JP2001216716A - Disk player - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively reduce the wobbling of surface of a disk even when large bending is generated in the disk in a disk player equipped with a turntable 2 to be rotated by a spindle motor 3, a chucking mechanism 8 for chucking a disk 1 on the turntable 2, and a microcomputer 5 for controlling the operations of the spindle motor 3 and the chucking mechanism 8. SOLUTION: A microcomputer 5 detects the generating position of the maximum amplitude generated in a disk 1 on a turntable 2, and calculates the relative deviation of angle between the detected maximum amplitude generating position and the maximum amplitude generating position of the turntable 2 itself. Then, the turntable 2 is rotated only at the angle of rotation corresponding to the calculated deviation of angle in a state that the chuck of the disk 1 is released, and then the chuck of the disk 1 is operated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk player provided with an optical pickup for optically reproducing a signal from a disk, and more particularly, to a disk player capable of effectively suppressing surface runout due to rotation of the disk. It is about.

[0002]

2. Description of the Related Art As shown in FIG.
A turntable (2) rotated by a spindle motor (3), and a disk is mounted on the turntable (2);
(1) is installed and rotated at a high speed, and a signal is reproduced from the disc (1) by an optical pickup (4).

In a disc player, a disc
Focusing for controlling the drive voltage of the focus coil mounted on the optical pickup (4) in order to focus the optical pickup (4) on the signal surface of the disc (1) when reproducing the signal from (1) The servo is executed. Therefore, the disk (1) is slightly warped,
Even if the distance between the optical pickup (4) and the signal surface of the disk (1) changes with the rotation of the disk (1),
The focus of the optical pickup (4) always matches the signal surface of the disk (1), and the signal can be reproduced.

[0004]

However, when the warpage of the disk (1) increases, the optical pickup (4)
The angle of inclination of the disk (1) with respect to the optical pickup (1) becomes large, the accuracy of signal reading by the optical pickup (4) deteriorates, and the reproduction of signals becomes difficult. In particular, turntables
(2) In some cases, run-out due to assembly errors or molding errors may occur.
(2) The surface runout component of the disk (1) itself is added to the surface runout component of the disk (1) itself, and the disk (1) on the turntable (2) is added.
In this case, a large surface runout occurs, and as a result, there is a problem that the signal cannot be reproduced.

An object of the present invention is to provide a disk player capable of effectively suppressing the disk runout even when the disk has a large warp.

[0006]

Therefore, in the disk player of the present invention, when the disk (1) is set on the turntable (2), the relative position of the disk (1) with respect to the turntable (2) is increased. By adjusting the rotation angle attitude, the run-out occurring on the disk (1) is offset by the run-out occurring on the turntable (2).

A disc player according to the present invention is a turntable that is driven to rotate by a spindle motor (3).
(2), a chucking mechanism (8) for chucking the disc (1) on the turntable (2), and an optical pickup for reproducing a signal from the rotating disc (1)
(4) a servo circuit (53) for controlling focusing by controlling a focusing drive voltage for the optical pickup (4); a spindle motor (3) and a chucking mechanism
And a control circuit for controlling the operation of (8). Here, the control circuit comprises: a first control means for starting the drive of the turntable (2) after chucking the disk (1) on the turntable (2) by the chucking mechanism (8); ) Detecting means for detecting the position of the maximum amplitude occurring on the disk (1), and the relative angle between the detected position of the maximum amplitude and the position of the maximum amplitude of the turntable (2) itself. Calculating means for calculating the deviation of
The chuck of the disk (1) by the chucking mechanism (8) is released, and the turntable (2) is driven by a rotation angle corresponding to the calculated angle shift, thereby turning the turntable.
(2) After rotating the turntable (2) to a position where the runout of the disc itself and the runout of the disc (1) cancel each other, chucking of the disc (1) by the chucking mechanism (8). And second control means for performing the following.

In the disk player according to the present invention, the maximum amplitude position in the negative direction of the surface deflection generated on the turntable (2) coincides with the maximum amplitude position in the positive direction of the surface deflection generated on the disk (1). Alternatively, the maximum amplitude position in the positive direction of the runout occurring on the turntable (2) and the disk (1)
The relative rotation angle posture of the disc (1) with respect to the turntable (2) is adjusted so that the maximum amplitude position of the surface runout occurring in the negative direction coincides with the maximum amplitude position. At this time, turntable
(2) The runout of the disk (1) on the disk (1) includes the runout component of the turntable (2) itself, and the magnitude of the runout component is equal to the runout component of the disc (1) itself. Smaller than, for example, a fraction of the size,
The surface deflection of the disk (1) itself can be approximated by the surface deflection of the disk (1) on the turntable (2).

Therefore, in the disk player according to the present invention, the position where the maximum amplitude occurs on the disk (1) on the turntable (2) is detected, and the maximum amplitude generation position and the position of the turntable (2) itself are detected. The rotation angle attitude of the disk (1) on the turntable (2) is adjusted by the relative angle deviation from the maximum amplitude generation position. In adjusting the rotation angle and attitude of the disk (1), the chuck of the disk (1) by the chucking mechanism (8) is once released, and the turntable is shifted by the relative angle.
(2) is driven. As a result, only the turntable (2) rotates, and the relative rotation angle between the turntable (2) and the disk (1) is adjusted.

The position where the maximum amplitude of the disk (1) occurs is detected by rotating the turntable (2) on which the disk (1) is installed, and detecting a change in the focusing drive voltage by the servo circuit (53). It can be detected as a position where the drive voltage has a maximum value or a minimum value.

In order to calculate a relative angle shift between the maximum amplitude generating position of the disk (1) and the maximum amplitude generating position of the turntable (2), the turntable (2) includes a turntable. The first sign is attached to the position where the table (2) generates the maximum displacement in either one of the positive and negative directions due to the surface deflection, and the second sign is placed on one side of the turntable (2) along the circumference.
Attach signs at regular intervals. Further, a first sensor for detecting the first sign and a second sensor for detecting the second sign are provided facing the turntable (2). Then, between the time when the first sensor detects the first sign and the time when the maximum displacement of the disc (1) in the direction opposite to the direction of the maximum displacement of the turntable (2) occurs, the second sensor Counts the number of times that the second marker is detected, and calculates the deviation of the angle based on the count value.

The detection of the maximum amplitude generation position, the calculation of the angle deviation, and the adjustment of the surface deflection are not executed for all the disks, but are performed for the disk (1) on the turntable (2). It is determined whether or not the maximum amplitude that occurs in a predetermined amplitude exceeds a predetermined threshold, and only when it is determined that the maximum amplitude is exceeded, if an acceptable small surface runout occurs, These operations are omitted, and it is possible to quickly shift to the reproducing operation.

[0013]

According to the disk player of the present invention, even when the disk is greatly warped, it is possible to effectively suppress the surface runout of the disk and reproduce the disk.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. As shown in FIG. 1, a disc player according to the present invention
A turntable (2) driven by (3) is provided. A disc (1) is set on the turntable (2) and rotated at high speed, and an optical pickup is taken from the disc (1).
The signal is reproduced by (4).

The focus coil voltage (focusing drive voltage) VF of the optical pickup (4) is converted to a binarizing circuit (5).
The binarized focus coil voltage signal VFD is supplied to the microcomputer (5) and supplied to the microcomputer (5). Further, the focus coil voltage VF of the optical pickup (4) is supplied to a servo circuit (53) to execute a focusing servo for the optical pickup (4).

As shown in FIG. 2, on the back surface of the turntable (2), the maximum amplitude generation position (rotation angle posture θ _H ) in the positive direction detected by rotating the turntable (2) in advance is set to 1
The first reflectors (6) are attached, and a plurality of second reflectors are provided on a circumferential line outside the first reflectors (6).
(61) are attached at equal intervals. Further, a first photo sensor (41) for detecting the first reflector (6) and a second photo sensor for detecting the second reflector (61) are opposed to the back surface of the turntable (2). A sensor (42) is provided. As shown in FIG. 1, a detection signal VPA of the first photosensor (41) and a detection signal VPB of the second photosensor (42) are provided.
Are supplied to the microcomputer (5).

The microcomputer (5) includes a motor driver (52) for supplying a drive current to the spindle motor (3).
And a control signal to the chucking mechanism (8) for performing the chucking operation of the disc (1) on the turntable (2) and the chucking release operation.

FIG. 3A shows a detection signal VPB of the second photosensor (42), and a plurality of pulses are generated at a constant period as the turntable (2) rotates.
FIG. 3B shows the detection signal V of the first photo sensor (41).
PA is generated, and one pulse is generated each time the maximum amplitude generation position (rotation angle posture θ _H ) of the turntable (2) in the positive direction faces the first photosensor (41).

FIG. 3 (c) shows a change in the focus coil voltage VF obtained from the optical pickup (4), which coincides with the rotation cycle of the disk (1) as the disk (1) fluctuates. A voltage that changes in a sine wave shape is generated at a predetermined cycle. Here, the negative peak position (rotational angle posture θ _L ) of the voltage waveform is determined by the disc on the turntable (2).
This corresponds to the maximum amplitude generation position in the negative direction of (1). The binarization circuit (51) binarizes the focus voltage VF obtained from the optical pickup (4) with a predetermined threshold value, as shown in FIG.
A binarized focus voltage signal VFD that changes in a pulse shape as shown in FIG.

When a reproduction command is issued by the user, the microcomputer (5) operates the first photo sensor (4).
1) First detection signal VPA, second photo sensor (42)
4 and 5 based on the second detection signal VPB, the focus coil voltage VF of the optical pickup (4), and the binarized focus voltage signal VFD.

First, in the initial setting of step S1 in FIG. 4, the number of pulses of the second detection signal VPB obtained by one rotation of the turntable is set to N (see FIG. 3A). Next, in step S2, it is determined whether or not a disc has been mounted on the turntable. If the determination is affirmative, the process proceeds to step S3 to start rotation of the turntable. Turn on the focusing servo of the optical pickup.

Subsequently, in step S5, the focus coil voltage VF obtained with the rotation of the disk is measured.
The measured value is detected as a disk runout amount. The focus coil voltage has a minimum value when the disk is closest to the optical pickup due to the surface deflection, and has a maximum value when the disk is farthest from the optical pickup.

Next, in step S6, it is determined whether or not the maximum amplitude of the focus coil voltage VF exceeds a predetermined threshold value VF0. If the determination is NO, the disk runout is within an allowable value. Then, the mode shifts to the playback mode.
On the other hand, if the determination is yes, step S7
Then, the binarization circuit (51) starts binarizing the focus coil voltage to obtain a binarized focus coil voltage signal VDF.

In step S8, it is determined whether or not a pulse (VPA pulse; see FIG. 3 (b)) has occurred in the first detection signal VPA. 2 Pulse included in the detection signal (VPB pulse)
Is started, and the count value is set to NC. Next, in step S10, the binarized focus coil voltage VDF
It is determined whether or not a falling edge (see FIG. 3D) has occurred in the pulse on the negative side, and if the determination is NO, the process returns to step S9 to repeat the counting of the VPB pulse. In contrast,
If the determination is yes, the process proceeds to step S10 ', where the count value NC at that time is set to the falling count value NL.
(See FIG. 3D).

Subsequently, the process proceeds to step S11 in FIG.
The counting of the VPB pulse is continued, and the count value is set to NC. Thereafter, in step S12, it is determined whether or not a rise (see FIG. 3D) has occurred in the negative pulse of the binarized focus coil voltage VDF, and if the determination is no, the process returns to step S11. To repeat the counting of the VPB pulse. On the other hand, when the determination is YES, the process proceeds to step S13, and the count value NC at that time is set as the rising count value NH (see FIG. 3D). Then, in step S14, the average value (NL + NH) / 2 of the falling count value NL and the rising count value NH is calculated, and the result is set as the angular deviation count value Np (see FIG. 3A).
Therefore, the angular offset count Np is, would represent the maximum amplitude position theta _H positive direction of the turntable, the deviation of the rotational angle between the maximum amplitude position theta _L in the negative direction of the disc.

Thereafter, in step S15, it is determined whether or not the angle deviation count value Np is 0. If the determination is YES, the process shifts to the reproduction mode. On the other hand, if the determination is no, the rotation of the turntable is stopped in step S16, the chucking of the disc is released in step S17, and the rotation of the turntable is started in step S18. As a result, only the turntable rotates. Then, in step S19, counting of the VPB pulse is started, and the count value is set to NC2. The count value NC2 indicates a rotation angle when only the turntable is rotated while the disk is stationary.

Next, at step S20, the count value NC
It is determined whether or not 2 is equal to the value of (N-Np). If the determination is no, the process returns to step S19 to repeat the counting of the VPB pulse. Here, the value of (N-Np) is the positive direction of the maximum amplitude position theta _H of turntable by rotation of the turntable, required to reach a negative maximum amplitude position theta _L of the disk at rest It represents a large rotation angle. Therefore, when the determination is YES in step S20, the rotation of the turntable is stopped in step S21. As a result, the maximum amplitude position theta _H positive direction of the turntable, and the maximum amplitude position theta _L in the negative direction of the disc, will be matched with each other. Then, step S2
In step 2, the disc is chucked, and the rotation of the turntable is started in step S23.

In the above procedure, step S6
The maximum amplitude of the focus coil voltage VF is a predetermined threshold value.
When it is determined that VF0 has not been exceeded, step S7 and subsequent steps are performed.
The procedure for skipping the step is skipped, and the mode shifts to playback mode.
If the disk run-out is acceptable, start playback immediately.
Rukoto can. If the runout exceeds the allowable value,
By the procedure after step S7, the turntable
Maximum amplitude position θ in the positive direction_HAnd the maximum swing of the disc in the negative direction
Width position θ _LOn the turntable so that
The rotation angle attitude of the disc with respect to
The runout of the disk itself is caused by the runout of the turntable itself.
And the runout of the disc on the turntable is effective.
This will eventually be suppressed.

FIGS. 6 (a), 6 (b) and 6 (c) show actual operations of the disc player for realizing the procedures of FIGS. As shown in FIGS. 6 (a), 6 (b) and 6 (c), a tray (7) for installing a disk (1) is supported on the front part of the apparatus main body so as to be reciprocally movable, and the inner side of the apparatus main body. The unit is provided with a chucking mechanism (8).
In the chucking mechanism (8), the mechanism chassis (8
0) is supported so that it can be raised and lowered, and the mechanism chassis (8
0), a turntable (2) rotationally driven by a spindle motor (3) and an optical pickup (4) reciprocally driven along a radial line of the disk (1) are provided. A pulley holding plate (81) is fixed to an upper portion of the apparatus main body, and a chucking pulley (9) is rotatably supported by the pulley holding plate (81).

As shown in FIG. 6 (a), the mechanism chassis (80) is lowered and the turntable (2) is pulled out of the main body of the apparatus, and the disk (1) is placed on the turntable (2). When a loading start command is issued,
As shown in FIG. 2B, the tray (7) is pulled into the inside of the apparatus main body, and the disc (1) is set between the turntable (2) and the chucking pulley (9). Subsequently, the mechanism chassis (80) is moved up, whereby the disc (1) is turned into the turntable (2) and the chucking pulley (9) as shown in FIG.
Chucked between. In this state, the spindle motor
The disk (1) rotates at a high speed by starting the (3) and driving the turntable (2). The optical pickup (4) reciprocates along the radius line of the rotating disc (1) and reproduces signals from the disc (1).

In the procedure for adjusting the runout according to the present invention, first, the chucking of the disc (1) is performed in the order of (a) → (b) → (c) in FIG. ) Is rotated to measure the focus coil voltage of the optical pickup (4), whereby the amount of surface deflection of the disk (1) is measured (steps S1 to S5 in FIG. 4). Then, in a state in which once releasing the chucking of the disc (1) as shown in FIG. 6 (b), by rotating the turntable (2), the positive direction of the maximum amplitude position theta _H and the disc of the turntable (2)
After matching the negative maximum amplitude position θ _L of (1) with each other (steps S7 to S21), the disk (1) is chucked again as shown in FIG. 6B (steps S22 and S21).
23) Then, it shifts to the reproduction mode.

The configuration of each part of the present invention is not limited to the above embodiment, and various modifications can be made within the technical scope described in the claims. For example, the configuration for detecting the maximum amplitude generation position of the turntable (2) and the rotation angle of the disk (1) is not limited to the combination of the reflection plate and the photosensor, and various known configurations may be employed. I can do it.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a disc player according to the present invention.

FIG. 2 is a perspective view showing a plurality of reflectors attached to the back surface of a turntable, and a pair of photo sensors arranged to face the back surface.

FIG. 3 is a time chart for explaining signal processing in the present invention.

FIG. 4 is a flowchart illustrating a first half of a surface runout adjustment procedure according to the present invention.

FIG. 5 is a flowchart showing the latter half of the procedure.

FIG. 6 is a cross-sectional view illustrating an operation of a chucking mechanism in surface deflection adjustment.

[Explanation of symbols]

 (1) Disc (2) Turntable Spindle motor Optical pickup (41) First photo sensor (42) Second photo sensor (6) First reflector (61) Second reflector (7) Tray (8) King mechanism (9) Chucking pulley

Claims (4)

[Claims] 1. A turntable (2) rotationally driven by a spindle motor (3), and a chucking mechanism for chucking a disk (1) on the turntable (2).
(8) A disc comprising an optical pickup (4) for reproducing signals from a rotating disc (1), and a control circuit for controlling the operations of a spindle motor (3) and a chucking mechanism (8). In the player, the control circuit comprises: first control means for starting driving of the turntable (2) after chucking the disc (1) on the turntable (2) by the chucking mechanism (8); 2) detecting means for detecting a position where the maximum amplitude occurs on the disk (1) on the upper surface;
(2) calculating means for calculating a relative angle shift between itself and the maximum amplitude generation position; and releasing the chuck of the disc (1) by the chucking mechanism (8), and calculating the angle shift. The turntable (2) is driven by the rotation angle corresponding to
After rotating the turntable (2) to a position where the runout of (2) and the runout of the disc (1) are offset,
A disc player comprising: a second control means for chucking the disc (1) by a chucking mechanism (8). 2. A servo circuit (53) for controlling a focusing drive voltage for an optical pickup (4) to perform focus adjustment, wherein a detecting means of the control circuit includes a turntable (1) on which a disk (1) is installed. 2. The disk player according to claim 1, wherein 2) is rotated to detect a change in the focusing drive voltage by the servo circuit (53), and a position where the maximum amplitude occurs on the disk (1) is detected based on the detection. . 3. A first marker mounted at a position where the turntable (2) generates a maximum displacement in one direction in either positive or negative direction due to surface runout, and an equal interval along a circumferential line on one surface of the turntable (2). A plurality of second markers attached to the vehicle, a first sensor for detecting the first marker, and a second sensor for detecting the second marker.
Between the time when the sensor detects the first sign and the time when the maximum displacement of the disc (1) in the direction opposite to the direction of the maximum displacement of the turntable (2) is generated, the second sensor is connected to the second sign. 3. The disc player according to claim 2, wherein the angle deviation is calculated by counting the number of times of detecting the angle. 4. The control circuit further comprises a judging means for judging whether or not a maximum amplitude generated on the disk (1) on the turntable (2) exceeds a predetermined threshold value. 4. The disc player according to claim 1, wherein the detection of the maximum amplitude occurrence position, the calculation of the angle shift, and the adjustment of the surface deflection are performed only when the determination is made.