JP2000105965A - Optical disc playback device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress vibration/noises by controlling a reproducing speed according to the amount of disk mass eccentricity in an optical disk reproducing device. SOLUTION: This optical disk reproducing device is provided with a mechanism section having a mechanism to rotate an optical disk 1 and feed an optical pickup in the radial direction of the optical disk 1, a driving means for driving the mechanism section, a vibration quantity detecting means 7 for detecting the vibration quantity of the mechanism section, and a control unit 8 for receiving a signal from the vibration quantity detecting means 7 and controlling the driving means. When a vibration quantity from the vibration quantity detecting means 7 exceeds a predetermined value, the control unit 8 controls the driving means 6 to reduce the rotational speed of the optical disk 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk reproducing apparatus, and more particularly to an optical disk reproducing apparatus that controls the number of rotations of a disk by the amount of vibration of a mechanism.

[0002]

2. Description of the Related Art An optical disk reproducing apparatus, in particular, a CD-ROM
2. Description of the Related Art In recent years, a reproducing apparatus has been actively developed for high-speed reproduction. For high-speed reproduction, a disk recorded by a constant linear velocity (CLV) method is reproduced by a constant disk speed (CAV) method. Has become mainstream. At present, CAV reproduction at a rotation speed of 14 times at the innermost circumference (usually referred to as 32x speed reproduction because the reproduction is 32 times at the outermost circumference) is fixed.

[0003] When the disk rotation speed is increased as described above, the center of gravity of the disk is shifted from the center due to a label sticker or the like on the disk or the printing state of the disk label. As described above, when a disc whose center of gravity is shifted from the center of the disc (hereinafter referred to as an eccentric disc) is reproduced, the vibration of the disc and the mechanism for reproducing the disc is caused by the centrifugal force of the rotating disc. It becomes intense. The vibration of the mechanism itself or the transmission of the vibration inside the reproducing apparatus causes a problem that the mechanical noise becomes intense, or the servo of the focus or tracking is deviated at the worst, so that the disk cannot be reproduced. This vibration becomes more intense as the amount of eccentricity of the disk is larger and as the disk is played back at high speed.

[0004] A CD-ROM reproducing apparatus is generally configured to be able to reproduce at a plurality of double speeds. For example, in the case of a playback device of 32 × speed, in addition to 32 × speed (14 × inner circumference),
Playback can be performed at a playback speed of 24 × (inner circumference 10 ×) or 16 × (inner circumference 8 ×). Usually, the user can specify this playback speed through the host computer. Therefore, when reproducing an eccentric disc, if the user slows down the reproduction speed in accordance with the eccentric amount of the disc, vibration and noise can be suppressed. However, at present, the user does not specify the playback speed for the CD-ROM playback device.

[0005]

As described above, when the eccentric disk is reproduced at a high speed, noise is generated due to the vibration of the mechanism. However, it is necessary to suppress this noise so as not to exceed a predetermined value. is there.

It is an object of the present invention to provide an optical disk reproducing apparatus in which the reproducing speed is adjusted in accordance with the amount of eccentricity of the disk to suppress vibration and noise even when the reproducing speed is not set by the user.

[0007]

In order to achieve the object of the present invention, an apparatus for reproducing an optical disk according to the present invention comprises a mechanism having a mechanism for rotating an optical disk and feeding an optical pickup in a radial direction of the optical disk. A driving unit that drives the mechanism unit, a vibration amount detection unit that detects a vibration amount of the mechanism unit, and a control unit that receives a signal from the vibration amount detection unit and controls the driving unit. The control unit controls the driving unit to reduce the rotation speed of the optical disk when the vibration amount from the vibration amount detecting unit exceeds a predetermined value. In this optical disk reproducing apparatus, a rotation number detecting means is provided, and a signal from the rotation number detecting means is supplied to the control unit.

In this optical disk reproducing apparatus,
The vibration amount detecting means is an error signal detecting means for detecting a focus error signal. In this optical disc reproducing apparatus, the focus error signal is smoothed, and when the smoothed value exceeds a predetermined value, the driving means is controlled to reduce the rotation speed of the optical disc. Further, in this optical disc reproducing apparatus, the control unit includes A
A / D converter, converts the focus error signal obtained from the error signal detection means into a digital value by the A / D converter, and counts that the digital value exceeds a predetermined value, When the count number per unit time exceeds a predetermined value, the driving unit is controlled so as to reduce the rotation speed of the optical disk.

In this optical disk reproducing apparatus, the vibration amount detecting means is an error signal detecting means for detecting a tracking error signal. In this optical disc reproducing apparatus,
The tracking error signal is smoothed, and when the smoothed value exceeds a predetermined value, the driving means is controlled to reduce the rotation speed of the optical disk. Further, in this optical disc reproducing apparatus, the control unit includes A
A / D converter, converts the tracking error signal obtained from the error signal detecting means into a digital value by the A / D converter, and counts that the digital value has exceeded a predetermined value. When the count number per unit time exceeds a predetermined value, the driving unit is controlled so as to reduce the rotation speed of the optical disk.

[0010] The optical disk reproducing apparatus according to the present invention comprises a mechanism provided with a mechanism for rotating the optical disk and feeding the optical pickup in a radial direction of the optical disk;
A driving unit that drives the mechanism unit, a vibration amount detection unit that detects a vibration amount of the mechanism unit, a rotation number detection unit that detects a rotation number of the optical disc, and a signal from the rotation number detection unit are supplied. A control unit that controls the driving unit so that the number of rotations of the optical disc becomes a predetermined plurality of rotation speeds, wherein the control unit controls the driving unit so that the vibration amount supplied from the vibration amount detecting unit is predetermined. When the value exceeds the value, the driving unit is controlled to control the rotation speed of the optical disc to a lower rotation speed among the predetermined rotation speeds. In this optical disk reproducing apparatus, the vibration amount detecting means is an error signal detecting means for detecting a focus error signal. Further, in this optical disk reproducing apparatus, the vibration amount detecting means is an error signal detecting means for detecting a tracking error signal.

An optical disk reproducing apparatus according to the present invention comprises: a mechanism for rotating an optical disk to feed an optical pickup in a radial direction of the optical disk; a driving unit for driving the mechanism;
Control means for controlling the drive unit, a rotation number detection means for detecting the rotation number of the disk, and a vibration amount detection means for detecting the vibration amount of the mechanism unit, the rotation number signal from the rotation number detection means From the vibration amount signal from the vibration amount detecting means, the rotation speed of the disk is controlled so that the vibration amount does not exceed a predetermined value. In this optical disk reproducing apparatus, the vibration amount detecting means is means for detecting a focus drive signal or a focus error signal. In this optical disk reproducing apparatus, the vibration amount detecting means is means for detecting a tracking drive signal or a tracking error signal.

Further, in order to achieve the above object, in the present invention, the amount of vibration of a mechanism for reproducing a disk is detected, and the rotational speed of the disk is controlled so that the amount of vibration does not exceed a predetermined amount. I made it.

[0013]

FIG. 1 is a block diagram showing an embodiment of an optical disk reproducing apparatus according to the present invention. In the figure, 1 is an optical disk, 2 is a disk motor for rotating the disk, 3 is an optical pickup, 4 is an optical pickup 3
Motor for sliding the disk 1 in the radial direction of the disk 1, driving means for driving the disk motor 2 and the slide motor 4; rotation speed detecting means 6 for detecting the rotation speed of the disk; Detecting means 8 for detecting the amount is a control means constituted by, for example, a microcomputer, and inputs the number of rotations of the disk from the rotation detecting means 6 and the vibration amount from the vibration amount detecting means 7 to control the driving means 5. . The mechanism unit 9 includes the disk motor 2, the pickup 3, the slide motor 4, a slider (not shown), and the like.

Next, the operation of the embodiment shown in FIG. 1 will be described. Now, an example in which the playback apparatus that plays back the optical disc 1 in the CAV method is a 32 × speed (14 × inner circumference) optical disc playback apparatus will be described. This disc reproducing apparatus has 24x speed (inner circumference 10x speed) and 16x speed in addition to 32x speed.
It has a reproduction speed of double speed (8 times the inner circumference). The rotation speeds of 32x, 24x, and 16x disks are generally 7000 rpm, 5000 rpm, and 4000 rpm.
It is. When CAV reproduction is performed at 7000 rpm, when the disc 1 is loaded, the control unit 8 starts the acceleration of the rotation of the disc 1 to the target 7000 rpm via the drive unit 5. The control unit 8 checks the rotation speed from the rotation speed detection means 6 and, when the rotation speed reaches 7000 rpm,
The CAV control is performed so as to rotate at a constant speed at 00 rpm. At this time, when the amount of eccentricity of the disk to be reproduced is small, the vibration level obtained from the vibration amount detecting means 7 remains small even if the rotational speed is 7000 rpm, but when the amount of eccentricity is large, the rotational speed is small. , The vibration level obtained from the vibration amount detection means 7 gradually increases.

FIGS. 2A and 2B are characteristic diagrams for explaining an optical disk reproducing apparatus according to the present invention. FIG.
2A and 2B, the horizontal axis represents the time t from when the disk is stopped, the vertical axis in FIG. 2A represents the rotation speed N of the optical disk, and the vertical axis in FIG. The axis indicates the vibration level V. As the vibration level, noise is not intense, and an allowable level is shown as an allowable vibration level V1. At time t ₁ during acceleration to the target rotational speed of 7000 rpm, the vibration amount of the disk 1 or the mechanism 9 for reproducing the disk from the vibration amount detecting means 7 exceeds the allowable level V 1,
The disk rotation speed at this time is 50 as shown in FIG.
It is assumed that it is between 00 rpm and 7000 rpm.

In this case, since a signal indicating that the vibration has exceeded the allowable level V1 is supplied from the vibration amount detecting means 7 to the control unit 8, the control unit 8 sets the CAV target rotational speed to 7000.
The speed is changed from 5000 rpm to 5000 rpm, and the number of rotations of the disk is reduced to 5000 rpm via the driving means 5. As a result, as shown in FIG. 2B, the vibration level can be reduced to the allowable level V1 or less after t1. Similarly, 700
50 rpm from 4000 rpm while accelerating to 0 rpm
When the vibration amount exceeds the allowable level V1 during the period of 00 rpm, the control unit 8 receives a signal from the vibration amount detection unit 8.
Changes the target rotation speed of the CAV to 4000 rpm. The driving means 5 controls the disk motor 2 in accordance with the control signal from the control unit 8 to increase the number of rotations of the disk to 4000 r.
pm, the vibration level falls below the permissible level V1 as shown in FIG.

FIG. 3 is a flowchart showing one embodiment of the processing contents of the control unit of the embodiment shown in FIG. In the embodiment shown in FIG. 1, when the optical disk 1 is loaded, acceleration of the disk 1 is started as shown in step 101.
In step 102, the rotational speed of the disk 1 is set to the target 700
It is determined whether 0 rpm or more has been reached. 7000 rp
Until m is reached, as shown in step 103, it is determined whether the vibration amount obtained from the vibration amount detecting means 7 is equal to or lower than the allowable level V1. As long as the rotation speed is equal to or lower than the allowable level V1, the process returns to step 102, and the rotation speed is continuously increased so that the rotation speed becomes equal to or higher than 7000 rpm. If the vibration level exceeds the allowable level V1 in step 103, and if the disk rotation speed at that time is 5000 rpm or more as shown in step 104, 5000 rpm is set to C in step 106.
If the target speed for AV control is 5000 rpm or less,
As shown in step 107, 4000 rpm is CAV
Let it be the target rotation speed for control. If the vibration amount reaches the target 7000 rpm without exceeding the allowable level V1, that is, if the answer is yes (Y) in step 102, the process proceeds to step 105, and the 7000 rpm is CAV as it is.
Let it be the target rotation speed for control. After the target rotation speed is determined, the routine proceeds to step 108, where CAV control is started.

In the above description of the flowchart, it is monitored whether or not the vibration level exceeds the allowable level V1 while increasing the rotation number of the optical disk 1. If the vibration level exceeds the allowable level V1, the current rotation number is checked. CAV control is performed by setting the target rotation speed to a lower rotation speed, but once the rotation speed is increased to the target 7000 rpm,
Therefore, it is determined whether or not the vibration level exceeds the allowable level V1, and if not, C is set to 7000 rpm.
Perform AV control. If the allowable level V1 is exceeded, the rotational speed may be reduced until the allowable level V1 is not exceeded, a lower rotational speed may be set as the target rotational speed, and CAV control may be performed on this rotational speed.

In this embodiment, attention has been paid to the amount of vibration, that is, the vibration level. However, noise is generated by the vibration, and the user is more concerned about the noise than the vibration itself. Focusing on the noise level, even if the vibration level is high, the noise level is not always high, and for users who are concerned about noise, if the vibration level is high and the noise level is low, it is necessary to reduce the number of rotations of the disk There is no. The vibration of the mechanism section 9 can be divided into a horizontal vibration and a vertical vibration with respect to the optical disc reproducing apparatus. However, the horizontal vibration does not generate much noise and the vertical vibration does not generate much noise. In an optical disc reproducing apparatus that generates noise with respect to vibration, vertical vibration becomes a problem, and therefore, it is sufficient to detect this vertical vibration. Also, an optical disc reproducing apparatus that does not generate much noise with respect to vertical vibration and generates noise with respect to horizontal vibration may detect horizontal vibration.
As described above, if the vibration in the direction in which the noise is generated can be detected, the rotation speed of the disk 1 can be controlled so as not to exceed the predetermined noise. Disappears.

In order to detect noise caused by vibration, a microphone is provided in the vicinity of the mechanism section 9, and the control section 8 receives an electrical signal corresponding to the volume from the microphone.
Can be controlled. However, a microphone must be installed in the optical disc playback device,
There is a disadvantage that the cost is high.

The present inventors have discovered that when the centrifugal force during rotation of the disk is not uniform due to the eccentricity of the optical disk, the focus error signal changes depending on the magnitude of the eccentricity. That is, the focus error signal is
If the vertical vibration of the optical disk player increases,
It has been found that the amplitude of the focus error signal of the focus servo increases. As the focus error signal increases, the focus drive signal also increases. Therefore, FIG.
The focus error signal (hereinafter, simply referred to as the focus error signal including the focus drive signal) is used as the vibration amount detection means 7 of the embodiment of the present invention described with reference to FIG. When used as a detecting means, noise generated by vibration can be detected more effectively. Similarly, it has been found that a tracking drive signal of a tracking servo or a tracking error signal can be used as a horizontal vibration amount detecting means of the optical disc reproducing apparatus. The amplitude of the tracking error signal (hereinafter, simply referred to as a tracking error signal including a tracking drive signal) increases as the horizontal vibration of the optical disk reproducing apparatus increases.

Therefore, the vibration amount detecting means 7 shown in FIG. 1 is used as a focus error signal or tracking error signal detecting means, and its amplitude is detected by the control unit 8. If the amplitude exceeds a predetermined value, When the rotation speed of the disk 1 is reduced by the driving means 5, the noise can be suppressed to a predetermined value or less. If the disturbance of the focus error signal or the tracking error signal is large, or if the signal period is short, and if this signal is used directly, the control unit 8 cannot correctly determine the amplitude of the error signal. Or smoothing. As a result, the present invention can be achieved by using existing signals without newly attaching a vibration amount detecting unit.

FIGS. 4A, 4B, and 4C are characteristic diagrams for explaining the embodiment of the present invention, and the horizontal axis indicates the time t from the stop of the disk. The vertical axis in FIG. 4 (a) indicates the number of rotations N of the disk, the vertical axis in FIG. 4 (b) indicates the voltage FVA of the focus error signal, and the vertical axis in FIG. 4 (c) indicates the absolute value of the focus error signal. 5 shows a voltage FVD of a smoothed signal.
As shown in FIG. 4A, as the rotational speed of the disk 1 increases, the amplitude of the focus error signal in FIG. 4B increases. Accordingly, as shown in FIG. 4C, the voltage of the signal obtained by converting the focus error signal into an absolute value and smoothed also increases as the rotational speed of the disk 1 increases. Therefore, the absolute value and the smoothed voltage are equal to the predetermined value (FVD
In the case of 1), the noise can be kept below a predetermined value by reducing the rotation speed of the disk 1. As a result, the present invention can be achieved by using existing signals without newly attaching a vibration amount detecting unit.

FIG. 5 is a block diagram showing still another embodiment of the optical disk reproducing apparatus according to the present invention. In the figure, reference numeral 7a denotes an error signal detecting means which is an example of the vibration detecting means 7, and the control section 8 comprises an A / D converter 8a of a microcomputer. The error signal detecting means 7a indicates a focus error signal or tracking error signal detecting means. Generally, the error signal detecting means 7a is connected to the optical pickup 3, and obtains a focus error signal and a tracking error signal from the pickup 3.

The focus error signal changes due to the vertical vibration of the disk 1 and the mechanism 9. The focus error signal is taken out from the error signal detecting means 7a, converted into a digital value by the A / D converter 8a of the microcomputer, and counted when the digital value exceeds a predetermined value. When the vibration becomes intense, the number of counts per unit time increases. Therefore, when the count per unit time exceeds a predetermined value, the drive unit 5 is controlled to reduce the rotation speed of the disk 1, or By reducing the target rotation speed to a target rotation speed lower than the current rotation speed, noise due to vibration can be kept below a predetermined value. According to an experiment conducted by the inventors of the present invention, it was possible to reduce the noise to a predetermined value or less by lowering the rotation speed of the disk 1 when counting was performed five times or more in 100 ms.

When noise is generated by horizontal vibration, a similar effect can be obtained by using a tracking error signal. That is, in this case, the tracking error signal is taken out from the error signal detecting means 7a, converted into a digital value by the A / D converter 8a of the microcomputer, and counted when the digital value exceeds a predetermined value. When the vibration becomes severe, the number of counts per unit time increases. Therefore, when the count per unit time exceeds a predetermined value, the drive unit 5 is controlled to reduce the rotation speed of the disk 1. As a result, noise due to vibration can be kept below a predetermined value.

As still another embodiment of the present invention,
The focus error signal detection means and the tracking error signal detection means are used as the error signal detection means 7a, and both the focus error signal and the tracking error signal are detected. Then, as the A / D converter 8a, the first
A / D converter and a second A / D converter are provided. The focus error signal is converted into a digital value by a first A / D converter, and when the digital value exceeds a predetermined value (first count number), the tracking error signal is converted to a second A / D signal. The digital value is converted by a / D converter, and it is counted that the digital value exceeds a predetermined value (second count number). When either one of the first and second counts per unit time exceeds a predetermined count, the drive means may be controlled to reduce the rotation speed of the disk 1.

In this embodiment, 32 × speed, 24 × speed, 16 ×
Although an optical disk reproducing apparatus having three reproduction speeds of double speed is taken as an example, the present invention can be achieved by having a plurality of reproduction speeds. In the present embodiment, the optical disk reproducing apparatus of the CAV reproducing method is taken as an example of the disk reproducing method. However, the present invention can be achieved even if one or more of the reproducing speeds is a CLV (constant linear velocity) reproducing method.

[0029]

As described above, according to the present invention, even when the playback speed is not set by the user, the playback speed can be adjusted in accordance with the amount of eccentricity of the disk, and vibration and noise can be suppressed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an optical disk reproducing apparatus according to the present invention.

FIG. 2 is a characteristic diagram for explaining an embodiment of the optical disc reproducing apparatus according to the present invention.

FIG. 3 is a flowchart showing an embodiment of an optical disk reproducing apparatus according to the present invention.

FIG. 4 is a characteristic diagram for explaining an embodiment of the optical disc reproducing apparatus according to the present invention.

FIG. 5 is a block diagram showing another embodiment of the optical disc reproducing apparatus according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical disk, 2 ... Disk motor, 3 ... Optical pickup, 4 ... Slide motor, 5 ... Drive means, 6 ... Rotation speed detection means, 7 ... Vibration amount detection means, 7a ... Error signal detection means, 8 ... Control part, 8a: microcomputer A / D converter

Claims (14)

[Claims] 1. A mechanism for rotating an optical disc and feeding an optical pickup in a radial direction of the optical disc, a driving unit for driving the mechanism, and a vibration detecting a vibration amount of the mechanism. An amount detection unit, and a control unit that is supplied with a signal from the vibration amount detection unit and controls the driving unit, wherein the control unit determines that the vibration amount from the vibration amount detection unit exceeds a predetermined value. An optical disk reproducing apparatus, wherein the driving means is controlled to reduce the number of rotations of the optical disk. 2. An optical disk reproducing apparatus according to claim 1, further comprising: a rotation number detecting means, wherein a signal from said rotation number detecting means is supplied to said control section. 3. An optical disk reproducing apparatus according to claim 1, wherein said vibration amount detecting means is an error signal detecting means for detecting a focus error signal. 4. The optical disk reproducing apparatus according to claim 3, wherein the focus error signal is smoothed, and when the smoothed value exceeds a predetermined value, the drive means is controlled to rotate the optical disk. An optical disc reproducing apparatus characterized in that the number is reduced. 5. An optical disk reproducing apparatus according to claim 3, wherein an A / D converter is provided in said control section, and said focus error signal obtained from said error signal detecting means is transmitted to said A / D converter.
It converts to a digital value by a D converter and counts that the digital value has exceeded a predetermined value. When the count number per unit time exceeds the predetermined value, the rotation speed of the optical disk is reduced. An optical disk reproducing apparatus characterized by controlling the driving means as described above. 6. An optical disk reproducing apparatus according to claim 1, wherein said vibration amount detecting means is an error signal detecting means for detecting a tracking error signal. 7. An optical disk reproducing apparatus according to claim 6, wherein said tracking error signal is smoothed, and when said smoothed value exceeds a predetermined value, said driving means is controlled to rotate said optical disk. An optical disc reproducing apparatus characterized in that the number is reduced. 8. An optical disk reproducing apparatus according to claim 6, wherein an A / D converter is provided in said control section, and said tracking error signal obtained from said error signal detecting means is transmitted to said A / D converter.
The digital value is converted by a / D converter and counted when the digital value exceeds a predetermined value. When the count number per unit time exceeds the predetermined value, the rotation speed of the optical disk is reduced. An optical disk reproducing apparatus characterized in that the driving means is controlled to cause the driving means to perform the driving. 9. A mechanism provided with a mechanism for rotating an optical disc and feeding an optical pickup in a radial direction of the optical disc, driving means for driving the mechanism, and vibration for detecting a vibration amount of the mechanism. Amount detection means, rotation number detection means for detecting the rotation number of the optical disk, and a signal from the rotation number detection means are supplied, and the drive is performed so that the rotation number of the optical disk becomes a plurality of predetermined rotation numbers. A control unit that controls the driving unit when the vibration amount supplied from the vibration amount detecting unit exceeds a predetermined value. An optical disk reproducing apparatus, wherein the number of rotations of the optical disk is controlled to a lower number of rotations. 10. An optical disk reproducing apparatus according to claim 9, wherein said vibration amount detecting means is an error signal detecting means for detecting a focus error signal. 11. An optical disk reproducing apparatus according to claim 9, wherein said vibration amount detecting means is an error signal detecting means for detecting a tracking error signal. 12. A mechanism for rotating an optical disk to feed an optical pickup in a radial direction of the optical disk, a driving unit for driving the mechanism, a control unit for controlling the driving unit, and detecting a rotation speed of the disk. A rotation amount detection means, and a vibration amount detection means for detecting a vibration amount of the mechanism section, wherein a vibration amount is determined in advance from a rotation number signal from the rotation number detection means and a vibration amount signal from the vibration amount detection means. An optical disk reproducing apparatus for controlling the number of rotations of a disk so as not to exceed a predetermined value. 13. An optical disk reproducing apparatus according to claim 12, wherein said vibration amount detecting means is means for detecting a focus drive signal or a focus error signal. 14. An optical disk reproducing apparatus according to claim 12, wherein said vibration amount detecting means is means for detecting a tracking drive signal or a tracking error signal.