JPH03266242A - Magneto-optical disk device - Google Patents

Abstract

PURPOSE:To realize high-speed access by installing an optical head for recording/reproducing/erasing and a magnetic field impressing means opposite to this head with a magneto-optical disk between so as to be movable independently as separated bodies. CONSTITUTION:A carriage 2B carrying, at least, an objective lens in a first optical head 2 and the carriage 20B carrying, at least, the objective lens in a second optical head 20 are supported as different pairs so as to be movable independently. Then, a first magnetic field impressing means 9 and a second magnetic field impressing means 90 whose length in a radial direction covers a whole recording area are arranged respectively at positions opposite to each other with the magneto-optical disk 1 between in the first optical head 2 and the second optical disk 20. Thus, the weight of a movable part is distributed and lightened, and inertia mass is reduced, and the high-speed access becomes possible.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a magneto-optical disk device, and more particularly to the structure of a pickup head that records, reproduces and erases information on both the front and back surfaces of a magneto-optical disk.

(Prior Art) As is well known, optical discs, which are one of the media that can record high-density information, include those that are used only for reading recorded information, and those that allow additional information to be recorded immediately after recording. There are recordable types that allow information to be read out, and then the same information can be retrieved any number of times. There is.

Among the above-mentioned types of disks, there is a magneto-optical disk that can use the magneto-optic effect as a disk that is applied to the erase/write type, and the structure for writing to this magneto-optical disk is shown in Fig. 8. structure is proposed.

That is, in the structure shown in FIG. 8, a carriage C is provided at the tips of two arms B and B' that face each other with a magneto-optical disk A in between and extend in the radial direction of the disk A. The optical head D and the magnetic field applying means E are arranged in pairs, and the optical head D and the magnetic field applying means E are movable over the recording area of the magneto-optical disk A in the radial direction. This movement is performed, for example, by a linear movement mechanism using a voice coil motor F.
Publication No.).

In the above-described structure, since the optical head and the magnetic field applying means are placed opposite to each other on both the front and back sides of the magneto-optical disk, it is possible to record/reproduce/erase information on both sides without having to flip and replace the magneto-optical disk. .

(Problem to be Solved by the Invention) However, in the above structure, the two sets of optical heads and magnetic field applying means, and the two arms provided on the carriage on which these parts are mounted are integrated. Since the magneto-optical disk is moved in the radial direction, the weight of the movable part increases, and the increase in inertial mass impedes high-speed access.

SUMMARY OF THE INVENTION In view of the above-mentioned problems with conventional magneto-optical disk devices, an object of the present invention is to provide a structure (that solves the problems) that enables high-speed access when recording/reproducing/erasing information on both the front and back sides of a magneto-optical disk. In order to achieve this object, the present invention is capable of recording/reproducing/erasing information by irradiating a light beam onto the first surface of a magneto-optical disk capable of recording/reproducing/erasing information on both the front and back sides. a first optical head for erasing; a second optical head for recording/reproducing/erasing information by irradiating a second surface with a light beam; and light beam irradiation by the first and second optical heads. In a magneto-optical disk device having first and second magnetic field applying means for applying a magnetic field for recording/erasing to a position, a carriage carrying at least an objective lens in the first optical head is attached to the magneto-optical disk. The first magnetic field applying means, which is movably supported over the entire radial recording area of the magneto-optical disk and faces the objective lens across the magneto-optical disk, is provided so as to be able to act over the entire radial recording area; A carriage carrying at least an objective lens in the second optical head at a position different from that of the first optical head is movably supported over the entire radial recording area, and a carriage is mounted on the second optical head with the magneto-optical disk in between. The second magnetic field applying means facing the objective lens in the optical head is provided so as to be able to act over the entire radial recording area, and
The present invention is characterized in that it includes an active mechanism that independently moves the optical head linearly in the radial direction of the optical disk.

(Function) According to the present invention, the carriage on which at least the objective lens of the first optical head is mounted and the carriage on which at least the objective lens of the second optical head is mounted are separate and independent bodies. Since it is movably supported, the weight of each carriage can be reduced.

(Embodiment) Hereinafter, details of an embodiment of the present invention will be explained with reference to FIGS. 1 to 7.

FIG. 1 is a schematic perspective view for explaining the arrangement of essential parts of a magneto-optical disk device according to an embodiment of the present invention.

The feature of this embodiment is that the magnetic field applying means, which is provided opposite to the optical head with the optical head and the magneto-optical disk sandwiched therebetween, is provided as an independent separate body on both the front and back sides of the magneto-optical disk.

That is, in FIG. 1, the optical heads disposed facing the magneto-optical disk 1 are arranged on both the front and back surfaces of the magneto-optical disk 1, and are configured as a first optical head 2 and a second optical head 20. and each optical head is
Fixed optical devices i2A of similar structure at positions close to each other
, 20A and carriages 2B, 20B.

The fixed optical devices i2A and 20A described above are equipped with a light beam output system including a semiconductor laser and a signal detection system that detects a focus error signal, a tracking error signal, and an information signal, and the carriages 2B and 20B are also equipped with It can be moved in the radial direction of the magneto-optical disk 1 by a moving mechanism.

Inside, as shown in the third diagram, one of which is shown,
triangular prism 2B] and an objective lens 2B2. The objective lens 2B2 inside the carriage 2B is supported so as to be able to float by a spring 2B3.

It is growing. The objective lens 2B2 in the carriage 2B is supported in a floating manner by a spring 283, and can be displaced in the optical axis direction and in the tracking direction of the magneto-optical disk 1 by a focusing mechanism and a tracking mechanism (not shown).

In FIGS. 2 and 3 showing one of the carriages 2B and 20B, the movement mechanism of the carriages 2B and 20B is fixed to the base member 3 of the apparatus (see FIG. 3) and moves in the radial direction of the magneto-optical disk 1. A guide rail 5 that is extended and slidably supports the carriage 2B via a bearing 4, a moving coil 2B4 provided on the carriage 2B side, and a permanent rail 5 fixed to the yoke 6 side facing the moving coil 2B4. It consists of a seek motor 8 equipped with a magnet 7.

On the other hand, the first optical head 2 and the second optical head 20 have a length that can cover the entire recording area in the radial direction of the magneto-optical disk 1 at positions facing each other across the magneto-optical disk 1. A first magnetic field applying means 9 and a second magnetic field applying means 90 are respectively arranged.

That is, the first and second magnetic field applying means 9.90 change the magnetization direction of the magnetic thin film by applying a weak magnetic force during heating with a laser beam, and the difference in magnetization direction is used to rotate the deflection plane of the reflected light. This is to enable detection as a change in angle (Kerr effect), and in FIGS. 4 and 5, one of which is shown, the length corresponds to the entire recording area in the radial direction of the magneto-optical disk 1. It consists of an electromagnet consisting of a yoke 9A extended by a yoke 9A and a coil 9B wound around this yoke 9A. Therefore, by energizing the coil 9B, the yoke 9B is magnetized, and recording/erasing is performed by changing the magnetization direction of the portion irradiated with the laser beam depending on the magnetization direction of the yoke 9A (see Fig. 4). (See (B)).

On the other hand, the structure of the magnetic field applying means shown in FIG. 5 uses a permanent magnet 9B10 instead of the electromagnet shown in FIG. This is what I did.

Since this embodiment has the above-described structure, the magneto-optical disk 1 is driven by the rotational drive spindle motor 1 in FIG.
The hub IA is chucked to the shaft of the 0 and rotated.

When recording/reproducing/erasing information on each of the front and back surfaces of the magneto-optical disk 1, a movable first disk is provided in parallel in parallel on each surface of the magneto-optical disk 1 and is movable.
, one of the second optical heads 2 and 20 moves independently of the other optical head to perform the above-mentioned recording/reproducing/
Perform one of the erase operations.

Furthermore, it goes without saying that the arrangement of the first and second optical heads 2.20 and the magnetic field application means 9.90 described above is not limited to the parallel relationship shown in FIG.

That is, FIGS. 6 and 7 show modified examples of the arrangement described above, and in the case shown in FIG. No. 2 optical head 2.20 and first and second magnetic field applying means 9
．． 90 is set in a 7-shape so that the moving directions of the carriages 2A, 20A in the first and second optical heads 2.20 are approximately at right angles. In this example, two carriages, 20A The moving direction of the magneto-optical disk 1 can be made to coincide with the radial direction of the magneto-optical disk 1.

In the example shown in FIG. 7, the first and second positions located on both the front and back surfaces are arranged along the diameter direction of the magneto-optical disk 1, in other words, so that the moving directions of the carriages are set in a straight line. Optical head 2.20 and the first. This is an example in which the second magnetic field applying means 9 and 90 are arranged opposite to each other with the center of the magneto-optical disk 1 interposed therebetween. In this example, as in the case of FIG. 6, the moving direction of the carriage and the magneto-optical disk 1 are
It is possible to match the radial direction of the

(Effects of the Invention) As described above, according to the present invention, the optical head for recording/reproducing/erasing and the magnetic field applying means facing this head with the magneto-optical disk sandwiched therebetween are independently provided on both the front and back sides of the magneto-optical disk. Since the optical head is provided separately and movably, it is possible to reduce the weight of the optical head on each side of the front and back surfaces, thereby reducing the inertial mass during movement and enabling high-speed access. .

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view for explaining the main parts of a magneto-optical disk device according to an embodiment of the present invention, FIG. 2 is a perspective view for explaining the moving mechanism of the main parts shown in FIG. Figure No. 4 is a sectional view taken in the direction indicated by line m-m in Figure 2;
Figures (A) and 5 (A) are perspective views showing specific examples of the magnetic field applying means in the main parts shown in Figure 1, and Figure 4.
Figures (B) and 5 (B) are arrow views in the direction indicated by the reference symbol B-B line in Figure 4 (A) and Figure 5 (A), respectively, and Figures 6 and 7 are FIG. 8 is a schematic diagram corresponding to FIG. 1 showing a modification of the essential parts shown in FIG. 1, and FIG. 8 is a perspective view for explaining the configuration of a conventional magneto-optical disk device. DESCRIPTION OF SYMBOLS 1... Magneto-optical disk, IA... Hub, 2... First optical head, 20... Second optical head, 2^,
20A... Fixed optical device, 28, 20B... Carriage, 2B2.2082... Objective lens, 9... First magnetic field application means, 90... Second magnetic field application means,
8... Seek motor, which is a linear arm movement mechanism. sI diagram? (and 1 other person) Figure 2 β , - (A) Figure 5 WiG Figure 7 Procedural amendment (voluntary) May 15, 1990 1. Case indication 1990 Patent Application No. 63515 2. Name of the invention Magneto-optical disk device 3, Relationship to the person making the amendment Patent applicant name (674) Ricoh Co., Ltd. 4, agent address 4-5-4 Kyodo, Setagaya-ku, Tokyo (tele) (0
3) 428-5106 (2) "It is shown in the first and second lines of page 8. The objective lens 2B2 in this carriage 2B is attached to the spring 2B.
3, and delete ". (3) "Yoke 9BJ on page 9, line 12 is changed to "Yoke 9AJ.""Detailed Description of the Invention" column of the specification. 6. Contents of amendment (1) Next to the end of the last line on page 4 of the specification, add ``For every magneto-optical disk device equipped with.''

Claims (1)

[Scope of Claims] A first optical head for recording/reproducing/erasing information by irradiating a light beam onto a first surface of a magneto-optical disk capable of recording/reproducing/erasing information on both the front and back surfaces; a second optical head that records/reproduces/erases information by irradiating a light beam onto the second surface; and a magnetic field for recording/erasing at the position where the light beam is irradiated by the first and second optical heads. In a magneto-optical disk device having first and second magnetic field applying means, a carriage carrying at least an objective lens in the first optical head is movable over the entire radial recording area of the magneto-optical disk. The first magnetic field applying means, which supports the magneto-optical disk and faces the objective lens, is provided so as to be able to act on the entire radial recording area, and is located at a position different from the first optical head. A carriage on which at least an objective lens in the second optical head is mounted is movably supported over the entire radial recording area, and the carriage faces the objective lens in the second optical head with the magneto-optical disk in between. 2
A magnetic field applying means is provided in a state where it can act on the entire radial recording area, and a drive mechanism is provided to independently move the first and second optical heads linearly in the radial direction of the optical disk. magneto-optical disk device.