JPH1198759A - Disk drive device - Google Patents

Abstract

(57) [Summary] (with correction) [PROBLEMS] To provide a disk drive device having an automatic alignment mechanism so that automatic alignment is reliably performed. SOLUTION: A moving space 1 made of a magnetic material and having an annular cross-sectional shape in a direction orthogonal to the rotation axis direction of a turntable 9
A mechanism 15 for performing automatic alignment so that the composite center of gravity of the rotating member is positioned on the rotation axis by a balance ball 17 disposed in the space 6 and a magnet 18 disposed in the center of the space.
Detecting means for detecting when the rotation of the turntable reaches the used rotation range and the self-alignment is not performed, and stopping the rotation of the turntable. A relocation means is provided to change the rotation speed to a rotation speed other than the used rotation range and then return to the rotation speed of the used rotation range again, even if the automatic alignment is not performed even if the rotation speed of the turntable reaches the used rotation range. The rotation speed of the turntable is changed to a rotation speed other than the rotation speed range including the stop, and then returned to the rotation speed in the rotation speed range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a novel disk drive device. More specifically, the present invention relates to a disk drive device provided with an automatic alignment mechanism, and to a technique for surely performing automatic alignment.

[0002]

2. Description of the Related Art For example, in a disk drive device provided in a computer for reproducing and recording data on a recording disk such as an optical disk or a magneto-optical disk, the recording disk is rotated by a rotary drive mechanism. The rotary drive mechanism includes a spindle motor serving as a rotary drive unit, and a turntable fixed to a tip end of a spindle shaft of the spindle motor and holding a central portion of a recording disk. Then, with respect to the recording disk rotated by such a rotation drive mechanism, recording and / or reproduction of information signals is performed by an optical pickup device or a magnetic head device.

Incidentally, the recording disks such as the above-mentioned optical disks may cause weight imbalance at the time of manufacturing or the like. When a recording disk having such a weight imbalance is rotated by a rotation drive mechanism,
Since the center of rotation and the center of gravity do not match, the recording disk vibrates together with the turntable. Due to this vibration, focusing and tracking on the signal recording surface of the recording disk by the optical pickup device and tracking of the recording track of the recording disk by the magnetic head device cannot be performed well.

[0004] In general, the amount of imbalance that occurs on a recording disk varies depending on the recording disk.

Furthermore, recently, it has become possible to record or reproduce data on or from a recording disk at a high speed, and there is a problem that the vibration of the recording disk increases as the rotation speed increases.

Therefore, the vibration of the recording disk cannot be suppressed unless there is a vibration suppressing means capable of coping with the weight imbalance amount or the rotation speed for each recording disk.

In view of the above, a plurality of balance members are movably arranged in a moving space rotated with the turntable.
The balance member is rotated along with the rotation of the moving space, and moves in the moving space. The member rotates together with the moving space such as a recording disk or a turntable (hereinafter, these rotating members are collectively referred to as “synthetic rotation”). A disk drive device having an automatic alignment mechanism that performs an automatic alignment so that the center of gravity (synthetic center of gravity) of the “body” is positioned on the rotation axis has been proposed.

[0008]

By the way, in the disk drive device having the above-described automatic alignment mechanism, a recording disk having a deviated center of gravity (hereinafter, such a recording disk is referred to as an "eccentric disk"). ), The self-centering action is not always performed. That is,
Even in the case of rotating a recording disk having a center of gravity deviation within the allowed range, the automatic alignment function is performed once, but sometimes the automatic alignment function is not performed,
Vibration may not stop forever.

However, even if the self-aligning operation is not performed, if the rotation is stopped once and then rotated again, or if the rotation speed is reduced to a low speed and then increased again to the used rotation range, the automatic alignment is performed. Often a wicking action is performed.

[0010] Therefore, an object of the present invention is to make the self-aligning action be performed by stopping the rotation once and then rotating it again when the self-aligning action is not performed.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the disk drive apparatus according to the present invention is designed so that the automatic alignment is not performed even when the rotation speed of the turntable reaches a used rotation range. Detecting means for detecting that,
Rearrangement means for changing the rotation of the turntable to a rotation speed other than the used rotation range including stop and then returning to the rotation speed of the used rotation range again, so that even if the rotation speed of the turntable reaches the used rotation range, automatic When the alignment is not performed, the rotation of the turntable is changed to a rotation speed other than the used rotation range including the stop, and then returned to the rotation speed of the used rotation range again.

Therefore, in the disk drive of the present invention, the automatic alignment is reliably performed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a disk drive according to the present invention will be described below.

The recording disk 1 is configured by forming a signal recording surface on a transparent substrate formed in a disc shape with a diameter of 120 mm from a synthetic resin material such as polycarbonate. The recording disk 1 has a circular opening (chucking hole) 1a at the center thereof. The recording disk 1 is positioned by fitting a positioning projection of a turntable described later into the circular opening 1a.

The disk drive device 2 includes a mechanical chassis 5 on which a spindle motor 3 and an optical pickup device 4 serving as rotation driving means are mounted, a plurality of dampers 6 for floatingly supporting the mechanical chassis 5 with respect to a base chassis (not shown), .. (See FIG. 1).

The optical pickup device 4 is supported by the mechanical chassis 5 via guide shafts 7, 7 so as to be movable in the radial direction of the recording disk 1 mounted on the turntable. The optical pickup device 4 includes a light source and a photodetector, and irradiates the recording disk 1 with a laser beam emitted from the light source via the objective lens 8 as described later. The reflected light is detected by a photodetector.

A turntable 9 for mounting and rotating the recording disk 1 is provided integrally with the rotor 3a of the spindle motor 3. Note that the turntable 9 does not necessarily need to be provided integrally with the rotor 3a of the spindle motor 3, and the turntable may be fixed to a rotating shaft fixed to the rotor 3a.

At the center of the upper surface of the turntable 9, a positioning projection 10 is projected, and the positioning projection 10 has a thick disk shape, and an upper half portion 10a has a tapered frustoconical shape. Is doing. The positioning protrusion 10 is formed with a fitting hole 10b opened at the center of the upper surface. The positioning protrusion 10 is formed of a magnetic material.

A chucking pulley 11 for holding the recording disk 1 in a sandwiched manner with the turntable 9 is provided. The chucking pulley 11 has a lower surface 12.
Is formed as a disc holding surface, and a fitting recess 12a is formed in the center of the disc holding surface 12 so as to fit the positioning protrusion 10 of the turntable 9, and the fitting protrusion 12b projects from the center of the fitting recess 12a. Has been established. A flange 11a protrudes outward from the peripheral edge of the upper end of the chucking pulley 11, and the flange 11a contacts an upper opening edge of a circular opening provided in a support member (not shown). It is supported rotatably and movably in the vertical and lateral directions with some margin. In the center of the chucking pulley 11, that is, just above the fitting recess 12a, a ring-shaped magnet 13 and the magnet 1 are fixed.
A ring-shaped yoke plate 14 is disposed in contact with the upper surface of the third yoke 3.

An automatic centering mechanism 15 is integrally formed with the chucking pulley 11. The self-centering mechanism 15 has a plurality of balance balls 17, 17,... Made of a magnetic material as a balance member disposed in an annular moving space 16 formed in the chucking pulley 11 so as to be movable. An annular magnet 18 is provided at the center of the moving space 16.

In a state where the chucking pulley 11 is not rotating, as shown in FIG.
Are attracted to the magnet 18 while being arranged at equal intervals in the circumferential direction. The state shown in FIG. 3 is the initial state of the balance balls 17, 17,...

When the recording disk 1 is inserted into the disk drive device 2 with the recording disk 1 being placed on a disk tray (not shown), the spindle motor 3 moves upward together with the mechanical chassis 5 and moves upward together therewith. The recording disk 1 is placed on the moving turntable 9,
As the recording disk 1 rises from the disk tray, the chucking pulley 1 is
The disc holding surface 12 is abutted, and the recording disc 1 is held in a state of being sandwiched between the turntable 9 and the chucking pulley 11. At this time, the positioning projection 10 of the turntable 9 is fitted into the fitting recess 12a of the chucking pulley 11, and the fitting projection 12b of the chucking pulley 11 is fitted into the fitting hole 10b of the turntable 9. Then, positioning between the turntable 9 and the chucking pulley 11 is performed.

When the spindle motor 3 is driven to rotate its rotor 3a, the turntable 9 is held together with the rotor 3a, the recording disk 1 mounted on the turntable 9, and the recording disk 1 is held together with the turntable 9. The chucking pulley 11 is integrally rotated, and the balance balls 17, 17,... Are also rotated in the moving space 16. That is, the rotor 3a, the turntable 9, the chucking pulley 11, the recording disk 1, and the balance balls 17, 17,... Constitute a composite rotating body (hereinafter, the center of gravity of each of these members, that is, The center of gravity of the composite rotating body is referred to as “composite center of gravity.”

When the rotation speed of the recording disk 1 reaches the working rotation range by the rotation of the spindle motor 3, the balance balls 17, 17,... Move by centrifugal force as shown in FIGS. Outer inner peripheral surface 16 of space 16
a has been reached.

Thus, the balance balls 17, 17,...
When the magnet 1 is in contact with the outer inner peripheral surface 16a,
Are attracted to the balance balls 17, 17,... By the magnetic force generated by the magnetic force generated by the magnetic force of the magnetic force generated by the magnetic force generated by the magnetic force of the magnetic force generated by the magnetic force.

When the recording disk 1 to be rotated has no weight imbalance (eccentricity) or when the recording disk 1 is not mounted on the turntable 9, the balance balls 17, 17,. Is as shown in FIG.
The chucking pulleys 11 are located at equal angular intervals around the rotation axis.

The recording disk 1 may have a weight imbalance during manufacturing. Here, the term “unbalance” means that the center of gravity of the recording disk 1 is not located at the center of the recording disk 1. For example, the unbalance means that the substrate thickness of the recording disk 1 is uneven or the density is uneven. Occurs when

If the recording disk 1 having such imbalance is rotated together with the turntable 9,
The spindle motor 3 rotating the recording disk 1 vibrates including the mechanical chassis 5. When the recording disk 1 having such a weight imbalance is mounted on the turntable 9 and rotated, the balance balls 17, 17,... According to the direction of the imbalance and the amount of the imbalance, the robot moves in the moving space 16 to a position where the imbalance is canceled. That is, each balance ball 1
, 17,... Rotate separately from the members forming the moving space 16, but are relatively stationary with respect to the moving space 16 and rotate with the moving space 16. . Each of the balance balls 17, 17,... Gradually moves to a position facing the unbalance direction of the recording disk 1.

Each balance sphere 17, 17,... In a state where the balance spheres 17, 17,.
.. (This position is referred to as “balance position”), as shown in FIG. 5, in the direction of unbalance (that is, the direction in which the center of gravity of the recording disk 1 is viewed from the rotation center). On the other hand, in the range from the position at the angle + θn to the position at the angle -θn via the opposite side of this unbalanced direction,
They are arranged at equal intervals (that is, in a range of an angle ± θn with respect to the direction of unbalance,
17,... Do not exist. ).

At this time, the balance balls 17, 17,...
The center of gravity of the whole is a position facing the above-mentioned unbalance direction via the center of rotation, and is located on the facing line.

Thus, each of the balance balls 17, 17,.
.. When the recording disk 1 having imbalance is rotated, the self-movement is appropriately performed by a so-called self-centering action,
Thereby, the position of the combined center of gravity is located on the rotation axis. Therefore, the composite rotating body rotates without vibrating, and
The unbalanced recording disk 1 can be rotated with its center of gravity positioned on the rotation axis.

As described above, the provision of the self-aligning mechanism 15 makes it possible to realize the rotation of the recording disk 1 without vibration.

In the disk drive device 2, the self-aligning mechanism 15 is formed integrally with the chucking pulley 11, but the invention is not limited to this. An alignment mechanism can be formed, or an automatic alignment mechanism can be formed separately from the chucking pulley and the turntable. Further, in the automatic alignment mechanism 15, the balance member is a spherical member 17, but the balance member is not limited to the spherical member. Anything that moves to a position where the balance is canceled can be used. Further, the recording disk 1 is not limited to one having a diameter of 120 mm, and can be applied to a disk drive device using recording disks of various sizes.

The information is read by the optical pickup device 4 while the recording disk 1 is held between the turntable 9 and the chucking pulley 11 and is driven to rotate by the spindle motor 3. The optical pickup device 4 irradiates the recording disk 1 with laser light, and reads, for example, information recorded in the recording disk 1 in a pit form from the reflected light.

Recording / recording on such a recording disk 1
In a disk drive device for reproduction, in order to control the tracking of a laser beam spot, the objective lens 8 of the optical pickup device 4 is driven by a tracking error signal obtained from reflected light for track guide information such as a pit row or a groove. A sled mechanism is provided for displacing the relative positions of the two-axis actuator, the entire optical pickup device 4 and the disk surface in the disk radial direction.

As a thread mechanism, a mechanism of moving the entire optical pickup device 4 with respect to a disk is known. As a control method of the sled mechanism, there is a method in which a midpoint error signal generated by extracting a low-frequency component from a tracking error signal by a low-pass filter is used as a sled drive signal and applied to a sled motor. The midpoint error signal is a signal indicating the offset amount of the entire optical pickup device 4 and the objective lens that is driven by tracking by the biaxial actuator of the optical pickup device 4.

The optical pickup device 4 has the objective lens 8 serving as an output end of a laser beam, and the objective lens 8 is moved by a biaxial actuator 19 in a radial direction of the disk (tracking direction) and in a direction of coming and going to the disk (focus direction). ) Is displaceably held. The entire optical pickup device 4 can be moved in the disk radial direction by a sled mechanism 20.

The information detected from the recording disk 1 by the optical pickup device 4 by the reproducing operation is supplied to the RF amplifier / arithmetic unit 21. RF amplifier / arithmetic unit 21
Performs arithmetic processing such as a reproduction RF signal, a tracking error signal TE, a midpoint error signal CE, and a focus error signal FE from the supplied information.

The tracking error signal TE, midpoint error signal CE and focus error signal FE obtained by the RF amplifier / arithmetic unit 21 are supplied to the servo processor 22. The servo processor 22 outputs the focus error signal F
In accordance with E, for example, a servo signal as a PWM modulation signal is generated and supplied to the servo driver 23. The servo driver 23 generates a focus drive signal FD based on the supplied PWM modulation signal, and applies it to the focus coil of the biaxial actuator 19. That is, the drive of the objective lens 8 in the focus direction of the biaxial actuator 19 is controlled based on the focus error signal FE.

The servo processor 22 generates a servo signal as a PWM modulation signal in accordance with the tracking error signal TE and supplies the servo signal to the servo driver 23. The servo driver 23 generates a tracking drive signal TD based on the supplied PWM modulation signal, and applies it to the tracking coil of the biaxial actuator 19. That is, the biaxial actuator 19 controls the driving of the objective lens 8 in the tracking direction based on the tracking error signal TE.

Further, the servo processor 22 generates a sled servo signal as a PWM modulation signal from the low frequency component of the middle point error signal CE, and supplies it to the servo driver 23. The servo driver 23 generates a thread drive signal SLD based on the supplied PWM modulation signal, and drives the thread mechanism 20.

Further, the servo processor 22 generates a spindle servo signal based on a spindle error signal SPE from the decoder section 24, a spindle kick and a spindle brake command from the system controller 25, and supplies the same to the servo driver 23. The servo driver 23 applies a spindle drive signal SPD based on the spindle servo signal to the spindle motor 3.
Thus, the rotation, stop, and constant linear velocity (CLV) control of the spindle motor 3 during rotation are executed.

The reproduced RF signal is supplied to the decoder 24.
, And are subjected to D / A conversion (digital / analog conversion), and then output as a reproduction output.

As described above, the provision of the automatic alignment mechanism 15 allows the recording disk 1 to be rotated without vibration. Automatic alignment may not be performed even after reaching the rotation range. Although the cause is not clear, for example, the outer inner peripheral surface 16a of the moving space 16 and the balance sphere 1
The frictional resistance between 7, 17,... Is considered as one of the causes. Then, even in such a case, if the spindle motor 3 is once stopped and rotated again, the automatic alignment is performed. Alternatively, the number of revolutions of the spindle motor 3 is reduced to such an extent that the centrifugal force acting on the balance balls 17, 17,... Decreases and the balance balls 17, 17,. When the rotation speed of the motor 3 is increased to a predetermined rotation speed, automatic alignment is performed. Further, the rotation speed of the spindle motor 3 is set to a rotation speed outside the used rotation range, that is, once lower than the used rotation range or higher than the used rotation range, and then the rotation speed of the spindle motor 3 is changed. When the number of rotations is again set in the operating rotation range, automatic alignment is performed.

That is, when the self-alignment is not performed even if the rotation speed of the spindle motor 3 enters the working rotation range, the rotation speed of the spindle motor 3 is changed from the rotation speed in the working rotation range, and the balance ball 17 is rotated. , 17,... And the moving space 16, the spindle motor 3
By returning the rotation to the used rotation range, the automatic alignment is performed.

Therefore, in the present invention, when the automatic alignment is not performed, the spindle motor 3 is temporarily stopped and restarted, or the rotational speed of the spindle motor 3 is once decreased, and then the spindle motor 3 is again rotated. The number of revolutions of the motor 3 is increased to a predetermined number of revolutions, or the number of revolutions of the spindle motor 3 is set to be equal to or more than the number of revolutions in the use revolution range, and then reduced to the number of revolutions in the use revolution range. is there.

The fact that the automatic alignment is not performed means that the recording disk is rotating eccentrically, and therefore the objective lens 8 is largely deflected in the tracking direction to follow the recording track. The magnitude of the shake, that is, the amplitude is detected, and the spindle motor 3 is restarted.

That is, until the self-alignment is performed in accordance with the procedure shown in FIG.

First, in step S1, the spindle motor 3 is started.

Next, in step S2, it is determined whether or not the rotation of the spindle motor 3 has reached the use rotation range. If the rotation of the spindle motor 3 has reached the use rotation range, the process proceeds to step S3, where the use rotation When the rotation speed has not reached the range, it is determined again whether the rotation speed has reached the use rotation range.

In step S3, it is determined whether or not the amplitude of the objective lens 8 is equal to or less than a certain value. If the amplitude of the objective lens 8 is equal to or less than a certain value, step S4 is performed.
If the value is equal to or more than the predetermined value, the process proceeds to step S5.

If the amplitude of the objective lens 8 is equal to or less than a predetermined value, automatic alignment has been performed, and therefore, step S4
Performs a reproducing operation.

If the amplitude of the objective lens 8 is equal to or greater than a predetermined value, it means that automatic alignment has not been performed. Therefore, in step S5, the rotation of the spindle motor 3 is stopped or Is changed from the rotation speed in the operating rotation range.

In step S5, when the rotation of the spindle motor 3 is stopped, the spindle motor 3 is restarted (see the solid line in FIG. 8), and when the rotation speed of the spindle motor 3 is changed, The rotation speed is again adjusted to be within the used rotation range (see the broken line in FIG. 8).

As a method for detecting the magnitude of the shake of the objective lens 8, there is a method using a middle point error signal. Hereinafter, a method of utilizing the midpoint error signal will be described.

The optical pickup device 4 is constituted by using the light emitting / receiving element 26 and the objective lens 8.
The objective lens 8 condenses the light beam L emitted from the optical disk 1 on the signal recording surface of the recording disk 1.

The objective lens 8 is moved by the biaxial actuator 19 in the tracking direction TRK and the focus direction F.
It is movably supported along the CS. The tracking direction TRK is a plane perpendicular to the optical axis of the objective lens 8 and the tangent direction of the recording track formed on the signal recording surface of the recording disk 1, and the focus direction FCS
Is the optical axis direction of the objective lens 8.

As shown in FIGS. 9 and 10, the light receiving / emitting element 26 has a case 27. The case 27 is composed of a substrate 27a, four side plates 27b, 27b,. The window glass 27c is formed of, for example, a transparent glass plate.

A semiconductor substrate 28 is mounted on the substrate 27a. A semiconductor element 29 and a trapezoidal prism 30 are disposed on the semiconductor substrate 28.

On the semiconductor substrate 29, a front photodetector group PD1 and a rear photodetector group PD2 as photodetectors are formed side by side under the prism 30. Further, a laser diode chip 31 is provided on the semiconductor element 29.

The prism 30 has a slope 30a. The inclined surface 30a is formed to have an angle θ with respect to the bottom surface of the prism 30, and the angle θ is 4 °.
Preferably it is 5 degrees.

The slope 30a is located substantially opposite to the laser beam emitting portion 31a of the laser diode chip 31. On the semiconductor element 29, a light receiving section 29a for monitoring a laser beam is further formed. The monitoring light receiving section 29a is for receiving laser light emitted from the rear portion of the laser diode chip 31 and detecting the amount of laser light.

As shown in FIG. 11, a total reflection surface 30b is formed on the upper surface of the prism 30.

In the optical pickup device 4 configured as described above, the laser light L emitted from the laser diode chip 31 is reflected by the inclined surface 30a of the prism 30 and enters the objective lens 8, where The light is condensed and irradiated on the signal recording surface of the recording disk 1 by the lens 8.

The laser light L is reflected on the signal recording surface of the recording disk 1 while modulating the amount of reflected light according to the information signal recorded on the signal recording surface. The reflected light beam on the signal recording surface of the recording disk 1 reaches the inclined surface 30a of the prism 30 via the objective lens 8.

A part of the reflected light passes through the inclined surface 30 a of the prism 30 and enters the prism 30. Then, as shown in FIG. 11, a part of the reflected light beam that has entered the prism 30 passes through the bottom surface 30c of the prism 30, and enters the front photodetector group PD1.

Then, the remaining reflected light beam is
Is reflected at the bottom surface 30c of the
And is incident on the rear photodetector group PD2.

Therefore, based on the combination of the light detection signals from the photo detectors constituting the front photo detector group PD1 and the rear photo detector group PD2,
By performing the predetermined calculation, an error signal and a middle point error signal necessary for the focusing servo and the tracking servo can be obtained.

The above photodetector groups PD1, PD2
12, a plurality of photodetectors A, B, C, D and E, F, G, H arranged adjacent to each other in the radial direction (X direction) of the recording disk 1 with a boundary line therebetween as shown in FIG.
And a light receiving section 32 composed of

The front photo detector group PD1 and the rear photo detector group PD2 are separated from each other in the recording track direction (Y direction) of the recording disk 1 and are arranged at intervals.

In this optical pickup device 4,
The photodetectors A and B of the front photodetector group PD1 and the photodetectors G and H of the rear photodetector group PD2 serve as “first light receiving portions”, and the photodetectors C and D of the front photodetector group PD1 and the photodetectors E of the rear photodetector PD2,
F is the “second light receiving unit”.

The “first light receiving section” and the “second light receiving section” receive the light beam reflected by the signal recording surface of the recording disk 1 and receive the “first light receiving section” and the “second light receiving section”. The first light detection output and the second light detection output corresponding to the “light receiving unit” are output.

The output signals of the photodetectors C, D, E, and F constituting the "second light receiving portion" are added and amplified to obtain a signal α, and the photo detector constituting the "first light receiving portion" is obtained. A, B, G, and H are added and amplified to obtain a signal β.

These signals are subtracted from each other to obtain a signal (α
-Β), this signal (α-β) becomes a tracking error signal by the so-called push-pull method.

The tracking error signal in the push-pull system has an error that the DC offset changes due to the movement of the objective lens 8 by the two-axis actuator 19, that is, the lens shift.

That is, as shown in FIG. 14, the peak value of the RF envelope waveform of the tracking error signal in the push-pull method fluctuates according to the lens shift. “A” in FIG. 14 represents the width of the change of the peak of the RF envelope waveform of the tracking error signal. A
The signal is a signal obtained by passing the RF envelope waveform through a low-pass filter, and is used for a tracking servo operation in a push-pull system. b indicates a change in the DC offset of the A signal.

In order to cancel the DC offset due to the movement of the objective lens (lens shift), the offset b may be subtracted from the A signal as shown in FIG.

Here, a constant K such that b = Ka (K
If <1) is determined, the signal from which the DC offset has been canceled can be represented by ((A signal)-(Ka)). This signal ((A signal)-(Ka)) is used for tracking control.

As described above, when a tracking error signal is detected by a so-called one-beam push-pull method, it is necessary to correct a DC offset generated in the tracking error signal.

That is, a K-fold peak hold signal (K × peak hold) is generated for the signal α, and the signal α is subtracted from the peak hold signal. This signal is TPP
(Top Hold Push-Pull) α signal.

A K-fold peak hold signal (K × peak hold) is generated for the signal β, and the signal β is subtracted from the peak hold signal. This signal is TPP
(TopHold Push-PuLL) β signal.

Then, from the TPPα signal, the TPP
The signal obtained by subtracting the β signal is a TPP tracking error (T
RK-ER), and the TPP tracking error (TRK-ER) signal is a tracking error signal in which the DC offset has been corrected.

The middle point error signal is output from the TP
P tracking error signal and a tracking error signal including a DC offset (that is, a push-pull signal (α-
β) is subtracted.

That is, this midpoint error signal is represented by (α-β)-((K · α peak hold) -α)-
According to the notation according to FIG. 14 and FIG. 15 described above, (A signal) − ((A signal) − (K · a change) ))).

The above signal processing is performed by the RF amplifier / arithmetic unit 21.

Then, as shown in FIGS. 16 and 17,
When reproducing a recording disk with an eccentric center, the change in the midpoint error signal CE is a standard disk (yellow disk).
(FIG. 16 shows the case of reproducing an eccentric disk, and FIG. 17 shows the case of reproducing a standard disk).
When the change in the value exceeds a certain value, the spindle motor 3
Is stopped and restarted, or the rotation speed of the spindle motor 3 is reduced (the balance balls 17, 17,...).
The centrifugal force acting on the balance spheres 17, 1
7 are reduced to such a degree that the magnets are attracted to the magnet. ) And then increase the rotation speed again. Therefore, the middle point error signal CE is output from the system controller 2
5, the system controller 25 determines the necessity of restarting the spindle motor 3 or the like, and a control signal based on the determination is input from the system controller 25 to the servo processor 22. Servo processor 2
2 uses the control signal from the system controller 25 to generate the spindle servo signal, and outputs the generated spindle servo signal to the servo driver 23. The servo driver 23 outputs a spindle drive signal SPD based on the spindle servo signal to the spindle driver. Apply to the motor 3. Thus, rotation, stop, and the like of the spindle motor 3 are controlled.

In FIGS. 16 and 17, TE indicates a tracking error signal, and TELP indicates a tracking error signal passed through a low-pass filter.

In the above description, the method of judging the magnitude of the shake of the objective lens 8 based on the middle point error signal has been described.
A method of determining the magnitude of the shake of the objective lens 8 using the midpoint sensor will be described (see FIGS. 18 and 19).

The biaxial actuator 19 has a bobbin 33 supporting the objective lens 8, a focus coil 34 is wound around the bobbin 33, and the tracking coil 3
5, 35 are attached. The bobbin 33 is supported by a fixing portion 37 via a support member 36. Support member 3
Numeral 6 is formed integrally with a sheet metal material having spring elasticity, and integrally connects four support arms 38, 38, 39, 39 and fixed-side ends of these support arms 38, 38, 39, 39. The connected connection fixing portion 40 and the left support arms 38 and 39
The supporting portions 41 and 42 are respectively connected to the supporting end sides of the bobbin 33 and the supporting ends 38 and 39 of the right side, and the left side surface of the bobbin 33 is fixed to the supporting portion 41.
, The right side surface of the bobbin 33 is fixed. Then, the connection fixing section 40 is fixed to the fixing section 37, whereby the bobbin 33 is movably supported in the tracking direction TRK and the focus direction FCS.

The two-axis actuator 19 is provided with a magnet (not shown) for generating a magnetic field on the fixed side, so that when the focus coil 34 is energized, the bobbin 3
3 is moved in the focus direction FCS, and when the tracking coils 35 are energized, the bobbin 33 is moved in the tracking direction TRK.

An extension 43 is formed on the support end side of one support arm 39, an LED light emitting element 44 is disposed above the extension, and an extension 43 is provided below the extension 43. Is provided with a two-divided PD 45. The extension part 43, the LED light emitting element 44, and the two-part PD 45 constitute a midpoint sensor 46.

When the bobbin 33 (therefore, the objective lens 8 (laser light)) is at the neutral position (middle point position), the light emitted from the LED light emitting element 44, as shown in FIG. It is cut off by the outlet 43 and is divided into two PDs 4
No. 5 photodetectors 45a and 45b are not incident.

When the bobbin 33 moves from the center position in the tracking direction (left or right in FIG. 19), 2
Light from the LED element 44 enters one of the photo detectors 45a and 45b of the divided PD 45, and the output pd1 from the detection circuit 47a of the photo detector 45a and the output pd2 from the detection circuit 47b of the photo detector 45b.
Changes according to the movement amount and direction of the bobbin 33, and a signal corresponding to this displacement is output from the subtraction circuit 48.

The output of the subtraction circuit 48 is
And a deviation from the neutral point, which can be supplied to the system controller as the output of the midpoint sensor and used as information for controlling the spindle motor 3.

The midpoint sensor is not limited to the one described above, and any sensor can be used as long as it can detect the direction and amount of deviation of the objective lens 8 from the neutral point. I can do it. For example, a bobbin 33 supporting the objective lens 8 and a magnet having a magnet on one of the fixed side and a Hall element on the other may be used.

[0096]

As is apparent from the above description, the disk drive of the present invention rotates together with the turntable on which the recording disk is mounted, and has an annular cross section in the direction perpendicular to the rotation axis direction. A balance member formed of a moving space and a magnetic material and movably disposed in the moving space; and a magnet disposed at a central portion of the moving space and adsorbing the balance member, and adapted to rotate the moving space. Along with the rotation of the balance member, the balance member moves in the moving space, and is a member that rotates together with the moving space, such as a recording disk and a turntable (hereinafter, these rotating members are collectively referred to as a “composite rotating body”). A disk drive device having an automatic alignment mechanism for performing automatic alignment so that a center of gravity (synthetic center of gravity) is located on a rotation axis, wherein a rotation of a turntable is performed. When automatic alignment is not performed even if the rotation speed reaches the operating speed range, detection means for detecting that, and after changing the rotation of the turntable to a rotation speed other than the operating speed range including stop A rearrangement means for returning to the rotation speed in the operating rotation range is provided again, and when the rotation of the turntable reaches the operating rotation range, the rotation of the turntable is stopped when the self-alignment is not performed. It is characterized in that the number of rotations is changed to a number of rotations and then returned to the number of rotations in the used rotation range again.

Therefore, in the disk drive of the present invention, the automatic alignment is reliably performed.

Further, in the invention described in claim 2, the detecting means determines that automatic alignment has not been performed based on a signal obtained by arithmetically processing a signal for obtaining a tracking error signal. Therefore, it is only necessary to add software processing without adding a special member, and the apparatus can be constructed at low cost.

Further, according to the third aspect of the present invention, the detecting means determines that the automatic alignment has not been performed by detecting the physical position of the objective lens. Whether the automatic alignment has not been performed can be determined by directly detecting the vibration state of the objective lens.

The specific shape and structure of each part shown in each of the above embodiments are merely examples of the embodiment of the present invention, and the present invention is not limited thereto. Should not be construed as limiting the technical scope of the present invention.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a disk drive device of the present invention, and FIG. 1 is an overall perspective view.

FIG. 2 is a vertical sectional side view of a rotation drive unit.

FIG. 3 is a sectional view taken along the line III-III in FIG. 2;

FIG. 4 is a vertical sectional side view of a main part showing a state where self-alignment is performed.

FIG. 5 is a sectional view taken along line VV in FIG. 4;

FIG. 6 is a cross-sectional view showing a state where a recording disk having no eccentricity is being rotated and cut along the same portion as in FIG. 5;

FIG. 7 is a block diagram of a main part.

FIG. 8 is a flowchart.

FIG. 9 is a schematic diagram illustrating a configuration of an optical pickup device.

FIG. 10 is a side view showing a configuration of a main part of the optical pickup device.

FIG. 11 is a side view showing a prism.

FIG. 12 is a plan view illustrating a configuration of a photodetector.

FIG. 13 is a list showing types of signals output from the optical pickup device.

FIG. 14 shows a TPP (Top H) in an optical pickup device.
FIG. 4 is a waveform chart showing the operation principle of an old Push-Pull) circuit.

FIG. 15 shows a TPP (Top H) in an optical pickup device.
FIG. 3 is a block diagram showing the operation principle of an old Push-Pull) circuit.

FIG. 16 is a waveform diagram showing a tracking error signal and a midpoint error signal when the eccentric disk is rotated.

FIG. 17 is a waveform diagram showing a tracking error signal and a midpoint error signal when a standard disk (yellow disk) is rotated.

FIG. 18 is a perspective view of a biaxial actuator.

FIG. 19 is a block diagram illustrating a configuration of a midpoint sensor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Recording disk, 2 ... Disk drive device, 8 ... Objective lens, 9 ... Turntable, 15 ... Automatic alignment mechanism,
16: moving space, 17: balance ball (balance member), 18: magnet, 21, 22, 25 ... detecting means, 21: RF amplifier / arithmetic unit, 22: servo processor, 25: system controller, 22, 23, 25 …
Rearrangement means, 23: servo driver, 25, 46, 47
a, 47b, 48 ... detecting means, 46 ... midpoint sensor, 47
a: detection circuit, 47b: detection circuit, 48: subtraction circuit

Claims (3)

[Claims] 1. A moving space which is formed of a magnetic material and a moving space which has an annular cross section in a direction perpendicular to the rotation axis direction while being rotated together with a turntable on which a recording disk is mounted, and is movably disposed in the moving space. A balance member and a magnet arranged in the center of the moving space and adsorbing the balance member are provided, and the balance member is rotated with the rotation of the moving space and moves in the moving space,
A self-aligning center such that a center of gravity (synthetic center of gravity) of a member that rotates together with the moving space such as a recording disk and a turntable (hereinafter, these rotating members are collectively referred to as a “synthetic rotator”) is positioned on the rotation axis. A disk drive device provided with an automatic alignment mechanism for performing automatic alignment, wherein when the rotation speed of the turntable reaches the used rotation range, automatic alignment is not performed, A rearrangement means for changing the rotation of the turntable to a rotation speed other than the used rotation range including stop, and then returning the rotation speed to the rotation speed of the used rotation range again, even if the rotation speed of the turntable reaches the used rotation range. A disk drive characterized in that when the automatic alignment is not performed, the rotation of the turntable is changed to a rotation speed other than the used rotation range including the stop, and then returned to the rotation speed of the used rotation range again. Location. 2. The apparatus according to claim 1, wherein said detecting means determines that automatic alignment has not been performed, based on a signal obtained by arithmetically processing a signal for obtaining a tracking error signal. Disk drive device. 3. The disk drive device according to claim 1, wherein the detecting means determines that automatic alignment has not been performed by detecting a physical position of the objective lens.