JPH0546923A - Magnetic head device - Google Patents

Abstract

PURPOSE:To comply with a floppy disk provided with a plurality of track densities by a method wherein a gap for write/readout use and a preceding erasure gap are formed in such a way that their center lines coincide. CONSTITUTION:With reference to a recording, medium in which a high-track- density track width is larger than 1/4 of a low-track-density track width, a gap 1, for write/readout use, whose width corresponds to the high-track-density track width and a preceding erasure gap 2 whose width corresponds to the low-track-density track width are formed in such a way that their center lines coincide. Thereby, the title head device can comply with a floppy disk provided with a plurality of track densities (widths), the title head device can be mass-produced, and it is possible to easily comply with a reduction in the production cost of the title head device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head device used for writing / reading a floppy disk having a plurality of track densities.

[0002]

2. Description of the Related Art In a floppy disk (FD), it is considered to write / read at 542 TPI with respect to the current 135 TPI (track density). In this case, the track width of, for example, 135 TPI is set to 115 μm, while 542
The track width of the TPI is set to 30 μm.

By the way, since writing is a digital signal on a floppy disk, writing can be performed only by overwriting. Therefore, in high track density writing in which the head position is controlled with high accuracy, writing can be performed without erasing the previous writing. However, in writing with low track density, the position of the head has not been controlled with high precision in the related art. For this reason, for example, when rewriting is performed on a floppy disk written by a conventional apparatus, the previous writing may remain due to the head position deviation of the conventional apparatus only with overwriting. Therefore, in writing with a low track density, it is necessary to erase (erase) the previous writing.

Therefore, in order to perform writing / reading on tracks having such different widths, conventionally, writing / reading heads having gap widths corresponding to the respective track widths are manufactured separately and combined with each other. It was supposed to be used. That is, in FIG. 2, reference numeral 21 denotes a write / read head for low track density, which is provided with a write / read gap 22 having a width of 115 μm, for example, and an erasing gap 23 having a width of 255 μm preceding the gap 22. Is provided. Reference numeral 24 is a write / read head for high track density, for example, a write / read gap 25 having a width of 30 μm.
Is provided.

In this apparatus, a low track density floppy disk is read by the gap 2 of the head 21.
2 and writing is performed in the gap 22 after erasing in the gap 23. Writing / reading of a high track density floppy disk is performed by the gap 25 of the head 24. However, in this device, separate heads 2
Since 1 and 24 are combined, they are not suitable for mass production and the manufacturing cost is high.

[0006]

The problem to be solved is that the conventional apparatus is not suitable for mass production because it combines separate heads, and the manufacturing cost is high.

[0007]

According to the present invention, the track width of high track density is 1/4 of the track width of low track density.
For a larger recording medium, a write / read gap 1 having a width corresponding to the track width of the above high track density.
And a preceding erase gap 2 having a width corresponding to the erase width of a low track density are provided with their center lines aligned with each other.

[0008]

According to this, it is possible to cope with floppy disks having a plurality of track densities (widths), and to easily cope with mass production and reduction of manufacturing cost.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1A shows a front view of the apparatus. In this figure, 1 is a write / read gap having a width of, for example, 30 μm corresponding to a track width of high track density, and 2 is a preceding erase gap having a width of, for example, 255 μm corresponding to an erase width of low track density. .. The gaps 1 and 2 are provided with their center lines aligned with each other.

Further, B of the same figure is a side view, and in this figure, a core 1C forming a magnetic circuit of the gap 1 and a core 2C forming a magnetic circuit of the gap 2 are provided. The coil 1D is wound around the core 1C, and the coil 2D is wound around the core 2C. Then, when a current corresponding to the write data is passed through the coil 1D, for example, 3
Data is written with a track width of 0 μm. In addition, when an erasing current is applied to the coil 2D, for example, 2
Erase with a width of 55 μm is performed.

In this device, when writing at a low track density, the coil 2 wound around the core 2C is used.
The erase current is applied to D, and the coil 1 is wound around the core 1C.
A current corresponding to the write data is applied to D. This erases the previous write of eg 255 μm width and
For example, data with a track width of 30 μm is written. When writing at high track density, the core 1
By passing a current according to the write data through the coil 1D wound around C, the data with a track width of, for example, 30 μm is written by overwriting.

Therefore, in this device, when writing at a low track density, data having a track width of, for example, 30 μm is written after erasing the previous writing having a width of, for example, 255 μm. In addition, when writing with a high track density, for example, data with a track width of 30 μm is written by overwriting. In this way, floppy disks having a plurality of track densities (widths) can be accommodated. In this case, the writing with a low track density has a track width of about ¼, but if it is about this, reading can be performed without any practical problems.

In this device, the gaps 1, 2 are
The cores 1C and 2C forming the can be manufactured by using the same parts, and mass production and reduction of manufacturing cost can be easily realized.

[0014]

According to the present invention, it is possible to cope with floppy disks having a plurality of track densities (widths), and to easily cope with mass production and reduction of manufacturing cost.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an example of a magnetic head device according to the present invention.

FIG. 2 is a configuration diagram of a conventional magnetic head device.

[Explanation of symbols]

1 write / read gap corresponding to track width of high track density 2 pre-erase gap of low track density 1C, 2C core 1D, 2D coil

Claims (1)

[Claims] 1. A write / read gap having a width corresponding to the track width of the high track density for a recording medium having a track width of the high track density larger than ¼ of the track width of the low track density. A magnetic head device, characterized in that a leading erase gap having a width corresponding to the erase width of a low track density is provided with its center lines aligned.