JP2797676B2 - Magneto-optical disk drive - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to a magneto-optical disk drive using a magneto-optical disk cartridge.

[Prior Art] A magneto-optical disk device is a storage device having a large storage capacity like a conventional write-once optical disk device, but it is capable of rewriting and erasing information that cannot be performed by a conventional write-once optical disk device. In recent years, products related to magneto-optical disks have been available, and magneto-optical disk technology is about to reach the stage of commercialization from the stage of trial manufacture.

With the development of such technology, the ISO (International Standardization Organization) for magneto-optical disks
n) Standards were reviewed and ISO standards were established for 130 mm (5.25 inch) diameter disk cartridges.

The 5-inch magneto-optical disk cartridge is easy to replace with a disk, has a protected recording surface, is easy to handle, and has a recording capacity several hundred times that of a high-density floppy disk despite its small size. Because of that,
It is anticipated that it will become a central player of magneto-optical disk media in the future.

[Problems to be Solved by the Invention] As described above, the magneto-optical disk drive is expected to be a large-capacity storage device of the next generation. There is a problem that reading and writing a file takes a very long time. Therefore, in a magneto-optical disk drive, how to process a large amount of data at high speed is a very important technical problem.

To process a large amount of data at a high speed, it is conceivable to rotate the magneto-optical disk at a higher speed. However, it is difficult to rotate the magneto-optical disk at a speed twice or more that of the related art in consideration of the mechanical characteristics of the actuator. Therefore, it is desired to increase the number of magneto-optical heads for reading and writing data. However, the head window of a standardized magneto-optical disk cartridge is determined on the assumption that one magneto-optical head is provided, and it is not mechanically possible to arrange a plurality of large magneto-optical heads in a narrow head window. It was very difficult.

An object of the present invention is to arrange a plurality of magneto-optical heads in a head window of a standardized magneto-optical disk cartridge,
An object of the present invention is to provide a magneto-optical disk device capable of processing a large amount of data at high speed.

[Means for Solving the Problems] An object of the present invention is to provide a magneto-optical disk drive for writing or reading data to or from a magneto-optical disk housed in a magneto-optical disk cartridge having a head window of a predetermined shape. A center rail provided substantially in the center of the head window along a diameter of the magneto-optical disk; first and second side rails provided in parallel on both sides of the center rail; And a first carriage slidably provided between the first and second side rails, the first carriage having at least a part of the first magneto-optical head mounted thereon, and a first carriage driving the first carriage along the center rail. And a second driving means which is slidably provided between the center rail and the second side rail, and at least a part of a second magneto-optical head is mounted. And a second driving means for driving the second carriage along the center rail, wherein the first and second magneto-optical heads are arranged in the head window and the magneto-optical disk is provided. This is achieved by a magneto-optical disk device characterized in that it is accessed.

According to the present invention, a plurality of magneto-optical heads are arranged in the head window of a standardized magneto-optical disk cartridge,
A large amount of data can be processed and read / written at high speed. Further, since the two magneto-optical heads are driven along the same center rail and the center rail serves as a reference, the apparatus of the present invention accurately maintains the relative positional relationship between the two independently moving carriages. It can be easily assembled and adjusted.

Embodiment A magneto-optical disk drive according to an embodiment of the present invention will be described with reference to FIGS. 1 is a front view of the magneto-optical disk drive, FIG. 2 is a plan view, and FIG. 3 is a sectional view.

Before describing the magneto-optical disk drive of the present embodiment,
A standard 5-inch disk cartridge will be described with reference to FIG.

The disc cartridge 10 has a diameter of 130 m as a recording medium.
This protects the m (5.25 inch) magneto-optical disk 12 and facilitates its replacement. The case 10a of the disk cartridge 10 has a rectangular shape and houses the magneto-optical disk 12 therein. On both sides of the case 10a, a circular motor window 10b is opened at the hub 12a of the stored magneto-optical disk 12. Also, in order to read and write data to the magneto-optical disk 12,
A rectangular head window 10c is opened at a portion of the 12 recording surfaces so as to be continuous with the motor window 10b. Note that the width of the head window 10c is set to a minimum of 40 mm.

Case to open and close motor window 10b and head window 10c
A shutter 10d that slides along the side of 10a is provided. When not mounted, the shutter 10d is the motor window 10b and the head window
The recording surface of the magneto-optical disk 12 is protected by covering 10c. At the time of mounting, the shutter 10d slides to open the motor window 10b and the head window 10c, so that the rotation of the magneto-optical disk 12 can be maintained and data can be read from and written to the recording surface.

Since the recording surface of the magneto-optical disk 12 is formed on both front and back sides, characters 10f ("A" and "B") for distinguishing the front surface from the back surface are provided on both surfaces of the case 10a of the disk cartridge 10 with arrows 10e indicating the insertion direction. Has been written. Case 10a
A label area 10g used by the user is provided beside the motor window 10b and the head window 10c on both sides of the printer.

An alignment hole 10h is located at the bottom of the case 10a.
Location hole 10i, write protection hole 10 for side A
j, a write protection hole 10k for the B side, a medium identification hole 101 for the A side, and a medium identification hole 10m for the B side.

Next, the magneto-optical disk device of the present embodiment will be described. FIGS. 1 to 3 show a state in which the above-described disk cartridge 10 is mounted on a magneto-optical disk device.

A clamp table 14b is formed at the tip of the rotating shaft 14a of the spindle motor 14, and the disc cartridge 1
The hub 12a of the magneto-optical disk 12 stored in the storage unit 0 is clamped by the clamp table 14b. In this embodiment, the magneto-optical disk 12 is rotated at 1800 rpm by the spindle motor 14.

A center rail 1 is located below the magneto-optical disk 12 in the center.
6, side rails 18 and 20 are provided on both sides thereof, and linear motors 22 and 24 are provided between the center rail 16 and the side rails 18 and 20, respectively. Linear motor 22,
24, upper yokes 22b, 24b are provided on U-shaped lower yokes 22a, 24a, and plate-like magnets 22c, 24c are provided on the bottom upper surface of the lower yokes 22a, 24a to form a magnetic circuit. doing.

Two carriages 26, 28 are provided corresponding to the two linear motors 22, 24.

The carriage 26 is provided between the center rail 16 and the side rails 18. The carriage 26 is slidably supported by two sets of bearings 26a, two for the center rail 16, and one set for the side rails 18. Is slidably supported by the bearing 26a. A preload is applied to the bearing 26a, and consideration is given to prevent a displacement from occurring during sliding. In the center of the carriage 26, a hole having a rectangular cross section through which the upper yoke 22b of the linear motor 22 passes is formed, and a coil 26b is embedded along the inner surface of the hole.

The carriage 28 is provided between the center rail 16 and the side rail 20 and is slidably supported by two sets of bearings 28a, two for the center rail 16 and two for the side rail 20. Is slidably supported by the bearing 28a. A preload is applied to the bearing 28a, and consideration is given to preventing a displacement during sliding. At the center of the carriage 28, a hole having a rectangular cross section through which the upper yoke 26b of the linear motor 26 penetrates is formed, and a coil 28b is embedded along the inner surface of the hole.

The carriages 26 and 28 include constituent lenses 30 and 32, which are constituent parts of the magneto-optical heads A and B, which are the minimum necessary parts for reading and writing data, and actuators thereof.
34, 36 are mounted. These actuators 34, 36
Is mounted at a position near the center rail 16 so as to fit in the head window 10c of the disk cartridge 10 having a width of 40 mm.

On the other hand, above the magneto-optical disk 12, an actuator
Bias magnets 38 and 40 for applying a bias magnetic field to positions corresponding to the movement ranges of 34 and 36 are provided. The bias magnets 38 and 40 are yokes 38 with an E-shaped cross section.
a, 40a and coils 38b, 40b. These bias magnets 38 and 40 are also provided at positions near the center rail 16 so as to be accommodated in the head window 10c of the disk cartridge 10.

The laser light (two-dot chain line) from the optical systems 42 and 44 passes through holes 26c and 28c formed in the carriages 26 and 28,
26, 28, the objective lens 30,
The light is guided to 32 and focused on the recording surface of the magneto-optical disk 12.
Similarly, the laser beam reflected from the recording surface of the magneto-optical disk 12 is guided to the optical systems 42 and 44 through the holes 26c and 28c by the rising mirrors 46 and 48 via the objective lenses 30 and 32.

Thus, in the present embodiment, the carriage 2
Objective lenses 30, 32 that require a minimum of parts to be mounted on 6, 28
And its actuators 34 and 36 only, optical systems 42 and 44
Separate from the weight. Thus, the load on the linear motors 22 and 24 can be reduced, and the access time can be reduced.

In addition, the objective lens 3 which is minimum necessary for the carriages 26 and 28
Only the rails 0 and 32 and their actuators 34 and 36 are mounted to reduce the size, and the center rail 16 which is one rail for sliding the carriages 26 and 28 is shared. This allows
Two magneto-optical heads can be accommodated in the head window 10c having a limited width of 40 mm.

Furthermore, by using the center rail 16 shared by the two magneto-optical heads as a reference, it is possible to easily assemble and adjust while maintaining the relative positional relationship between the independently moving carriages 26 and 28 accurately. It is.

Next, details of the structure of the actuator 36 will be described with reference to FIG. 1A is a front view, FIG. 1B is a plan view, FIG. 1C is a side view, and FIG. 1D is a cross-sectional view. Since the structure of the actuator 34 is the same, the description is omitted.

Actuator base as base for actuator 36
36a is provided. Actuator base 36a-2
The two yokes 36b extend vertically upward and are integrally formed. A magnet 36c is mounted inside the two yokes 36b. Actuator base 36a, yoke 36b,
A magnetic circuit is constituted by the magnet 36c.

The driven objective lens 32 is supported by a coil bobbin 36d. The coil bobbin 36d is provided with a focusing coil 36e for generating a driving force in the optical axis direction and a tracking coil 36f for generating a driving force in a track direction perpendicular to the optical axis. Coil bobbin 36d
On the side opposite to the objective lens 32, a counterweight 36g for balancing weight is attached.

The coil bobbin 36d is movably supported by four suspension wires 36h (up, down, left and right). A wire locking portion 36i extending vertically from one side of the actuator base 36a is formed, and a bobbin locking portion 36j is formed on a side portion of the coil bobbin 36d. A rubber damper is provided between the wire locking portion 36i and the bobbin locking portion 36j. The coil bobbin 36d is supported by a suspension wire 36h embedded in 36k so that it can move in any direction.

The entire actuator 36 is protected by the objective lens 32
It is covered by a cover 361 having a hole formed above.

The coil bobbin 36d is driven in the optical axis direction according to the current flowing through the focusing coil 36e,
The coil bobbin 36d is driven in the track direction according to the current flowing through 6f.

Next, details of the structure of the optical system 44 will be described with reference to an enlarged view of FIG. Note that the structure of the optical system 42 is the same except that it is symmetrically arranged, and a description thereof will be omitted.

Laser light emitted from a laser diode 44a, which is a light source, is converted from a divergent light beam into a parallel light by a collimator lens 44b. The laser light converted into parallel light is incident on the composite prism 44c. The compound prism 44c is a beam shaping prism 44d and two beam splitter prisms 44c.
e, 44f. The incident laser beam is shaped by a beam shaping prism 44d so that the intensity distribution of the cross section of the parallel laser beam is shaped.
Laser light.

The laser beam that has traveled straight through the beam splitter prism 44e has its optical path changed at a right angle by a mirror 44g, is guided in the direction of the above-described actuator 36, and is irradiated on the magneto-optical disk 12 via a rising mirror 48 and an objective lens 32.

On the other hand, the laser light reflected by the beam splitter prism 44e is guided to the PIN photodiode 44i by the plano-convex lens 44h. The intensity of the laser light output from the laser diode 44a is detected by the PIN photodiode 44i, and the detection signal is fed back to control the radiation output of the laser diode 44a.

The reflected light from the magneto-optical disk 12 is guided to the optical system 44 via the objective lens 32 and the rising mirror 48, and is reflected by the mirror 44.
The optical path is changed at a right angle by g, and the light enters the composite prism 44c. The laser beam reflected by the beam splitter prism 44e is split into two laser beams by the beam splitter prism 44f.

The optical path of the laser light that has traveled straight through the beam splitter prism 44f is bent at a right angle by the mirror 44j. The laser beam bent at a right angle is converged by a plano-convex lens 44k and a cylindrical lens 44l, and is passed through a plano-concave lens 44m.
The light is focused on the split photodetector 44n. A focusing error and a tracking error are detected by the four-division photodetector 44n. In addition, the quadrant photodetector 44
The reason why the plano-concave lens 44m is provided immediately before n is to increase the magnification of the astigmatism detection system described above.

On the other hand, the laser light reflected by the beam splitter prism 44f is incident on the polarization beam splitter 44q via the / 4 wavelength plate 44o and the 波長 wavelength plate 44p. 1/4 wavelength plate 44o
Compensates the phase of the optical component, and rotates the polarization plane by 45 degrees by the half-wave plate 44p.

The polarizing beam splitter 44q has two prisms 44r and 44s
And converts the rotation of the polarization plane due to the Kerr effect into a change in intensity. Polarizing beam splitter
44q transmits the p component and reflects the s component. Penetrated p
The component light is transmitted to the PIN photodiode 44 by the plano-convex lens 44t.
Focused on u. The reflected s component light is a plano-convex lens 44v
Is focused on the PIN photodiode 44w. The rotation direction due to the Kerr effect is detected from the detection signals of the PIN photodiodes 44u and 44w, and the information recorded from the magnetization direction recorded on the magneto-optical disk 12 is read.

The magneto-optical disk drive according to the present embodiment is configured as described above.
Magneto-optical disk cartridge 1 defined by ISO standards
Two magneto-optical heads are provided in a head window 10c having a width of 0 and a width of 40 mm. By controlling the two magneto-optical heads to efficiently write and read information, a large amount of data can be processed at high speed.

In this embodiment, since the magneto-optical disk 12 is rotated at 1800 rpm by the spindle motor 14, data of 500 Kbyte / sec can be transferred for each magneto-optical head. Therefore, data can be transferred at a rate of 1 Mbyte / sec by reading and writing simultaneously by the two magneto-optical heads A and B.

If the spindle motor 14 is further rotated at a higher speed, data can be transferred at a higher speed. However, considering mechanical resonance, it is difficult at present to rotate the spindle motor 14 twice or more at a high speed. In this embodiment, high-speed data transfer comparable to high-speed rotation exceeding the conventional limit is possible without increasing the load on the spindle motor 14.

[Effects of the Invention] As described above, according to the present invention, a large amount of data can be processed at high speed by disposing a plurality of magneto-optical heads in the head window of a standardized magneto-optical disk cartridge.

[Brief description of the drawings]

1 is a front view of a magneto-optical disk drive according to an embodiment of the present invention, FIG. 2 is a plan view of the magneto-optical disk drive, FIG. 3 is a cross-sectional view of the magneto-optical disk drive, and FIG. FIG. 5 is a perspective view of an ISO standard 5-inch disk cartridge used in the magneto-optical disk device. FIG. 5 is a view showing details of an actuator of the magneto-optical disk device. FIG. 6 is a detail of an optical system of the magneto-optical disk device. FIG. In the figure, 10: Disc cartridge 10a: Case 10b: Motor window 10c: Head window 10d: Shutter 10e: Arrow 10f: Character 10g: Label area 10h: Alignment hole 10i: Location hole 10j ...... A-side write protection hole 10k ... B-side write protection hole 10l ... A-side medium identification hole 10m ... B-side medium identification hole 12 ... Magneto-optical disk 12a ... Hub 14 Spindle motor 14a Rotating shaft 14b Crank table 16 Center rail 18, 20 Side rail 22, 24 Linear motor 22a, 24a Lower yoke 22b, 24b Upper yoke 22c , 24c Magnets 26, 28 Carriage 26a, 28a Bearing 26b, 28b Coil 26c, 28c Hole 30, 32 Objective lens 34, 36 Actuator 36a Actuator base 36b York 36c… Magnet 36d Coil bobbin 36e Focusing coil 36f Tracking coil 36g Counter weight 36h Suspension wire 36i Wire locking part 36j Bobbin locking part 36k Rubber damper 36l Cover 38, 40 Bias magnets 38a, 40a Yoke 38b, 40b Coil 42, 44 Optical system 44a Laser diode 44b Collimator lens 44c Composite prism 44d Beam shaping prism 44e, 44f Beam splitter prism 44g Mirror 44h Plano-convex lens 44i PIN photodiode 44j Mirror 44k Plano-convex lens 44l Cylindrical lens 44m Plano-concave lens 44n Quadrant photodetector 44o 1/4 Wave plate 44p… 1/2 wave plate 44q… Polarizing beam splitter 44r, 44s… Prism 44t… Plano-convex lens 44u …… PIN photo die Over de 44v ...... plano-convex lens 44w ...... PIN photodiode 46, 48 ...... rising mirror

Claims (2)

(57) [Claims] 1. A magneto-optical disk device for writing or reading data to or from a magneto-optical disk housed in a magneto-optical disk cartridge having a head window of a predetermined shape. A center rail provided along the diameter of the magneto-optical disk, first and second side rails provided in parallel on both sides of the center rail, and between the center rail and the first side rail. A first carriage slidably provided on which at least a part of a first magneto-optical head is mounted, first driving means for driving the first carriage along the center rail, and the center rail A second carriage slidably provided between the second magneto-optical head and at least a part of a second magneto-optical head; Second driving means for driving a carriage along the center rail, wherein the first and second magneto-optical heads are arranged in the head window to access the magneto-optical disk. Magneto-optical disk drive. 2. The magneto-optical disk drive according to claim 1, wherein the first carriage drives a first objective lens for irradiating the magneto-optical disk with a laser beam, and the first objective lens. A second actuator mounted on the first carriage; a second objective lens for irradiating the magneto-optical disk with laser light; and a second actuator for driving the second objective lens mounted on the second carriage. A magneto-optical disk device characterized by the above-mentioned.