JP2000195146A - Optical disk player - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably control the rotation of an optical disk even though rotational control signals, which rotatively drive an optical disk with a constant linear velocity, are not detected for a long time. SOLUTION: When it is determined that detection of synchronization information is normally conducted from an optical disk on which the information is recorded so that a linear density is made constant, a linear velocity constant rotation control section 11 controls the rotational speed with respect to a spindle motor driving section 12. If it is determined that the detection of the information is not conducted normally, a switching is made so that an angular velocity constant rotation control section 13 controls the rotational speed with respect to the section 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an optical disk recording / reproduction for reproducing an optical disk such as a CD or DVD on which synchronization information is recorded.

[0002]

2. Description of the Related Art In an optical disk reproducing apparatus, a CD, DVD,
During recording and playback of an optical disk such as the one described above, information such as frame sync and wobble recorded on tracks on the optical disk so that the linear density is constant is detected, and the detected data is compared with a reference signal generated by a crystal oscillator or the like. In addition, a constant linear velocity rotation control is performed.

In order to detect the synchronization information from the optical disk, it is necessary that the optical pickup stably follows tracks on the optical disk. However, if tracking deviates due to an external impact or a scratch on the optical disk, a signal used in rotation control at a constant linear velocity cannot be detected, and in the worst case, the spindle motor runs away.

When the spindle motor runs away,
Since vibration occurs in the motor and tracking of the optical pickup cannot be performed, a normal reproducing operation cannot be performed.

Therefore, conventionally, when reproducing the optical disk, when the deviation of the track of the laser beam is detected, the CLV control loop is cut off to prevent runaway of the spindle motor (for example, see Japanese Patent Application Laid-Open No. H05-205605).
No. 109182).

According to such an optical disk reproducing apparatus,
When the track is off, the motor drive signal is not transmitted to the motor and the motor is rotated by inertia, whereby runaway of the spindle motor can be prevented.

When reproducing the optical disk, when the reproduction data clock is within a predetermined range, the CLV control is performed, and the driving method of the spindle motor is stored, so that when the clock cycle of the reproduction data is out of the predetermined range. There has been an optical disk reproducing apparatus (for example, see Japanese Patent Application Laid-Open No. 9-282790) in which the runaway of the spindle motor is prevented by switching from the CLV control to the driving processing of the stored driving method.

According to such an optical disk reproducing apparatus,
When the synchronization information detected from the optical disc can be detected,
The drive method of the spindle motor is stored while the rotation control at a constant linear velocity is performed. If the synchronization information cannot be detected, the control method is switched from the rotation control at a constant linear velocity to the previously stored drive method. Runaway of the spindle motor can be prevented by adopting the driving method immediately before the detection becomes impossible.

[0009]

However, in the above-mentioned optical disk reproducing apparatus, when no signal can be detected from the optical disk, the spindle motor is not driven, and the rotation is far from the rotation control at a constant linear velocity. There was a problem that would.

In the latter optical disk reproducing apparatus, the spindle motor is driven by a driving method immediately before the signal can no longer be detected from the optical disk. Therefore, when a signal cannot be detected for a long time due to poor quality writing by another optical disk drive, etc. Also, there is a problem that the rotation is far from the rotation control at a constant linear velocity.

That is, in the above-described conventional optical disk reproducing apparatus, when a reference signal cannot be read from an optical disk such as a CD or a DVD, there is a problem that a runaway of a spindle motor that rotationally drives the optical disk cannot be prevented.

The present invention has been made in view of the above points, and stabilizes the rotation control (spindle control) of an optical disk even when a rotation control signal for driving the optical disk to rotate at a constant linear velocity cannot be detected for a long time. The purpose is to be able to be.

[0013]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an optical disk reproducing apparatus for reproducing an optical disk on which synchronous information is recorded so that a linear density is constant by rotating the optical disk by a rotation drive unit. Synchronization information detection means for detecting synchronization information from the optical disc, determination means for determining whether or not the synchronization information is normally detected by the means, and a first means for generating a first reference signal having a constant frequency. And a rotation of the rotation drive unit such that a frequency difference between the synchronization information detected by the synchronization information detection means and the first reference signal generated by the first reference signal generation means is eliminated. A first rotation control unit for controlling a speed, and a radial position on the optical disk for detecting synchronization information by the synchronization information detection unit. Radial position detection means, rotation speed detection means for detecting the rotation speed of the optical disc and outputting a frequency proportional to the rotation speed, and second reference signal generation means for generating a second reference signal having a constant frequency. A constant rotation corresponding to the radial position detected by the radial position detecting means based on the frequency output by the rotational speed detecting means and the second reference signal generated by the second reference signal generating means; Second rotation control means for controlling the rotation speed of the rotation drive unit so as to rotate by a number,
When it is determined by the determination means that the synchronization information has been normally detected, the first rotation control means controls the rotation speed of the rotation drive unit, and the detection of the synchronization information is normally performed. When it is determined that the rotation has not been performed, switching control means for switching the second rotation control means so as to control the rotation speed of the rotation drive unit is provided.

In the above-mentioned optical disk reproducing apparatus, the synchronization information detecting means may be means for detecting a frame on the optical disk as synchronization information, and the determining means may be configured to detect a track on the optical disk by an optical pickup. It is preferable to use means for determining whether or not the synchronization information is normally detected based on a track error signal indicating whether or not the spot is following.

Further, in the above optical disk reproducing apparatus, the synchronization information detecting means is a means for detecting a wobbled track on the optical disk as synchronization information, and the determining means is a wobble detected from the optical disk. A means for determining whether or not the synchronization information is normally detected based on whether or not the frequency of the signal is within a predetermined range may be used.

In the above-mentioned optical disk reproducing apparatus, the synchronization information detecting means may be means for detecting a frame on the optical disk as synchronization information, and the determining means may determine an error rate of a reproduction signal from the optical disk. It is preferable to use a means for calculating and determining whether or not the synchronization information is normally detected based on the error rate.

Further, in the above optical disk reproducing apparatus, an optical disk type determining means for determining the type of the optical disk, and the first reference signal and the second optical signal based on the type of the optical disk determined by the means. It is preferable to provide means for changing the reference signal and the internal settings of the first rotation control means and the second rotation control means.

Further, in an optical disk reproducing apparatus for reproducing an optical disk on which the first synchronization information and the second synchronization information are recorded so that the linear density is constant, by rotating the optical disk with a rotation drive unit, First synchronization information detecting means for detecting synchronization information;
Second synchronization information detecting means for detecting the synchronization information, and first determining means for determining whether or not the first synchronization information is normally detected by the first synchronization information detecting means; Second determining means for determining whether the second synchronization information is normally detected by the second synchronization information detecting means, and a first reference for generating a first reference signal having a constant frequency. Signal generating means, and the rotation so that the frequency difference between the first synchronization information detected by the first synchronization information detecting means and the first reference signal generated by the first reference signal generating means is eliminated. First rotation control means for controlling the rotation speed of the driving unit;
A second reference signal generating means for generating a reference signal, a second synchronization information detected by the second synchronization information detecting means, and a second reference signal generated by the second reference signal generating means. Second rotation control means for controlling the rotation speed of the rotation drive unit so as to eliminate the frequency difference between the first synchronization information and the first synchronization information detection means and the second synchronization information detection means. Radial position detecting means for detecting a radial position on the optical disk for detecting information and second synchronization information, and rotational speed detecting for detecting a rotational speed of the optical disk and outputting a frequency proportional to the rotational speed Means, a third reference signal generating means for generating a third reference signal having a constant frequency, a frequency output by the rotational speed detecting means, and a frequency generated by the third reference signal generating means. A third rotation control for controlling the rotation speed of the rotation drive unit based on the obtained third reference signal so as to rotate at a constant rotation speed corresponding to the radial position detected by the radial position detection means. Means, and when the first determination means determines that the first synchronization information is normally detected, the first rotation control means controls the rotation speed of the rotation drive unit. The first determining means determines that the first synchronization information is not normally detected, and the second determining means determines that the second synchronization information is normally detected. The second rotation control unit controls the rotation speed of the rotation drive unit, and the first determination unit determines that the first synchronization information has not been normally detected, And the second determination A switching control unit that switches the third rotation control unit to control the rotation speed of the rotation drive unit when it is determined that the detection of the second synchronization information is not normally performed by the stage; Provide things.

Further, in the above optical disk reproducing apparatus, the first synchronization detecting means is a means for detecting a frame on the optical disk as first synchronization information, and the second synchronization detecting means is It is preferable that the wobbled track on the optical disc is detected as second synchronization information.

In the above optical disk reproducing apparatus, the first synchronization detecting means may be means for detecting a frame on the optical disk as first synchronization information,
The second synchronization detection means is means for detecting a wobbled track on the optical disk as second synchronization information, and the first determination means calculates an error rate of a reproduction signal from the optical disk, A means for determining whether or not the first synchronization information is normally detected based on the error rate. The second determining means determines whether a track on the optical disk is followed by a light spot of an optical pickup. Based on a track error signal indicating whether or not
It is preferable to use means for determining whether or not the synchronization signal is normally detected.

Further, in the above optical disk reproducing apparatus, the first synchronization detecting means is a means for detecting a frame on the optical disk as first synchronization information, and the second synchronization detecting means is Means for detecting a wobbled track on the optical disc as second synchronization information, wherein the first determination means calculates an error rate of a reproduction signal from the optical disc, and performs a first synchronization based on the error rate. Means for determining whether or not information has been normally detected; and determining the second determination means based on whether or not the frequency of a wobble signal detected from the optical disk is within a predetermined range. It is preferable to use means for determining whether or not the detection of the second synchronization information is normally performed.

Further, in the above optical disk reproducing apparatus, an optical disk type determining means for determining the type of the optical disk, and the first reference signal and the second optical signal based on the type of the optical disk determined by the means. Reference signal, the first rotation control means and the second rotation control means.
The internal setting of the rotation control means is changed, and only one type of synchronization information of the optical disc is recorded, and the detection of the first synchronization information by the first determination means is normal. If it is determined that the rotation has not been performed, means for switching the rotation speed of the rotation drive unit to be controlled by the third rotation control means may be provided.

[0023]

Embodiments of the present invention will be specifically described below with reference to the drawings. First, various terms used in this embodiment will be described.

(1) FG signal: a signal having a frequency proportional to the rotation speed of the spindle motor. For example, when a brushless DC motor is used as a spindle motor, the drive unit of the motor often has an FG signal generation unit inside. The FG signal generator generates a pulse (FG signal) having a frequency proportional to the rotation speed of the spindle motor.

(2) Frame synchronization signal: CD-ROM,
This is a synchronization signal that detects a synchronization pattern (synchronization information) recorded at regular intervals together with data on an optical disc on which CLV recording is performed, such as a DVD-ROM. By controlling the rotation of the spindle motor so that the detection of the synchronizing signal has a constant period, the constant linear speed rotation control can be performed. When recording a recordable optical disc such as a CD-R, CD-R / W, DVD-R, etc., a frame synchronization signal is recorded together with data.

(3) Wobble signal: CD-R, CD-R
On recordable optical disks such as / W and DVD-R, synchronization information is recorded in a state before data recording. CD-
R, CD-R / W, and DVD-R realize synchronization information by meandering tracks so that the linear density is constant. It is called wobble. By controlling the rotation of the spindle motor so that the signal (wobble signal) detecting the wobble has a constant period, the constant linear speed rotation control can be performed.

Next, a conventional optical disk reproducing apparatus will be described briefly. Normally, the rotation control at a constant linear velocity when reproducing a CD-ROM generates a reproduction signal from a signal detected by an optical pickup, and a frame detection circuit detects the frame synchronization signal from the reproduction signal, and the detected signal is detected. The spindle control unit generates a control signal so as to eliminate the difference between the frequency of the frame synchronization signal and the frequency of the reference signal generated by the crystal oscillator or the like, and drives the spindle motor via the spindle drive unit.

However, since the frame synchronization signal is detected based on the signal from the optical head, if the optical head goes out of track for some reason, the frame synchronization signal cannot be detected or an erroneous signal is detected. Sometimes.

Therefore, when the linear velocity constant control is performed using the frame synchronization signal, the spindle motor runs away when the track goes off track. Therefore, in the optical disk drive according to the embodiment of the present invention, runaway of the spindle motor due to the above-described causes is prevented.

Next, the configuration of an optical disk drive which is an embodiment of the optical disk reproducing apparatus of the present invention will be described. FIG. 1 is a block diagram showing a configuration of an optical disk drive according to a first embodiment of the present invention.

This optical disk drive has a CPU, RO
An optical disk 1, a spindle motor 2, an optical pickup 3, a drive unit 5, an optical pickup position control unit 7, a radial position detector 8, an analog signal processing unit 9, a frame detector realized by a microcomputer including M, RAM, and the like. 10, a constant linear velocity rotation control section 11, a spindle motor drive section 12, a constant angular velocity rotation control section 13, a control section 14, a switch 15, and the like.

The optical disk 1 is a CD-ROM or a DVD-ROM.
An optical disc such as a ROM in which synchronization information is recorded so as to have a constant linear density along with data and addresses. The spindle motor 2 is a motor for rotating the optical disc 1 at an arbitrary rotation speed, and is, for example, a brushless DC motor.

The optical pickup 3 is driven by an actuator (not shown) for moving the objective lens on the optical pickup 3 and a carriage mechanism (not shown) for moving the entire position of the optical pickup 3 in the radial direction of the optical disk 1. The spot can be made to follow the track.

The optical pickup position controller 7 controls the optical spot to follow the track of the rotating optical disk 1, optically reads information on the optical disk 1, converts the information into an electric signal, and performs analog signal processing. Output to the unit 9.

The drive unit 5 drives the carriage mechanism, and moves an actuator (not shown) on the optical pickup 3 in the focus direction and the track direction according to a control signal output from the optical pickup position control unit 7. Drive.

The optical pickup position control unit 7 receives servo signals such as a focus error signal and a track error signal output from the analog signal processing unit 9 and, based on these signals, shifts an optical spot on the optical disc 1 onto a track. Output a control signal so as to follow. Also, a signal (TROK) indicating whether tracking is normal or not is output as an output signal.

The radial position detector 8 detects the radial position of the optical pickup 3 and outputs it to the control unit 14. The radial position detector 8 may have, for example, the following three types of configurations. (1) A radial position detector including a rotary encoder that magnetically detects a rotation angle of a sledge motor and outputs a pulse, and a counter that counts pulses output by the rotary encoder.

(2) A radial position detector comprising a rotary encoder that optically detects the rotation angle of the sledge motor and outputs a pulse, and a counter that counts the pulse output from the rotary encoder. (3) A linear encoder for directly detecting the position of the optical pickup 3 and a radial position detector comprising a counter.

The analog signal processor 9 outputs a servo signal such as a focus error signal and a track error signal and a reproduction signal based on the signal output from the optical pickup 3. The frame detector 10 receives a reproduction signal output from the analog signal processing unit 9, detects a synchronization pattern recorded at regular intervals together with data on the optical disc 1 from the reproduction signal, and detects the synchronization pattern. Output as a synchronization signal.

The constant linear velocity rotation control unit 11 includes a frame synchronization signal output from the frame detector 10 and a first reference signal having a constant period generated by dividing the output of a crystal oscillator (not shown). And outputs a control signal for controlling the rotation speed of the spindle motor 2 so that the cycle of the frame synchronization signal and the first reference signal are the same. The spindle motor drive unit 12 outputs a drive signal for rotating the spindle motor 2 according to a control signal input via the switch 15.

The constant angular speed rotation control unit 13 divides the rotation speed detection signal output from the spindle motor drive unit 12 at a frequency proportional to the rotation speed of the spindle motor 2 and the output of a crystal oscillator (not shown) to generate a frequency. The second reference signal has m periods (second period) in one period of the rotation speed detection signal based on the second reference signal having a given period and the rotation speed set value: m set by the control unit 14. A control signal for controlling the rotation speed of the spindle motor 2 is output so that the frequency of the reference signal becomes m times the frequency of the rotation speed detection signal).

That is, this optical disk drive is an optical disk reproducing apparatus for reproducing an optical disk on which synchronization information is recorded so that the linear density is constant by rotating the optical disk with a rotation drive unit. Fulfill.

Synchronization information detecting means for detecting synchronization information from the optical disc; determining means for determining whether or not the synchronization information detection means has normally detected the synchronization information;
First reference signal generating means for generating a first reference signal having a constant frequency; synchronization information detected by the synchronization information detecting means; and a first reference signal generated by the first reference signal generating means.
The first rotation control means controls the rotation speed of the rotation drive unit so that the frequency difference with the reference signal is eliminated.

Further, a radial position detecting means for detecting a radial position on the optical disk for which the synchronous information is detected by the synchronous information detecting means, and a rotational speed of the optical disk and outputting a frequency proportional to the rotational speed. A rotation speed detecting means for generating a second reference signal having a constant frequency;
And a radial position detected by the radial position detecting means based on the frequency output by the rotational speed detecting means and the second reference signal generated by the second reference signal generating means. The second rotation control means controls the rotation speed of the rotation drive unit so as to rotate at a constant rotation speed.

Further, when the judging means judges that the detection of the synchronization information is normally performed, the first rotation control means controls the rotation speed of the rotation drive unit, and the detection of the synchronization information is normally performed. Switching control means for switching the second rotation control means to control the rotation speed of the rotation drive unit when it is determined that the rotation is not performed.

The synchronization information detecting means is means for detecting a frame on the optical disk as synchronization information.
The determining means corresponds to a means for determining whether or not synchronization information has been normally detected based on a track error signal indicating whether or not a light spot of an optical pickup is following a track on an optical disk. .

It should be noted that the crystal oscillator for generating the second reference signal has a different frequency division ratio from the crystal oscillator for generating the first reference signal input to the constant linear velocity rotation controller 11. You may make it generate | occur | produce by producing | generating. In that case, the configuration becomes cheaper than when each has a different crystal oscillator.

The second reference signal is the first reference signal 1
It may be the same as. In that case, a crystal oscillator for generating the first reference signal and a crystal oscillator for generating the second reference signal may be provided one by one, so that the configuration is more inexpensive.

The control unit 14 receives information on the radial position of the optical pickup 3 from the radial position detector 8 and a signal indicating whether or not the light spot of the optical pickup 3 follows the track from the optical pickup position control unit 7, respectively. The rotation speed set value m is set in a register in the constant angular speed rotation control unit 13 according to the radial position information. Further, based on a signal from the optical pickup position control unit 7 indicating whether or not the light spot of the optical pickup 3 is following the track,
The switch 15 is set so that the output of the constant linear velocity rotation control unit 11 is guided to the spindle motor drive unit 12 when the vehicle is following, and the output of the constant angular velocity rotation control unit 13 is not guided.

The switch 15 selects one of the output of the constant linear velocity rotation control section 11 or the output of the constant angular velocity rotation control section 13 according to a signal input from the control section 14 and outputs the selected output to the spindle motor driving section 12. I do.

Next, the operation of the optical disk drive of the first embodiment during reproduction will be described. When the optical spot of the optical pickup 3 is following the track of the optical disc 1, the optical disc drive makes the track ON signal valid from the optical pickup position control section 7 and outputs it to the control section 14; The detected frame is output from the optical disc 1. At that time, the control unit 14 outputs a control signal to the switch 15 so that the output of the constant linear velocity rotation control unit 11 is input to the spindle motor driving unit 12.

A frame is recorded on the optical disc 1 so as to have a constant linear density, and a constant linear velocity rotation control section 11 synchronizes an input frame signal with a first reference signal having a constant frequency. Output the spindle motor control signal to the spindle motor drive unit 12 as follows.
The rotation of the spindle motor 2 is controlled at a constant linear velocity.

Here, if the light spot of the optical pickup 3 does not follow the track of the optical disc 1 due to some cause, for example, the occurrence of an external impact or the bad quality of the optical disc, The above information cannot be reproduced, and the signal output from the analog signal processing unit 9 is not normal.

Further, since the frame signal output from the frame detector 10 is not normal, the constant linear speed rotation control section 11, which performs spindle rotation control using this frame signal, performs accurate spindle rotation control. In the worst case, the spindle motor may run away.

Therefore, when the light spot of the optical pickup 3 does not follow the track of the optical disk 1, the track ON signal is invalidated from the optical pickup position control unit 7 and output to the control unit 14. At that time, the control unit 14
Outputs a control signal to the switch 15 so that the output of the constant angular velocity rotation control unit 13 is input to the spindle motor drive unit 12.

On the other hand, the rotational speed set value: m held in the internal register of the constant angular velocity rotation control unit 13 includes the control unit 1
4, a value corresponding to the radial position output from the radial position detector 8 is set.

As the value of the rotation speed set value: m, the number of rotations at each reading radius position when the spindle rotation control is performed at a constant linear speed is set in advance. For example, a table corresponding to the radius position and the rotational speed set value: m is provided.
Then, the control unit 14 sets each time the reading radius position changes. The rotation control at that time is based on the radius C zone C
Since it is AV, it is possible to approach the rotation control of the CLV control by reducing the detection accuracy of the radial position.

By controlling the rotation speed of the spindle motor as described above, it is possible to prevent the spindle motor 2 from running out of control even when the optical pickup 3 cannot follow the track. It is possible to perform substantially the same spindle rotation control as when the control is performed.

Next, the configuration of an optical disk drive according to a second embodiment of the present invention will be described. FIG. 2 is a block diagram showing a configuration of an optical disk drive according to a second embodiment of the present invention. Components common to those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

In the optical disk drive according to the second embodiment, the error rate of the reproduced signal output from the analog signal processing section 9 is generated, and it is determined whether or not the error rate is equal to or less than a predetermined value. An error rate generation unit 21 is provided for causing the control unit 14 to switch the type of rotation control processing based on the result.

That is, in the optical disk drive of the second embodiment, the synchronization information detecting means functions as a means for detecting a frame on the optical disk as the synchronization information, and the determining means determines whether an error in the reproduction signal from the optical disk has occurred. It functions as a means for calculating the rate and determining whether or not the synchronization information is normally detected based on the error rate.

In the optical disk drive of the first embodiment, the optical pickup 3 follows the track.
In the case where the reproduction signal cannot be detected normally, for example, when reproducing an optical disk on which data has been recorded by a poor recording device, there is a possibility that the spindle motor 2 may run away. In the optical disk drive of the example, it is determined whether or not the frame is normally detected based on the error rate of the reproduction signal. Therefore, when the reproduction signal cannot be normally detected, the spindle motor 2 is rotated by using the constant angular velocity rotation control unit 13. Is performed, more stable rotation speed control can be performed.

Next, the configuration of an optical disk drive according to a third embodiment of the present invention will be described. FIG. 3 is a block diagram showing a configuration of an optical disk drive according to a third embodiment of the present invention. Parts common to those in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof is omitted.

The analog signal processor 9 'of the optical disk drive according to the third embodiment differs from the analog signal processor 9 shown in FIGS. 1 and 2 in that it detects a wobble signal together with a servo signal and a reproduction signal. Further, a determination unit 31 is provided for determining whether or not the detection of the wobble signal is normally performed by the analog signal processing unit 9 '. The determination unit 31 may measure the cycle of the wobble signal and evaluate whether the cycle is within a predetermined range.

That is, in the optical disk drive of the third embodiment, in each of the above sections, the synchronization information detecting means is means for detecting a wobbled track on the optical disk as synchronization information. The function of a unit that determines whether or not the synchronization information is normally detected based on whether or not the frequency of the detected wobble signal is within a predetermined range.

The optical disk drive of the third embodiment is
If the detection of the wobble signal is normal, the rotation control using the wobble signal is performed at a constant linear velocity. If the detection of the wobble signal cannot be performed normally, the rotation control is performed at a constant angular velocity. Therefore, the wobble signal cannot be detected normally. Even in this case, stable rotation control can be performed.

The set values such as the gain of the servo system constituting the constant linear velocity rotation control section 11 and the constant angular velocity rotation control section 13 shown in FIGS. 1 to 3 depend on the type of the optical disc 1 such as a CD or DVD. Although it is necessary to change the setting, a means for detecting the type of the optical disc 1 is provided, and the internal settings of the constant linear velocity rotation control unit 11 and the constant angular velocity rotation control unit 13 are dynamically changed based on the type, whereby a plurality of Types of optical discs 1.

That is, in each of the units, an optical disc type discriminating means for discriminating the type of the optical disc, the first reference signal and the second reference signal based on the type of the optical disc discriminated by the optical disc type discriminating means, The function of the first rotation control means and the internal setting of the second rotation control means is changed.

Further, by combining the control processing executed by the optical disk drive shown in FIGS. 1 to 3, when the frame is detected, the rotation speed of the spindle motor 2 is controlled by the linear speed constant rotation control using the frame synchronization signal. When the wobble signal can be detected when the frame cannot be detected, the rotation speed of the spindle motor 2 is controlled by the linear speed constant rotation control using the wobble signal. When neither the frame nor the wobble signal can be detected,
The rotation speed of the spindle motor 2 is controlled by the constant angular speed rotation control.

That is, in each of the above-described units, when the optical disk on which the first synchronization information and the second synchronization information are recorded so that the linear density is constant is reproduced by rotating the optical disk by the rotation driving unit, the following functions are performed. To fulfill.

The first synchronizing information detecting means for detecting the first synchronizing information from the optical disc, the second synchronizing information detecting means for detecting the second synchronizing information from the optical disc, and the first synchronizing information detecting means. First determining means for determining whether or not the first synchronization information is detected normally;
The second determination means determines whether or not the second synchronization information is normally detected by the second synchronization information detection means.

Also, a first reference signal generating means for generating a first reference signal of a constant frequency, a first synchronizing information detected by the first synchronizing information detecting means and a first reference signal generating means. The first rotation control means controls the rotation speed of the rotation drive unit so that the frequency difference from the generated first reference signal is eliminated.

Further, a second reference signal generating means for generating a second reference signal of a constant frequency, a second synchronization information detected by the second synchronization information detecting means, and a second reference signal generating means. The second rotation control means controls the rotation speed of the rotation drive unit so that the frequency difference with the generated second reference signal is eliminated.

Further, the first synchronization information and the second synchronization information are respectively detected by the first synchronization information detecting means and the second synchronization information detecting means.
Radial position detecting means for detecting the radial position on the optical disk which detects the synchronization information of the optical disk, and rotational speed detecting means for detecting the rotational speed of the optical disk and outputting a frequency proportional to the rotational speed.

Further, a third reference signal generating means for generating a third reference signal having a constant frequency, a frequency output by the rotational speed detecting means and a third reference signal generated by the third reference signal generating means. A third rotation control unit that controls the rotation speed of the rotation drive unit based on the signal so that the rotation unit rotates at a constant rotation speed corresponding to the radial position detected by the radial position detection unit.

Further, the first judging means makes the first
When it is determined that the synchronization information is normally detected, the first rotation control means controls the rotation speed of the rotation drive unit, and the first determination means detects the first synchronization information. Is determined not to be performed normally and the second
When it is determined by the determining means that the detection of the second synchronization information is performed normally, the second rotation control means controls the rotation speed of the rotation drive unit, and the first determining means If it is determined that the detection of the first synchronization information is not performed normally and the second determination unit determines that the detection of the second synchronization information is not performed normally, the third rotation control is performed. The switching control unit switches the means to control the rotation speed of the rotation drive unit.

Further, the first synchronization detecting means is means for detecting a frame on the optical disk as the first synchronization information, and the second synchronization detecting means is for detecting the wobbled track on the optical disk in the second. Function as means for detecting as synchronization information of

Further, the first synchronization detecting means is means for detecting a frame on the optical disk as first synchronization information, and the second synchronization detecting means is for detecting the wobbled track on the optical disk in the second. The first determining means calculates an error rate of a reproduction signal from the optical disk, and based on the error rate, whether the first synchronization information is normally detected. A second synchronization means for detecting a second synchronization signal based on a track error signal indicating whether a light spot of an optical pickup follows a track on an optical disk. The function of a means for determining whether or not the operation is performed normally is performed.

Further, the first synchronization detecting means is means for detecting a frame on the optical disk as the first synchronization information, and the second synchronization detecting means is for detecting the wobbled track on the optical disk to the second. The first determining means calculates an error rate of a reproduction signal from the optical disk, and based on the error rate, whether the first synchronization information is normally detected. The second determination means performs normal detection of the second synchronization information based on whether or not the frequency of the wobble signal detected from the optical disk is within a predetermined range. It performs the function of means for determining whether or not it has been performed.

Further, an optical disk type determining means for determining the type of the optical disk, the first reference signal and the second reference signal based on the type of the optical disk determined by the means, and the first rotation signal The control means and the internal setting of the second rotation control means are respectively changed, and only the synchronization information of one type of the optical disc is recorded. When it is determined that the detection of the synchronization information is not performed normally, a means for switching the third rotation control means to control the rotation speed of the rotation drive unit is provided.

Therefore, when reproducing an optical disk on which two frames and wobbles are recorded, stable linear velocity constant rotation control can be performed when one of the synchronization signals is detected. Even when the detection cannot be performed, the angular velocity constant control is performed at the rotational speed corresponding to the radial position, so that the same rotational control as when the substantially linear velocity constant rotational control is performed can be performed.

In this way, the type of the optical disk is detected, and in the case of an optical disk such as a CD-R or DVD-R in which two synchronization signals may be recorded, the two synchronization signals are detected. , Determine whether the detection is normal,
In the case of an optical disk such as a D-ROM or a DVD-ROM on which only one synchronization signal is recorded, power consumption can be reduced by detecting only one synchronization signal. This is effective in the case of an optical disk recording / reproducing apparatus which can be used.

(1) Effects of the Optical Disc Drive in the Optical Disc Reproducing Apparatus of Claim 1 of the Present Invention When synchronization information cannot be detected, the rotation control is switched to a rotation control method that does not require the detected synchronization information.

Therefore, even if the synchronization information cannot be detected, the spindle motor does not run out of control, and the stable rotation control can be performed substantially in the same manner as when the linear velocity constant control is performed.

(2) Effects of the optical disk drive according to claim 2 of the present invention in the optical disk drive A frame is detected as synchronization information, and whether or not the detection of the synchronization signal is normally performed is determined based on the track error signal. Judgment.

Therefore, even when the optical pickup cannot follow the track, the spindle motor does not run out of control, and stable rotation control almost the same as when the linear velocity constant control is performed can be performed. it can.

(3) Effect of the optical disk drive according to the third aspect of the present invention in the optical disk drive The wobble signal detected as a synchronization information and whether or not the detection of the synchronization signal is normally performed. Is determined based on whether or not the frequency is within a predetermined value.

Therefore, even if the wobble cannot be detected when recording / reproducing the optical disk having the wobbled track, the spindle motor does not run out and the same stable operation as when the linear velocity constant control is performed. Rotation control can be performed.

(4) Effects of the optical disk drive according to the fourth aspect of the present invention in the optical disk drive The frame is detected as synchronization information, and it is determined whether or not the detection of the synchronization signal is normally performed. Is determined based on

Therefore, although the light spot of the optical pickup follows the track, even when the reproduction signal cannot be reproduced normally, the spindle motor does not run away and is almost the same as when linear velocity constant control is performed. Can perform stable rotation control.

(5) Effects of the optical disk drive according to the fifth aspect of the present invention in the optical disk drive The type of the optical disk to be recorded / reproduced is determined, and the rotation control unit performs a rotation control corresponding to the type of the optical disk. Since rotation control is performed by changing internal settings,
It is possible to perform stable rotation control for several types of optical discs such as a DVD system without runaway and substantially the same as when performing constant linear velocity control.

(6) Effects of the Optical Disc Drive in the Optical Disc Reproducing Apparatus of Claim 6 of the Present Invention Normally, the first synchronization information on the optical disc is detected and the linear velocity constant control is performed. If it cannot be detected, the second synchronization information on the optical disk is detected to perform constant linear velocity control. If the first and second synchronization information cannot be detected, the rotation control process is switched to a rotation control process that does not require the synchronization information on the optical disk. .

Therefore, when only the first synchronization information cannot be detected, the second synchronization information is used, and the same rotation control as when the linear velocity constant control based on the first synchronization information is performed can be performed. Even if the first and second synchronization information cannot be detected, the spindle motor does not run out of control, and stable rotation control can be performed substantially in the same manner as when the linear velocity constant control is performed.

(7) Effects of the optical disk drive according to the optical disk reproducing apparatus of claim 7 of the present invention Since a frame is detected as the first synchronization information and a wobble is detected as the second synchronization information, recording is particularly possible. If a frame cannot be detected when reproducing information recorded on an optical disk, constant control of linear velocity can be performed by detecting wobble. Therefore, rotation control is performed at a constant linear velocity even on an optical disk in a poorly recorded state. be able to.

Further, since the control system is switched so as to perform the rotation control in the zone CAV even if the wobble cannot be detected, the spindle motor does not run out of control and is substantially the same as when the linear velocity constant control is performed. Can perform stable rotation control.

(8) Effects of the optical disk drive according to the optical disk reproducing apparatus of claim 8 of the present invention. A frame is detected as first synchronization information, a wobble is detected as second synchronization information, and an error rate of a reproduction signal is detected. It is determined whether the detection of the frame is normal based on the wobble, and based on the track error signal.

When a frame for reproducing information recorded on a recordable optical disc cannot be detected, but a wobble can be detected because the light spot of the optical pickup follows the track, a rotation at a constant linear velocity is performed. Control can be performed. Therefore, the rotation can be controlled at a constant linear velocity even in an optical disc in a poor recording state.

Further, since the normal actuator control section includes a judgment section for judging whether or not the light spot of the optical pickup follows the track based on the track error signal, it needs to be installed again. Without
It can be configured at low cost.

Further, even if the light spot of the optical pickup cannot follow the track and the wobble cannot be detected, the control system is switched so as to perform the rotation control in the zone CAV, so that the spindle motor goes out of control. This can eliminate the problem, and can perform substantially the same stable rotation control as when the constant linear velocity control is performed.

(9) Effects of the optical disk drive according to the ninth aspect of the present invention in the optical disk drive The frame is detected as the first synchronization information, the wobble is detected as the second synchronization information, and the error rate of the reproduced signal is detected. It is determined whether or not the detection of the frame is normal based on the wobble, and whether or not the detection of the wobble is normal is based on whether or not the frequency of the detected wobble is within a predetermined frequency range.

Therefore, particularly when reproducing information recorded on a recordable optical disk, when a frame cannot be detected but a wobble can be detected, constant linear velocity control can be performed. In the optical disc of the above, the rotation can be controlled at a constant linear velocity.

Further, since whether or not the detection of the wobble is normal is not determined indirectly but based on the detected wobble, more reliable rotation control of the spindle motor can be performed.

Further, even if the optical spot of the optical pickup cannot follow the track and the wobble cannot be detected, the control system is switched by performing the rotation control in the zone CAV, so that the spindle motor may run out of control. And stable rotation control substantially the same as when the linear velocity constant control is performed can be performed.

(10) Effects of the optical disk drive according to claim 10 of the present invention in the optical disk drive In order to determine the type of the optical disk for recording and reproducing and to perform the rotation control corresponding to the type of the optical disk, a rotation control unit is provided. Since the rotation control is performed by changing the setting of
It is possible to perform stable rotation control for several types of optical disks such as DVDs without running out of control and substantially the same as when performing constant linear velocity control.

In the case of an optical disk such as a CD-ROM in which only frames are recorded as synchronization information, when a frame cannot be detected, rotation in the zone CAV is performed without performing rotation control at a constant linear velocity by wobble. Since control is performed, stable rotation control can be performed more reliably.

[0106]

As described above, according to the optical disk reproducing apparatus of the present invention, the rotation control of the optical disk can be stably performed even when the rotation control signal for rotating the optical disk at a constant linear velocity cannot be detected for a long time. Can be done.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an optical disk drive according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an optical disk drive according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of an optical disk drive according to a third embodiment of the present invention.

[Explanation of symbols]

 1: optical disk 2: spindle motor 3: optical pickup 5: drive unit 7: optical pickup position control unit 8: radial position detector 9, 9 ': analog signal processing unit 10: frame detector 11: constant linear velocity rotation control unit 12: spindle motor drive unit 13: constant angular velocity rotation control unit 14: control unit 15: switch 21: error rate generation unit 31: determination unit

Claims (10)

[Claims] 1. An optical disc reproducing apparatus for reproducing an optical disc on which synchronization information is recorded so that a linear density is constant by rotating the optical disc by a rotation drive unit, comprising: a synchronization information detecting means for detecting the synchronization information from the optical disc; Determining means for determining whether or not the synchronization information is normally detected by the means; first reference signal generating means for generating a first reference signal having a constant frequency; and detection by the synchronization information detecting means. First rotation control means for controlling the rotation speed of the rotation drive unit such that the frequency difference between the synchronization information and the first reference signal generated by the first reference signal generation means is eliminated; A radial position detecting means for detecting a radial position on the optical disc for which synchronization information is detected by the information detecting means, and a rotational speed of the optical disc for detecting A rotation speed detecting means for outputting a frequency proportional to the rotation speed; a second reference signal generating means for generating a second reference signal having a constant frequency; a frequency output by the rotation speed detecting means; The rotation speed of the rotation drive unit is set so as to rotate at a constant rotation speed corresponding to the radial position detected by the radial position detection unit based on the second reference signal generated by the second reference signal generation unit. Second rotation control means for controlling the rotation speed of the rotation drive unit when the determination means determines that the detection of the synchronization information is normally performed. And if it is determined that the synchronization information has not been properly detected, the switching control means switches the second rotation control means to control the rotation speed of the rotation drive unit. Optical disk reproducing apparatus characterized in that a and. 2. The synchronization information detecting means detects a frame on the optical disk as synchronization information, and the determination means determines whether a light spot of an optical pickup follows a track on the optical disk. 2. An optical disc reproducing apparatus according to claim 1, wherein said means is a means for judging whether or not synchronization information has been normally detected based on a track error signal indicating the following. 3. The synchronization information detecting means detects a wobbled track on the optical disk as synchronization information, and the determining means determines that a frequency of a wobble signal detected from the optical disk is within a predetermined range. 2. The optical disc reproducing apparatus according to claim 1, wherein said means is a means for judging whether or not synchronization information has been normally detected based on whether or not the optical disk is synchronized. 4. The synchronization information detecting means is means for detecting a frame on the optical disk as synchronization information, and the determining means calculates an error rate of a reproduction signal from the optical disk, and calculates the error rate based on the error rate. 2. The optical disc reproducing apparatus according to claim 1, wherein said means is a means for judging whether or not synchronization information is normally detected. 5. An optical disk type determining means for determining the type of the optical disk, and the first reference signal and the second reference signal based on the type of the optical disk determined by the means.
5. A means for changing each of the reference signal and the internal settings of the first rotation control means and the second rotation control means is provided. Optical disc playback device. 6. An optical disk reproducing apparatus for reproducing an optical disk on which first synchronization information and second synchronization information are recorded so that a linear density is constant by rotating the optical disk with a rotation drive unit, First synchronization information detection means for detecting synchronization information; second synchronization information detection means for detecting second synchronization information from the optical disc; and detection of first synchronization information by the first synchronization information detection means. First determining means for determining whether or not the second synchronization information is normally detected, and second determining means for determining whether or not the second synchronization information is normally detected by the second synchronization information detecting means. Determination means; first reference signal generation means for generating a first reference signal having a constant frequency; first synchronization information detected by the first synchronization information detection means; and the first reference signal generation means By First rotation control means for controlling the rotation speed of the rotation drive unit so that the frequency difference between the first reference signal and the first reference signal is eliminated, and a second rotation control means for generating a second reference signal having a constant frequency. And a second synchronization signal detected by the second synchronization information detection means and a second reference signal generated by the second reference signal generation means. A second rotation control unit for controlling a rotation speed of the rotation drive unit; and a first synchronization information and a second synchronization information, respectively, by the first synchronization information detection unit and the second synchronization information detection unit. A radial position detecting means for detecting a radial position on the optical disk which is performing detection; a rotational speed detecting means for detecting a rotational speed of the optical disk and outputting a frequency proportional to the rotational speed; A third reference signal generating means for generating a third reference signal; and a third reference signal generated by the third reference signal generating means and a frequency output by the rotational speed detecting means. Third rotation control means for controlling the rotation speed of the rotation drive unit so as to rotate at a constant rotation speed corresponding to the radial position detected by the radial position detection means; When it is determined that the detection of the synchronization information is performed normally, the first rotation control unit controls the rotation speed of the rotation drive unit, and the first determination unit determines the first synchronization information. When the second rotation control unit determines that the detection of the second synchronization information is not normally performed and that the second determination unit determines that the detection of the second synchronization information is normally performed, Said times Performs control of the rotational speed of the drive unit, the first
When it is determined by the determining means that the detection of the first synchronization information is not normally performed, and when it is determined that the detection of the second synchronization information is not normally performed by the second determining means, An optical disc reproducing apparatus, comprising: a switching control unit that switches the third rotation control unit to control the rotation speed of the rotation drive unit. 7. The first synchronization detecting means is means for detecting a frame on the optical disk as first synchronization information, and the second synchronization detecting means is for detecting a wobbled track on the optical disk. 7. The optical disk reproducing apparatus according to claim 6, wherein the optical disk reproducing device is means for detecting the second synchronization information. 8. The first synchronization detecting means is means for detecting a frame on the optical disk as first synchronization information, and the second synchronization detecting means is for detecting a wobbled track on the optical disk. Means for detecting as second synchronization information, wherein the first determination means calculates an error rate of a reproduction signal from the optical disk, and normally detects the first synchronization information based on the error rate. Means for determining whether or not the light spot of the optical pickup is following the track on the optical disk. 7. The optical disk reproducing apparatus according to claim 6, wherein said means is a means for judging whether or not signal detection is normally performed. 9. The first synchronization detecting means is means for detecting a frame on the optical disk as first synchronization information, and the second synchronization detecting means is for detecting a wobbled track on the optical disk. Means for detecting as second synchronization information, wherein the first determination means calculates an error rate of a reproduction signal from the optical disk, and normally detects the first synchronization information based on the error rate. And determining whether the frequency of the wobble signal detected from the optical disk is within a predetermined range. 7. An optical disk reproducing apparatus according to claim 6, wherein said means is a means for judging whether or not said operation is normally performed. 10. An optical disk type determining means for determining the type of the optical disk, the first reference signal and the second reference signal based on the type of the optical disk determined by the means, and the first rotation signal Control means and the second
The internal setting of the rotation control means is changed respectively, and only one type of synchronization information of the optical disc is recorded, and the detection of the first synchronization information by the first determination means is normal. A switching means for controlling the rotation speed of the rotation driving unit by the third rotation control means when it is determined that the rotation has not been performed. An optical disk playback device according to any one of the preceding claims.