JPH07141755A - Disk cartridge and disk device - Google Patents

Abstract

PURPOSE:To simplify the device and to reduce its thickness by composing a motor of a bearing disposed within a disk cartridge, a permanent magnet for contactless rotational driving disposed at the disk and plural coils for rotational driving disposed at the disk device. CONSTITUTION:The cartridge 11 has the disk 1 and a revolving shaft 13 fixed to the disk 1 within a cartridge case 12. The disk 1 has the permanent magnet 14 disposed for contactless rotational driving. The permanent magnet 14 is magnetized to plural poles in its circumferential direction. The coils 15 for rotational driving form one motor together with the permanent magnet 14. Further, the cartridge case 12 has a pair of yokes 16a, 16b and the magnetic field generated by an auxiliary magnetic field generating means 17 passes the yokes 16a, 16b which generate the magnetic field of a perpendicular direction at a beam spot position. Recording or erasing is made possible by the direction of the magnetic field of an auxiliary magnetic field generating means 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc cartridge and a disc device for recording, reproducing or erasing information.

[0002]

2. Description of the Related Art A conventional example of a magneto-optical disc cartridge and its magneto-optical device will be described below as an example of a disc cartridge and a disc device. FIG. 5 is a schematic explanatory view of a conventional disk cartridge containing a magneto-optical disk and a disk device for a magneto-optical disk.
FIG. 6A is a top view of the disc cartridge, FIG.
6B is a sectional view taken along the line XX ′ in FIG. 6A and shows a recording / reproducing state of the apparatus.

The disc 1 is housed in a cartridge case 12 to form a disc cartridge 11. In FIG. 6B, the disk 1 is positioned on the shaft 4 of the spindle motor 3 by the center hub 2.
The center hub 2 is adjusted so that the track on the disk 1 is concentric with the hole 5 of the center hub 2, and is adhesively fixed to the disk 1. Also, the center hub 2 is a part of it,
Alternatively, it is made entirely of a magnetic material and is attracted by a chucking magnet 6 fixed to the spindle motor 3, so that the disk 1 is pressed against the turntable surface 7 of the spindle motor 3 and rotates together with the spindle motor 3. On the other hand, the pickup 8 has a laser light source, and the objective lens 9 forms a spot on the track of the disc 1. Further, an auxiliary magnetic field generating permanent magnet 10 is installed on the side opposite to the pickup 8 with respect to the disk 1, and generates a magnetic field on the disk 1 in a direction indicated by an arrow 10 '. With such a configuration, information is recorded on the disc according to the magnitude of the laser power.

[0004]

When the disc cartridge 11 as described above is used, in order to load the disc 1 onto the spindle motor 3, the disc 1,
Alternatively, it is necessary to move the spindle motor 3 in the vertical direction in FIG. 6B, which causes a problem that the entire device becomes thicker. Further, the existence of the permanent magnet 10 for generating the auxiliary magnetic field also causes the thickening of the entire apparatus.

[0005]

In order to solve the above-mentioned problems, a disk cartridge and a disk device of the present invention include a cartridge case, a disk housed in the cartridge case, and a rotation shaft of the disk. A disk cartridge having a radial bearing of the rotary shaft is constructed, and a dynamic fluid bearing is formed on the disk as thrust bearing means on both sides of the disk. Further, the disk is provided with a non-contact rotation driving permanent magnet, and the disk device is provided with a plurality of disk rotation driving coils configured to apply an acting force to the permanent magnet in the tangential direction of the disk. At this time, when the pickup accesses the innermost recording area of the disc, the first area occupied by the pickup and the second area which is symmetric to the first area with respect to the rotation axis of the disk are rotated. No drive coil is placed. Further, regarding the magneto-optical disk, in the above structure, a pair of yokes are built in the cartridge case as a recording or erasing auxiliary magnetic field generating means.

That is, the present invention comprises a cartridge case,
A disk cartridge having a disk housed in the cartridge case, a rotary shaft of the disk, and a radial bearing of the rotary shaft, wherein the disk cartridge is provided with thrust bearing means. The thrust bearing is the disc,
And a disk cartridge which is a hydrodynamic bearing formed between the cartridges.
The hydrodynamic bearing provides a disc cartridge formed on both sides of the disc. The hydrodynamic bearing formed on the first surface of the disc;
The present invention provides a disc cartridge configured so that the dynamic pressure fluid bearings formed on the second surface of the disc have different radii.

A disk cartridge having a cartridge case, a disk housed in the cartridge case and provided with thrust bearing means, a rotary shaft of the disk, and a radial bearing of the rotary shaft is non-contact rotationally driven on the disk. (EN) A disk device provided with a permanent magnet provided for a disk and provided with a plurality of disk rotation driving coils configured to apply an acting force to the permanent magnet in a tangential direction of the disk. . When the pickup for recording / reproducing or erasing accesses the innermost recording area of the disc, the first area occupied by the pickup and the first axis with respect to the rotation axis of the disc.
The second area, which is symmetric to the area (1), provides a disk device in which the rotation driving coil is not arranged. A cartridge case, a magneto-optical disk housed in the cartridge case, a rotating shaft of the magneto-optical disk,
A disk cartridge having a radial bearing of the rotating shaft, wherein the cartridge case contains a pair of yokes of an auxiliary magnetic field for recording or erasing. The present invention provides a disc cartridge in which the first yoke and the second yoke of the pair of yokes are arranged so that they do not overlap each other when viewed from the direction of the rotation axis of the disc.

[0008]

According to the above construction, the motor is constituted by the bearing provided in the disc cartridge, the non-contact rotary drive permanent magnet provided in the disc, and the plurality of rotary drive coils provided in the disc device. The disk can be driven to rotate. Since there is a gap between the rotation drive coil and the cartridge, it is not necessary to move the disk cartridge or the spindle motor up and down when loading the disk cartridge, and it is no longer necessary to take the vertical dimension required previously. Can be made thinner.

Further, by incorporating the yoke in the disk cartridge, the magnetic resistance is reduced and the magnetic energy applied from the outside of the cartridge can be reduced, so that the magnet can be miniaturized and the apparatus can be miniaturized.

[0010]

The embodiments of the present invention will be described below by taking a magneto-optical disk as an example, but the present invention can be applied to other optical disks, magnetic disks, and disk devices thereof. An embodiment of the present invention is shown in FIGS. Members having the same functions as the members shown in the drawings of the conventional example are designated by the same reference numerals.

1 (a) to 1 (c) show one embodiment of the present invention, and FIG. 1 (a) shows a cross section YY 'in FIG. 1 (b). Further, FIG. 1B shows a cross section ZZ ′ in FIG. 1A, and FIG. 1C shows a view seen from below. In FIG. 1, a cartridge 11 has a disc 1 and a rotary shaft 13 fixed to the disc 1 in a cartridge case 12.

The disk 1 also has a permanent magnet 14 provided for non-contact rotation drive. Permanent magnet 14
Are magnetized to a plurality of poles in the circumferential direction, and a magnetic field from the other can generate an acting force in a tangential direction to rotate the disk 1. The rotation driving coil 15 provided in the disk device outside the cartridge 11 gives a magnetic field for generating a rotational force, and the permanent magnet 14 and the rotation driving coil 15 form one motor. Here, the rotation driving coils 15 are not arranged at equal intervals in the circumferential direction, but in order to avoid interference with the objective lens 9 and an objective lens driving device (not shown), and to suppress rotational vibration, interference is prevented. The rotary drive coil is omitted at the location where the rotation is performed and the location symmetrical to the rotation axis.

Further, the cartridge case 12 includes a pair of yokes 16a and 16b. One of the first yokes 16a is located directly above the recording medium surface 1a of the disk 1, and the other is located very close to one end of the auxiliary magnetic field generating means 17. Further, one of the second yokes 16b is located near the end of the lower surface of the disk 1, and the other is located near the end of the auxiliary magnetic field generating means 17. With such a structure, the magnetic field generated by the auxiliary magnetic field generating means passes through the yokes 16a and 16b, and a vertical magnetic field is generated at the beam spot position. Now, when the auxiliary magnetic field generating means is made of an electromagnet as shown in FIG. 1B, recording or erasing becomes possible depending on the direction in which the current is applied.

2A and 2B show auxiliary magnetic field generating means 1
7 is an embodiment in which 7 is a permanent magnet, and when a permanent magnet magnetized to the N pole and the S pole is placed close to the end of the yoke as shown in FIG. 2, recording is performed as in the case of the electromagnet, or It can be erased. In this case, the reversal of the magnetic field can
It is performed by rotating in the direction of the arrow in (b).

FIG. 3 (b) shows a detailed view of the main part of FIG. 1 (b). In FIG. 3B, a portion surrounded by a dotted line forms a thrust bearing portion in the circumferential direction, and
The first bearing portion 19a formed by the first surface 1b of the disk and the second bearing portion 19 formed by the second surface 1c of the disk 1.
The disk 1 is supported from both sides by b. Figure 3
(A) is a top view of the disk 1, and the first bearing 19a is a hydrodynamic bearing having a spiral groove 20a,
When the disc 1 rotates in the direction of the arrow, pressure is generated on the bearing surface, and it functions as a bearing. Figure 3
(C) is a bottom view of the disk 1, and the second bearing 19b is a hydrodynamic bearing having a spiral groove 20b. When the disk 1 rotates in the direction of the arrow, pressure is generated on the bearing surface. , Acts as a bearing.

In FIG. 3, the first bearing portion 19a and the second bearing portion 19b have different radial positions with respect to the center of the disk 1. The second bearing portion 19b is located inside the light beam window 18, and the groove 20b does not block the light beam. In addition, the first bearing portion 19
The symbol a is directly above the light beam, and the disc position on the beam spot is supported by the bearing portion 19a, the disc vibration is small, and more stable servo performance can be expected.

FIG. 4 is a detailed view of another main part of FIG. 1 (b). In FIG. 4, a portion surrounded by a dotted line forms a thrust bearing portion of a sliding type in the circumferential direction, and a first bearing portion 19a formed by the first surface 1b of the magneto-optical disc 1;
The second bearing portion 19b formed by the second surface 1c of the magneto-optical disk 1 supports the magneto-optical disk from both sides. In this case, the bearing surface has a low friction coefficient,
For example, it is effective to attach Teflon tape or the like, and the rotation loss can be reduced by reducing the bearing radius.

FIG. 5 shows another embodiment of the present invention. FIG. 5A is a sectional view W- in FIG.
W'is shown. Further, FIG. 5B shows a cross section VV ′ in FIG. 5A, and FIG. 5C shows a view seen from below. The disc cartridge shown in FIG. 5 has the first yoke 16a and the second yoke 16a in the disc cartridge shown in FIG.
The yokes 16b are characterized in that they are arranged so as not to overlap with each other when viewed from the direction of the rotation axis of the disk 1. By doing so, it is intended to suppress the leakage of the magnetic field at a place other than the necessary place and effectively utilize the magnetic field energy.

[0019]

As described above, the disc cartridge and the disc device of the present invention include the bearings provided in the disc cartridge, the non-contact rotary drive permanent magnets provided in the disc, and the plurality of disc devices provided in the disc device. Since the motor is configured by the rotation driving coil of (1) and the disk can be rotationally driven in a non-contact manner, a particularly complicated loading mechanism is unnecessary, and the apparatus can be simplified and thinned. Further, the noise generated by the ball bearing of the conventional motor can be quietened by the hydrodynamic bearing.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention and is a diagram showing an example in which an electromagnet is used as auxiliary magnetic field generating means.

FIG. 2 is a diagram showing an embodiment of the present invention and is a diagram showing an example in which a permanent magnet is used as auxiliary magnetic field generating means.

3A and 3B are a detailed view of a main part of FIG. 1B and a diagram showing a dynamic pressure groove formed on a disc.

FIG. 4 is a diagram showing another yoke shape in the present invention.

5 is a detailed view of another main part of FIG. 1 (b).

FIG. 6 is a diagram showing a conventional example.

[Explanation of symbols]

 1 disk, 3 spindle motor, 6 chucking magnet, 7 turntable, 8 pickup, 9 objective lens, 11 disk cartridge, 12 cartridge case, 13 rotary shaft, 15 rotary drive coil, 16a, 16b yoke, 17 auxiliary magnetic field generation Means, 18 Light beam window, 19a, 19b Bearing portion, 20a, 20b Groove

Claims (8)

[Claims] 1. A disk cartridge having a cartridge case, a disk housed in the cartridge case, a rotation shaft of the disk, and a radial bearing of the rotation shaft, wherein the disk is provided with thrust bearing means. A disk cartridge characterized by. 2. The thrust bearing is the disk,
The disk cartridge according to claim 1, wherein the disk cartridge is a hydrodynamic bearing formed between the cartridge and the cartridge. 3. The disc cartridge according to claim 2, wherein the hydrodynamic bearings are formed on both sides of the disc. 4. The dynamic pressure fluid bearing formed on the first surface of the disc and the dynamic pressure fluid bearing formed on the second surface of the disc have different radii. The disk cartridge according to claim 3, wherein 5. A disk cartridge having a cartridge case, a disk housed in the cartridge case and provided with thrust bearing means, a rotating shaft of the disk, and a radial bearing of the rotating shaft, the disk cartridge being in non-contact with the disk. A disk comprising a permanent magnet provided for rotational drive, and a plurality of disk rotational drive coils configured to apply an action force to the permanent magnet in a tangential direction of the disk. apparatus. 6. A first area occupied by the pickup and a rotation axis of the disk when the pickup for recording / reproducing or erasing accesses an innermost recording area of the disk. 6. The disk device according to claim 5, wherein the rotation drive coil is not arranged in the second area that is symmetrical with respect to the second area. 7. A disk cartridge having a cartridge case, a magneto-optical disk housed in the cartridge case, a rotation shaft of the magneto-optical disk, and a radial bearing of the rotation shaft, wherein the cartridge case records or 5. The disk cartridge according to claim 1, wherein a pair of yokes for the erasing auxiliary magnetic field are built in. 8. The pair of yokes, wherein the first yoke and the second yoke are arranged so as not to overlap with each other when viewed from the rotation axis direction of the disk. Disc cartridge.