JPH01176347A - Magneto-optical recording device - Google Patents

Abstract

PURPOSE:To contrive the miniaturization of a magnetic bias means by providing a rotary piece to hold a permanent magnet so that the direction of magnetization can be inverted for recording, reproducing and erasing. CONSTITUTION:The title device is provided with a laser beam projecting means, which projects a laser beam to a recording medium, and a magnetic bias means to impress an external bias magnetic field to the recording medium part where the laser beam is projected. In such a case, the magnetic bias means is composed of the rotary piece 2 to hold a permanent magnet 1 arranged in a relative position pinching and facing the laser converging position of the recording medium with the recording medium, so that the direction of the magnetization can be changed by the rotation at the time of the recording, reproducing and erasing, holding means 2b and 2c holding this rotary piece 2 rotatably and driving means 4 and 5 to rotate the rotary piece 2. Accordingly, a distance with a recording medium 10 can be shortened at the recording and erasing times. Thus, the device can be made compact and efficiency can be obtained.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a magneto-optical recording device.

Conventional magneto-optical recording devices converge the laser beam irradiated from an optical pickup to a diameter of 0.9 μm and 8 degrees at the medium surface, locally heat the recording medium surface to the cue point, and then The coercive force of the perpendicular magnetization of the irradiation part is reduced and a constant magnetization state is achieved by an external magnetic field placed on the opposite surface.In this way, the magnetic domains of perpendicular magnetization are aligned depending on the direction of the magnetic field from the magnetic bias, and the magnetic domains are Information is recorded by changing the arrangement direction. When a laser beam is focused and irradiated onto the surface of a recording medium with vertically oriented magnetic domains, the plane of polarization of the laser beam rotates by a small angle due to the Kerr effect depending on the direction of the magnetic domains, so the plane of polarization of the light reflected from the recording film is By detecting it, the recorded information can be reproduced. On the other hand, erasing recorded information can be achieved by rearranging the magnetic domains in the area to be erased in a certain direction determined by the system in the same manner as during recording. The polarity of the magnetic field must be opposite when recording and erasing information. Here, an electromagnet is often used as the magnetic bias, and the electromagnet is also moved to a predetermined position on the recording medium section along with the movement of the optical pickup.

Problems to be Solved by the Invention However, in the case of a mobile type, the clearance between the recording medium and the electromagnet must be approximately 2.2 to 2.6 fl, and the bias magnetic field required for recording and erasing cannot be effectively applied. In order to add this, a large-sized device is required, making it unsuitable for a magneto-optical recording device aiming at miniaturization.

In view of the above problems, the present invention provides a compact magnetic biasing means.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a rotating piece that holds a permanent magnet so that the direction of magnetization can be changed by rotation during recording, reproduction, and erasing, and this rotating piece. It is composed of a holding means that rotatably holds the rotary piece, and a driving means that rotates the rotary piece.

Effect: With this configuration, the distance to the recording medium surface during recording and erasing can be shortened, so a compact and efficient magnetic bias can be obtained.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a magnetic bias means of a magneto-optical recording device according to an embodiment of the present invention.

The magnetic bias is made up of a permanent magnet 1 which is a magnetic field generating element, and this permanent magnet 1 is inserted and fixed into a rectangular hole of the rotating piece 2. A rack 3a is formed on the drive piece 3 so as to engage with a gear 2a formed on the rotating piece 2, and the linear motion of the drive piece 3 is transmitted to the spur gear 2a of the rotating piece 2 by the rack 3a. , convert to rotational motion. The drive piece 3 has grooves 3b and 3c at both ends thereof which engage with the solenoid shafts, and these grooves engage with the drive shafts 4a and 5& of the solenoids 4 and 5. There are claws 3d and 3e on both ends of the drive piece 3 for hooking the spring, and this claw 3d.

The hooks of springs 7 and 8 are respectively hooked on 3e, and the hooks on the opposite side are hooked on claws 6a and 6b, respectively, which are cut and raised on the cartridge case 6. These springs 7.8'' are the same, and the driving piece 3 is balanced at the center of its movable range. There are small-diameter cylindrical projections 2b and 2c at both ends of the rotating piece 2, which are rotatably supported by a claw 6C cut and raised from the cartridge holder 6. In the above configuration, when the solenoid 4 is energized, the solenoid shaft 4a is pulled by a certain stroke, the drive piece 3 engaged therewith also moves, and the rotary piece 2 rotates via the gear 2a. At this time, the spring 7 is deflected and the spring 8 is stretched, so that the perpendicular magnetic field component of the permanent magnet 1 is applied to the surface of the recording medium in a state where the balance is lost. When the solenoid 4 is de-energized, the tension of the spring 8 causes it to return to its original central position. At this time, the magnetic field of the recording medium has a horizontal component. Next, when the solenoid 6 is energized, it performs the same operation as described above, but the perpendicular magnetic field component applied to the recording medium of the permanent magnet 1 is reversed.

FIG. 2a shows the position of the permanent magnet during recording, and it can be seen that the magnetic field of the S pole is applied perpendicularly to the recording medium 1o of the disk 9. b indicates the position of the permanent magnet 1 at the time of foundation, and the magnetic field is horizontal to the recording medium 10 so as not to affect the recording medium 10 during reproduction. C
is the opposite of a and indicates the direction of the perpendicular magnetic field during erasing. However, the arrangement in this case is due to system considerations and may be in the opposite direction.

As a result of the above, it can be easily achieved both mechanically and in terms of circuitry.
The magnetic bias itself can also be made smaller.

Effects of the Invention As described above, in the magneto-optical recording device of the present invention, the magnetic bias means can be miniaturized, so that a compact magneto-optical recording device can be provided.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a magnetic bias means section of a magneto-optical recording device according to an embodiment of the present invention, and FIGS. 2a, b, and c are sectional views showing the positions of permanent magnets during recording and erasing of the same embodiment. be. 1...Permanent magnet, 2...Rotating piece, 3.
... Drive piece, 4.6 ... Solenoid.

Claims (1)

[Claims] Laser light irradiation means for irradiating the recording medium with laser light;
magnetic bias means for applying an external bias magnetic field to the recording medium portion irradiated with the laser beam; One permanent magnet arranged, a rotating piece that holds this permanent magnet so that the direction of magnetization can be reversed by recording, reproducing, and erasing, a holding means that rotatably holds this rotating piece, and this rotating piece. A magneto-optical recording device comprising: a driving means for rotating a magneto-optical recording device;