JPH0453065A - Magneto-optical disk device - Google Patents

Abstract

PURPOSE:To prevent the S/N of a signal from deteriorating and to improve the reliability against a crush by rotating a disk at even higher revolving speed prior to its steady rotation. CONSTITUTION:First of all, a main power source is turned on (a), and a cassette of a magneto-optical disk is inserted into the device (b). Next, a disk rotating motor is turned on (c) for the purpose of reproducing and recording the disk. The disk is rotated by the motor, and its revolving speed is once raised even higher than the steady rotation, and is afterward restored to the steady rotation. Now, an optical head and a magnetic head, etc., are loaded (d), and the reproducing and recording are carried out under this rotating state. Then, in the case of stopping, the heads are unloaded (e), the motor is turned off (f), the cassette is taken out (g) and the main power source is turned off or a new cassette is inserted (h), if new cassette is inserted, to return to (c).

Description

[Detailed description of the invention] [Industrial application fields] The present invention relates generally to magneto-optical disk devices.

[Prior art] There are two types of magneto-optical disk devices: read-only devices and overridable devices. Overridable devices are currently the mainstream in development, and the device is based on the IEE
Transaction on Magnetic
MAG20 Vol, 5 P10], 3 (1984), and those described in JP-A-51-107121 and JP-A-63-217548.

FIG. 3 shows an outline of a conventional magnetic field modulation type magneto-optical disk device. In the figure, (1) is a magneto-optical disk,
(2) is the spindle motor, (3) is the optical head, (4)
(5) is a magnetic head, (6) is a magnetic head drive circuit, and (7) is a moving mechanism. As shown in the figure, a head (5) that applies a magnetic field is placed to sandwich the disk (1) and face the optical head (3).

FIG. 2 is a state diagram showing the operation of the conventional device.

The present invention relates to magneto-optical disks in general, regardless of whether they are playback-only machines or overridable devices.

[Problems to be Solved by the Invention] This magneto-optical disk device operates in the general atmosphere, and the magneto-optical disk is inserted into and taken out from a cassette, so it is inevitable that some dust will accumulate on the disk.

Since the S/N of the signal of a magneto-optical disk device is proportional to the spot diameter of the laser beam, the disk within the spot, ■
- If there is dust, the S/N will deteriorate.

Furthermore, since the floating magnetic head facing the optical head is suspended at a distance smaller than the disk surface, there is a problem in that the presence of dust increases the likelihood of head crashes.

The present invention has been made in order to solve the problems mentioned in item L, and it is an object of the present invention to obtain a highly reliable magneto-optical disk device that does not cause deterioration of S/N.

[Means for Solving the Problems] In the optical disk device according to the present invention, when the magneto-optical disk device is used, the rotation speed of the disk is lower than the steady rotation speed from the start of rotation to the steady rotation speed for recording or reproducing. This allows the rotation speed to be even higher.

[Function] The magneto-optical disk device of the present invention rotates the disk at a higher rotation speed before it reaches steady rotation (the rotation speed at which recording or reproduction is performed), thereby removing dust attached to the disk due to airflow and centripetal force. This makes it possible to obtain a signal with a good S/N ratio and improve reliability against head crashes.

"Example" An embodiment of the present invention will be explained with reference to FIG.

The first figure shows the state of the operating points of the device. First, turn on the main power (a) and insert the magneto-optical disk cassette into the device (b). Next, the disc rotation motor is turned on for playback and recording (c). The disk is rotated by a motor, increases to a rotation speed even higher than normal rotation by -degrees, and then returns to steady rotation. Here, an optical head, a magnetic head, etc. are loaded (d), and reproduction and recording are performed in this rotating state.

Next, to stop, unload the head and turn the motor to 0.
FF (f) L, remove the cassette g) Turn off the main power
F or insert a new cassette (h), return to (e) when a new cassette is inserted.

The device configuration, reproduction operation, recording operation, etc. of the present invention are all the same as those of the conventional device.

[Effects of the Invention] As explained above, according to the present invention, signal S/N deterioration can be prevented without increasing the cost of conventional products, and there is an extremely large effect of improving reliability against crashes.

[Brief explanation of drawings]

FIG. 1 is a state diagram showing the operation of the apparatus of the present invention, FIG. 2 is a state diagram showing the operation of the conventional apparatus, and FIG. 3 is a configuration diagram of the conventional optical disk apparatus. In the figure, (1) is a magneto-optical disk, (2) is a spindle motor, (3) is an optical head, (4) is an optical head drive circuit, (5) is a magnetic head, (6) is a magnetic head drive circuit, ( 7) shows the moving mechanism 5, (A) shows the rotation direction of the magneto-optical disk, and (B) shows the direction of the air flow generated as the magneto-optical disk rotates. Figure 1 +-BOn Cassette insertion motor on Head loading Head unloading motor ott Cassette removal Main power OFF, or insert another cassette Figure 2

Claims (1)

[Claims] In a magneto-optical disk device using a magnetic field modulation method or a modulation method, the motor for rotating the magneto-optical disk is turned on, and the rotation speed of the disk is higher than the predetermined rotation speed until it reaches a predetermined rotation speed. Features of magneto-optical disk device.