JPH0366079A - Flying head for magneto-optical disk - Google Patents

Abstract

PURPOSE:To prevent adsorption between a flying head and an overcoat layer and to ensure a stable flying characteristic by limiting a maximum height and a direction of flaws on a lapping face for a prescribed measuring range for surface roughness of a bottom face. CONSTITUTION:A maximum height of surface roughness on a bottom face of a flying head 14 for a measuring range of 200mum is specified as 0.1 - 0.3mum and the direction of flaws of lapping is selected within an angular range of + or -30 deg. with respect to the running direction of the head 14. Thus, a gap (flaws of the flying head) is provided between the head 14 and the overcoat layer 13 to prevent the adsorption due to the vacuum between the both, and since the direction of flaws is selected within + or -30 deg. with respect to the running direc tion of the head 14, stable flying characteristic is ensured.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention relates to a flying rewritable magneto-optical disk used not only for optical reproduction, but also for data files that can record and erase information using light and magnetism. It is related to the head.

Conventional technology In recent years, rewritable magneto-optical disks have become highly dense.

It is being applied to data files due to its advantages such as large capacity, high speed access, and portability.

However, conventionally, in order to rewrite data, a bias magnetic field is applied in the opposite direction to that during recording, and light is continuously irradiated to erase the rewritten area.Then, the direction of the bias magnetic field is changed again to the recording direction, tracking is returned, and the data is erased. A method has been used to write by irradiating light onto the exposed areas. Such a method requires time for access and requires a large amount of power for the bias coil.

Therefore, in recent years, two types of overwriting methods have been researched and developed: magnetic field modulation overwriting and optical modulation overwriting. For example, IEICE Technical Report MR87-61. PP19
-25 (1987).

The magnetic field modulation method is a method of overwriting by installing a flying head in the opposite direction of the light input side on a single substrate and reversing the direction of the bias magnetic field at high speed and irradiating the laser.The size of the recording pit is determined by the laser. It is determined by the beam diameter of the light spot and the reversal time of the magnetic field in the flying head.

For example, Japanese Patent Application Laid-Open No. 63-217548.

On the other hand, the optical modulation method uses a two-layer recording layer and uses the negative layer as a bias layer to perform recording and erasing based on the magnitude of laser power.

The present invention relates to the former method. In the magnetic field modulation method, a flying head made of a ferrite material such as Mn--Zn ferrite is also operated in synchronization with the optical section on the light input side, so it is necessary to simplify the flying mechanism as much as possible and reduce the weight. There, the head and disk rotate from the contact state, and return to the contact state after stopping.CS
The S (abbreviation for Contact Start 5 top) method is mainly adopted.

The disk structure has a film configuration in which a thin film such as a magnetic film is formed, and then a protective film (overcoat layer J) is formed using an ultraviolet curing resin as a spin cord. Figure 3 shows the surface roughness of a conventional flying head.

Problems to be Solved by the Invention However, with the above-mentioned film structure, there was a problem in that in the C3S method, the head and overcoat layer were in contact with each other on a flat surface, so that they were attracted to each other.

In view of the above-mentioned problems, the present invention provides a C3S type flying head for a magneto-optical disk in which the head and the overcoat layer are not attracted even when they come into contact with each other.

Means for Solving the Problems In order to solve the above problems, the present invention provides a method for determining the maximum height R in a measuring section of 200 um of surface roughness on the bottom surface of a flying head.
A flying head for a magneto-optical disk was used in which the max was 0.1 μm or more and 0.3 μm or less, and the direction of the lapping scratch was within an angular range of ±30 degrees with respect to the running direction of the flying head.

Function According to the present invention, a gap (flaw in the flying head) is provided between the flying head and the overcoat layer by the above-described structure, and it is possible to prevent the two from being attracted to each other due to the vacuum state.

At this time, the maximum surface roughness of the flying head is 0.1μ.
If it is less than m, there is a high possibility that adsorption with the disk will occur. On the other hand, if the maximum height in the surface roughness measurement section of 200 .mu.m is 0.3 .mu.m or more, the flying characteristics of the flying head deteriorate and head crash is likely to occur.

In addition, stable flying characteristics can be ensured by setting the direction of the scratch within ±30 degrees with respect to the traveling direction relative to the disk.

EXAMPLE A flying head for a magneto-optical disk according to an example of the present invention will be described below. FIG. 1 shows a configuration diagram of a magnetic field modulation type overwrite magneto-optical disk according to an embodiment of the present invention, in which 11 is a transparent substrate, 12 is a thin film layer, and 13 is a transparent substrate.
The overcoat layer 14 is a flying head, 15 is an optical part, and 16 is a driving part.

A protective film such as 5i02, etc. is applied to a transparent substrate 11 in which guide grooves are formed on a glass plate using an ultraviolet curable resin using a Supanotar device.
A 1111 layer 12 consisting of a magnetic film such as TbFeCo and a protective film such as SiO□ was formed. Next, apply an epoxy acrylate ultraviolet curing resin onto the thin film layer 12 using a spin cord (
3000 PPM for 8 seconds), and then irradiated with a metal halide ultraviolet lamp (200 mW/cal) for 30 seconds to cure the ultraviolet curing resin, thereby forming an overcoat layer 13.

Next, after processing the Mn-Zn ferrite into a predetermined shape,
Using wrapping tape, wrap the bottom of the flying head #1OOO in the running direction of the head.

Wrapping was performed sequentially with #4000 roughening tape, and the maximum height of the surface roughness was approximately 0.1 μm (measurement section 2).
A flying head 14 (gaussop length 25 μm, 2 windings 10 times) having a scratch of 00 μm) was produced. FIG. 2 shows the surface roughness of the flying head measured using a surface roughness meter CRISTETUB manufactured by Rank Taylor Hobson. A C3S experiment (rotation speed 360 ORPM) was conducted for 25 minutes using the magneto-optical disk and flying head prepared in this way.
The test was carried out under the conditions of °C and 60% RH. As a result, no adsorption occurred between the flying layer and the overcoat layer. Although a slight fluctuation was observed in the flying height during flying, ranging from 2 μm to 4 μm, there was no effect on the recording and reproducing characteristics.

The maximum height of the surface roughness of the flying head was varied by varying the number (roughness) of the wrapping tape. As a result, 0.05 μm.

0.1μm, 0.2μm, 0.3μm, 0.4μm, 0
．． A flying head with a maximum height of 5 μm was fabricated. When C3S floating experiments were conducted using these heads, adsorption occurred at a maximum height of 0.05 μm, and at a maximum height of 0.05 μm, adhesion occurred.
When the thickness was 4 μm or more, head crash occurred. Therefore, the maximum height of the surface roughness of the flying head in the measurement section of 200 μm is preferably 0.1 μm or more and 0.3 μm or less. In addition, the wrapping direction is preferably within ±30 degrees with respect to the running direction; exceeding this range causes deterioration of flying characteristics such as head crash. This is thought to be because the scratches disrupt the airflow, making the flying condition unstable and causing a loss of lift.

Effects of the Invention As described above, the present invention has a surface roughness of the bottom surface of a flying head for a magnetic field modulation type overwrite magneto-optical disk whose maximum height in a measuring section of 200 μm is 0.1 μm or more and 0.3 μm.
m or less, and by making the direction of the scratches on the lapping surface within an angle range of ±30 degrees with respect to the running direction of the flying head, C5S has excellent flying characteristics and improves adsorption between the flying head and the overcoat layer. This provides a flying head that can prevent this.

Furthermore, by lapping and scratching the surface of the flying head, the N friction coefficient is lowered, requiring less driving power, and processing is also easier because rough lapping of approximately #4000 is required.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a magnetic field modulation type overwrite magneto-optical disk according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing the surface roughness of a flying head according to an embodiment of the present invention, and FIG. 3 is a conventional diagram. FIG. 3 is an explanatory diagram showing the surface roughness of the flying head of FIG. 11...Transparent substrate, 12...Thin film layer,
13... Overcoat layer, 14...
Flying head, 15...Optical section, 16...
····Drive part. Figure 2 11-11 Crying X Night, S° -1 Optical Section 16- Eyebrow 1 Movement Group Figure 3

Claims (2)

[Claims] (1) Measurement section of surface roughness of the bottom surface of the flying head for magnetic field modulation overwrite magneto-optical disks: 200 μm
1. A flying head for a magneto-optical disk, characterized in that the maximum height thereof is 0.1 μm or more and 0.3 μm or less. (2) A magneto-optical disk according to claim (1), wherein the direction of the scratch on the wrapping surface of the flying head for a magneto-optical disk is within an angular range of ±30 degrees with respect to the running direction of the flying head. Flying head for.