JPH01173403A - Exciting element for magneto-optical recording - Google Patents

Abstract

PURPOSE:To improve reliability by providing a difference in grade between a slider part (part to generate air pressure) and a bias magnetic field generating part to constitute an exciting element, and making the least gap part to a recording medium be the slider part. CONSTITUTION:The difference in grade is provided between the slider part 11 and the bias magnetic field generating part 15 of the exciting element 14 for magneto-optical recording. Accordingly, even if the exciting element 14 for the magneto-optical recording falls on the recording medium 5, the bias magnetic field generating part 15 is never brought into contact with the recording medium 5 directly, and damage is prevented. Thus, at the same time that a floating head for an optical disk with high reliability can be obtained, since the floating head of a dynamic pressure type is used, a servo for adjusting floating quantity can be dispensed with, and cost can be reduced.

Description

[Detailed description of the invention] [Industrial application field]

This invention relates to a magneto-optical recording device that uses both optical means and magnetic means to record, erase, and read information on a recording medium. The present invention relates to an excitation element for magnetic recording.

[Conventional technology]

FIG. 10 is a block diagram showing the outline of a magneto-optical disk drive equipped with a bias magnetic field generating device using a conventional electromagnet. In FIG. 10, (1) is a bias magnetic field generating device; ) consists of a soft magnetic core (2) and a magnetic 8iK (
3) and the coil (4) wrapped around this magnetic pole (3)
It is made up of. (5) is a magneto-optical recording medium (hereinafter simply referred to as a recording medium) which is rotated by a spindle motor (not shown), and includes a magnetized layer (6) and a magnetized layer (6).
) and a protective layer (8). (9) is a light converging lens that focuses the light beam emitted from the laser light source (10) onto the recording medium (5). Note that the bias magnetic field generating device (1) has a recording medium (
5) is capable of simultaneously applying a magnetic field over the entire recording track width, and more specifically, the one disclosed in, for example, Japanese Unexamined Patent Publication No. 61-3305 is used. Incidentally, recently, an example has been announced as the above-mentioned bias magnetic field generating device that uses a slider having the same structure as a floating head used in a fixed magnetic disk device instead of an electromagnet. (T, Nakao et al., International
onal Symposium on 0pt
ical Memory1987, Sep.)
The reason for using this type of head (see FIG. 11) is that it does not require a servo to maintain a predetermined flying height and is inexpensive. The floating head used here is 11.12
As shown in the figure, the air inflow side is the slider part that generates air pressure, and the outflow side is the bias magnetic field generation part.As shown in the figure, the thickness 11 of the slider part and the thickness 12 of the bias magnetic field generation part are It's the same, there's no difference. Next, the operation will be explained with reference to FIGS. 10 to 12. In FIG. 11, air pressure is generated between the recording medium and the floating head (13) due to the rotation of the recording medium (5). This pressure causes the floating head to move away from the recording medium by h (2-4 μm).
only to surface. More precisely, this floating height is the 12th
As shown in the figure, it is best known that the flying height is smaller on the bias magnetic field generating portion (12) side. At this time, the recording medium is magnetized by the magnetic field generated from the bias magnetic field generating portion. That is, as shown in FIG.
) on the magnetized JW (6) of the recording medium (5) using a light converging lens (9).
Recording is performed by narrowing down to a minute spot of μmφ and raising the temperature of the recording medium, and at the same time applying a bias magnetic field by the bias magnetic field generator (1) to form a reversal magnetic domain.The bias magnetic field is generated by the coil (4). It is generated from the magnetic pole (3) by applying a current to the magnetic pole (3) by a driving device (not shown). This magnetic field magnetizes the recording medium. By the way, in a device using a floating head as shown in Figure 11, the gap between the recording medium and the floating head is as small as 2 to 4 μm, so the floating head easily falls onto the recording medium due to dust, moisture, etc. The head is damaged (particularly the bias magnetic field generating portion near the medium is easily damaged), and the recording medium cannot be magnetized. For the recording medium, the protective layer (8) shown in the figure
Therefore, even if the floating head falls, it will not be directly damaged. To prevent this, fixed magnetic disk drives take measures such as supplying clean air from the outside using a forced air circulation system.

[Problems to be solved by the invention]

Since the conventional excitation element for magneto-optical recording is configured as described above, the floating head easily falls onto the recording medium due to dust and moisture in the usage environment, and the floating head easily falls onto the recording medium. (causing a so-called head crash), and the bias magnetic field generation part collides directly with the recording medium.
There is a problem in that the bias magnetic field generating portion is damaged and cannot function as a magnetic head. Further, the head crash occurs at the moment when the excitation element for magneto-optical recording lands on a predetermined position on the medium after the medium reaches a predetermined rotational speed, or conversely, when the excitation element for magneto-optical recording There is also a high possibility that this occurs at the moment of so-called landing-off, when the magnetic field is separated from a predetermined position on the medium, and even in this case, there is a problem that the bias magnetic field generating portion is damaged. This invention was made to solve the above-mentioned problems, and its purpose is to obtain a highly reliable excitation element for magneto-optical recording by preventing damage to the direct bias magnetic field generating part even if a head crash occurs. shall be.

[Means to solve the problem]

In the excitation element for magneto-optical recording according to the present invention, a step is provided between the slider part (the part that generates air pressure) constituting the excitation element and the bias magnetic field generation part, so that the part of the minimum gap between the slider part and the recording medium is It was designed to be a part.

[Effect]

The excitation element for magneto-optical recording according to the present invention has a difference in level between the slider portion and the bias magnetic field generating portion.
The slider part has the smallest gap with the body, so even if the excitation element for magneto-optical recording falls onto the recording medium, the bias magnetic field generating part will not be damaged and the reliability of the device will be maintained. Increase.

【Example】

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, (14) is an excitation element for magneto-optical recording, (11)
) is the slider part, (15) is the bias magnetic field generating part, and the same is true for other embodiments), (16)
Main core of (17), auxiliary core of (4), coil of (4), (
3) Magnetic f! (The part where magnetic flux is concentrated and generated) , (1
8a) and (18b) glass fusion part (the part where the main core and the auxiliary core are bonded, which is blacked out in the figure).The coordinate axis X in the depth direction and the coordinate axis y in the height direction are It is determined as shown in the figure. Note that the step d is the difference between the slider part and the bias magnetic field generating part in the y direction, with the X position as the magnetic pole degree. Figure 2 shows an optical disk equipped with the above excitation element for magneto-optical recording. In the perspective view showing the outline of the drive, (14) is the excitation element for magneto-optical recording, 19) is the suspension that supports the excitation element for magneto-optical recording, and 1) is the laser light source (10).
This is a light converging lens that focuses the light beam emitted from the recording medium (5) onto the recording medium (5). An arrow A indicates the direction of rotation of the recording medium. The zero-order operation will be described. To magnetize a recording medium, it is necessary to apply a magnetic field. When the shape of the magnetic pole for applying a magnetic field is modeled as shown in FIG. 3, the generated magnetic field can be obtained as follows. Assuming rotational magnetization of σ on the magnetic pole surface, the magnetic field Hy(x, y) in the y direction at the coordinate (x, y) point is expressed by equation (1). Coordinate(
x, y), see Figure 1. Hy(x,y) =2σtan-'((x+t)/y
)-2a tan ((x-t)/y)...
・ (1) By the way, the positioning of the magnetized position π on the recording medium (
The accuracy of the position of the light converging lens that determines the laser spot position and the alignment of the excitation element for magneto-optical recording) and the amount of deviation between the track on the recording medium and the center of rotation of the recording medium (the amount of track deviation is 50 μm as a standard) ), the magnetic pole width 2t is required to be approximately 100 μm. Therefore, if the magnetic field in the y direction at t=50 μm and x-=O1y→0 is 1, then the magnetic fields at y=10 μm, 20 μm, and 40 μm are 0.87, 0.75, respectively, from equation (1).
,0.56. This shows that even if the distance between the magnetic pole and the magnetized medium surface is about 10 μm to 20 μm, the magnetization efficiency does not decrease and there is no practical problem. From the above description, it can be seen that there may be a gap of at most 20 μm between the recording medium and the bias magnetic field generating portion. This quantity will be explained using an actual system. When recording I# (5) rotates in the direction of arrow A shown in FIG. 2, the magneto-optical recording excitation element (14) shown in FIG. As shown in Fig. 4, it floats at an angle θ. Since this angle θ is usually very small, the height difference d, hl (minimum distance between the recording medium and the slider part), and h2 (recording medium and bias magnetic field generation) are Δh, which is the difference between the minimum distances between the two parts, is approximately equal. From the figure, the minimum clearance position is at the slider part indicated by hl, and the bias magnetic field generation part is approximately at the maximum clearance 2 above.
The distance can be increased to 1lh2 corresponding to 0 μm. In the conventional example,
Since hl was 2 to 4 μm, in this figure, Δh can be set to approximately a maximum of 16 to 18 μm. Therefore,
The step difference d can also be set to approximately a maximum of 16 to 18 μm. As shown in the conventional example, if there is a protective layer in the recording medium, it goes without saying that the above-mentioned step difference is reduced by this thickness, but this thickness is usually 0.5 to 10 μm, and the above-mentioned step difference is A minimum of 6 μm can be obtained. Due to the above step, even if the excitation element for magneto-optical recording falls onto the recording medium due to dust etc., the bias magnetic field generating part will not come into direct contact with the recording medium. The thickness 11 of the part and the thickness 12 of the bias magnetic field generating part are 11
〉12, but as shown in Figure 5, 11
Even if ≦12, the above discussion holds true as long as h2>hl. Further, in the above embodiment, the surface of the slider portion facing the recording medium is a flat surface, but it may be a convex surface as shown in FIG. The step may be provided in the form shown in Figures 7 and 8 (the speckled area is the bias magnetic field generating area).
Figure 7 shows a case where the same level difference d is uniformly applied over the entire upper surface of the bias magnetic field generating part, and Figure 8 shows a case where the height difference gradually increases from the air inflow side to the air outflow side. There is. In addition, the adhesive portion between the main core and the auxiliary core may be placed as shown in FIG. 9 in addition to the position shown in the above embodiment (blacked out area (24)).

【Effect of the invention】

As described above, according to the present invention, since a step is provided between the slider part of the excitation element for magneto-optical recording and the bias magnetic field generating part, even if the excitation element for magneto-optical recording falls onto the recording medium, However, since the bias magnetic field generating portion does not come into direct contact with the recording medium, damage can be prevented and a floating head for optical disks with high reliability can be obtained. Additionally, since a dynamic pressure type floating head is used, there is no need for a servo to adjust the flying height, which of course has the effect of reducing costs.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an excitation element for magneto-optical recording according to an embodiment of the present invention, FIG. 2 is a perspective view showing an overview of an optical disk drive, FIG. 3 is a model diagram for magnetic field calculation, and FIG. In FIG. 0, which is a sectional view seen from the direction DD in FIG. 1, FIGS. 5 to 9 are configuration diagrams showing other embodiments of the present invention, and FIGS. 5) is a recording medium, (
9) is a light converging lens, (11 is a slider part, (14)
) is an excitation element for magneto-optical recording, (15) is a bias magnetic field generating portion, and (20) to (23) are excitation elements for magneto-optical recording in other embodiments. In addition, in the figure, the same symbols are the same,
or a significant portion.

Claims (1)

[Claims] A bias magnetic field is applied at a position of a light spot focused by a light converging lens that focuses a light spot on a rewritable magneto-optical recording medium, and at a position facing the light converging lens and the magneto-optical recording medium. In an excitation element for magneto-optical recording having a bias magnetic field generating means that generates a bias magnetic field and can reverse the direction of the bias magnetic field, the bias magnetic field generating means is a dynamic pressure type floating head that utilizes air pressure generated as the disk rotates; By providing a step between the slider portion that generates air pressure of the head and the bias magnetic field generating portion, the gap between the magneto-optical recording medium and the bias magnetic field generating portion is reduced. An excitation element for magneto-optical recording, characterized in that the excitation element is larger than the gap between the parts.