JP2001118320A - Disk drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform stable recording/reproducing according to a use state. SOLUTION: This device is provided with a detection circuit 21 detecting a rotational speed of a spindle motor 8 (drive means) rotation-driving a hard disk 2 (disk-like recording medium), a servo control circuit 22 performing servo control of the spindle motor 8 based on the rotational speed detected by the detection circuit 21 and a characteristic control circuit switching the servo characteristic of the servo control circuit 22 according to the use state of a recording/reproducing device 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk drive for rotating a disk-shaped recording medium.

[0002]

2. Description of the Related Art For example, a disk drive device which is used by being externally connected to a computer and records / reproduces information signals to / from a hard disk is generally mounted on a stationary electronic device such as a computer main body, or is mounted on a computer main body. It is used as a stationary device for external connection and is not intended to be carried around. For this reason, in the conventional disk drive device, the servo band of the servo circuit that controls the rotation of the disk-shaped recording medium is set to, for example, 5H.
It is set relatively low, such as about z. As described above, in the disk drive device, the jitter is reduced when the hard disk is rotating at a steady speed by setting the servo band low.

[0003]

On the other hand, in recent years, the size and capacity of disk drive devices have been remarkably reduced, so that they are mounted on portable devices such as digital cameras and video cameras. Proposals have been made to digitally record video information in this disk drive device.

[0004] However, in the case of being used by being mounted on a portable electronic device or used as a portable device,
There is a problem that various disturbances are applied to the hard disk that is driven to rotate during recording and reproduction. Specifically, for example, when the disk drive device is rotated about an axis perpendicular to the rotation axis of the hard disk, a gyro moment acts on the rotation axis of the hard disk, and the gyro moment becomes a disturbance, and The rotation speed fluctuates.

However, the conventional disk drive device cannot maintain the required rotation speed during recording and reproduction when the rotation speed of the hard disk fluctuates sharply because the servo band is set low. This makes it difficult to maintain a stable recording / reproducing operation.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a disk drive capable of stably rotating a disk-shaped recording medium irrespective of a use state.

[0007]

According to the present invention, there is provided a disk drive apparatus comprising: a disk-shaped recording medium on which information signals are recorded; a driving means for rotating the disk-shaped recording medium; and a rotation speed of the driving means. There is provided a detecting means for detecting, and a servo control means for performing servo control of the driving means based on the rotation speed detected by the detecting means. Also, the servo characteristics of the servo control means are
There is provided a characteristic control means for switching according to a use state.

[0008] In the disk drive device according to the present invention configured as described above, the servo characteristics of the servo control means can be switched by the servo control means so as to always be optimal in accordance with the use state. A stable recording / reproducing operation can be performed regardless of the use state of the drive device.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A recording / reproducing apparatus using a disk cartridge as a recording medium to which a disk drive according to the present invention is applied will be described below with reference to the drawings.

The recording / reproducing apparatus 1 is used by being mounted on a portable electronic device such as a notebook personal computer, a digital camera, and a video camera. In addition, as shown in FIG.
Is used as a recording medium for recording and reproducing information signals. The recording / reproducing apparatus 1 is configured such that the disk cartridge 4 is detachable as shown by an arrow A in FIG. 1, and is configured as a so-called removable recording / reproducing apparatus.

The hard disk 2 is, for example, formed on a disk-shaped substrate made of a glass material or a resin material.
The magnetic layer is formed in a thin film shape. A center hole (not shown) having a predetermined diameter is formed in the center of the hard disk 2, and a hub (not shown) made of a metal material is attached to the center hole. ing. The hard disk 2 is used when the disk cartridge 4 is mounted on the recording / reproducing apparatus 1 to perform recording / reproducing.
The recording / reproducing apparatus 1 is rotationally driven, for example, in a direction indicated by an arrow B in FIG.

The cartridge body 3 is formed in a substantially rectangular box shape, for example, of a resin material, and the hard disk 2 is rotatably housed in its internal space. The cartridge main body 3 has a recording / reproducing opening 3 a for allowing a recording / reproducing mechanism of the recording / reproducing device 1 to enter, on one side to be inserted into the recording / reproducing device 1. The recording / reproducing opening 3a is inserted into the cartridge body 3
It is opened and closed by a shutter (not shown) movably attached to the camera.

The cartridge body 3 has a central opening (not shown) for chucking at a position where the hub of the hard disk 2 is provided.

The recording / reproducing apparatus 1 using the disk cartridge 4 as a recording medium as described above has a box-shaped cover 5
Each component is disposed inside a housing 7 composed of a base 6 made of a metal plate such as an aluminum alloy. On one side of the cover 5, the recording / reproducing device 1
Slot 5a for attaching and detaching disk cartridge 3 to and from
Are formed.

The base 6 has a loading mechanism for mounting the disk cartridge 4 in the cartridge mounting section, a rotation driving mechanism for driving the hard disk 2 of the disk cartridge 4 to rotate, and recording of information signals to the hard disk 2. And a recording / reproducing mechanism for performing reproduction.

The loading mechanism guides the disc cartridge 4 to be detached from the insertion opening 5a at the time of attachment and detachment, and a holder (not shown) for fixing and supporting the disc cartridge 4, and opens and closes the shutter when the disc cartridge 4 is attached and detached. And a shutter opening / closing mechanism (not shown).

The rotary drive mechanism includes a spindle motor 8 for generating a driving force applied to the hard disk 2 and a disk table 9 attached to a tip of a drive shaft of the spindle motor 8.

The spindle motor 8 is connected to the hard disk 2
Is rotated at a constant angular velocity, and servo control is performed by a servo circuit described later. The disk table 9 has a built-in magnet, and when the disk cartridge 4 is mounted on the recording / reproducing apparatus 1, the disk table 9 is chucked by a metal hub provided on the hard disk 2 to fixedly support the hard disk 2. .

The recording / reproducing mechanism includes a magnetic head 10 for recording / reproducing information signals to / from the hard disk 2, a magnetic head arm 11 for supporting the magnetic head 10, and a voice coil motor for driving the magnetic head arm 11 to rotate. And 12.

The magnetic head 10 is disposed, for example, on a flying slider attached to the distal end of a magnetic head arm 11, and floats on the main surface of the rotationally driven hard disk 2. Performs recording and reproduction of information signals.

The magnetic head arm 11 is attached to the base 6 so as to be rotatable about a rotation shaft 11a, and is driven to rotate by a voice coil motor 12. Thus, the magnetic head arm 11 operates to move the magnetic head 10 in the radial direction of the hard disk 2 as shown by an arrow C in FIG.

The voice coil motor 12 has a voice coil 13 attached to the rear end of the magnetic head arm 11.
And a magnet 14 disposed on the base 6 at a position facing the voice coil 13. The voice coil motor 12 drives the magnetic head arm 11 by utilizing an electromagnetic action generated between the voice coil 13 and the magnet 14 when a current is supplied to the voice coil 13.

A printed circuit board (not shown in FIG. 1) constituting a control circuit for controlling each part of the recording / reproducing apparatus 1 is attached to the base 6.
This control circuit includes, for example, a servo circuit that controls the rotation speed of the spindle motor 9, an arm control circuit that controls the driving operation of the magnetic head arm 11, and the like.

In the recording / reproducing apparatus 1, a servo circuit 20 for controlling the rotation speed so that the angular speed of the spindle motor 8 is constant is provided with a detection circuit 21 for detecting the rotation speed of the spindle motor 8 as shown in FIG. A servo control circuit 22 for performing servo control of the spindle motor 8 based on the rotation speed detected by the detection circuit 21; and a gain characteristic and / or a phase characteristic of the servo control circuit 22. A characteristic control circuit 23 that switches according to the state.

The detection circuit 21 detects the rotation speed of the spindle motor 8 based on a predetermined signal output from the spindle motor 8, for example, and outputs a speed signal indicating the rotation speed to the servo control circuit 22. .

As shown in FIG. 3, the servo control circuit 22 includes, for example, an oscillator 31 that oscillates a target speed signal indicating a target rotation speed of the spindle motor 8, and a speed signal input from the detection circuit 21 and an oscillator 31. A subtractor 32 for calculating a difference from an input target speed signal, and a compensator 33 for stabilizing a control loop in the servo control circuit 22
And a drive circuit 34 for driving the spindle motor 8.

The target speed signal oscillated from the oscillator 31 indicates the target rotation speed of the spindle motor 8.
This target rotation speed is the rotation speed of the spindle motor 8 required when recording and reproducing data on and from the hard disk 2. That is, in the recording / reproducing apparatus 1, it is possible to perform stable recording / reproducing when the spindle motor 8 rotates the hard disk 2 at the target rotational speed.

To the subtractor 32, a speed signal indicating the rotation speed of the spindle motor 8 is input from the detection circuit 21 and a target speed signal is input from the oscillator 31. Then, by performing arithmetic processing on the target speed signal and the speed signal, a difference between the rotation speed of the spindle motor 8 and the target rotation speed is calculated, and the result is output to the compensator 33.

The compensator 33 stabilizes the control loop based on the result input from the subtractor 32 and outputs a motor control signal for controlling the rotation speed of the spindle motor 8 to the drive circuit 34. The compensator 33 is provided with a plurality of sets of capacitors and resistors, which are components for determining its transfer characteristics, and these sets of capacitors and resistors are input from the characteristic control circuit 23 as described later. Switching is performed according to a predetermined signal. Thereby, the servo characteristics in the servo control circuit 22 are switched between, for example, the first servo characteristics as shown in FIG. 4 and the second servo characteristics as shown in FIG. In addition, these 1st and 2nd
Will be described later.

The drive circuit 34 controls the spindle motor 8 based on the motor control signal input from the compensator 33.
Is controlled to rotate at a predetermined rotation speed.

The servo control circuit 2 configured as described above
The characteristic control circuit 23 in the servo circuit 20 outputs a predetermined signal to the second compensator 33 according to the use state of the recording / reproducing apparatus 1.

Here, the usage state of the recording / reproducing apparatus 1 is as follows.
For example, it indicates whether the recording / reproducing apparatus 1 is used in a dynamic state or in a static state. The dynamic state refers to an external acceleration during use of the recording / reproducing apparatus 1 such as when the recording / reproducing apparatus 1 is used by being mounted on a portable device or when the recording / reproducing apparatus 1 is used as a portable device. , Vibration, or a gyro moment. In addition, the static state means that the recording / reproducing device 1 is mounted on a stationary device or used as a stationary device, such as when the recording / reproducing device 1 is used. A state in which no physical disturbance is applied.

The characteristic control circuit 23 is configured to detect acceleration applied from the outside by an acceleration sensor, for example, and based on the magnitude and frequency of the detected acceleration, etc.
The use state of the recording / reproducing apparatus 1 is automatically determined. Also,
The characteristic control circuit 23 may be configured in combination with, for example, a switch that can be manually operated, and the user may manually switch this switch according to the use state of the recording / reproducing apparatus 1.

The characteristic control circuit 23 controls the compensator 33 according to the use state of the recording / reproducing apparatus 1 determined as described above.
Of the servo control circuit 22.
Switch the servo characteristics. Specifically, for example, when the recording / reproducing apparatus 1 is used in a static state, the servo characteristics of the servo control circuit 22 are set to the first servo characteristics as shown in FIG. I do. When the recording / reproducing apparatus 1 is used in a dynamic state, the servo characteristics of the servo control circuit 22 are set to the second servo characteristics as shown in FIG.
The servo band is set to 15 Hz.

As described above, the characteristic control circuit 23 switches the servo characteristics of the servo control circuit 22 according to the use state of the recording / reproducing apparatus 1.

The servo circuit 20 configured as described above
May be realized by, for example, combining various electronic components, or may be realized by a one-chip integrated circuit. Further, it may be realized as software operating on an information processing device such as a computer. Further, in the servo circuit 20, the servo control circuit 22 and the characteristic control circuit 23 may be integrally configured. In this case, for example, an electronic component that determines the transfer characteristic of the compensator 33 may be physically switched by a switch or the like included in the servo control circuit 22.

The recording / reproducing apparatus 1 configured as described above
Operates as described below.

First, the disc cartridge 4 in a state where the shutter closes the opening 3a is inserted into the recording / reproducing apparatus 1 from the insertion port 5a in the direction shown by the arrow A in FIG.
At this time, the disk cartridge 4
And is mounted guided by a holder configured as a loading mechanism, and the shutter is opened by a shutter opening / closing mechanism. When the disk cartridge 4 is inserted into the recording / reproducing apparatus 1 up to the last end, the disk cartridge 4 is mounted on the cartridge mounting portion formed on the base 6 by the holder.

At this time, the disk table 9 attached to the drive shaft of the spindle motor 8 chucks on the hub of the hard disk 2. Thereby, the hard disk 2 is in a state where the drive shaft of the spindle motor 8 and the hard disk 2 can rotate integrally.

When recording an information signal on the hard disk 2, first, the hard disk 2 is driven to rotate at a predetermined rotation speed by the spindle motor 8. Then, by supplying a current to the voice coil 14, the magnetic head arm 11 is driven to rotate, and the opening 3 is opened.
a to enter the inside of the disk cartridge 4.

Then, the recording / reproducing apparatus 1 is mounted on the main surface of the hard disk 2 which is rotationally driven at a predetermined rotational speed.
By causing the magnetic head 10 to fly and travel, and applying a magnetic field corresponding to the information signal to be recorded to the magnetic layer of the hard disk 2 by the magnetic head 10,
A magnetic domain is formed in this magnetic layer. Thereby, the information signal is recorded as a magnetic domain on the magnetic layer of the hard disk 2.

When reproducing an information signal recorded on the hard disk 2, a leakage magnetic field generated from a magnetic domain formed in the magnetic layer is detected by the magnetic head 10, and a signal corresponding to the detection result is output. Thus, the information signal recorded on the hard disk 2 is reproduced.

When taking out the disk cartridge 3 from the recording / reproducing apparatus 1, first, the spindle motor 8
Is stopped, and the rotation of the hard disk 2 is stopped. Next, by rotating and driving the magnetic head arm 11,
The magnetic head 10 is removed from the disk cartridge 4. Next, the holder holding the disk cartridge 4 is moved upward from the base 6, and the hub of the hard disk 2 is separated from the disk table 9 attached to the drive shaft of the spindle motor 8. Next, the disk cartridge 4 is moved by the holder in the direction of arrow A in FIG. At this time, the shutter is operated by the shutter opening / closing mechanism, and the opening 3a is closed.

Since the recording / reproducing device 1 is used by being mounted on a portable device, the recording / reproducing device 1 can be subjected to acceleration and vibration while recording / reproducing on the hard disk 2. Alternatively, various physical disturbances such as a gyro moment are applied.

As described above, the recording / reproducing apparatus 1
The servo characteristics of the servo control circuit 22 can be switched by the characteristic control circuit 23 in accordance with the use state of the recording / reproducing apparatus 1, so that a stable recording / reproducing operation can be performed even when a physical disturbance is applied. Can be maintained.

More specifically, in the recording / reproducing apparatus 1, for example, when the mounted portable device is used in a static state such as being mounted on a stable place, the servo control circuit 22 The servo characteristics are controlled by the characteristic control circuit 23.
As shown in FIG. 4, the gain characteristic and the first servo characteristic having a relatively low servo band are set. Thus, the divergence of the control system in the servo control circuit 22 can be prevented, the rotation speed of the spindle motor 8 can be kept stable, jitter can be suppressed, and stable recording and reproduction can be performed.

Further, in the recording / reproducing apparatus 1, for example, when the portable device to be mounted is used in an unstable state, that is, when it is used in a dynamic state, such as when the portable device is used in a hand, As shown in FIG. 5, the servo characteristic of the servo control circuit 22 is set to a second servo characteristic having a higher gain characteristic and a higher servo band than the first servo characteristic, as shown in FIG.

In the recording / reproducing apparatus 1, by setting the gain characteristic of the servo control circuit 22 high as described above,
The servo in the servo control circuit 22 can be more strongly applied to the low-frequency rotation speed fluctuation of the spindle motor 8. That is, even for a slow and large fluctuation in the rotation speed of the spindle motor 8,
The servo control circuit 22 can reliably respond. In the recording / reproducing apparatus 1, the servo control circuit 2
By setting the servo band of No. 2 high, it is possible to reliably apply the servo in the servo control circuit 22 even to a high-frequency fluctuation in the spindle motor 8. That is, the servo control circuit 22 can reliably respond to a steep change in the rotation speed of the spindle motor 8.

Therefore, when the recording / reproducing apparatus 1 is used in a dynamic state and a physical disturbance such as acceleration, vibration, or gyro moment is applied, the rotation speed of the spindle motor 8 fluctuates greatly. However, the rotation speed can be stably maintained by reliably applying the servo in the servo control circuit 22. Therefore, even when the device is used in a dynamic state, a stable recording / reproducing operation can be performed.

By the way, in a disk drive such as the recording / reproducing apparatus 1 for recording / reproducing information signals by using a disk-shaped recording medium, generally, the disk-shaped recording medium is subject to vibration and impact in the in-plane direction. Is relatively insensitive. However, for example, when the entire apparatus is rotated around an axis perpendicular to the rotation axis of the disk-shaped recording medium, the action of the gyro moment causes
The rotational speed of the disk-shaped recording medium is likely to fluctuate, which may make it difficult to perform a stable recording / reproducing operation. In particular, in a hard disk drive such as the recording / reproducing device 1, the mass of the hard disk 2 is larger than, for example, an optical disk in a compact disk drive. Therefore, the effect of the gyro moment generated when the hard disk drive device is rotated around an axis perpendicular to the rotation axis of the hard disk becomes remarkable.

Therefore, in the following, among various physical disturbances applied when the recording / reproducing apparatus 1 is used in a dynamic state, the fluctuation of the rotation speed of the hard disk 2 due to the gyro moment will be described with reference to FIG. This will be specifically described. In the following, as shown in FIG. 6, the inner radius, outer radius, thickness, and density of the hard disk 2 are respectively
Let r, R, t, and ρ.

[0052] When the hard disk 2 when rotating at a predetermined rotational speed omega _x as the rotation axis x-axis, and topple the rotation axis around the z-axis at a predetermined rotational speed omega _z, 6 and As shown in Equation 1 below, a gyro moment of magnitude N acts around the y-axis.

[0053] In the _{N = ω x · ω z ·} π · ρ · t (R 4 -r 4) / 2 ··· ( Equation 1) recording and reproducing apparatus 1, a spindle motor 8 corresponding to the hard disk 2 rotating shaft The gyro moment acts on the drive shaft of the hard disk drive 2, and thus the rotational speeds of the spindle motor 8 and the hard disk 2 fluctuate.

For example, as shown in FIG. 4, the recording / reproducing apparatus 1 sets the servo band of the servo control circuit 22 to 5 Hz, and sets the servo characteristics of the hard disk 2 in the state where the servo characteristics are set in a static state. When an angular velocity as shown in FIG. 7A is applied around an axis perpendicular to the rotation axis, the servo control circuit 22 operates later than when the angular velocity is applied, as shown in FIG. 7B. Thus, the current supplied to the spindle motor 8 is increased. As a result, the rotation speeds of the spindle motor 8 and the hard disk 2 vary greatly as shown in FIG. Also,
FIG. 8 shows the jitter measured during the steady rotation of the hard disk 2 when the servo band is 5 Hz.

Therefore, when the recording / reproducing apparatus 1 is used in a dynamic state, the characteristic control circuit 23 uses the gain characteristic of the servo control means 22 in a static state as shown in FIG. 5, for example. It is set higher than the case, and the servo band is set to about 15 Hz.

Thus, in the recording / reproducing apparatus 1, when an angular velocity as shown in FIG. 9A is applied around the axis perpendicular to the rotation axis of the hard disk 2, the servo control circuit 22
Operates to increase the current supplied to the spindle motor 8 as shown in FIG. As a result, as shown in FIG. 9C, the fluctuation of the rotation speed in the spindle motor 8 and the hard disk 2 is larger than the fluctuation in the case of using in the dynamic state with the setting in the case of using in the static state. Become smaller. At this time, the angular velocity applied to the recording / reproducing apparatus 1 as shown in FIG. 9A is equal to the angular velocity applied to the recording / reproducing apparatus 1 as shown in FIG. FIG. 10 shows the jitter measured when the hard disk 2 is rotated at a steady speed when the servo band is set to 15 Hz.

As is clear from comparison of the results shown in FIGS. 7C and 9C, the recording / reproducing apparatus 1
The characteristic control circuit 23 can switch the gain characteristic of the servo control circuit 22 to a high setting, so that the fluctuation of the rotation speed of the hard disk 2 can be reduced even when used in a dynamic state. it can. Therefore, the recording / reproducing apparatus 1 can perform a stable recording / reproducing operation even when used in a dynamic state.

Further, from the results shown in FIG. 10, even in the case where the servo band is set high in the recording / reproducing apparatus 1, the jitter generated during the steady rotation of the hard disk 2 is
As shown in FIG. 8, it can be seen that there is not much difference from the case where the servo band is set low. That is, no increase in jitter caused by setting the servo band high is observed.

When the recording / reproducing apparatus 1 is used in a dynamic state, the servo band of the servo control circuit 22 is 10 Hz.
At least 20 Hz or less. In the recording / reproducing device 1,
In order to reduce the fluctuation of the rotation speed of the hard disk 2,
If a servo band exceeding 20 Hz is set, the control system in the servo control circuit 22 may oscillate. When the servo band is set to less than 10 Hz,
This is because fluctuations in the rotation speed of the hard disk 2 when used in a dynamic state cannot be effectively reduced.

When the recording / reproducing apparatus 1 is used in a static state, the servo band is set to about 5 Hz to 10 Hz. When the servo band is set to less than 5 Hz, even if no external physical disturbance is applied,
It becomes difficult to maintain the hard disk 2 at a predetermined rotation speed. Further, when the disk is used in a static state, fluctuations in the rotation speed of the hard disk 2 can be sufficiently suppressed by setting the servo band to 10 Hz or less. Also, considering the increase in jitter, it is not desirable to set a servo band exceeding 10 Hz.

As described above, the recording / reproducing apparatus 1
Can be switched by the characteristic control circuit 23 so that the servo characteristics of the servo control circuit 22 are always optimized in accordance with the use state of the recording / reproducing apparatus 1. Therefore, even when the recording / reproducing apparatus 1 is used in a dynamic state, for example, when the recording / reproducing apparatus 1 is mounted on a portable device or used as a portable device, stable recording / reproducing is performed. Can be performed. Further, when the recording / reproducing apparatus 1 is used in a static state, such as when mounted on a stationary apparatus or used as a stationary apparatus, jitter should be minimized. To
The servo characteristics of the servo control circuit 22 can be appropriately set.

Therefore, the recording / reproducing apparatus 1 is used while being carried, such as a notebook personal computer, a digital camera, or a video camera, and when it is used in a stable state by being set on a desk or the like. When mounted on a certain device, the maximum performance can be exhibited in accordance with the usage form.

The recording / reproducing apparatus 1 is used, for example, when connected to the outside of a notebook personal computer and used as a recording / reproducing apparatus, when it is used while being carried together with the notebook personal computer, or when it is placed on a desk or the like. When used in a stable state,
For the same reason as described above, the maximum performance can be exhibited according to the usage form.

Further, even when the same recording / reproducing apparatus 1 is used by being mounted on a portable device and a stationary device, for example, the servo characteristics of the servo control circuit 22 are switched by the characteristic control circuit 23. Therefore, for the same reason as described above, the maximum performance can be exhibited in accordance with the usage form of each device. Therefore, by using the recording / reproducing apparatus 1, a disk drive device mounted on each of the portable device and the stationary device can be commonly used. This can contribute to a reduction in product cost.

In the above description, the hard disk 2 is housed in the disk cartridge 4 and is used detachably with respect to the recording / reproducing apparatus 1. For example, the disk cartridge 4 in which the hard disk 2 is housed is The hard disk 2 may be configured integrally with the recording / reproducing apparatus 1 without being detachable from the recording / reproducing apparatus 1.

Although the above description has been made based on the recording / reproducing apparatus 1 shown in FIG. 1, the present invention is limited to the mechanical configuration of the apparatus to be applied and the recording / reproducing method for a disk-shaped recording medium. However, the present invention can be widely applied to disk drive devices using various disk-shaped recording media.

The disk drive to which the present invention can be applied is not limited to a so-called magnetic disk drive, such as a hard disk drive, but includes an optical disk drive, a magneto-optical disk drive, and a phase-change disk drive. be able to. That is, as the disk-shaped recording medium, the hard disk 2
It is not limited to a disk-shaped recording medium having a magnetic layer formed on a substrate as described above, for example, for a substrate on which a concavo-convex pattern corresponding to a recorded information signal is formed,
It may be a read-only optical disc in which the information signal is reproduced by irradiating the recording and reproducing means with a laser beam. In addition, a so-called magneto-optical device in which recording / reproducing is performed by irradiating a laser beam, applying an external magnetic field, or detecting a magnetic field to a recording / reproducing layer formed on a substrate. It may be a disc or a phase change optical disc.

The present invention is also applicable to a so-called optical hard disk drive in which information signals are recorded and reproduced on a disk-shaped recording medium by an optical head and a magnetic head mounted on a flying slider. Can be.

Further, the present invention is not limited to the rotating system of the disk-shaped recording medium. In the above description, the hard disk 2 is controlled by the spindle motor 8.
Are driven to rotate at a predetermined angular velocity, but for example, the hard disk 2 may be driven to rotate at a predetermined linear velocity.

[0070]

As described above, in the disk drive device according to the present invention, the characteristic control means can switch the servo characteristics of the servo control means so as to always be optimal according to the state of use. So, for example,
When using this disk drive device mounted on a portable device, or when using it as a portable device,
Set the servo characteristics so that stable recording / reproduction is possible, and minimize the jitter when using this disk drive device mounted on a stationary device or when using it as a stationary device. Servo characteristics can be set so that

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a recording / reproducing apparatus shown as one configuration example of a disk drive device to which the present invention is applied.

FIG. 2 is a block diagram showing a servo circuit of the recording / reproducing apparatus.

FIG. 3 is a block diagram more specifically showing a servo control circuit in the servo circuit of the recording / reproducing apparatus.

FIG. 4 is a diagram illustrating an example of a gain characteristic of a servo control circuit when the recording / reproducing apparatus is used in a static state.

FIG. 5 is a diagram illustrating an example of a gain characteristic of a servo control circuit when the recording / reproducing apparatus is used in a dynamic state.

FIG. 6 is a diagram for explaining a gyro moment acting on a hard disk of the recording / reproducing apparatus.

FIG. 7 is a diagram showing a change in the rotational speed of the hard disk when the servo control circuit of the recording / reproducing apparatus is set to be used in a static state, and (a) is a time change of an externally applied angular velocity; (B) shows the time change of the current supplied to the spindle motor, and (c) shows the time change of the rotation speed of the hard disk.

FIG. 8 is a diagram showing a jitter during a steady rotation of the hard disk when the servo control circuit of the recording / reproducing apparatus is set to be used in a static state.

FIG. 9 is a diagram showing a change in the rotation speed of the hard disk when the servo control circuit of the recording / reproducing apparatus is set to be used in a dynamic state, and FIG. (B) shows the time change of the current supplied to the spindle motor, and (c) shows the time change of the rotation speed of the hard disk.

FIG. 10 is a diagram showing jitter at the time of steady rotation of the hard disk when the servo control circuit of the recording / reproducing apparatus is set to be used in a dynamic state.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Recording / reproducing apparatus, 2 hard disk, 8 spindle motor, 20 servo circuit, 21 detection circuit, 22
Servo control circuit, 23 characteristic control circuit

Continuation of the front page F term (reference) 5D109 KA02 KB05 KB31 KD02 5H550 AA10 AA13 BB08 DD01 FF03 GG03 HA01 JJ03 JJ25 LL01 MM05

Claims (4)

[Claims] 1. A disk-shaped recording medium on which an information signal is recorded; a driving unit for driving the disk-shaped recording medium to rotate; a detecting unit for detecting a rotation speed of the driving unit; A disk drive device comprising: a servo control unit that performs servo control of the driving unit based on a rotation speed; and a characteristic control unit that switches a servo characteristic of the servo control unit according to a use state. 2. The characteristic control means sets the gain characteristic of the servo control means to be higher when used in a dynamic state than when used in a static state. The disk drive device according to claim 1. 3. The characteristic control means sets the servo band of the servo control means to 10 when used in a dynamic state.
3. The disk drive device according to claim 2, wherein the servo band of the servo control means is set to 5 Hz or more and less than 10 Hz when the frequency band is set to 20 Hz or more and 20 Hz or less, and is used in a static state. 4. The disk drive device according to claim 1, wherein said drive means rotationally drives said disk-shaped recording medium based on said servo control means so that an angular velocity becomes constant.