JP2929463B2 - 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.

Further, since the magneto-optical disk drive has a very large number of tracks and a narrow track pitch, it is necessary to perform very high-accuracy tracking servo.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a magneto-optical disk drive capable of transferring and reading / writing a large amount of data at high speed and capable of performing accurate tracking servo.

[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. And a first magneto-optical head for accessing a recording area on an outer peripheral side of the magneto-optical disk, and moving independently of the first magneto-optical head to access a recording area on an inner peripheral side of the magneto-optical disc. A second magneto-optical head is provided so as to be located within the head window, and a direction of a division line of a division photodetector for detecting a tracking error of the magneto-optical disk is set in a direction corresponding to each recording area of the magneto-optical disk. Wherein the dividing lines of the divided photodetector are inclined at a predetermined angle so as to be substantially in the track direction of the magneto-optical disk. Is achieved.

Further, the above object is to provide 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. Two magneto-optical heads that move independently in a direction substantially parallel to the radial direction and access the magneto-optical disk are provided so as to be positioned within the head window, and a tracking error of the magneto-optical disk is detected. The direction of the division line of the division photodetector is within the recording area of the magneto-optical disk,
So that it is almost in the track direction of the magneto-optical disk,
The driving direction of the tracking coil for performing the tracking control by inclining the division line of the division photodetector by a predetermined angle and driving the objective lens of the magneto-optical head is substantially perpendicular to the track in the recording area of the magneto-optical disk. This is also achieved by a magneto-optical disk device characterized in that the axis of the tracking coil is inclined at a predetermined angle.

Further, the above object is to provide 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. Two magneto-optical heads, each independently moving in a direction substantially parallel to the radial direction and accessing the magneto-optical disk, are provided so as to be positioned within the head window, and drive the objective lens of the magneto-optical head. The axis of the tracking coil is inclined at a predetermined angle so that the driving direction of the tracking coil for performing tracking control is substantially perpendicular to the track of the magneto-optical disk within the recording area of the magneto-optical disk. This is also achieved by a magneto-optical disk drive.

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

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 10l 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 disk cartridge 10
The hub 12a of the magneto-optical disk 12 stored in the optical disk 12 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. ing.

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 objective lenses 30 and 32, which are components of the magneto-optical heads A and B, which are the minimum components required for reading and writing data, and their actuators 3.
4, 36 are installed. 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 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, as described above, 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,
The driven objective lens 32 constituting a magnetic circuit by the magnet 36c is supported by the 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. On the opposite side of the coil bobbin 36d from the objective lens 32, a counterweight 36g for balancing weight is mounted.

The coil bobbin 36 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 a direction perpendicular to the track direction in a plane perpendicular to the optical axis 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 arranged symmetrically, 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. Therefore, the seek direction of each magneto-optical head does not match the diameter direction of the magneto-optical disk 12.

The state of movement of the magneto-optical heads A and B with respect to the magneto-optical disk 12 is schematically shown in FIG. 5 inches in diameter (130mm)
With respect to the magneto-optical disk 12, the seek directions Da and Db of the magneto-optical heads A and B are parallel to the diametric direction Dr and are 10 mm to the left and right.
It is out of alignment. The recording area R on the magneto-optical disk 12 has an innermost radius of 29 mm and an outermost radius of 60 mm. The deviation angle θ between the seek direction Da and the diameter direction of the magneto-optical head A is 9 ゜ 36 ′ at the outermost position Pao, but is 2 ゜ 10 ′ at the innermost position Pai. Seek direction in magneto-optical head B
The deviation angle θ of Db is 9 36 ′ at the outermost position Pbo and 20 10 ′ at the innermost position Pbi.

If the seek direction and the diametric direction deviate in this way, tracking servo cannot be performed accurately. In other words, when the direction of theta deviates from the diameter direction, the dividing line of the four-divided photodetector 44n for detecting the tracking error signal deviates, the modulation degree of the tracking error signal decreases, and the direction of the tracking coil 36f of the actuators 34, 36 changes. This causes two problems that the jitter amount due to the tracking servo drive increases.

In the present embodiment, these problems are solved so that accurate tracking servo can be performed. Next, these problems and their solutions will be described in detail.

First, a method for preventing the modulation degree of the tracking error signal from being lowered due to the inclination of the dividing line of the four-divided photodetector will be described.

In this embodiment, the tracking error signal is detected by the push-pull method. The push-pull method irradiates a laser beam onto a groove of a magneto-optical disk, detects reflected light on both sides of the groove by a photodetector divided into at least two parts, and determines a tracking error based on whether the intensities of the right and left reflected lights are equal to each other. Is a method for detecting

FIG. 8 shows the groove of the magneto-optical disk 12, the objective lens 32, and the four-divided photodetector 44n in principle, with the intermediate paths omitted, for explaining the push-pull method. FIG. 8 (a) shows a case where the seek direction Db and the diametric direction Dr match, and FIG. 8 (b) shows a case where the seek direction Db and the diametric direction Dr are shifted.

Light reflected from the left and right edges of the groove of the magneto-optical disk 12 is irradiated onto the four-divided photodetector 44n. 4
Two diffraction patterns Q1 and Q on split photodetector 44n
Detection signal I ₁ by 2, tracking a difference _{I 1-2 (= I 1 -I 2} ) the overall intensity _{I 0 (= I 1 + I} 2) values I _1-2 / I ₀ divided by the I ₂ Detected as an error signal.

As shown in FIG. 8 (a), the seek direction Db and the diametric direction
If the four-part photodetector 44n is arranged so that the direction of the dividing line coincides with the direction of the groove of the magneto-optical disk 12 when Dr coincides, if the seek direction Db and the diametric direction Dr are shifted, As shown in FIG. 8B, the direction of the groove and the direction of the dividing line are shifted by the angle θ.
For this reason, the modulation degree of the tracking error signal I _1-2 / I ₀ decreases, and the tracking servo control based on the tracking error signal cannot be performed accurately.

That is, when the four-divided photodetector 44n is arranged so as to be optimal when the seek direction Db coincides with the diameter direction Dr, for example, in the magneto-optical head B, FIG.
As shown in the figure, the deviation angle θ is 9 ゜ 3 at the outermost position Pbo.
6 ', but the deviation angle θ is 20 at the innermost position Pbi.
It becomes ゜ 10 ′, and the four-divided photodetector 44n crosses the dividing line, and the diffraction patterns Q1 and Q2 enter each other, and the degree of modulation of the tracking error signal decreases.

For this reason, in the present embodiment, the quadrant photodetector 44
The dividing line of n is inclined from the position shown in FIG. 9A so that the deviation angle θ does not increase at the outermost position Pbo or the innermost position Pbi. Specifically, as shown in FIG. 9 (b), the angle of deviation θ is the same between the outermost position Pbo and the innermost position Pbi from the position in FIG. 9 (a) by 14 °. Five
The dividing line of the four-divided photodetector 44n is inclined by 3 '(= (9 ゜ 36' + 20 ゜ 10 ') / 2). The deviation angle θ at the outermost position Pbo and the innermost position Pbi is 5 最大 17 ′ at maximum,
In the recording area R in the meantime, the deviation angle θ is within 5 ゜ 17 ′.

Note that the magneto-optical head A is also arranged so that the dividing line is inclined by 14 ゜ 53 ′ from the optimal arrangement of the four-segmented photodetector when the seek direction Da matches the diametric direction Dr. Thus, the deviation angle θ of the magneto-optical head A in the recording area R can be reduced to 5 ゜ 17 ′ or less.

Next, a method for preventing an increase in the amount of jitter due to the inclination of the tracking coil of the actuator will be described.

FIG. 10 schematically shows the tracking coil 36f of the actuator 36 of the magneto-optical head B.

The tracking coil 36 of the actuator 36 is optimized so that the seek direction Db matches the diametric direction Dr.
When f is arranged, as shown in FIG. 10 (a), the shift angle θ is about 9 ゜ 36 ′ at the outermost position Pbo, but is 20 角度 10 ′ at the innermost position Pbi. Also. When the actuator 36 is driven to eliminate a tracking error by passing a current through the tracking coil 36f, a component of the force by the tracking coil 36f is also applied in the diameter direction to generate jitter.

For this reason, in the present embodiment, the tracking coil 36f of the actuator 36 is inclined from the position shown in FIG. 10 (a) so that the deviation angle θ does not increase at the outermost position Pbo or the innermost position Pbi. As shown in FIG. 10 (b), the actuator 36 is shifted by 14 位置 53 ′ from the position in FIG. 10 (a) so that the deviation angle θ is the same between the outermost position Pbo and the innermost position Pbi. Tilt the tracking coil 36f. The deviation angle θ at the outermost position Pbo and the innermost position Pbi
Is 5 最大 17 ′ at the maximum, and 5 ゜
The deviation angle θ is within 17 ′, and the jitter amount due to the tracking servo drive can be reduced.

For the magneto-optical head A, the seek direction Da is the diameter direction.
When the position of the tracking coil coincides with Dr, the tracking coil is disposed at an inclination of 14 ゜ 53 ′ from the optimum position. As a result, the deviation angle θ of the magneto-optical head A in the recording area R is set to 5
The jitter amount can be reduced by setting it to be less than or equal to 17 '.

The specific arrangement of the actuators 34 and 36 in this embodiment is shown in the enlarged view of FIG. The actuator 34 of the magneto-optical head A is tilted 14 ° 53 ′ clockwise from the seek direction Da, and the actuator 36 of the magneto-optical head B is tilted 14 ° 53 ′ counterclockwise from the seek direction Db.

As described above, according to the present embodiment, even if the seek direction deviates from the diameter direction, the tracking servo can be accurately performed on all the recording areas of the magneto-optical disk.

In the above embodiment, in consideration of the case where both the magneto-optical heads A and B seek the entire recording area R of the magneto-optical disk 12, the shift angle at the innermost circumference is equal to the shift angle at the outermost circumference. However, in the case where the entire recording area R of the magneto-optical disk 12 is divided into a recording area on the inner peripheral side and a recording area on the outer peripheral side, and each of the magneto-optical heads A and B is separately accessed, the magneto-optical head is required. By adjusting the inclination of the A and B quadrant photodetectors and the tracking coil, the tracking servo control can be performed more accurately.

As shown in FIG. 12, the entire recording area R 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 sought by the magneto-optical head A, and the outer recording area Rb is sought by the magneto-optical head B. The innermost position Pai of the 29 mm radius of the magneto-optical head A
Is 20 ゜ 10 ′, and the deviation angle θ of the position Pam with a radius of 45 mm at the boundary between the recording area Ra and the recording area Rb is 12 ゜ 50 ′. On the other hand, the deviation angle θ of the position Pbm with a radius of 45 mm at the boundary between the recording area Ra and the recording area Rb of the magneto-optical head B is 12 ゜ 50 ′, and the deviation angle θ of the outermost position Pbo with a radius of 60 mm is 9 ゜ 53 ′. Become.

Therefore, for the magneto-optical head A, the four-divided photodetector and the tracking coil are inclined at the center position of the recording area Ra so that the deviation angle becomes zero.

That is, the dividing line of the four-divided photodetector of the optical system 42 is set to 16 ゜ 30 '(= 20 ゜ 10' + 12 ゜ 50 ') from the optimum arrangement when the seek direction Db coincides with the diametric direction Dr.
/ 2) tilt only. Position Pai of magneto-optical head A
And the deviation angle θ of the dividing line at the position Pam is 3 ゜ 4
It becomes 0 '.

Further, the tracking coil of the actuator 34 of the magneto-optical head A is tilted by 16 ゜ 30 ′ from the optimum position when the seek direction Db coincides with the diametric direction Dr. The deviation angle θ of the tracking coil at the position Pai and the position Pam of the magneto-optical head A is 3 ゜ 40 ′.

On the other hand, for the magneto-optical head B, the four-divided photodetector and the tracking coil are inclined at the center position of the recording area Rb so that the deviation angle becomes zero.

That is, 44 quadrant photodetectors 44n of the optical system
From the optimum arrangement when the seek direction Db coincides with the diametric direction Dr, 11 ゜ 22 '(= (12 ゜ 50' + 9
゜ 53 ') / 2). The deviation angle θ of the dividing line at the position Pbm and the position Pbo of the magneto-optical head B is both 1 ゜ 38 ′.

Further, the tracking coil of the actuator 34 of the magneto-optical head A is tilted by 11 ゜ 22 ′ from the optimum arrangement when the seek direction Db coincides with the diametric direction Dr. The deviation angle θ of the tracking coil at the position Pai and the position Pam of the magneto-optical head A is both 1 ゜ 38 ′.

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

For example, in the above embodiment, the magneto-optical head is tilted so that the deviation angle between the innermost circumference and the outermost circumference of the recording area to which the magneto-optical head seeks is the same, but the recording / reproducing conditions on the inner circumference side are more severe. Therefore, the magneto-optical head may be arranged such that the shift angle on the inner circumferential side is smaller than the shift angle on the outer circumferential side of the magneto-optical head.

In the above embodiment, the dividing line of the four-divided photodetector of the magneto-optical head and the tracking coil of the actuator are both tilted, but only one of them may be tilted.

Further, in the above-described embodiment, the separated type magneto-optical head in which the actuator and the optical system are separated from each other, but an integrated magneto-optical head in which the actuator and the optical system are integrated may be used.

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

[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. 7 is a diagram showing an example of a moving state of a magneto-optical head of the magneto-optical disk device. FIG. 8 is an explanatory diagram of a push-pull method in the magneto-optical disk device. FIG. FIG. 10 and FIG. 11 are explanatory diagrams of the arrangement of actuators of the magneto-optical disk device, and FIG. 12 is a diagram of the magneto-optical head of the magneto-optical disk device. Moving state It is a figure showing other examples. 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

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁶ , DB name) G11B 7/135 G11B 7/09-7/095 G11B 7/13 G11B 11/10

Claims (3)

(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 first magneto-optical head for accessing the recording area on the side of the disk, and a second magneto-optical head which moves independently of the first magneto-optical head and accesses the recording area on the inner peripheral side of the magneto-optical disk. The direction of the dividing line of the divided photodetector for detecting the tracking error of the magneto-optical disk is substantially within the recording area of each of the magneto-optical disks. Wherein the dividing lines of the divided photodetector are inclined by a predetermined angle so as to be in the track direction. 2. A magneto-optical disk drive for writing or reading data to or from a magneto-optical disk stored in a magneto-optical disk cartridge having a head window of a predetermined shape. Two magneto-optical heads, each independently moving in a direction substantially parallel to the direction and accessing the magneto-optical disk, are provided so as to be positioned within the head window, and a division for detecting a tracking error of the magneto-optical disk is provided. Tilting the dividing line of the photodetector at a predetermined angle so that the direction of the dividing line of the photodetector is substantially in the track direction of the magnetooptical disk within the recording area of the magnetooptical disk; The driving direction of the tracking coil for performing tracking control by driving the objective lens is substantially the same as that in the recording area of the magneto-optical disk. So that the vertical direction of the click, the magneto-optical disk device characterized by the axis of the tracking coil is inclined a predetermined angle. 3. 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 that move independently in a direction substantially parallel to the direction and access the magneto-optical disk are provided so as to be located in the head window, and the objective lens of the magneto-optical head is driven. The axis of the tracking coil is inclined at a predetermined angle so that the driving direction of the tracking coil for performing the tracking control is substantially perpendicular to the track of the magneto-optical disk in the recording area of the magneto-optical disk. Magneto-optical disk drive.