10 with a conventional track width to perform a write operation, the write operation is performed by the write/read circuit section 20 and the magnetic head assembly 8. Magnetic flux leakage occurs.

However, although the amount is small and does not stain the magnetic recording medium, if the magnetic head assembly 8 is installed in a floppy disk device and the DC magnetic field generated by the step motor acts on it, it will cause a type of DC bias recording. This causes magnetization reversal in the magnetic material of the medium, causing a phenomenon in which tracks other than the intended track are written and stained.

[Purpose of the invention]

The present invention improves the disadvantages of the conventional example, and in particular, significantly reduces writing smudges on tracks other than the target track, thereby obtaining highly accurate reproduced information with less noise when reading information. The purpose is to provide a write/read circuit that can perform the following functions.

[Means for Solving the Problems] The present invention includes a magnetic head section having two magnetic cores with different track widths installed close to each other, and two write/read coils respectively wound around the two magnetic cores. ing. A configuration is adopted in which one end of at least one of the two write/read coils is grounded via a resistor. This aims to achieve the above-mentioned purpose.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG.

Here, the same reference numerals are used for the same constituent members as in the conventional example described above.

The embodiment shown in FIG. 1 has a magnetic head part 8 having two magnetic cores 9 and 10 with different track widths installed in close proximity, and a magnetic head 8 having two magnetic cores 9 and 10 wound around these two magnetic cores 9 and 10, respectively. Two write/read coils 1112 are provided. One end of the write/read coil 11 of the two write/read coils 11, 12 is grounded via a resistor.

To explain this in more detail, in FIG. 1, the write/read circuit section 20 includes a write/read coil 11 wound around a magnetic core 9 with a narrow track width, and a write/read coil 11 wound around a magnetic core 10 with a conventional track width. A write/read coil 12 and a side erase coil 13 are connected, and each of them can be selectively used as required.

A DC voltage is always applied to the center taps of the two read/write coils 9 and 10. Further, a grounding resistor 1 for supplying a minute current is attached to one end of a write/read coil 11 wound around a magnetic core 9 having a narrow track width. That is, a minute direct current magnetic flux always flows through the magnetic core 9 with a narrow track width, and by setting the direction of the magnetic flux to cancel the direct current magnetic field received from the step motor of a floppy disk device, the magnetic core 9 with a conventional track width can be When the core 10 performs a write operation, the magnetic recording medium is no longer smudged due to the inflow of magnetic flux, and at the same time, waveform asymmetry during reproduction is also improved. In this case, the value of the DC current that is constantly passed may be about 1/20 of the write current, and it has been experimentally confirmed that there is no adverse effect due to this.

(Effects of the Invention) As described above, according to the present invention, in order to flow DC magnetic flux into the magnetic core in a direction that cancels the DC magnetic field from the outside of a magnetic head assembly such as a step motor, a grounding resistor for passing a minute current is provided. Since it is attached to one end of the write/read coil, it is possible to reduce writing smudges on tracks other than the target track to below the measurement limit, and it is also possible to reduce waveform asymmetry during playback. Therefore, it is possible to provide an unprecedented and excellent read/write circuit that can obtain highly accurate reproduction information with little noise.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, FIG. 2 is a circuit diagram showing a conventional example, and FIG. 3 is a perspective view showing a magnetic head assembly equipped with the circuit shown in FIG. 1...Grounding resistor, 9, 10...Magnetic core, 11.12...Writing/reading coil, 2
0...Writing/reading circuit section. Applicant Gunma NEC Co., Ltd. Agent Patent Attorney Isamu Takahashi

Claims (1)

[Claims] (1) A magnetic head unit having two magnetic cores with different track widths installed in close proximity to each other, and two write/read coils wound around the two magnetic cores, each of the two write/read coils A read/write circuit characterized in that one end of at least one write/read coil in the read/write circuit is grounded via a resistor.