JP2808134B2 - Magneto-optical disk drive - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magneto-optical disk drive having a bias magnetic field applying device for performing magneto-optical recording.

[Conventional technology]

Conventionally, a magneto-optical disk drive having a bias magnetic field applying device for performing magneto-optical storage has been disclosed in
One such as disclosed in US Pat. No. 261802 is known.
In this magneto-optical disk drive, a magnetic field for recording and erasing of a magneto-optical disk is provided by providing a bias magnetic field applying means in which a permanent magnet having a plurality of different magnetic poles is formed on a member obtained by dividing a circular or cylindrical column in the longitudinal direction. The reversal was performed quickly and the size of the apparatus was reduced.

[Problems to be solved by the invention]

By the way, in the above-described magneto-optical disk drive, in order to make the magneto-optical disk removable, the bias magnetic field applying means is set to a position which does not hinder the transport of the magneto-optical disk when the magneto-optical disk is inserted or ejected. It is necessary to provide an evacuation mechanism for evacuation.

As this kind of retreat mechanism, there is a mechanism as shown in FIGS. 5 (a) and 5 (b). In this mechanism, before inserting the disk case 22 accommodating the magneto-optical disk, the bias magnetic field applying device 23 sets the return spring as shown in FIG.
It is lifted to the retreat position via the link 26 by the tensile force of 27. When the disk case 22 is inserted to a predetermined position, the loading plate 24 is lowered as shown in FIG. 5 (b), and the bias magnetic field applying device 23 is moved by the push rod 28 via the link 26 to the magneto-optical disk 21. The voltage is lowered to a value close to that, and a bias magnetic field for recording or erasing can be applied.

As described above, in the related art, it is necessary to provide a special mechanism for retracting the bias magnetic field applying device, so that the number of components is large and the occupied space is large, and the size and cost of the magneto-optical disk drive are reduced. Had limitations.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a magneto-optical disk drive capable of having a low-cost and simple configuration without requiring a special mechanism for retracting a bias magnetic field applying device.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a bias magnetic field applying means provided with a permanent magnet for applying a bias magnetic field in opposite directions to a magneto-optical disk according to a recording mode or an erasing mode; And a rotating means for rotating the bias magnetic field applying means so as to switch the mode. The rotating magnetic means applies a bias magnetic field applying means to a retracted position which does not hinder the transport when the magneto-optical disk is transported. The feature is that it is also designed to rotate.

[Action]

In the magneto-optical disk drive having the above-described configuration, the bias magnetic field applying means is rotated by the rotating means so that the bias magnetic field generated by the permanent magnet provided in the bias magnetic field applying means is inverted with respect to the magneto-optical disk for recording. Mode and erasing mode. By the way, when the bias magnetic field applying means is rotated to a predetermined retreat position when the magneto-optical disk is inserted or ejected by using the rotating means, the magneto-optical disk can be transported without any trouble.

〔Example〕

 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a side view of an embodiment of a magneto-optical disk drive according to the present invention, and FIG. 2 is a schematic sectional view taken along line AA of FIG. Referring to FIGS. 1 and 2, the magneto-optical disk drive of this embodiment comprises a housing 16 and a disk case 11 containing a magneto-optical disk 4 as a recording carrier.
Load / ejection mechanism 13 for insertion / ejection to / from 16
A sensor 14 for detecting that the disk case 11 has been inserted, an eject switch 12 for outputting an eject signal by an operation of an operator, a spindle motor 8 for rotating the mounted magneto-optical disc 4, and a magneto-optical disc. A bias magnetic field applying device which is disposed opposite to one surface of the disk and applies a bias magnetic field to the magneto-optical disk;
And an optical pickup 15 provided opposite to the other surface of the magneto-optical disk 4 and provided with an objective lens 5 for irradiating a light beam focused on the recording film of the magneto-optical disk 4 in a spot shape. I have.

The optical pickup 15, that is, the objective lens 5 is movable in the radial direction of the magneto-optical disk 4. Further, the bias magnetic field applying device 10 includes a plate-shaped holding member 2 and a permanent magnet 3 attached to a tip of the holding member 2. As can be seen from FIG. 2, the permanent magnet 3 has a prism shape magnetized at two different magnetic poles, that is, an S pole and an N pole, and its longitudinal direction is the objective lens as shown in FIG. 5 are arranged along the moving radial direction, and the S pole or N
The poles are of a length necessary to cover the recording area of the magneto-optical disk 4.

The holding member 2 is attached to the rotating shaft 1 and drives the motor 7 by a motor driving circuit 9 to transmit the rotation to the rotating shaft 1 via the gears 6a and 6b, thereby applying the holding member 2, that is, the bias magnetic field application. The device 10 can be rotated about the rotation axis 1. The width w of the two adjacent magnetic poles of the permanent magnet 3, that is, the sum of the S pole and the N pole, is shorter than the distance d from the rotating shaft 1 to the tip of the permanent magnet 3.

The operation of the magneto-optical disk drive having such a configuration will now be described.

The disk case 11, that is, the magneto-optical disk 4 is
When mounted in the bias magnetic field applying device 10
Applies an erasing bias magnetic field or a recording bias magnetic field to the magneto-optical disk 4 by the permanent magnet 3 provided at the tip of the holding member 2. FIG. 2 shows a state in which the N pole of the permanent magnet 3 is positioned at the light beam irradiation position P. When the bias magnetic field applying device 10 is rotated about the rotation axis 1 from this state, the permanent The S pole of the magnet 3 can be positioned at the irradiation position P of the light beam, and the bias magnetic field applying device 10 can be moved in the opposite direction from the state where the S pole of the permanent magnet 3 is positioned at the irradiation position P. When rotated, the N pole of the permanent magnet can be positioned at the irradiation position P of the light beam, whereby the bias magnetic field for erasing and the bias magnetic field for recording can be switched. By moving the magnetic disk 4 to a predetermined position in the radial direction and irradiating a predetermined track with a light beam, it is possible to record or erase information on the predetermined track. The switching between the erasing mode and the recording mode is performed by applying a switching signal to the motor drive circuit 9.
The motor drive circuit 9 controls the rotation of the motor 7 and the rotating shaft 1.

By the way, when the bias magnetic field applying device 10 is at the position shown in FIGS. 1 and 2, the disk case 11 is used for recording and reproducing on the magneto-optical disk 4 and the like. The disk case 11 cannot be inserted from the housing 16 or cannot be ejected from the housing 16.

For this reason, in the present embodiment, the drive of the motor 7 can be controlled so that the bias magnetic field applying device 10 is rotated by 90 ° around the rotation axis 1 by the motor drive circuit 9. FIG. 3 is a schematic side view of the magneto-optical disk drive when the bias magnetic field applying device 10 is rotated by 90 °, and FIG.
It is a schematic sectional drawing in the B line. As can be seen from FIGS. 3 and 4, when the bias magnetic field applying device 10 is rotated by about 90 ° around the rotation axis 1 from the state shown in FIGS. Directly below the rotating shaft 1
The space is increased by an interval (d−w / 2) obtained by subtracting half of the width w of the permanent magnet 3 from the distance d from the distance d to the tip of the permanent magnet 3, thereby enabling insertion, ejection, or conveyance of the disk case 11. State. In other words, when the disk case 11 is ejected from the housing 16 after the bias magnetic field applying device 10 performs recording, reproduction, etc. of the magneto-optical disk 4 at the positions shown in FIGS. Press 12. Eject switch
When the button 12 is pressed, an eject signal is sent to the motor drive circuit 9. The motor drive circuit 9 rotates the bias magnetic field applying device 10 about the rotation axis 1 by about 90 ° based on the eject signal, and FIGS. From the position shown in FIG. 3, FIG.
The retracted position shown in FIG. As a result, the disc case 11 is ready to be ejected, and the disc case 11 is ejected from the housing 16 under the control of the load / ejection mechanism based on the eject signal.

After the disk case 11 is ejected, the bias magnetic field applying device 10 is held at the retracted position shown in FIGS. 3 and 4, so that when the disk case 11 is inserted again, the insertion of the disk case 11 is prevented. Never. Disk case 11
Is completed, a signal from the sensor 14 is sent to the motor drive circuit 9, and the motor drive circuit 9 drives and controls the rotation of the motor, and moves the bias magnetic field applying device 10 around the rotation axis 1 in FIG. 4 is rotated from the retracted position shown in FIG. 4 to the position shown in FIG. 1 and FIG. When the bias magnetic field applying device 10 is at the position shown in FIGS. 1 and 2,
As described above, it becomes possible to apply the bias magnetic field in the recording mode or the erasing mode.

As described above, in the present embodiment, the bias magnetic field applying device 10 is provided by using a rotating mechanism for switching the bias magnetic field applying device 10 between the recording mode and the erasing mode without providing a special retracting mechanism as in the related art. With an inexpensive and simple configuration that only allows retraction, it is possible to insert and eject the disk case 11 that houses the magneto-optical disk 4.

Further, in the present embodiment, the magnetic poles of the permanent magnet 3 are only the minimum necessary two magnetic poles, that is, the S pole and the N pole, and the width w of the two magnetic poles is from the rotation axis 1 to the tip of the permanent magnet 3. Since the distance d is shorter than the distance d, even when the bias magnetic field applying device 10 is at the retracted position shown in FIGS. 3 and 4, the amount by which the bias magnetic field applying device 10 protrudes to the opposite side of the disk case 11 is small. Accordingly, a space for retracting the bias magnetic field applying device 10 can be reduced, and the magneto-optical disk drive can be downsized.

〔The invention's effect〕

As described above, according to the present invention, a rotating mechanism used for switching between the recording mode and the erasing mode is also used for retracting the bias magnetic field applying means. The bias magnetic field applying means can be retracted with a simple and inexpensive configuration without the need.

[Brief description of the drawings]

FIG. 1 is a side view of an embodiment of a magneto-optical disk drive according to the present invention, FIG. 2 is a schematic sectional view taken along line AA of FIG. 1, and FIG. FIG. 4 schematically shows a state rotated by 90 ° from the position shown in FIG. 4, FIG. 4 is a schematic sectional view taken along the line BB in FIG. 3, FIG.
(B) is a diagram for explaining a conventional retracting mechanism. DESCRIPTION OF SYMBOLS 1 ... Rotating shaft, 2 ... Holding member, 3 ... Permanent magnet, 4 ... Magneto-optical disk, 5 ... Objective lens, 6a, 6b ... Gear, 7 ... Motor, 8 ... Spindle motor, 9 …… Motor drive circuit, 10 …… Bias magnetic field applying device, 11 …… Disc case, 12 …… Eject switch, 13 …… Load / ejection mechanism, 14… Sensor

Claims (1)

(57) [Claims] 1. A bias magnetic field applying means provided with two different permanent magnets for applying bias magnetic fields in opposite directions to a magneto-optical disk according to a recording mode or an erasing mode, and a recording mode and an erasing mode. Rotating means for rotating the bias magnetic field applying means around a predetermined rotation axis so as to switch between, the bias magnetic field applying means, on the same side with respect to the predetermined rotation axis of the rotating means, The different two-pole permanent magnets are arranged side by side, and the rotating means is arranged side by side by rotating the bias magnetic field applying means by a predetermined angle around the predetermined rotation axis. The opposing state of the different two-pole permanent magnets facing the magneto-optical disk is switched to switch between the recording mode and the erasing mode. Wherein the rotating means rotates the bias magnetic field applying means around the predetermined rotation axis to a retracted position which does not hinder the transport when the magneto-optical disk is transported. Magneto-optical disk drive.