JP2797675B2 - 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, easy to handle because the recording surface is protected, and has a recording capacity of about 700 high-density floppy disks despite its small size. For this reason, it is predicted that the magneto-optical disk medium will become a central player in the future.

[Problems to be Solved by the Invention] As described above, the magneto-optical disk device is expected to be a large-capacity storage device of the next generation. However, the number of tracks is very large, and a large amount of data is handled. There is a problem that reading and writing a file takes a very long time. For this reason, in a magneto-optical disk device, how to record / reproduce a large amount of data at high speed is a very important technical problem.

An object of the present invention is to provide a magneto-optical disk drive capable of transferring and reading / writing 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. , Two magneto-optical heads provided to be located within the head window and accessing the magneto-optical disk, and driving means for driving the two magneto-optical heads to move independently of each other; Control means for writing or reading data to or from different areas of the magneto-optical disk by one magneto-optical head.

[Operation] According to the present invention, a large amount of data can be transferred and read / written at high speed.

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 side 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. 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. 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.

Actuators 34 and 36 for driving the objective lenses 30 and 32 are mounted on the carriages 26 and 28, respectively. These actuators 34 and 36 are provided with a width 40 of the disk cartridge 10.
It is mounted at a position near the center rail 16 so as to fit in the head window 10c of 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.

In this embodiment, as described above, the parts mounted on the carriages 26 and 28 are separated from the optical systems 42 and 44 by using only the minimum necessary objective lenses 30 and 32 and their actuators 34 and 36. This is to reduce the load on the linear motors 22 and 24 to shorten the access time, and to accommodate two magneto-optical heads in the head window 10c having a limited width of 40 mm.

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.

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 upward 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 36l 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 composite prism 44c includes a beam shaping prism 44d and two beam splitter prisms 44e,
It consists of 44f. The incident laser light is shaped into a parallel laser light cross section by a beam shaping prism 44d, and split into two laser lights by a beam splitter prism 44e.

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. In this embodiment, a large amount of data is transferred at high speed by efficiently writing and reading information by devising control of two magneto-optical heads.

Next, details of control of the two magneto-optical heads in the present embodiment will be described with reference to FIGS.

As shown in FIG. 7, the entire recording area of the magneto-optical disk 12 is divided into an inner recording area Ra and an outer recording area Rb. The inner recording area Ra is accessed by the magneto-optical head A, and the outer recording area Rb is accessed by the magneto-optical head B. The actuator 34 of the magneto-optical head A is
The actuator 36 of the magneto-optical head B is mounted on the carriage 28 between the center rail 16 and the side rail 20 shown in FIG. Have been.

DM for managing defective sectors at the innermost circumference of the recording area Ra
An A (Defect Management Area) area Rad is provided, and a DMA area Rad is also provided at the outermost periphery of the recording area Rb. The rest of the recording area Ra is a user area Rau, and the rest of the recording area Rb is a user area Rbu.

The details of the layout of the magneto-optical disk 12 are shown in FIG.

The magneto-optical disk 12 is composed of 1875 tracks from track 0 to track 18750, and each track is composed of 17 sectors from sector 0 to sector 16.

The DMA area Rad of the recording area Ra is an area of three tracks from the 0th track to the 2nd track. Track 0 Track 0
The sector is a recording area of a DDS (Disk Definition Structure), in which information on the structure of the magneto-optical disk 12 is recorded. PDL (Primary Defect List) and SDL (Sec.
ondary Defect List). PDL is a list of sectors having a primary defect (PD = Primary Defect) which is a defect detected when the magneto-optical disk 12 is formatted, and SDL is a defect which is a defect detected when the magneto-optical disk 12 is actually written and read. Next defect (SD = Secondary Defe
ct) is a list of certain sectors. The eighth sector on the first track is a DDS recording area, and the ninth sector on the first track to the fifteenth sector on the second track are PDL and SDL recording areas. The 16th sector of the last second track of the DMA area Rad is a reserve (Res = Reserve) sector.

The DMA area Rbd of the recording area Rb extends from track 18748 to track 187.
It is an area of three tracks up to 50 tracks. DMA area Rad
Similarly to the above, recording areas for DDS, PDL, and SDL are provided, and the last sector is a spare sector.

The user area Rau of the recording area Ra is divided into groups 1 to 4, and the user area Rbu of the recording area Rb is also divided into groups 5 to 8. Each group includes a data sector provided for recording data, and a spare sector provided as a substitute sector for a secondary defect (SD) sector in the data sector. If there is a secondary defective sector in the data sector, data is recorded in the spare sector instead of the secondary defective sector.

Details of the recording state of the magneto-optical disk 12 are shown in FIG. 9 by taking the group 1 of the recording area Ra and the group 5 of the recording area Rb as an example. 128 for group 1 and group 5 respectively
This shows a state in which data for a sector has been written.

If a defect (primary defect) is detected during formatting,
The primary defective sector PD is excluded from the logical space and is treated as if it did not exist. For example, since the fifth track and the seventh sector are the primary defective sectors PD,
The next data <41> following the data <40> recorded on the fifth track and the sixth track is recorded on the fifth track and the eighth track. The information on the primary defective sector PD is DMA
It is already recorded as PDL in the area Rad.

If a defect (secondary defect) is detected at the time of actual reading / writing, this secondary defective sector SD cannot be excluded from the logical space and is recorded in a spare sector of the same group. For example, if a defect is detected in the second sector of the sixth track and data cannot be recorded as the secondary defective sector SD, the 13th sector of the 10th track at the head of the spare sector becomes a substitute sector, and data <52> is recorded. You. The information on the secondary defective sector SD is stored in the secondary defective sector SD.
Each time an alternate sector is set in SD, the DM
Recorded in the A area Rad.

The control by the control means (not shown) when recording continuous data D covering several sectors on the magneto-optical disk 12 by such a magneto-optical disk device will be described with reference to FIG.

The continuous data D to be recorded is divided into data d1, data d2,... In units of sector capacity. First, the first data
d1 is written by the one magneto-optical head A in the fifth track, sixth sector of the recording area Ra (group 1). The next data d2 is written by the other magneto-optical head B in the seventh sector of the (n + 2) th track of the recording area Rb (group 5). Subsequently, the next data d3 is skipped again by the magneto-optical head A to skip the primary defective sector (seventh sector of the fifth track) and to return to the fifth data d3.
The data is written to the eighth sector of the track. The next data d4 is written by the magneto-optical head B in the eighth sector of the (n + 2) th track following the seventh sector of the (n + 2) th track. In the same manner, continuous data is recorded using the two magneto-optical heads A and B simultaneously.

In this way, by writing continuous data separately to the two magneto-optical heads A and B, the recording time can be halved.

When reading the continuous data D from the magneto-optical disk 12 recorded in this manner, first, the magneto-optical head A accesses the sixth sector of the fifth track to read the data d1. At the same time, the seventh sector of the (n + 2) th track is accessed by the magneto-optical head B, and the data d2 is read. Subsequently, the magneto-optical head A accesses the eighth sector of the fifth track to read the data d3, and the magneto-optical head B accesses the eighth sector of the (n + 2) -th track to read the data d4. Similarly, the data d5, d6,... Are read by the two magneto-optical heads A, B, and the data d1, d2,. Is configured.

By reading data by the two magneto-optical heads A and B in this manner, the reading time can be reduced to half.

Therefore, according to this embodiment, a large amount of data can be transferred at high speed and read / written.

In this embodiment, since the magneto-optical disk 12 is rotated at 1800 rpm by the spindle motor 14, data of 522 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 objective lens servo system and the signal processing system.

The present invention is not limited to the above embodiment, and various modifications are possible.

For example, in the above embodiment, continuous data is divided into sector capacities and distributed to two magneto-optical heads. However, if long continuous data can be distributed to two magneto-optical heads, free data can be freely assigned without being restricted by the sector capacity. It may be divided by a large amount of data.

In the above embodiment, the magneto-optical disk is divided into two recording areas, and each recording area is divided into four groups. However, the recording area may be divided in another manner.

[Effects of the Invention] As described above, according to the present invention, a large amount of data can be transferred at high speed and read / written.

[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. FIGS. 7 and 8 show details of the recording area of the magneto-optical disk used in the magneto-optical disk device. FIG. 9 shows data of the magneto-optical disk used in the magneto-optical disk device. FIG. 3 is a diagram illustrating details of a recording state. 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 Counterweight 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 (1)

(57) [Claims] 1. 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. Two magneto-optical heads for accessing the magneto-optical disk, driving means for driving the two magneto-optical heads to move independently of each other, and the magneto-optical head by the two magneto-optical heads Control means for writing or reading data to or from different areas of the disk.