JPH02193345A - Magneto-optical recording medium driving device - Google Patents

Abstract

PURPOSE:To attain the high speed movement of each head by making an optical head and a magnetic head movable individually and detecting and controlling the relative position of the heads through the detection of a transmissive light from the optical head. CONSTITUTION:When the movement of an optical head 4 is started by a seek instruction from an external device, a laser beam 6 with weak power from the head 4 irradiates a disk 2, its reflected light is detected by a photodetector 10 in the head 4, the number of track slots of the disk 2 is counted and a linear motor 14 moves the head up to a desired track accordingly. In this case, a part of the laser beam 6 is transmitted through the disk 2, detected by the photodetector 10 having two-split light receiving faces 10a, 10b in the magnetic head 7 and the difference of the detection signals of the light receiving faces 10a, 10b is obtained by a differential amplifier 11. Then the linear motor 15 is subjected to feedback control so as to make the difference zero, thereby tracing the head 7 to the head 4. Thus, the weight of the movable part is made light.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magneto-optical recording medium drive device that records, reproduces and erases information on a recording medium such as a magneto-optical disk using light and magnetism.

[Conventional technology]

FIG. 4 is a schematic side view showing the configuration of a conventional optical modulation type magneto-optical disk drive. In the figure, l is a base, and on one end side of the base 1 is a disk motor 3 that rotates a disk 2 that is disk-shaped and has a concentric or spiral track groove, with its rotating shaft protruding upward. installed. A turntable 31 equipped with a permanent magnet for attracting the disk 2 is attached to the tip of the rotating shaft of the disk motor 3. A linear motor 1 is mounted on the lower surface of the disk 2 in its radial direction (hereinafter referred to as the X direction).
an objective lens 5 for converging a laser beam 6 from an optical head 4 movable with respect to the base 1 by a driving means consisting of 4 into a light spot with a diameter of about lus on a magnetic layer (not shown) made of an amorphous alloy in the disk 2; is coming. A magnetic head 7 is provided above the optical spot position on the disk 2 for applying a magnetic field 8 to the optical spot position on the magnetic layer.

The optical head 4 and the magnetic head 7 are connected by an L-shaped support arm 9, and the magnetic head 7 is moved in the X direction of the disk 2 together with the optical head 4 by driving means for the optical head 4.

Next, the operation will be explained.

Information is recorded on the disc 2 as follows. That is, the magnetization direction in the magnetic layer is aligned in one direction in advance, and the laser beam 6 is focused by the objective lens 5.
Continuously irradiate the magnetic layer as a light spot with a diameter of about 1 μm,
The temperature at the optical spot position is raised to the Curie point to eliminate its coercive force, and a magnetic field 8 in a direction different from the magnetization direction is applied to the optical spot position by the magnetic head 7 to reverse the magnetization direction and record. .

Erasing is performed by irradiating the laser beam 6 with the same power as during recording and applying a magnetic field 8 in the same direction as the predetermined magnetization direction.

Furthermore, reproduction is performed by irradiating the laser beam 6 with a power weaker than that during recording and detecting a change in the phase of the reflected light due to the Kerr effect.

Further, during seek, the desired track is detected by irradiating the laser beam 6 with the same power as during reproduction and counting the number of track grooves.

[Problem to be solved by the invention]

Magneto-optical disks are large-capacity rewritable information recording media, and therefore their drive devices are required to have high-speed access. Another large-capacity rewritable information recording device is a fixed magnetic disk device, but the average access speed in this case is about 20111 seconds or less for a high-speed type.

However, in magneto-optical disk drives, it is approximately 8 (1ws)
EC, and increasing the access speed is an important consideration in the future.

A conventional magneto-optical disk drive, as shown in FIG.
A support arm was extended from the optical head to a position opposite to the optical spot position with the disk in between, and a magnetic head was attached thereto to interlock the magnetic head and the optical head.

However, in order to load and unload the disk, the support arm needs to have a length comparable to the radius of the disk, which increases the mass of the movable part, which is disadvantageous for high-speed access operations. Furthermore, since the support arm becomes long, its rigidity is low and vibration occurs, which adversely affects the positioning of the optical head and magnetic head.

Furthermore, when accessing the outer periphery of the disk, the support arm retreats, which requires space in the apparatus, increasing the size of the apparatus.

This invention was made in view of the above circumstances, and it makes it possible to move the optical head and the magnetic head separately, detects their relative position by detecting the transmitted light from the optical head, and keeps it constant at all times. The aim is to reduce the mass of the moving parts of the optical head and magnetic head, enable high-speed movement of each head, and create a magneto-optical recording medium drive device that is compact and capable of high-speed access. Make it a purpose.

[Means to solve the problem]

The magneto-optical recording medium drive device according to the present invention drives an optical head and a magnetic head separately, and detects their relative positions by a position detection means that detects transmitted light from the optical head, which is provided on the magnetic head. Accordingly, the driving means is controlled to cause the magnetic head to follow and interlock with the optical head in order to keep the relative position constant.

[Effect]

In this invention, the relative positions of the optical head and the magnetic head, which are driven separately, are detected by the position detecting means, and the driving means for the optical head and the magnetic head are controlled to keep the relative position constant, and the magnetic head is moved between the optical head and the magnetic head. Since the magnetic head and the optical head are made to follow and interlock, a connecting member between the magnetic head and the optical head can be made unnecessary, and the weight of the movable part can be reduced.

〔Example〕

The present invention will be explained below based on the drawings showing one embodiment thereof.

FIG. 1 is a schematic side view showing the configuration of a magneto-optical disk drive device which is a magneto-optical recording medium drive device according to the present invention. In the figure, 1 is a base, and a disk motor 3 for rotating a disk 2 having a disk shape and having a concentric or spiral track groove is attached to one end of the base with its rotating shaft protruding upward. ing. Further, on the other end side of the base 1, an L-shaped plaquette a extending across the disk 2 toward the center thereof is fixed.

A turntable 31 equipped with a permanent magnet for attracting the disk 2 is attached to the tip of the rotating shaft of the disk motor 3. The lower surface of the disk 2 is marked in its radial direction (hereinafter referred to as
The laser beam 6 from the optical base 4, which is movable relative to the base 1 by a driving means consisting of a linear motor 14 in the direction of
An objective lens 6 for converging a light spot with a diameter of about 1 μm is facing (see FIG. 2). Objective lens 6
can be moved minutely in the X direction and in the vertical direction by a magnetic drive means (not shown).

The optical head 4 includes a semiconductor laser as a light source, a photodetector, and an optical system, and outputs laser light with different power during recording and erasing, and during reproducing and seeking.

Further, above the optical spot position, a magnetic head 7 is provided which applies a magnetic field 8 in a predetermined direction to the optical spot position of the magnetic layer 22 in accordance with recording/erasing thereon. The magnetic head 7 is attached to one end of the lower surface side of an excitation system holder 13 which is movable in the X direction by a driving means consisting of a linear motor 15, facing the disk 2.

FIG. 2 is an enlarged side sectional view showing the structure of the magnetic head.

The disk 2 is formed by laminating a magnetic layer 22 and a protective layer 23 on a substrate 21, and the laser beam 6 from the optical head 4 is made of magnetic N2.
2, it becomes a light spot with a diameter of 1 μm and is reflected to the optical head 4.
A portion of the light is detected by a photodetector inside the disk 2, and a portion thereof is transmitted through the disk 2. The magnetic head 7 has a coil 71 and a core 72 around which the coil 71 is wound. A two-part photodetector 10 serving as a position detection means is provided at a light transmitting position of the core 72, and each light receiving surface 10a , 10b is outputted via the differential amplifier 11 to the optical head 4 and the magnetic head 7.
Detects the relative position with. Note that in order to stabilize the detection signal of the photodetector lO, the distance between the magnetic herador and the protective layer 23 needs to be a constant value between several μm and 100 μm. It can move up and down following the disc 2.

Next, the operation of the magneto-optical disk drive device configured as described above will be explained.

The magnetic head 7 and the optical head 4 are moved when the disk 2 is sought, when tracking, when the disk access ends, and the like. When the optical head 4 starts moving in response to a seek command from an external device, a weak power laser beam 6 is irradiated from the optical head 4 onto the disk 2, and the reflected light is detected by a photodetector inside the optical head 4. The number of track grooves on the disk 2 is counted, and the speed of the linear motor 14 is controlled accordingly to move the optical head 4 to a desired track.
move. At this time, a part of the laser beam 6 is transmitted to the disk 2.
The light-receiving surface 10a divided into two parts in the magnetic head 7
, 10b, a difference signal between the detection signals of the respective light receiving surfaces 10a and 10b is obtained by the differential amplifier 11, and the linear motor 15 is feedback-controlled so that the difference signal becomes zero, The magnetic head 7 is caused to follow the optical head 4.

Next, other embodiments will be described.

FIG. 3 is an enlarged side sectional view of a magnetic head used in a magneto-optical disk drive device according to another embodiment of the present invention.

In this embodiment, a thin film coil 72 is used as the coil, and a recess 73 is provided in the center of the coil, and a two-part photodetector 10 is provided in the recess 73, each having a light receiving surface 10a.

The detection signal from 10h is outputted via the differential amplifier 11 to detect the relative position between the optical head 4 and the magnetic head 7.

The other configurations and operations are the same as those of the previous embodiments, so their explanations will be omitted.

In this embodiment, a two-part type photodetector is used, but the present invention is not limited to this, and any type of photodetector may be used as long as the relative position can be detected by transmitted light.

Further, although this embodiment has been described using a light modulation type magneto-optical disk drive device, this is merely an example, and the present invention is not limited to this, but can also be applied to a magnetic field modulation type.

[Effects of the Invention] As explained above, according to the present invention, the optical head and the magnetic head are driven separately, and their relative positions are detected by detecting the transmitted light from the optical head. By controlling each separate drive means to keep it constant,
The magnetic head can be linked to follow the optical head, eliminating the need for connecting members, reducing the weight of the moving parts, enabling high-speed movement of each head, and high-speed access. This eliminates the need for space associated with the movement of members, and provides excellent effects such as miniaturization of the device.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view showing the structure of a magneto-optical disk drive according to the present invention, FIG. 2 is an enlarged side sectional view showing the structure of a magnetic head, and FIG. 3 is a magneto-optical disk drive of another embodiment. FIG. 4 is an enlarged side sectional view showing the configuration of the magnetic head of the device, and FIG. 4 is a schematic side view of a conventional magneto-optical disk drive device. 2...Disk 4...Optical head 7...Magnetic helad 10...Photodetector 14...Linear motor 1
5...Linear motor In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] (1) It is movable along one surface of the magneto-optical recording medium,
A magneto-optical head comprising: an optical head that irradiates a light beam onto the one surface; and a magnetic head that works in conjunction with the optical head and applies a magnetic field to the irradiation position of the light beam from the optical head with the magneto-optical recording medium in between. In the recording medium driving device, a driving means for driving the optical head and the magnetic head separately, and a driving means provided in the magnetic head and configured to detect the transmitted light of the light beam from the magneto-optical recording medium to drive the optical head and the magnetic head. What is claimed is: 1. A magneto-optical recording medium drive device, comprising: position detection means for detecting a relative position with respect to a head, and based on the detection result, the magnetic head is caused to follow and interlock with respect to the optical head.