JP4249473B2 - Disk drive controller and disk drive device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a disk drive controller incorporated in, for example, a disk drive device for an optical disk, and more particularly to a technique for removing dust on a disk.
[0002]
[Prior art]
For example, optical disks such as MO and DVD generally tend to hinder read / write access due to dust adhering to the reading surface as the recording density increases. Therefore, various methods for removing dust in the disk drive device have been proposed.
[0003]
The objective is to remove dust from the objective lens in the disk drive device. However, as a conventional method, before starting the read / write access, the disk rotation speed is set to the normal rotation speed (normal rotation speed) during normal playback. There is a method in which dust is blown off by wind pressure at a time when the rotational speed reaches a peak (see, for example, Patent Document 1).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 62-24448
[Problems to be solved by the invention]
However, in the conventional dust removal method, the disk is rotated at a high speed until the normal rotational speed is exceeded, so a motor with a high-speed rotation specification must be employed for rotating the disk, which increases the cost. . In addition, it is disadvantageous in terms of design flexibility, motor durability, heat generation, power consumption, and the like.
[0006]
DISCLOSURE OF THE INVENTION
Accordingly, the present invention has been conceived under the circumstances described above, and a disk drive controller that can easily remove dust on the disk without incurring a cost increase in hardware and the like. An object of the present invention is to provide a disk drive device.
[0007]
In order to solve the above problems, the present invention takes the following technical means.
[0008]
According to the first aspect of the present invention, the rotational speed of the disk is changed in the normal rotational speed region from the highest rotational speed corresponding to the innermost peripheral zone of the disk to the lowest rotational speed corresponding to the outermost peripheral zone. , a disk drive controller for controlling the read / write access to the disk, said prior to the first read / write access control to the disk, the rotational speed of the disc immediately after changing to the maximum speed A disk drive controller is provided which is characterized in that the speed is changed to a minimum speed .
[0009]
As a preferred embodiment, immediately after the disk is set at a predetermined rotational position, the rotational speed of the disk can be changed from the highest rotational speed to the lowest rotational speed .
[0010]
Further, during the read / write access standby for the disk, the rotation speed of the disk can be changed from the maximum rotation speed to the minimum rotation speed .
[0011]
According to a second aspect of the present invention, there is provided a disk drive device comprising the disk drive controller according to the first aspect.
[0012]
According to the present invention, in the disk drive device, for example, immediately after the disk is set at a predetermined rotational position, or while waiting for access to the disk , the rotational speed of the disk is the maximum within a range not exceeding the normal rotational speed area at the time of access. It can be changed from the number to the minimum speed . At this time, a change in wind pressure, a change in centrifugal force, and a change in moment of inertia occur abruptly on the disk. Due to such a sudden change in the acting force, the dust on the disk becomes unstable and is shaken off. Therefore, since it is not necessary to employ a motor with a high-speed rotation specification exceeding the normal rotation speed region, dust on the disk can be easily removed without causing an increase in hardware cost.
[0013]
Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the drawings.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.
[0015]
FIG. 1 is a block diagram of a disk drive device according to an embodiment of the present invention.
[0016]
The disk drive device is, for example, a peripheral device of a personal computer, and rotates a magneto-optical disk A such as an MO disk and performs read / write access thereto. The disk drive device is centered on a disk drive controller 10 including a disk controller 1, a drive controller 2, and a servo controller 3, and a spindle motor 11 for disk rotation, a pickup unit 12, a bias coil 13, an optical system fixing unit 14, And an interface circuit 15 for exchanging data with a host such as a bus master in the personal computer.
[0017]
The disk controller 1, the drive controller 2, and the servo controller 3 are connected to each other. An optical system fixing unit 14 is connected to the disk controller 1 via a laser diode (LD) driver 24 and a read amplifier 25, and an interface circuit 15 is connected. The drive controller 2 is connected to a spindle motor 11 via a spindle driver 21, a bias coil 13 via a bias coil driver 23, an LD driver 24 and an optical system fixing part 14 via a read amplifier 25. The servo controller 3 is connected to a pickup unit 12 via an actuator / voice coil type linear motor (VCM) driver 22 and an optical system fixing unit 14.
[0018]
The spindle motor 11 rotates the magneto-optical disk A. The pickup unit 12 has an objective lens 12A facing the reading surface of the magneto-optical disk A, an actuator 12B that minutely changes the attitude of the objective lens 12A up and down, left and right, and a reading surface of the laser beam emitted from the optical system fixing unit 14. A voice coil linear motor (not shown) that translates the mirror 12C that guides reflected light from the reading surface side to the optical system fixing unit 14 and the entire pickup unit 12 in the radial direction of the magneto-optical disk A. Etc. are provided. The bias coil 13 applies a magnetic field to the magnetic recording layer in the magneto-optical disk A from the opposite side of the reading surface when writing or erasing data. The optical system fixing unit 14 is provided with a laser diode, a photo sensor, a beam splitter, and the like.
[0019]
The disk drive controller 10 performs the same control as before as long as it is limited to read / write access. That is, the disk controller 1 controls the laser irradiation power of the laser diode in accordance with data writing, reading, and erasing. Further, the disk controller 1 transfers the data read through the photo sensor to the interface circuit 15. The drive controller 2 controls the magnetic field direction of the bias coil 13 when writing or erasing data. The drive controller 2 controls the rotational speed of the spindle motor 11, that is, the rotational speed of the magneto-optical disk A. The servo controller 3 controls the movement of the actuator 12B based on the photosensor signal obtained from the optical system fixing unit 14 via the drive controller 2. As a result, a focusing operation in which the objective lens 12A is moved up and down to focus, and a tracking operation in which the objective lens 12A is moved left and right to align the laser beam with the target track of the magneto-optical disk A are performed. The servo controller 3 controls the voice coil linear motor. As a result, a seek operation for moving the pickup unit 12 to the target track of the magneto-optical disk A is performed.
[0020]
In particular, in this embodiment, a ZCLV (Zone Constant Linear Velocity) method is employed as a read / write access method. In the ZCLV system, as shown in FIG. 2, the track format corresponding to this is a plurality of zones in which a large number of tracks T1 to T16 (actually a larger number of tracks) in the magneto-optical disk A are arranged from the inner circumference side to the outer circumference side. This is a system in which read / write access is performed by changing the number of rotations of the magneto-optical disk A for each of the zones Z1 to Z4. According to the ZCLV method, the same number of sectors (fan-shaped unit sections) of the tracks T1 to T16 are set in the same zone Z1 to Z4, and random access is performed as long as read / write access is performed in the same zone Z1 to Z4. Even so, the access speed is relatively fast. On the other hand, for example, when the access zone moves from the zone Z1 to the other zones Z2 to Z4, the access speed becomes slow because the rotational speed of the magneto-optical disk A needs to be adjusted stepwise.
[0021]
FIG. 3 is an explanatory diagram for explaining the relationship between the recording length (unit recording length) per bit and the rotational speed, and FIG. 4 is an explanatory diagram for explaining the relationship between the disk diameter and the rotational speed. is there. FIG. 3 shows an example in which the disk diameter is 130 mm, the innermost track T1 has a radius of 24 mm, and the outermost track T16 has a radius of 64 mm. FIG. 4 shows an example in which the unit recording length of each track T1 to T16 is 0.1 μm and the data transfer rate is 100 Mbps. As shown in these figures, the rotational speed of the magneto-optical disk A varies depending on the data transfer rate at the time of access, the unit recording length of each track T1 to T16, and the access radius position according to the disk diameter.
[0022]
For example, as shown in FIG. 3, when the data transfer rate is 100 Mbps and the unit recording length is 0.1 μm, the rotational speed when accessing the innermost track T1 is approximately 4000 rpm. On the other hand, the rotational speed when accessing the outermost track T16 is approximately 1500 rpm. As apparent from the data transfer rate of 50 Mbps or 25 Mbps, the rotational speed when accessing the track on the inner circumference side is higher than that on the outer circumference side.
[0023]
Further, as shown in FIG. 4, even if the access radius position changes as the radius of the innermost track T1 or the outermost track T16 according to the disk diameter, the rotational speed when accessing the inner circumference from the outer circumference is changed. Is expensive. Further, as the disk diameter decreases, the rotational speed generally increases. In short, at the time of read / write access by the ZCLV method, from the maximum rotational speed corresponding to the innermost peripheral zone Z1 to the lowest rotational speed corresponding to the outermost peripheral zone Z4 (this is referred to as “normal rotational speed region”). The rotation speed is controlled so as to change for each zone.
[0024]
On the other hand, the disk drive controller 10 controls an operation for removing dust adhering to the reading surface of the magneto-optical disk A as an operation other than the read / write access. This is performed by the drive controller 2 controlling the spindle motor 11 independently. Hereinafter, the dust removal operation will be described.
[0025]
5 and 6 are explanatory diagrams for explaining the dust removal operation from the change in the rotational speed of the disk. First, the magneto-optical disk A is loaded into the disk drive device and set at a predetermined rotational position. Immediately thereafter, the drive controller 2 quickly increases the rotation speed of the spindle motor 11 from 0 to the lower limit of the normal rotation speed range (hereinafter referred to as “minimum rotation speed”), and further increases the upper limit of the normal rotation speed range (hereinafter referred to as “low rotation speed”). , Called the “maximum speed”). The minimum rotation speed and the maximum rotation speed are 1600 rpm and 4000 rpm, respectively, as shown in FIG. The drive controller 2 can automatically start the spindle motor 11 by detecting the magneto-optical disk A based on the photosensor signal. In addition, a sensor for directly detecting the presence / absence of the magneto-optical disk A may be separately provided, and the spindle motor 11 may be automatically started by using a detection signal from the sensor as a trigger.
[0026]
The rotation speed of the spindle motor 11 is rapidly lowered again to the minimum rotation speed immediately after reaching the maximum rotation speed. A series of movements up to this point is an operation for dust removal. As an example, if the time T from the minimum rotation speed to the maximum rotation speed is 100 ms, the angular acceleration α during that time is approximately 2512 rad / s ^ 2 by linear approximation. As a result, on the reading surface of the magneto-optical disk A, an abrupt change in inertia moment occurs, and an abrupt wind pressure change and centrifugal force change also occur. Due to such a sudden change in the acting force, the state of dust adhering to the reading surface becomes unstable, and eventually the dust is shaken off from the reading surface.
[0027]
Thereafter, the rotation speed of the spindle motor 11 is controlled so as to change for each of the zones Z1 to Z4 in accordance with the read / write access while being within the range of the normal rotation speed range from the minimum rotation speed to the maximum rotation speed. For example, when a read / write access is performed from the innermost zone Z1 to the outermost zone Z4, as shown in FIG. 5, the rotational speed of the spindle motor 11 is changed from the highest rotational speed to the lowest rotational speed. Can be changed. However, when there is only one zone for read / write access, the rotational speed of the spindle motor 11 is kept at a constant rotational speed corresponding to the zone.
[0028]
When the read / write access is completed, the rotation speed of the spindle motor 11 is kept at the minimum rotation speed as an idle operation, and a standby state is prepared for the subsequent read / write access.
[0029]
Even during such a read / write access standby, an operation for dust removal is executed. That is, as shown in FIG. 5, immediately before the next read / write access, the rotational speed of the spindle motor 11 is rapidly increased from the minimum rotational speed to the maximum rotational speed with the same degree as the angular acceleration α described above, Immediately after reaching the maximum number of revolutions, it is rapidly lowered again to the minimum number of revolutions. Thereafter, the rotational speed of the spindle motor 11 is controlled to be the rotational speed corresponding to each of the zones Z1 to Z4 along with the read / write access. Even in such a dust removal operation while waiting for access, the dust on the reading surface is shaken off by the sudden change in the acting force described above. The drive controller 2 receives a read / write command from the host via the disk controller 1 or the like and immediately changes the rotation speed of the spindle motor 11 as a dust removal operation immediately before executing a read / write access corresponding thereto. Can be made. In addition, the rotational speed of the spindle motor 11 may be rapidly changed immediately after execution of the read / write access.
[0030]
Further, as shown in FIG. 6 as an example, when the target of read / write access changes from zone Z2 to zone Z3, for example, the rotational speed of spindle motor 11 also changes from zone Z2 to the rotational speed corresponding to zone Z3. However, during the rotation speed adjustment period, an operation for dust removal may be executed. This also dusts off the dust on the reading surface.
[0031]
Therefore, according to this embodiment, immediately after loading of the magneto-optical disk A, during access standby, or during the rotational speed adjustment period, the rotational speed of the magneto-optical disk A is only changed rapidly within the normal rotational speed region. The dust on the magneto-optical disk A can be easily removed. For this reason, it is not necessary to employ a high-speed rotation motor that exceeds the normal rotational speed region as in the conventional case, as a component of the disk drive device of the present embodiment, so that an increase in hardware costs can be prevented. Further, the hardware configuration of the spindle motor 11 and the like need not be specially devised for dust removal, which is advantageous in terms of design freedom, motor durability, heat generation, power consumption, and the like. Can do.
[0032]
In addition, this invention is not limited to the said embodiment.
[0033]
As another embodiment, with respect to a change in the rotation speed of the spindle motor 11 accompanying the dust removal operation, as shown by a solid line in FIG. 7, the cycle from the minimum rotation speed to the maximum rotation speed is reached as shown in FIG. You may make it repeat. Or you may make it repeat 3 times or more. In such a case, the effect of removing dust can be further enhanced. Further, as indicated by a broken line in the figure, the maximum rotational speed may be maintained for a certain time after the rotational speed of the spindle motor 11 is rapidly changed from the minimum rotational speed to the maximum rotational speed. By doing so, it is possible to remove dust that is difficult to shake off instantaneously over a certain period of time.
[0034]
The rotational speed of the spindle motor 11 may be changed at least once from the minimum rotational speed to the maximum rotational speed by the dust removing operation. Therefore, immediately after reaching the maximum number of rotations, it is not necessary to decrease to the minimum number of rotations, and control may be performed so as to quickly shift to the number of rotations according to read / write access. Further, the control is not limited to the increase from the minimum number of rotations to the maximum number of rotations, but may be controlled so as to decrease only once from the maximum number of rotations to the minimum number of rotations.
[0035]
During the read / write access standby, the operation of the spindle motor 11 may be completely stopped. In such a case, when performing the dust removal operation during standby, the rotational speed of the spindle motor 11 can be changed in the same manner as immediately after the magneto-optical disk A is set at a predetermined rotational position.
[0036]
As the disc, for example, an optical disc such as a DVD or a CD-ROM may be used.
[0037]
The read / write access method is not limited to the ZCLV method and may be a CLV method.
[0038]
【The invention's effect】
As described above, according to the present invention, since it is not necessary to employ a motor with a high-speed rotation specification exceeding the normal rotation speed range, dust on the disk can be easily obtained without causing an increase in hardware cost. Can be removed.
[Brief description of the drawings]
FIG. 1 is a block diagram of a disk drive device according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram for explaining a track format corresponding to the ZCLV system;
FIG. 3 is an explanatory diagram for explaining a relationship between a recording length per bit and a rotational speed.
FIG. 4 is an explanatory diagram for explaining a relationship between a disk diameter and a rotational speed.
FIG. 5 is an explanatory diagram for explaining the dust removal operation from a change in the rotational speed of the disc.
FIG. 6 is an explanatory diagram for explaining the dust removal operation from a change in the rotational speed of the disc.
FIG. 7 is an explanatory diagram for explaining a dust removal operation according to another embodiment from a change in the rotational speed of a disc.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Disk controller 2 Drive controller 3 Servo controller 10 Disk drive controller 11 Spindle motor 12 Pickup unit 13 Bias coil 14 Optical system fixing | fixed part 15 Interface circuit A Magneto-optical disk

Claims (4)

The rotational speed of the disc, while changing in a conventional speed range from the maximum rotation speed corresponding to the innermost zone of the disc to the lowest rotational speed corresponding to the outermost peripheral zone, controlling the read / write access to the disk A disk drive controller that
A disk drive controller characterized in that, prior to the first read / write access control to the disk, the rotational speed of the disk is changed to the minimum rotational speed immediately after being changed to the maximum rotational speed . 2. The disk drive controller according to claim 1, wherein the rotation speed of the disk is changed from the maximum rotation speed to the minimum rotation speed immediately after the disk is set at a predetermined rotation position. 2. The disk drive controller according to claim 1, wherein the number of revolutions of the disk is changed from the maximum number of revolutions to the minimum number of revolutions during standby for read / write access to the disk.   A disk drive device comprising the disk drive controller according to claim 1.

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