JPH03254463A - Perpendicular magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To attain saturation recording with a small recording current in a perpendicular single layer magnetic recording medium by using a magnetic substance as a pad material. CONSTITUTION:A magnetic substance with a high permeability is used for a pad 1 opposite to a ring magnetic head 4 in a magnetic recording and reproducing device comprising the pad 1, a mmgnetic recording medium drive motor 3 and a ring magnetic head 4. Since magnetic lines of force generated from the ring magnetic head 4 are extracted in the direction of the pad, the magnetic field strength in the perpendicular direction is strengthened. Thus, the recording current to apply saturation recording to the magnetic recording 2 is decreased and the recording current characteristic is improved.

Description

[Detailed description of the invention] [Industrial application fields] The present invention relates to a perpendicular magnetic recording/reproducing device.

[Conventional technology] Television broadcasting in Japan uses the NTSC system.
The SC signal consists of 525 scanning lines.

A so-called interlace scan is performed in which even or odd scan lines (feed signals) are alternately scanned every 1760 seconds, and the
One complete image is constructed every 30 seconds.

In recent years, 1-field video signals have been FM modulated.

So-called still videos, which are recorded and played back on one track of a 2" magnetic recording medium called a video floppy, have been put into practical use, and are beginning to be used in a wide range of fields such as sightseeing records, medical image files, and school teaching materials.

Current video floppies use metal-coated media, and the horizontal resolution of the resulting reproduced image is about 500 TV lines, but the image quality is clearly inferior when compared to a 36 mm silver halide photograph.

Horizontal resolution is proportional to the frequency band of the FM signal being recorded, and in order to achieve even higher image quality.

It is necessary to record up to higher frequencies.

However, in the case of metal-coated media, it is difficult to dramatically improve the recording density, that is, to improve the quality of one image, since the media are used at a position where the capabilities of the two media themselves are considerably high.

On the other hand, perpendicular magnetic recording is a magnetic recording method that can achieve high image quality and resolution because it is capable of high-density recording.
Research and development is being actively carried out with a view to practical application.

A perpendicular single-layer magnetic recording medium that has only a perpendicular magnetic recording layer with perpendicular magnetic anisotropy such as Co-Cr on a substrate film can record and reproduce data using a two-ring magnetic head.
It has the great advantage that it can be used as is in conventional still video recording and reproducing devices.

[Problems to be Solved by the Invention] Due to its structure, the ring-shaped magnetic head of the magnetic recording/reproducing device used in still video.

It generates strong lines of magnetic force in the longitudinal direction and relatively weak lines of magnetic force in the vertical direction. In the case of a longitudinal magnetic recording medium, recording is performed using the strong lines of magnetic force in the longitudinal direction, and in the case of a perpendicular single-layer magnetic recording medium, the lines of magnetic force in the perpendicular direction are used for recording.

On the other hand, in order to protect information against external magnetic fields and to suppress reduction in residual magnetization due to demagnetizing fields, the coercive force of a magnetic recording medium must be large to some extent.

Therefore, when recording on a perpendicular single-layer magnetic recording medium with a large coercive force using a ring-type magnetic head, weak perpendicular magnetic lines of force are used. There was a problem in that a large recording current was required.

One technical object of the present invention is to provide a perpendicular magnetic recording/reproducing apparatus capable of performing saturation recording with a small current in view of the above-mentioned drawbacks.

[Means for Solving the Problems] As a result of intensive studies, the inventors of the present invention discovered that recording current characteristics can be improved by orienting the lines of magnetic force generated from one magnetic head in the perpendicular direction.

By the way, in order to maintain stable head contact over all tracks, for 5" or 3.5" magnetic recording media, it is necessary to sandwich the magnetic recording medium between two double-sided heads or one-sided heads with felt pads, etc. In the case of still video, since the video floppy rotates at a high speed of 3600 rpm, if the same method is used, the durability of the head and media will be a problem, so the 2-butt shape is used. By optimizing this, an air film is formed between the disc and the pad, and air pressure presses the front and rear of the disc head, making no contact with the pad, and combined with the low-friction air bearing effect to create a stable head. I'm getting contact.

On the other hand, the magnetic lines of force generated from the ring-shaped magnetic head are arcuate as shown in FIG. Therefore, if a magnetic material with high magnetic permeability is used for the pad facing the ring-shaped magnetic head so that the magnetic field lines can easily pass through, the magnetic field lines generated from the ring-shaped magnetic head are drawn in the direction of the pad, as shown in Figure 3. The vertical component of magnetic lines of force can be increased.

As a result, the recording current required to generate perpendicular magnetic lines of force of the same strength becomes smaller, and even perpendicular single-layer magnetic recording media with high coercive force can perform saturation recording with a small recording current.

That is, the present invention provides a perpendicular magnetic recording/reproducing apparatus using a perpendicular single-layer magnetic recording medium, which is characterized in that a magnetic material is used as the material of the pad.

[Function] By using a magnetic material with high magnetic permeability in the pad facing the ring-shaped magnetic head, the lines of magnetic force generated from the ring-shaped magnetic head are drawn in the direction of the pad, thereby increasing the magnetic field strength in the perpendicular direction.

As a result, the recording current required to perform saturation recording on the magnetic recording medium becomes smaller, and the recording current characteristics improve.

[Example code] Next, embodiments of the present invention will be described with reference to the drawings.

As shown in FIG. 1, bad 1. In a magnetic recording/reproducing device comprising a magnetic recording medium driving motor 3 and a ring-shaped magnetic head 4, ferrite (relative initial permeability: 5000) was used as the pad 1 as a magnetic material with high magnetic permeability.

FIG. 4 shows recording current characteristics in the case of using the magnetic recording/reproducing apparatus according to the present invention and in the case of a conventional magnetic recording/reproducing apparatus using a non-magnetic plastic pad as a comparative example.

From Figure 4, when using a magnetic pad, the recording sensitivity l90 (recording current that provides 90% of the saturated output) is about 1 from 36 mA to 20 mA, compared to the case of a conventional non-magnetic pad. The recording current characteristics have been significantly improved.

Here, the purpose of this embodiment is to use a magnetic body located at a position facing the ring-shaped magnetic head.

The purpose is to strengthen the perpendicular component of the recording magnetic field generated from the ring-shaped magnetic head.In this embodiment, ferrite is used as the magnetic material, but any material having magnetic permeability sufficient to obtain the same effect may be used. There are no restrictions on the type and thickness of the magnetic material.

[Effects of the Invention] As described above, the present invention provides a perpendicular magnetic recording/reproducing device capable of performing saturation recording with a small recording current on a perpendicular single-layer magnetic recording medium.

FIG. 2 is a schematic diagram showing the state of magnetic lines of force generated from a ring-shaped magnetic head when a non-magnetic pad is used. FIG. Schematic diagram showing the state of magnetic force lines generated from a ring-type magnetic head when a magnetic pad is used, No. 4
The figure is a diagram showing recording current characteristics of two examples of the present invention and a comparative example.

1... Bad (magnetic material), 2... (Perpendicular magnetic recording)
Medium, 3...Magnetic recording medium drive motor 14...Ring type magnetic head.

ξEmbedded (77ε3) Patent attorney Noriyasu Ikeda \1. Kosei, 'F
.

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[Brief explanation of drawings]

Figure 1 is a side sectional view showing v1 essential points of the present invention and a second protrusion. Figure 3

Claims (1)

[Claims] 1. In a magnetic recording and reproducing device that performs recording and reproducing on a perpendicular magnetic recording medium having a perpendicular magnetic recording layer on a substrate film,
In the bad part located opposite the ring-shaped magnetic head,
A perpendicular magnetic recording/reproducing device characterized by using a magnetic material.