JPH04219679A - Magneto-optical recording device - Google Patents

Abstract

PURPOSE:To prevent generation of scratching and wear to the magneto-optical recording medium or a slider by forming the slider in a floating magnetic head from ceramics including at least hexagonal boron nitride. CONSTITUTION:The floating magnetic head 5 is provided with the slider 6 which can be slid on a magneto-optical disk 1 and the magnetic head main body 7 supported on an end tip part of the slider 6. This slider 6 is formed from the ceramics consisting of sintered body of the hexagonal system boron nitride provided with lubricity. Thus, when the slider 6 is slid on the disk 1 when the rotation of the magneto-optical disk 1 is started or finished, the generation of scratching and wear is cut down.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magneto-optical recording device using a floating magnetic head.

0002

2. Description of the Related Art In recent years, magneto-optical recording media have been actively researched and developed as high-density, large-capacity memory elements. The above-mentioned magneto-optical recording medium has a perpendicularly magnetized film made of a magnetic metal material formed on a substrate made of glass, plastic, ceramics, etc., and the direction of magnetization of a desired recording region in the perpendicularly magnetized film is reversed. It is designed to record information.

That is, when recording information, first, by applying an external magnetic field from an external magnetic field applying device, etc., the direction of magnetization of the perpendicularly magnetized film in the magneto-optical recording medium is changed upward in the direction perpendicular to the film surface. or facing downward, and initialize the magneto-optical recording medium.

[0004] When the initialization is completed, a laser beam is irradiated from the light emitting means onto a desired recording area on the recording medium. The temperature of the recorded area irradiated by the laser beam increases,
When the temperature eventually reaches or exceeds the vicinity of the Curie point of the perpendicularly magnetized film or the vicinity of the magnetic compensation point, the coercive force of the recording region becomes zero or almost zero.

In this state, an external magnetic field (bias magnetic field) opposite to the magnetization direction set in the recording region at the time of initialization is applied to reverse the magnetization direction. After that, when the laser beam irradiation to the recording area is stopped,
The temperature of the recording site decreases and eventually returns to room temperature. In this way, the reversed magnetization direction of the recording region is maintained, and desired information is recorded.

[0006] When reproducing information recorded in the recording area, the recording area is irradiated with a linearly polarized laser beam having a smaller power than that used during recording. Then, the recorded information is detected by detecting the reflected light or transmitted light from the recording area irradiated with the laser beam, and determining the rotation angle of the polarization plane of the reflected light or transmitted light. That is, since the rotation angle of the plane of polarization differs depending on the direction of magnetization of the recording region (magnetic Kerr effect or magnetic Faraday effect), information can be read out optically by utilizing this.

Magneto-optical recording, such as magnetism, is attracting attention as a rewritable large-capacity memory element, but when rewriting information recorded on a recording medium, the recorded information must first be erased and then a new one can be created. I try to record relevant information.

In that case, an initialization device is required. For example, when a magnetic head is used as the initialization device,
Two magnetic heads are required including the recording magnetic head, which increases the number of parts. Furthermore, when rewriting is performed using only one magnetic head, erasing before recording new information takes the same amount of time as recording, so there is a problem that the time required for rewriting becomes extremely long.

[0009] Therefore, attempts have been made to record new information directly over recorded information without performing an erasing operation during rewriting. In order to realize this direct rewriting, it is necessary to add some innovation to the external magnetic field (bias magnetic field) generator or the recording medium. Among these, when making improvements to the recording medium, it is difficult to control the composition and film thickness of the magnetized film.

[0010] Therefore, it seems most promising to realize direct rewriting by modifying the external magnetic field generator. That is,
Direct rewriting becomes possible by keeping the output of the laser beam constant and rapidly reversing (switching) the external magnetic field generated by the external magnetic field generator. By the way, in order to reverse the external magnetic field at high speed, the coil and coil core for generating the external magnetic field must be sufficiently miniaturized, and along with the miniaturization, the magnetic field generation area also becomes smaller.

[0011] Therefore, it is necessary to bring the magnetic head as an external magnetic field generator and the recording medium as close as possible.
Therefore, conventionally, a floating magnetic head 3 as shown in FIG.
0 is adopted. As shown in FIG. 5, this floating magnetic head 30 has a suspension 41 made of a plate spring or the like.
The slider 31 is pressed toward the magneto-optical disk 36 by the magneto-optical disk 36 and can slide on the magneto-optical disk 36 (recording medium). At the bottom of the slider 31, there are provided an inclined part 32 and a flat part 33, which serve as an introduction part for an air flow generated as the magneto-optical disk 36 rotates. The slider 31 is made of ceramics such as CaTiO3 or Al2O3+TiC in consideration of wear resistance.

A magnetic head body 34 having a coil and a coil core (not specifically shown) is provided at the rear end of the slider 31. A power source 35 for generating a magnetic field is connected to the coil, and the direction of the generated magnetic field is reversed depending on the polarity of the power source 35. Note that the magneto-optical disk 36 includes a substrate 37 and a recording film 38.
and a protective film 39. The above protective film 39 is
For example, it is made of an ultraviolet curing resin, and is applied onto the recording film 38 by spin coating or the like and cured by irradiation with ultraviolet rays.

By the way, the above-mentioned floating magnetic head 30 slides while contacting the magneto-optical disk 36 when the magneto-optical disk 36 starts and stops rotating. In order to reduce the wear of the magneto-optical disk 36 and floating magnetic head 30 caused by this sliding, similar to applying a lubricant such as fluorine-based oil to the disk surface of a hard disk or the like,
It is conceivable to apply a lubricant 40 on the protective film 39.

[0014]

However, the magneto-optical disk 36 is portable, that is, can be removed from the apparatus, and is different from the hard disk described above in this respect. Therefore, when the lubricant 40 made of liquid lubricating oil or the like is applied to the surface of the magneto-optical disk 36, dust etc. tend to adhere to the surface, which causes damage to the surface of the magneto-optical disk 36. Because there is a fear
Applying the lubricant 40 may actually reduce the reliability of the magneto-optical disk 36. Also,
Due to the above circumstances, magneto-optical disks 36 whose surfaces are not coated with lubricant 40 are also used; This may cause incompatibility between the two.

On the other hand, it is conceivable to apply a lubricant to the bottom surface of the floating magnetic head 30, but in that case, the manufacturing process of the floating magnetic head 30 will be increased, and the lubricant of the floating magnetic head 30 will not be exposed to light. It has been difficult to apply lubricant to the floating magnetic head 30 because the lubricant 40 for the magnetic disk 36 needs to have several hundred times the durability.

Furthermore, it is also conceivable that the slider 31 be made of polyacetal resin or graphite having lubricating properties. However, when polyacetal resin is used, it is difficult to obtain sufficient dimensional accuracy due to molding shrinkage.On the other hand, when graphite is used, it has electrical conductivity, so when graphite comes into contact with the coil of the magnetic head body 34, the above-mentioned There is a risk of changing the magnetic properties of the external magnetic field.

[0017]

[Means for Solving the Problems] In order to solve the above-mentioned problems, a magneto-optical recording device according to the present invention includes a magnetic head main body that generates an external magnetic field for recording information on a magneto-optical recording medium, and a magnetic head main body that generates an external magnetic field for recording information on a magneto-optical recording medium. In a magneto-optical recording device including a floating magnetic head that supports a magnetic head main body and has a slider that can slide on the magneto-optical recording medium, the slider is formed of ceramics containing at least hexagonal boron nitride. (Structure of claim 1)

Another magneto-optical recording device according to the present invention includes a magnetic head body that generates an external magnetic field for recording information on a magneto-optical recording medium, a magnetic head body that supports the magnetic head body, and a magnetic head that generates an external magnetic field for recording information on a magneto-optical recording medium. In a magneto-optical recording device equipped with a floating magnetic head having a slider capable of sliding on the magneto-optical recording medium, the bottom surface of the slider that contacts the magneto-optical recording medium is formed of ceramics containing at least hexagonal boron nitride. (Claim 2)
configuration).

[0019]

[Function] According to the above structure, at least the bottom portion of the slider is made of ceramic containing hexagonal boron nitride, which has lubricating properties, so that the slider can perform magneto-optical recording when the magneto-optical recording medium is started or stopped. Scratching, abrasion, etc. are less likely to occur on the magneto-optical recording medium or the slider when sliding on the medium.

[0020]

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

As shown in FIG. 1, a magneto-optical disk 1 as a magneto-optical recording medium includes a substrate 2, a recording film 3 provided on the substrate 2, and a protective resin film 4 covering the recording film 3. ing. The substrate 2 is made of, for example, glass, polycarbonate (PC), or polymethyl methacrylate (PMMA).
It is made of a translucent resin such as amorphous polyolefin (APO).

Although not shown in detail, the recording film 3 is, for example, a first film made of AlN (film thickness of about 800 Å).
Transparent dielectric film, DyFeCo (film thickness approximately 200 Å)
Perpendicular magnetization film consisting of rare earth transition metal alloy thin film such as Al
It has a multilayer structure in which a second light-transmitting dielectric film made of N (film thickness of about 250 Å) and a reflective film made of Al (film thickness of about 500 Å) are laminated on the substrate 2 by sputtering, vapor deposition, etc. (Al
is aluminum).

The protective resin film 4 prevents the recording film 3 from being damaged and dust attached, and also prevents the recording film 3 from being oxidized. As a material for the protective resin film 4, for example, a mixture of urethane acrylate and acrylic acid ester monomer (viscosity 300c), which is advantageous in terms of workability, process time, etc.
It is possible to use an ultraviolet curing resin such as (on the order of PS). In forming the protective resin film 4, after coating the above-mentioned ultraviolet curable resin on the recording film 3, ultraviolet rays are applied to the recording film 3 at approximately 60° C.
It is sufficient to cure the ultraviolet curing resin by irradiating the resin at a dose of about 0 mJ/cm2.

FIG. 2 shows an enlarged view of the floating magnetic head 5 in the magneto-optical recording device. The floating magnetic head 5 includes a slider 6 that can slide on the magneto-optical disk 1 and a magnetic head body 7 supported by the rear end of the slider 6. The bottom surface of the slider 6, which faces the surface of the protective resin film 4 on the magneto-optical disk 1, introduces an air flow generated as the magneto-optical disk 1 rotates to start the floating magnetic head 5. It is provided with an inclined part 8 having an inclination of 10 degrees or less, and a flat part 9 for receiving the levitation pressure due to the air flow on its entire surface and maintaining a stable levitation state.

Further, a groove 10 is provided in the upper part of the slider 6, and the end of a suspension 11 (FIG. 1) made of a plate spring or the like that urges the slider 6 toward the magneto-optical disk 1 is inserted into the groove 10 and It is connected to the.

The slider 6 is made of ceramic made of a sintered body of hexagonal boron nitride. As hexagonal boron nitride, for example, "KC" manufactured by Shin-Etsu Chemical Co., Ltd.
” (product name), “UHS-D” (product name) manufactured by Showa Denko Co., Ltd., “NB-100” (product name) manufactured by Denki Kagaku Kogyo Co., Ltd., “N” (product name) manufactured by Koransha, etc. are used. can do.

Mn-Zn ferrite or the like is used as the coil core in the magnetic head body 7, and after a coil made of Cu fine wire or the like is wound around this coil core for about 20 to 50 turns, the magnetic head body 7 is made of glass or It is adhered to the slider 6 using epoxy resin or the like.

The coil of the magnetic head main body 7 is connected to a power source 12.
The polarity of the power source 12 is changed depending on the direction of the generated external magnetic field. Further, an optical head 13 is arranged at a position facing the floating magnetic head 5 with the magneto-optical disk 1 in between, and the floating magnetic head 5 and the optical head 13 are moved by a moving means such as a linear motor (not shown). They are moved in the radial direction of the magneto-optical disk 1 in conjunction with each other. Note that the magneto-optical disk 1 is rotationally driven by a spindle motor 14.

In the above configuration, when the magneto-optical disk 1 is loaded into the magneto-optical recording device, the flying magnetic head 5 is first moved to a predetermined flying start position (for example, the innermost position). When the floating magnetic head 5 reaches the floating start position, the spindle motor 14 starts rotating the magneto-optical disk 1.

As the rotational speed of the magneto-optical disk 1 increases, the floating magnetic head 5 is subjected to floating pressure by the airflow flowing between the magneto-optical disk 1 and the floating magnetic head 5, while the suspension 11 It receives pressure in the opposite direction to the levitation pressure and balances at a predetermined height. As a result, the distance between the surface of the magneto-optical disk 1 and the surface is, for example, several μm to
The floating magnetic head 5 is placed while maintaining a gap of several tens of μm.
emerges.

When recording by the magnetic field modulation method, a laser beam with a laser power of about 2.5 to 10.0 mW is irradiated from the optical head 13 to the recording region of the recording film 3 of the magneto-optical disk 1, and the recording region is The temperature of the recording film 3 is raised to above the Curie point of the perpendicularly magnetized film or above the magnetic compensation point, and the coercive force is made zero or almost zero. In this state, the floating magnetic head 5 applies an upward or downward external magnetic field depending on the information to be recorded in the recording region, thereby setting the direction of magnetization to a desired direction. Thereafter, when the laser beam irradiation to the recording area is completed, the temperature of the recording area decreases and eventually returns to room temperature. In this way, the direction of magnetization set in the recording region is maintained and desired information is recorded.

On the other hand, information is reproduced from the optical head 13.
Laser power 0.5-2.0mW, smaller than during recording
This is done optically by irradiating a laser beam of approximately 100 mL and detecting the rotation of the plane of polarization in the reflected light.

In this embodiment, since the slider 6 of the floating magnetic head 5 is made of hexagonal boron nitride, which has lubricating properties, the slider 6 touches the magneto-optical disk at the start and end of rotation of the magneto-optical disk 1. When sliding on the magneto-optical disk 1 or the slider 6, scratching, abrasion, etc. are less likely to occur. Note that the slider 6 can also contain components other than hexagonal boron nitride.

Next, another embodiment of the present invention will be described.

As shown in FIG. 3, in this example,
The magneto-optical disk 1 is composed of a substrate 2, a recording film 3, and a protective resin film 4 as in the above embodiment, and of these, the substrate 2 and the protective resin film 4 can have the same structure as in the above embodiment. The recording film 3 may have a structure similar to that of the above embodiment, but may also include, for example, a first light-transmitting dielectric film made of SiAlON (film thickness of about 800 Å), a TbF
A perpendicularly magnetized film made of eCo (about 1000 Å thick) and a second transparent dielectric film made of SiAlON (about 800 Å thick) may be laminated on the substrate 2.

Further, as shown in FIG. 4, in this embodiment, the slider 6 in the floating magnetic head 5 has a base portion 15 and a bottom layer 16 formed on the bottom surface of the base portion 15.
(shown by hatching for convenience). The base portion 15 is made of, for example, a mica-based sintered body. On the other hand, the bottom layer 16 is formed from a free-cutting ceramic containing hexagonal boron nitride. The above-mentioned free-cutting ceramics include AlN + hexagonal boron nitride (for example, Shapal M (trade name) manufactured by Tokuyama Soda Co., Ltd.), or S
i3 N4 + hexagonal boron nitride (for example, SNB-20 (trade name) manufactured by Kawasaki Steel Corporation), etc. can be used.

The bottom surface of the base portion 15 is composed of an inclined portion and a flat portion, similar to the slider 6 of the above embodiment, and thus the bottom layer 16 has an inclined portion 17 having an inclination of 10° or less and a flat portion. 18 are provided. Further, a groove 19 for connecting the suspension 11 is formed in the upper part of the base part 15. Furthermore, a magnetic head main body 7 similar to the above embodiment is attached to the rear end of the base portion 15.

[0038] Other parts having the same configuration as those in the above embodiment are simply designated by the same reference numerals. Furthermore, since the recording and reproducing operations in the magneto-optical recording device of this embodiment are the same as those of the above embodiment, the explanation will be omitted.

In this embodiment, the bottom layer 16 made of free-cutting ceramics containing lubricating hexagonal boron nitride is provided at the bottom of the slider 6, so that when the magneto-optical disk 1 starts or stops rotating. When the slider 6 slides on the magneto-optical disk 1, the magneto-optical disk 1 or the slider 6 is less likely to be scratched or worn.

[0040]

In the magneto-optical recording device according to claim 1 of the present invention, the slider in the floating magnetic head is formed of ceramics containing at least hexagonal boron nitride. Further, in a magneto-optical recording device according to a second aspect of the present invention, the bottom portion of the slider that contacts the magneto-optical recording medium is formed of ceramics containing at least hexagonal boron nitride.

As described above, since at least the bottom surface of the slider is made of ceramic containing hexagonal boron nitride, which has lubricating properties, the slider does not move over the magneto-optical recording medium when the magneto-optical recording medium is started or stopped. Scratching, abrasion, etc. are less likely to occur on the magneto-optical recording medium or the slider when sliding.

Furthermore, by imparting lubricity to the slider side, the process of applying lubricant to the magneto-optical recording medium becomes unnecessary, and the specification of the magneto-optical recording medium can be unified without applying lubricant, so that each Compatibility can be provided between magneto-optical recording media.

Furthermore, since ceramics containing at least hexagonal boron nitride have free machinability, precise machining is possible, and compared to the use of other materials with lubricity, such as polyacetal resin, high dimensional accuracy can be obtained.

Furthermore, unlike graphite, for example, ceramics containing hexagonal boron nitride do not have electrical conductivity, so even if they come into contact with the coil of the magnetic head body, their magnetic properties do not change.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing a magneto-optical recording device in an embodiment of the present invention.

FIG. 2 is a perspective view showing a floating magnetic head in the magneto-optical recording device of FIG. 1;

FIG. 3 is a schematic configuration diagram showing a magneto-optical recording device in another embodiment of the present invention.

4 is a perspective view showing a floating magnetic head in the magneto-optical recording device of FIG. 3; FIG.

FIG. 5 is a schematic configuration diagram showing a conventional magneto-optical recording device.

6 is a perspective view showing a floating magnetic head in the magneto-optical recording device of FIG. 5. FIG.

[Explanation of symbols]

1 Magneto-optical disk (magneto-optical recording medium) 5 Floating magnetic head 6 Slider 7 Magnetic head body 16 Bottom layer

Claims (2)

[Claims] 1. A floating type comprising a magnetic head body that generates an external magnetic field for recording information on a magneto-optical recording medium, and a slider that supports the magnetic head body and can slide on the magneto-optical recording medium. 1. A magneto-optical recording device including a magnetic head, wherein the slider is made of ceramics containing at least hexagonal boron nitride. 2. A floating type comprising a magnetic head body that generates an external magnetic field for recording information on a magneto-optical recording medium, and a slider that supports the magnetic head body and can slide on the magneto-optical recording medium. 1. A magneto-optical recording device equipped with a magnetic head, characterized in that a bottom portion of the slider that contacts the magneto-optical recording medium is formed of ceramics containing at least hexagonal boron nitride.