JPH04305839A - Magneto-optical disk device - Google Patents

Abstract

PURPOSE:To provide a magnetic field generation device being suited for thinning of magneto-optical disk device and capable of generating a uniform magnetic field on the recording surface of the disk. CONSTITUTION:In a loading process of a cartridge 5 into the device body 8, the device has a magnetomotive generation part 15 except the upper and lower regions including the disk 1, as seen from the rotary shaft 3b direction of the turntable 3a and thin yolks 17, 18 conducting the magnetic flux from the magnetomotive generation part 15 on the disk 1 are provided, and a taper is formed at the disk surface side of the thin yolks 17, 18 so as to narrow from the outer periphery side of the disk 1 to the inner periphery side and the coating of resin, etc., is applied on the relevant taper part.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magneto-optical disk device used as an external storage device for a computer.

0002

2. Description of the Related Art The configuration of a conventional magneto-optical disk device will be described below.

FIG. 23 is a schematic diagram of the inside of the apparatus, in which 1 is a disk as a recording medium, 2 is an optical pickup that reads and writes information to and from the disk 1, 2a is an objective lens that emits a laser beam, 3 is a motor, 3a is a rotating table on which the disk 1 is mounted and rotated, and a permanent magnet 3c is provided around the rotating shaft 3b. 14 is provided on the opposite side of the optical pickup 2 across the disk 1,
This is a magnetic field generating device consisting of an electromagnet that generates magnetic fields in opposite directions at predetermined positions on the disk 1 when writing and erasing information. In order to generate this magnetic field, a large magnetomotive force is required, and many coils 16 are wound around the disk 1. The optical pickup 2 is guided by a guide shaft 4 and moved in the radial direction of the disk 1 by a drive source (not shown).

5 to 8 show a cartridge 5 consisting of a disc 1 as a recording medium and a case for storing the disc 1.
FIG. 5 to 8 are views seen from the side facing the magnetic field generator 14, with FIG. 5 in the closed state and FIG. 6 in the open state. 7 and 8 are views seen from the side facing the optical pickup 2, with FIG. 7 showing the closed state and FIG. 8 showing the open state. In FIG. 8, a ferromagnetic metal plate 6 is provided at the center of the disk 1, and a positioning hole 6a is further provided. The cartridge 5 is provided with a first opening 5a and a second opening 5b. A shutter 7 is provided with a slider 7a, and is normally biased by a spring (not shown) and closed to prevent dust and scratches from forming on the disk 1 (
5 and 7). In addition, by sliding the slider 7a, it becomes an open state (the state shown in FIGS. 6 and 8), and the first
The opening 5a and the second opening 5b appear outside.

In FIGS. 24 and 25, the main body 8 constitutes an exterior case. A base 9 serves as a guide for the cartridge 5. The rotary table 3a is positioned at a distance from the base 9 so as not to obstruct the cartridge 5 from entering the main body. The magnetic field generator 14 is fixed to the base 9 because it is more efficient to place it as close to the disk 1 as possible, and because magneto-optical disk devices are made thinner and lower in cost, they are configured at a position several mm from the disk surface. (not shown). A release lever 11 is provided in a groove 10 on the upper surface of the base 9. A cam surface 1 is provided around the groove portion 10.
2 is provided, and the first lever 11 of the release lever 11
Although the tip of a can slide on this cam surface 12, it is normally in the position shown in FIG. 24 due to the force of the spring 13.

Next, the operation of the embodiment will be explained. 26 and 27, when the cartridge 5 is inserted into the main body 8, the pin 20 fixed to the first lever 11a hits the recess 5c of the cartridge 5. When the cartridge 5 is further pushed in, the pin 20 is inserted into the main body 8, and as shown in FIGS. The lever 11a rotates clockwise around the connecting shaft 21 while sliding on the cam surface 12, pushes the slider 7a of the shutter 7, and at the position where it overlaps the magnetic field generator 14, the shutter 7 is already fully opened. state, and there is no interference with the magnetic field generator 14. When the cartridge 5 is further pushed in from this point, the cartridge 5 is completely accommodated within the main body 8 as shown in FIGS. 30 and 31, and the center of the disk 1 is in a position that almost coincides with the center of the rotary table 3a. From this state, the rotating table 3a is raised by a mechanism not shown, and the rotating table 3a is raised.
The disk 1 is mounted on the rotary table 3a by the magnetic attraction force between the permanent magnet 3c inside and the metal plate 6 of the disk 1 (this state is shown in FIG. 32).

Contrary to this method, disk 1 is
is attached to the rotary table 3a, and in order to create a state in which the disk 1 and the magnetic field generator 14 are close to each other, the center of the disk 1 is almost aligned with the center of the rotary table 3a, and the same steps are taken. The cartridge 5 (including the disk 1) and the magnetic field generator 14 are simultaneously lowered by a mechanism not shown in FIG. It is also possible to create a state in which the rotary table 3a is mounted on the rotary table 3a (this method is shown in FIG. 33).

After the disk 1 is mounted on the rotary table 3a,
The rotary table 3a rotates together with the disk 1, and the optical pickup 2 irradiates a weak laser beam (not shown) to a desired position on the disk 1 to read information. Alternatively, a strong laser beam may be irradiated to a desired position on the disk 1 to heat a part of the disk 1 and reduce the magnetic field holding force, or at the same time, or before reducing the magnetic field holding force, the magnetic field generator 14 may be heated. Information is written and erased by applying a current to the coil 16 from a power source (not shown) to generate magnetic fields in opposite directions on the recording surface of a predetermined disk 1.

[0009]

[Problems to be Solved by the Invention] However, in this conventional magneto-optical disk device, the magnetomotive force generating section, which occupies the most space in the magnetic field generating device, is placed above the disk, which requires extra space on the disk. This made it difficult to make the device thinner and smaller. Furthermore, in order to make magneto-optical disk drives thinner, the magnetic field generator and the disk were arranged in close proximity, which caused problems such as contact when inserting the disk, damaging the recording surface of the disk and damaging the disk. Ta.

The object of the present invention is to solve these conventional problems, make the device thinner and smaller, eliminate scratches when inserting a disk, and generate a magnetic field uniformly on the recording surface of the disk. The object of the present invention is to provide a magneto-optical disk that can

[0011]

[Means for Solving the Problems] The magneto-optical disk device of the present invention arranges the magnetomotive force generating section of the magnetic field generating device outside the circumference of the disk, and efficiently transmits the magnetic flux obtained from the magnetomotive force generating section to the disk surface. A pair of yokes that induce good guidance are provided, and the magnetic resistance between the yokes is made uniform by changing the gap or thickness between the yokes, and the tips of the yokes are inclined in a direction that opens outward.

0012

[Operation] In the present invention, since the magnetomotive force generating part is not placed above the disk, the extra space on the disk is significantly reduced, and the yoke is coated, so there is no possibility of contact occurring when the disk is inserted. also no longer destroys the disk. This also allows the device to be made thinner,
This made it possible to downsize. Further, by changing the magnetic resistance between the yokes by changing the gap or thickness between the yokes, it was possible to obtain a uniform magnetic flux density on the recording surface of the disk.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1, 2, and 3 are a plan view, a front view, and a perspective view of a magneto-optical disk device according to an embodiment of the present invention. FIG. 4 is an enlarged perspective view of the main parts of the present invention. Figure 5~
8 is a detailed diagram of the cartridge used in the explanation of the conventional example, in which 1 is a disk, 2 is an optical pickup, 2a is an objective lens, 3 is a motor, 3a is a rotating table, 3b is a rotating shaft, 3c
is a permanent magnet that attracts and fixes the disk 1, 4 is a guide shaft,
5 is a cartridge, 5a is a first opening, 5b is a second opening, 6 is a metal plate, 6a is a hole, 7 is a shutter, and 7a is a slider, and these are the same as those described in the conventional example, so they will not be described here. The explanation will be omitted.

Reference numeral 8 denotes a main body, and 9 a base. Below this base 9, a motor 3 and an optical pickup 2 are placed, and a rotary table 3a and an objective lens 2 of the optical pickup 2 are placed in the base opening 9a.
a is placed. A release lever 11 is provided in a groove 10 on the upper surface of the base 9. In FIG. 1, the groove 10
A cam surface 12 is provided around the release lever 1.
The tip of the first lever 11a in FIG. 1 can slide on this cam surface 12, but normally the force of the spring 13 causes
The shutter is in the closed position. A magnetic field generating device 14 is disposed on the opposite side of the optical pickup 2 across the disk 1, and generates magnetic fields in opposite directions at predetermined positions on the disk 1 when writing and erasing information (as shown in FIG. 4). Reference numeral 15 denotes a magnetomotive force generating section that generates a magnetic field, and a coil 16 is wound around an iron core 17a that is one end of a first yoke 17 having high magnetic permeability. The other end yoke 17b, which is the first yoke 17 and is located above the disk 1, is thinner in the direction perpendicular to the disk. Further, the tip 17c of the first yoke 17 has an inclination with respect to the insertion direction of the cartridge 5 (including the disk 1), so that even if the disk 1 swings to the maximum when the cartridge 5 is inserted, it will hit the said inclination. The slope is designed. In addition, the first yoke 17b is coated on the first side of the disk.
Even if the disk 1 comes into contact with the cartridge 5 when it is inserted, the cartridge 5 is inserted along the slope so that the surface of the disk 1 is not damaged. 18 is a second yoke with high magnetic permeability for efficiently generating a magnetic field on the magnetic circuit of the magnetic field generating device 14. The other end yoke 1 which is the second yoke 18
8b is thinner in the vertical direction of the disk 1 like the other end yoke 17b. Also, the second yoke 1
The tip 18c of the cartridge 8 has an inclination with respect to the insertion direction of the cartridge 5 (including the disk 1), and is designed to have an inclination so that even if the disk 1 swings to the maximum when the cartridge 5 is inserted, it will hit the said inclination. There is. Furthermore, the disk 1 side of the other end yoke 18b is coated with a resin or the like, so that even if the disk 1 comes into contact with the cartridge 5 when it is inserted, it will be inserted along the slope and will not damage the disk 1 surface. It has become. Further, the iron core 17a, which is one end of the first yoke, and one end 18a of the second yoke are joined by a method not shown. On the other hand, the first yoke 17
The other end yoke 17b and the second yoke 18
In part b, a predetermined gap 19 is opened in order to obtain a magnetic field at a predetermined position on the disk surface. Furthermore, the gap 19b that is far from the gap 19a that is close to the magnetomotive force generating section 15
The gap 19 is made narrower so that the magnetic circuit has the same magnetic resistance at any part of the gap 19, creating a uniform magnetic field on a predetermined recording surface of the disk 1 (as shown in FIGS. 11 and 12). Similarly, by making the gap 19 a uniform parallel gap and adjusting the inclinations of the yoke tips 17c and 18c, the magnetic resistance can be made equal in any part of the gap 19 in terms of the magnetic circuit, and a predetermined recording surface of the disk 1 can be It is also possible to create a uniform magnetic field on the top (Figs. 9, 10
).

Next, the operation of the embodiment will be explained. 13 and 14, when the cartridge 5 is inserted into the main body 8, the pin 20 fixed to the first lever 11a abuts against the recess 5c of the cartridge 5, and when the cartridge 5 is further pushed in, the pin 20, as shown in FIGS. The lever 11a rotates clockwise around the connecting shaft 21 while sliding on the cam surface 12, pushes the slider 7a of the shutter 7, and at the position where it overlaps the magnetic field generator 14, the shutter 7 is already fully opened. state, and there is no interference with the magnetic field generator 14. When the cartridge 5 is pushed in further, the cartridge 5 is completely accommodated in the main body 8, as shown in FIGS. 17 and 18, and the center of the disk 1 is in a position that almost coincides with the center of the rotary table 3a. From this state, the rotating table 3a is raised by a mechanism not shown, and the rotating table 3a is raised.
The disk 1 is mounted on the rotary table 3a by the magnetic attraction force between the permanent magnet 3c inside and the metal plate 6 of the disk 1 (as shown in FIG. 19).

Contrary to this method, disk 1 is
is attached to the rotary table 3a, and in order to create a state in which the disk 1 and the magnetic field generator 14 are close to each other, the center of the disk 1 is almost aligned with the center of the rotary table 3a, and the same steps are taken. The cartridge 5 (including the disk 1) and the magnetic field generator 14 are simultaneously lowered by a mechanism not shown in FIG. It is easily possible to create a state in which the rotary table 3a is attached to the rotary table 3a (as shown in FIGS. 20, 21, and 22).

After mounting, the rotary table 3a rotates together with the disk 1, and the optical pickup 2 irradiates a laser beam (not shown) from the objective lens 2a to a desired position on the disk 1, and calculates the rotation angle of the polarization plane of the reflected light (Kerr effect). ) is detected and the information is read out. Similarly, a strong laser beam (not shown) is irradiated to a desired position on the disk 1 to heat a part of the disk 1 and reduce the magnetic field retention, or at the same time, generate a magnetic field before reducing the magnetic field retention. device 14
Writing and erasing of information is performed by applying a current from a power source (not shown) to the coil 17 inside the disk 1 to generate magnetic fields in opposite directions on the recording surface of a predetermined disk 1.

[0018]

As described above, in the present invention, the magnetomotive force generating section, which occupies the most space in the magnetic field generating device, is arranged outside the circumference of the disk, and the magnetomotive force generating section, which occupies the most space in the magnetic field generating device, is placed outside the circumference of the disk, and the magnetomotive force generating section is placed at the tip of the thin yoke for guiding magnetic flux onto the disk. By adding a taper, the extra space on the disc can be significantly reduced.
This makes it possible to make the device thinner and smaller, and eliminates scratches caused by contact when inserting a disk. Moreover, by making the magnetic resistance between the yokes uniform by changing the gap or thickness between the yokes, it is possible to generate a uniform magnetic field on the recording surface.

[Brief explanation of drawings]

FIG. 1: Plan view of an embodiment of the present invention.

[Fig. 2] Front view of the embodiment of the present invention

FIG. 3 is a perspective view of an embodiment of the present invention.

[Fig. 4] Exploded perspective view of main parts of the embodiment

[Fig. 5] A perspective view from above of the cartridge in the closed state used in the example.

[Fig. 6] Perspective view of the cartridge in the open state seen from above.

[
Figure 7: Perspective view of the cartridge in the closed state seen from below

[Fig. 8] Perspective view of the cartridge in the open state seen from below.

[Figure 9
] Plan view showing the magnetic field generating device of the example

[Figure 10] Front view of the same

[Fig. 11] A plan view showing another example of the magnetic field generation device.

[Figure 12
] Same front view

FIG. 13 is a plan view showing the embodiment with the cartridge inserted halfway

[Figure 14] Front view of the same

FIG. 15 is a plan view showing the embodiment with the cartridge fully inserted.

[Figure 16] Front view of the same

FIG. 17 is a plan view showing the embodiment with the cartridge fully inserted.

[Figure 18] Front view of the same

[Fig. 19] Front view of the embodiment with the disk mounted on the rotating table

FIG. 20 is a plan view showing the embodiment with the cartridge fully inserted.

[Figure 21] Front view of the same state

[Figure 22] Front view of the same state with the cartridge lowered

[
FIG. 23 is a perspective view showing the main parts of a conventional magneto-optical disk device.

FIG. 24 is a plan view showing a conventional magneto-optical disk device.

[Figure 25] Front view of the same

FIG. 26 is a plan view showing a conventional magneto-optical disk device with a cartridge inserted halfway.

[Figure 27] Front view of the same

FIG. 28 is a plan view showing a conventional magneto-optical disk device with a cartridge fully inserted.

[Figure 29] Front view of the same

FIG. 30 is a plan view showing a conventional magneto-optical disk device with a cartridge fully inserted.

[Figure 31] Front view of the same

FIG. 32 is a front view showing a conventional magneto-optical disk device with the rotary table raised.

FIG. 33 is a front view showing a conventional magneto-optical disk device with the cartridge lowered.

[Explanation of symbols]

1 Disc 2 Optical pickup 2a Objective lens 3 Motor 3a Turntable 3b Rotation axis 3c permanent magnet 4 Guide shaft 5 Cartridge 6 Metal plate 7 Shutter 8 Main body 9 Base 10 Groove 11 Release lever 12 Cam surface 13 Spring 14 Magnetic field generator 15 Magnetomotive force generation part 16 Coil 17 First yoke 18 Second yoke 19 Gap 20 pin 21 Connecting shaft

Claims (2)

[Claims] 1. A cartridge comprising a disc made of a disc-shaped information recording medium, a case housing the disc therein and having openings on the upper and lower surfaces to expose a part of the stored disc, and the disc. Shine light on top,
It has an optical pickup for reading and writing information, a rotary table on which the disk is mounted and rotates, and a magnetomotive force generating section located outside the circumference of the disk mounted on the rotary table. A pair of thin yokes are provided to guide magnetic flux to the recording area of the disk, and the tips of the yokes are sloped outward, and the yokes are arranged so that the magnetic resistance between the yokes is approximately uniform along the longitudinal direction of the yokes. 1. A magneto-optical disk device comprising: a magnetic field generator whose gap or thickness is adjusted. 2. The magneto-optical disk device according to claim 1, wherein an inclined portion attached to the thin yoke of the magnetism generating device is coated with a resin or the like.