JPH06150433A - Sliding type magnetic head for magneto-optical recording and magneto-optical recording and reproducing device - Google Patents

Abstract

PURPOSE:To extremely lessen the generation of flaws on a medium surface by the hard fillers on the front surface of a sliding surface. CONSTITUTION:The sliding part 3 of this sliding type magnetic head 10 for magneto-optical recording consists of a material contg. the fillers (more particularly fillers having <=1mum average grain size and <=20mum particle length) in a resin. As a result, the sliding part 3 can be easily molded and inexpensively produced. In addition, the wear of the sliding part 3 sliding in contact with the recording medium 1 is suppressed by incorporating the hard fillers therein. The wear of the sliding surface 6 of the magnetic head 10 for sliding in contact with the recording medium 1 is suppressed and the sliding surface is smoothly finished.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding magnetic head for magneto-optical recording and a magneto-optical recording / reproducing apparatus.

[0002]

2. Description of the Related Art One of so-called writable optical disks capable of writing, erasing and reading information by using a light beam is called a magneto-optical disk.

Although not shown, the magneto-optical disk is not shown.
A magneto-optical recording layer made of a perpendicular magnetization film is provided on the substrate,
A reflective film made of a metal thin film (for example, an Al thin film) is laminated on the magneto-optical recording layer, and a protective film made of an ultraviolet curable resin or the like is further formed on the reflective film.

Magnetic recording methods such as a magnetic field modulation method and an optical modulation method are known as recording methods for a magneto-optical disk. Among them, the magnetic field modulation method enables so-called overwriting in which a new signal is overwritten on an old signal. In this magnetic field modulation type magneto-optical recording, an optical pickup that irradiates a laser beam to one side (disk substrate side) and the other side (protective film side) sandwiches a magneto-optical disk having a magneto-optical recording layer of a perpendicular magnetization film. Magnetic field generating means that moves in synchronization with the laser spot (ie,
A magnetic head) is arranged and the direction of the magnetic field is changed by changing the direction of the current flowing through the magnetic head.

The magneto-optical disk is rotated at a predetermined rotational speed with its central portion as the center of rotation, and a magnetic field corresponding to a recording signal is formed in the vicinity of the laser spot. After being heated above the temperature and demagnetized, when it moves from the laser spot and falls below the Curie temperature, it is magnetized in the magnetic field direction for recording.

The conventional magneto-optical disk is a non-contact medium, and therefore the magnetic head is arranged at a necessary and sufficient distance from the disk.

Since the conventional magneto-optical disk records in a non-contact manner as described above, the magnetic head for magneto-optical recording causes surface wobbling of the disk (rotation of the disk, thickness inconsistency, etc.) which occurs when the disk is rotated away from the disk. The electromagnetic servo mechanism is attached so as to follow (due to uniformity, etc.). For this reason, in a recording / reproducing device that employs a non-contact method with respect to a magneto-optical disk, there are limits to reduction of power consumption, downsizing of equipment (particularly to reduce thickness of equipment), and the like.

Therefore, the present applicant previously proposed a sliding type magnetic head in which the magnetic head is slid on the magneto-optical disk. This sliding type magnetic head is constructed by providing a sliding portion having a coefficient of friction lower than that of the core material around the head element.

In this sliding type magnetic head, the sliding portion is brought into contact with and slid on the disk, the central magnetic pole cores are opposed to each other at a minute interval by the disk, and are not in direct contact with the disk.

Since the magnetic head is of a contact type in which it slides in contact with the magneto-optical disk, a simple mechanism of attaching the magnetic head to the head arm via a supporting elastic body of the magnetic head is sufficient. Can be omitted. Therefore, reduction of the power consumption of the recording and reproducing device,
This is advantageous for downsizing equipment. Further, since the magnetic head approaches the disk as compared with the non-contact type, the magnetic field applied to the disk becomes stronger, so that the recording power can be reduced.

In a magneto-optical recording / reproducing apparatus having such a sliding type magnetic head for magneto-optical recording, at least during recording, the sliding portion of the magnetic head constantly slides in contact with the recording medium (optical disk). Therefore, the sliding portion of the magnetic head and the recording medium are abraded by the sliding friction.

As a material of the sliding portion of the magnetic head, since a complicated shape can be easily formed, and since it is inexpensive and can be mass-produced, since plastic is used, wear is generally higher than that of metal or ceramic. growing.

[0013]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a magnetic head which can not only easily form a magnetic head sliding portion at low cost, but also can suppress its wear and improve the reliability of the apparatus. It is to provide a device having.

Further, in addition to the above, another object of the present invention is to provide a magnetic head which does not cause scratches or the like on the recording medium and does not cause sliding scratches or the like between the head and the medium, and an apparatus having the same. To provide.

[0015]

That is, the present invention provides a sliding type magnetic head for magneto-optical recording, comprising a head body having a head element and a sliding portion that makes sliding contact with a recording medium. The sliding portion is related to a sliding magnetic head for magneto-optical recording, characterized in that it is made of a resin containing a filler.

In the present invention, the filler preferably has an average particle size of 1 μm or less and a particle length of 20 μm or less.

Further, the present invention provides a magneto-optical recording magneto-optical recording magneto-optical recording medium having a sliding magnetic head (preferably having a sliding portion containing a filler having an average particle size of 1 μm or less and a particle length of 20 μm or less). A recording / reproducing apparatus is also provided.

[0018]

EXAMPLES Examples of the present invention will be described below.

First, a magneto-optical recording / reproducing system using the magnetic head according to this embodiment will be described. FIG. 1 is a schematic diagram of a magneto-optical recording / reproducing apparatus including a sliding magnetic head for magneto-optical recording.

A magnetic head 10 is disposed so as to face one surface of a disk type magneto-optical recording medium (magneto-optical disk) 1 which is rotationally driven. The magnetic head 10 includes a head element 2 including a core and a coil, a sliding portion 3 for constantly sliding on the recording medium 1 at least during a recording operation,
It is constituted by a spring 4 for pressing the sliding portion 3 onto the recording medium 1.

Further, with the recording medium 1 interposed, the magnetic head 10
An optical head 5 facing the recording medium 1 in a non-contact manner is provided on the opposite side.

In the magnetic field modulation type magneto-optical recording, the magnetic head 10
Although magnetic recording is performed by using both the magnetic field and the optical head 5, the reproduction is performed only by the optical head 5. Therefore, the magnetic head 10 slides on the recording medium 1 only at least during the recording operation, but the magnetic head 10 may always slide during the reproduction depending on the system.

FIG. 2 is a perspective view of the magnetic head 10 as seen from the sliding surface direction. The sliding surface 6 of the magnetic head sliding portion 3 is along the sliding direction in order to reduce sliding friction, for example. The head element 2 is arranged on the leading side in the sliding direction of the cylindrical surface having such a longitudinal direction.

A thermoplastic resin is mainly used as a material forming the sliding portion 6, and a thermosetting resin is used in view of its effect.
So-called plastics are applied, including photocurable resins. The filler contained in the resin of the sliding portion 6 includes glass fibers, carbon fibers, whisker particles such as potassium titanate, carbon particles, chromium oxide, alumina, glass beads, talc, silicon carbide, silicon nitride. Etc.

The sliding portion 3 can be manufactured inexpensively and with good mass productivity by molding a resin containing a filler. In this case, the main body 11 including the sliding portion 3 is integrally molded, but only the sliding portion 3 may be molded and fixed to the main body.

The content of the filler in the resin constituting the sliding portion 3 is preferably 5 to 50% by weight, more preferably 10 to 40% by weight. The size of the filler is preferably 1 μm or less in average particle diameter and 20 μm or less in particle length. Here, the average particle size means a predetermined number of fillers (for example, 100
The average value of the measured values of each particle size).

Next, this embodiment will be specifically described. PA (polyacetal) as a plastic base material for the sliding part 3
And PPS (polyphenylene sulfide), respectively, with no filler, Φ1 μm or less, and containing 30% by weight of potassium titanate with a length of 10 to 20 μm, Φ to 5 μm, and carbon with a length of 50 to 200 μm. Fiber containing 30% by weight Φ to 10 μm and glass fiber having a length of 100 to 500 μm containing 30% by weight in the shape shown in FIG. It was manufactured by injection molding so as to have a size of 10 mm.

Next, each sample was attached to the tip of the spring 4 as shown in FIG. 1, and pressed so that a load of 1 mN was applied to the disk 1, and 10 million continuous passes (1 The path was contacted and slid for one rotation of the disk, and the reduction of the sliding surface 6 of the head after the sliding and the scratches and reduction of the sliding portion of the disk 1 were measured.

The disk used for sliding each head is a polycarbonate substrate on which a sputtered film such as a magnetic thin film is formed, and a photocurable resin film is formed thereon as a protective film.

Table 1 below summarizes the above measurement results. In the table, the wear depth (d) of the head sliding surface is shown in FIG. 3, and the scratch width (w) and depth (d ') of the disk sliding surface are shown in FIG.

[0031]

According to this result, the sliding surface of the head using the sliding material containing no filler has a clear reduction of the sliding surface, and a sliding mark remains on the disk surface at that time.
On the other hand, the sliding surface of the head using the sliding material containing the filler does not show any decrease (“wear depth 1 μm in Table 1
"Below" indicates that the wear was lower than the surface roughness of the sliding surface, and thus the wear was too small to be quantified).

Therefore, by using the resin containing the filler as the sliding material, it becomes possible to manufacture a large number of heads with very little wear at low cost.

Further, according to Table 1, the depth of scratches generated on the sliding surface of the disk due to sliding is 10 .mu.m or less and .ltoreq.10 .mu.m for a head made of a sliding material without filler.
It is almost the same as a head made of a sliding material containing a filler of m, and in this case, it is extremely difficult for the naked eye to recognize a scratch on the disk.

In the case of a filler of such a size, when injection-molded in a state of being mixed with the resin, the roughness of the molding surface is not affected by the filler, and the resin is molded in the same manner as the resin not containing the filler. It is possible to finish the surface extremely smoothly.

On the other hand, Φ to 5 μm and l 50 to 200 μ
In the case of sliding by a head composed of a sliding material containing a filler of m, or Φ-10 μm and l100-500 μm, scratches observable with the naked eye are apt to occur at the sliding portion of the disk. In the latter case, the magnetic recording layer may be damaged through the protective film of the disk.

When these fillers are injection-molded in a state of being mixed with a resin, the end portions of the fillers have their heads everywhere on the molding surface, making it difficult to form a smooth molding surface. There is. Further, since the filler is hard, it may promote the occurrence of scratches and wear on the other side during sliding.

Although the present invention has been described with reference to the embodiments, the above-mentioned embodiments can be further modified based on the technical idea of the present invention.

For example, the structure, material, shape and the like of the above-mentioned head may be variously changed, and the kind, content, size and the like of the filler of the sliding portion can be appropriately changed.

[0040]

As described above, according to the present invention, since the sliding portion of the sliding magnetic head for magneto-optical recording is made of the material containing the filler in the resin, the sliding portion can be easily formed. Can be manufactured at low cost, and by incorporating a hard filler, abrasion of the sliding portion that comes into contact with the recording medium can be suppressed.

Further, in this sliding type magnetic head, when the resin constituting the sliding portion contains a filler having an average particle size of 1 μm or less and a particle length of 20 μm or less, the magnetic head comes into contact with the recording medium and slides. The wear of the sliding surface can be suppressed, and the sliding surface can be finished smoothly, so that the scratches on the medium surface due to the hard filler on the sliding surface can be extremely small.

If a hard filler is contained in order to suppress abrasion in the resin, the filler may be exposed on the surface of the sliding portion, which may cause scratches on the sliding surface of the recording medium. The occurrence of these abrasions and scratches is a serious problem in the reliability of the apparatus and the recording medium, and it is necessary to prevent abrasion as much as possible and to have a structure in which there is no occurrence of sliding scratches between the head and the medium. As described above, it can be surely realized by defining the particle diameter and particle length of the filler.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a magneto-optical recording / reproducing device.

FIG. 2 is an enlarged perspective view of a sliding side of a sliding magnetic head.

FIG. 3 is a schematic cross-sectional view for explaining wear of a sliding surface of a magnetic head.

FIG. 4 is a schematic cross-sectional view for explaining occurrence of scratches on a sliding surface of a recording medium.

[Explanation of symbols]

 1 ... Magneto-optical disk (recording medium) 2 ... Head element 3 ... Sliding part 4 ... Spring 5 ... Optical pickup 6 ... Sliding surface 10 ... Sliding type magnetic Head 11 ... Main body

Claims (3)

[Claims] 1. A sliding magnetic head for magneto-optical recording, comprising a head body having a head element and a sliding portion that slides in contact with a recording medium, wherein the sliding portion is a resin containing a filler. A sliding type magnetic head for magneto-optical recording, comprising: 2. The sliding magnetic head for magneto-optical recording according to claim 1, wherein the filler has an average particle size of 1 μm or less and a particle length of 20 μm or less. 3. A magneto-optical recording / reproducing apparatus having the sliding magnetic head for magneto-optical recording according to claim 1.