WO2009154003A1 - 焦点位置制御装置及びそれを備えた光ディスク装置並びに焦点位置制御方法 - Google Patents
焦点位置制御装置及びそれを備えた光ディスク装置並びに焦点位置制御方法 Download PDFInfo
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- WO2009154003A1 WO2009154003A1 PCT/JP2009/002803 JP2009002803W WO2009154003A1 WO 2009154003 A1 WO2009154003 A1 WO 2009154003A1 JP 2009002803 W JP2009002803 W JP 2009002803W WO 2009154003 A1 WO2009154003 A1 WO 2009154003A1
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- focal position
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
- G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
- G11B7/094—Methods and circuits for servo offset compensation
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/10—Digital recording or reproducing
- G11B20/10009—Improvement or modification of read or write signals
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/10—Digital recording or reproducing
- G11B20/10009—Improvement or modification of read or write signals
- G11B20/10046—Improvement or modification of read or write signals filtering or equalising, e.g. setting the tap weights of an FIR filter
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/10—Digital recording or reproducing
- G11B20/10009—Improvement or modification of read or write signals
- G11B20/10222—Improvement or modification of read or write signals clock-related aspects, e.g. phase or frequency adjustment or bit synchronisation
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/10—Digital recording or reproducing
- G11B20/10009—Improvement or modification of read or write signals
- G11B20/10305—Improvement or modification of read or write signals signal quality assessment
- G11B20/10388—Improvement or modification of read or write signals signal quality assessment control of the read or write heads, e.g. tracking errors, defocus or tilt compensation
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/10—Digital recording or reproducing
- G11B20/10009—Improvement or modification of read or write signals
- G11B20/10305—Improvement or modification of read or write signals signal quality assessment
- G11B20/10398—Improvement or modification of read or write signals signal quality assessment jitter, timing deviations or phase and frequency errors
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
- G11B20/10—Digital recording or reproducing
- G11B20/14—Digital recording or reproducing using self-clocking codes
- G11B20/1403—Digital recording or reproducing using self-clocking codes characterised by the use of two levels
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
- G11B7/085—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam into, or out of, its operative position or across tracks, otherwise than during the transducing operation, e.g. for adjustment or preliminary positioning or track change or selection
- G11B7/08505—Methods for track change, selection or preliminary positioning by moving the head
- G11B7/08511—Methods for track change, selection or preliminary positioning by moving the head with focus pull-in only
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
- G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
- G11B7/0901—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for track following only
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
- G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
- G11B7/0908—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for focusing only
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
- G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
- G11B7/0941—Methods and circuits for servo gain or phase compensation during operation
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
- G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
- G11B7/095—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following specially adapted for discs, e.g. for compensation of eccentricity or wobble
- G11B7/0953—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following specially adapted for discs, e.g. for compensation of eccentricity or wobble to compensate for eccentricity of the disc or disc tracks
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B2007/0003—Recording, reproducing or erasing systems characterised by the structure or type of the carrier
- G11B2007/0009—Recording, reproducing or erasing systems characterised by the structure or type of the carrier for carriers having data stored in three dimensions, e.g. volume storage
- G11B2007/0013—Recording, reproducing or erasing systems characterised by the structure or type of the carrier for carriers having data stored in three dimensions, e.g. volume storage for carriers having multiple discrete layers
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B2220/00—Record carriers by type
- G11B2220/20—Disc-shaped record carriers
- G11B2220/25—Disc-shaped record carriers characterised in that the disc is based on a specific recording technology
- G11B2220/2537—Optical discs
Definitions
- the present invention relates to a focus position control of a light beam such as focus control and tracking control in an optical disc apparatus that performs recording and reproduction on an optical disc.
- the thrust generated by the lens actuator of the optical head is small and thin, so that it is very difficult to extend the control band to a high frequency.
- the track pitch is 0.32 micrometers, which is as small as 43% of the conventional DVD disc, and high tracking accuracy is required.
- the disc may have local runout or eccentricity that changes at a higher frequency than the runout or eccentricity that changes at the rotational frequency. This is due to local distortion occurring in the stamper of the master disk when the disk is manufactured.
- An optical disc manufactured with such a stamper has the same track distortion or distortion in the direction of the recording surface at almost the same location, which causes partial surface wobbling and eccentricity, greatly affecting focus control and tracking control. give.
- Such distortion often exists at every rotation in a plurality of tracks in the radial direction, and becomes a very high-order disturbance with respect to the rotation frequency, and thus cannot be suppressed by normal control. For this reason, a large control residual is generated, and local recording and reproduction may be impossible.
- an apparatus using feedforward control in which information on the eccentricity and surface shake is temporarily stored in a memory and used for focus position control is known.
- the device writes eccentricity and runout information to the memory in synchronization with the rotational frequency of the disk, reads the data from the memory, and uses it for tracking control, focus control, etc. (for example, (See Patent Documents 1 and 2).
- Such a device can perform normal control with reduced runout and eccentricity using data read from the memory, and suppresses control residuals even when a disk with large runout and eccentricity is rotated. can do.
- a repetitive control device in which a tracking error signal of a normal feedback control system is sequentially stored in a memory in synchronization with the rotation of the disk, and is sequentially output after one rotation delay and used for tracking control.
- the apparatus adds the tracking error signal before one rotation stored in the memory to the tracking error signal via a compensation means having a transfer function that is the reciprocal of the transfer function of the feedback control system, thereby forming a tracking control system.
- a compensation means having a transfer function that is the reciprocal of the transfer function of the feedback control system, thereby forming a tracking control system.
- control residuals due to run-out and eccentricity which are rotational frequency components
- control residuals of higher-order frequency components such as partial surface runout and eccentricity due to disk distortion described above.
- the degree of influence due to the delay time differs depending on the difference in frequency. Therefore, if the timing is adjusted in consideration of only the rotational frequency component, the control residual of the higher-order frequency component such as partial surface shake or eccentricity may be worse than the normal feedback control.
- the timing shift due to the delay time when data is stored or read in this way hinders high-precision focus control and tracking control, and thus becomes a serious obstacle to realizing high-speed recording / reproducing and high-density recording / reproducing. .
- an object of the present invention is to realize a highly accurate focus control or tracking control by suppressing a timing shift due to a delay time when data is stored or read.
- the focal position of the light beam Error signal generating means for generating an error signal indicating the amount of deviation from a desired position of the light source, and control means for generating a control signal for controlling the focal position of the light beam to a desired position based on the error signal;
- Rotation synchronization signal generation means for generating a clock signal synchronized with the rotation of the optical disc, and the control signal in sequence as stored data at a clock address that is synchronized with the clock signal and makes a round with one rotation of the optical disc
- Storage means for storing and storage for sequentially reading out the storage data stored in the storage means in synchronization with the clock signal Data output means, and when the stored data output means reads the stored data from the storage means, a phase correction means for correcting the phase of the clock address related to storage and the
- the focal position of the light beam Error signal generating means for generating an error signal indicating the amount of deviation from a desired position of the light source, and control means for generating a control signal for controlling the focal position of the light beam to a desired position based on the error signal;
- Rotation synchronization signal generation means for generating a clock signal synchronized with the rotation of the optical disc, and the control signal in sequence as stored data at a clock address that is synchronized with the clock signal and makes a round with one rotation of the optical disc
- First and second storage means for storing; and the description stored in the first and second storage means in synchronization with the clock signal.
- First and second storage data output means for sequentially reading data, and the first and second storage data output means for storing data when reading the storage data from the first and second storage means, respectively.
- Phase correction means for correcting the phases of the clock address and the clock address for reading, respectively, and addition means for adding the output signals of the first and second stored data output means to the control signal
- the focal position of the light beam Error signal generating means for generating an error signal indicating the amount of deviation from a desired position of the light source, and control means for generating a control signal for controlling the focal position of the light beam to a desired position based on the error signal;
- Rotation synchronization signal generation means for generating a clock signal synchronized with the rotation of the optical disc, and the control signal in sequence as stored data at a clock address that is synchronized with the clock signal and makes a round with one rotation of the optical disc
- a storage means for storing, and a first read out sequentially from the storage data stored in the storage means in synchronization with the clock signal;
- the focal position of the light beam is based on an output signal from an optical head that records or reproduces data by irradiating the optical disk with a track on the recording surface.
- Generating an error signal indicating an amount of deviation from a desired position generating a control signal for controlling the focal position of the light beam to a desired position based on the error signal,
- a step of generating a clock signal synchronized with rotation a step of sequentially storing the control signal as stored data in a clock address that is synchronized with the clock signal and makes a round in one rotation of the optical disc; Sequentially reading out the stored data in synchronism with the data, and when reading out the stored data Correcting the phase of the clock address related to storage and the clock address related to reading, adding the read storage data to the control signal, and controlling the focal position of the light beam based on the addition result
- the present invention it is possible to adjust a timing shift due to a delay time when data is stored or read according to a desired frequency band. Further, by having a plurality of storage means, it is possible to generate correction signals corresponding to a plurality of frequencies and adjust the output timing of each correction signal. As a result, high-precision and stable focus control and tracking control corresponding to high-speed recording / reproducing and high-density recording / reproducing can be realized.
- FIG. 1 is a configuration diagram of an optical disc apparatus incorporating a focal position control apparatus according to the first embodiment.
- FIG. 2 is a configuration diagram of an optical system of the optical head.
- FIG. 3 is a configuration diagram of the photodetector.
- FIG. 4 is a configuration diagram of a reproduction signal processing circuit, a focus error signal generation circuit, and a tracking error circuit.
- FIG. 5 is a configuration diagram of the focus memory processing circuit.
- FIG. 6 is an operation flowchart of the focal position control apparatus according to the first embodiment.
- FIG. 7 is a diagram illustrating the relationship between the FG signal, the clock signal, and the focus control signal.
- FIG. 8 is a diagram showing the timing of writing and reading data to the drive memory.
- FIG. 8 is a diagram showing the timing of writing and reading data to the drive memory.
- FIG. 9 is a waveform diagram of a focus control signal and a focus error signal when only focus control is performed.
- FIG. 10 is a waveform diagram of the focus control signal and the focus error signal to which the memory output signal is added.
- FIG. 11 is a waveform diagram of the focus control signal and the focus error signal to which the memory output signal is added.
- FIG. 12 is a waveform diagram of the focus control signal and the focus error signal to which the memory output signal is added.
- FIG. 13 is a waveform diagram of the focus control signal and the focus error signal to which the memory output signal is added.
- FIG. 14 is a waveform diagram of the focus control signal and the focus error signal to which the memory output signal is added.
- FIG. 15 is a characteristic diagram of the bandpass filter.
- FIG. 16 is a diagram illustrating the relationship between the phase correction amount and the maximum amplitude of the focus error signal.
- FIG. 17 is a configuration diagram of an optical disc apparatus incorporating the focal position control apparatus according to the second embodiment.
- FIG. 18 is a configuration diagram of the tracking memory processing circuit.
- FIG. 19 is an operation flowchart of the focal position control apparatus according to the second embodiment.
- FIG. 20 is an operation flowchart of the focal position control apparatus according to the third embodiment.
- FIG. 21 is a configuration diagram of a focus memory processing circuit in the focus position control apparatus according to the fourth embodiment.
- FIG. 22 is an operation flowchart of the focal position control apparatus according to the fourth embodiment.
- FIG. 23 is a diagram showing a change in reproduction jitter with respect to the phase correction amount.
- FIG. 24 is an operation flowchart of the focal position control apparatus according to the fifth embodiment.
- FIG. 25 is an operation flowchart of the focus position control apparatus according to the sixth embodiment.
- FIG. 26 is a waveform diagram of a drive signal when the tracking operation is stopped.
- FIG. 27 is a waveform diagram of a track crossing signal corresponding to FIG.
- FIG. 28 is a waveform diagram of a drive signal when the tracking operation is stopped.
- FIG. 29 is a waveform diagram of a track crossing signal corresponding to FIG.
- FIG. 30 is a configuration diagram of a focus memory processing circuit in the focus position control apparatus according to the seventh embodiment.
- FIG. 31 is an operation flowchart of the focal position control apparatus according to the seventh embodiment.
- 32 is a characteristic diagram of the bandpass filter shown in FIG. FIG.
- FIG. 33 is a waveform diagram of a focus control signal obtained by adding only one memory output signal.
- FIG. 34 is a waveform diagram of a focus control signal obtained by adding only one memory output signal.
- FIG. 35 is a waveform diagram of a focus control signal and a focus error signal obtained by adding two memory output signals.
- FIG. 36 is a configuration diagram of a focus memory processing circuit in the focus position control apparatus according to the eighth embodiment.
- FIG. 37 is an operation flowchart of the focal position control apparatus according to the eighth embodiment.
- FIG. 1 shows the configuration of an optical disc apparatus incorporating a focal position control apparatus according to Embodiment 1 of the present invention.
- the optical disk 1 is rotationally driven by a spindle motor 2.
- the rotation frequency of the spindle motor 2 is controlled by the spindle motor control circuit 5.
- the spindle motor control circuit 5 rotates the optical disc 1 at a rotation frequency designated by the spindle controller 62 of the system controller 61.
- the spindle motor control circuit 5 generates an FG signal from the rotation synchronization signal output from the spindle motor 2, and controls the rotation frequency of the spindle motor 2 while detecting the rotation frequency based on the FG signal.
- the optical head 3 focuses the light beam 39 on the recording surface of the optical disc 1 to record or reproduce data.
- Data to be recorded is converted into a recording signal by a recording signal processing circuit (not shown) and sent to the optical head 3.
- a reproduction signal read from the optical disc 1 is processed by a reproduction signal processing circuit 19 to generate signals such as an RF signal, a focus error signal, and a tracking error signal that are data reproduction signals.
- the objective lens 4 of the optical head 3 is driven in the optical axis direction (focus direction) of the light beam 39 by a focus actuator 7 constituted by a magnet and a focus drive coil.
- the focus error signal generation circuit 52 generates a focus error signal indicating the defocus of the light beam 39 with respect to the recording surface of the optical disc 1.
- the focus control circuit 6 outputs a focus control signal for controlling the voltage applied to the focus drive coil in order to adjust the focal position of the light beam 39 emitted from the optical head 3 to the recording surface of the optical disc 1 based on the focus error signal. Output.
- the optical head moving means 13 for moving the optical head 3 to different radial positions includes a traverse motor 14, a lead screw 15, a rack 16, and a guide shaft 17.
- a lead screw 15 formed on the rotation shaft of the traverse motor 14 is engaged with a rack 16 fixed to the optical head 3 mm.
- the optical head 3 is supported by a guide shaft 17 so as to be able to advance straight.
- the optical head 3 is moved in the radial direction of the optical disc 1 by the rotational torque of the traverse motor 14 transmitted through the lead screw 15 and the rack 16.
- the rotation of the traverse motor 14 is controlled by the traverse motor control circuit 18 in accordance with a command from the traverse control unit 63, and the radial position of the optical head 3 is controlled.
- FIG. 2 is a diagram showing the configuration of the optical system of the optical head 3.
- An objective lens 4 a laser light source 31, a coupling lens 32, a polarizing beam splitter 33, a 1 ⁇ 4 wavelength plate 34, a reflection mirror 35, a detection lens 36, a cylindrical lens 37, and a photodetector 38 are attached to the optical head 3. ing.
- the light beam 39 generated from the laser light source 31 is collimated by the lens 32, passes through the polarization beam splitter 33 and the quarter-wave plate 34, is bent by the reflection mirror 35, and is reflected on the optical disk 1 by the objective lens 4.
- the light is focused on the recording surface.
- the return light reflected by the recording surface of the optical disc 1 passes through the objective lens 4, is bent by the reflection mirror 35, passes through the quarter-wave plate 34, etc., and is focused and irradiated on the photodetector 38.
- FIG. 3 shows the relationship between the configuration of the photodetector 38 and the reflected light from the optical disc 1.
- the photodetector 38 includes four divided light receiving elements A, B, C, and D. Outputs a, b, c, and d of each light receiving element are output to the reproduction signal processing circuit 19.
- FIG. 4 shows the reproduction signal processing circuit 19, the focus error signal generation circuit 52, and the RF signal generation circuit 54.
- the reproduction signal processing circuit 19 outputs the outputs a, b, c, and d of the photodetector 38 to a circuit that generates an RF signal and a focus error signal, respectively.
- the focus control circuit 6 compensates the frequency characteristics of the amplitude and phase of the focus control signal to be output so that the focus control has a desired response characteristic and performs a stable operation.
- the output of the focus control circuit 6 is input to the focus drive circuit 51 via the control operation switch 71 and the adder 72.
- the focus actuator 7 is driven by the voltage applied to the focus drive coil output from the focus drive circuit 51.
- the focus drive signal generation circuit 21 emits a light beam from the current recording layer to another recording layer when the focus control is drawn from a state where the focus control is not operating or when recording / reproducing is performed on a multi-layer disc having a plurality of recording layers.
- an acceleration drive signal and a deceleration drive signal for the focus actuator 7 are generated.
- the control operation switch 71 stops the focus control circuit 6, shuts off the output, and inputs the output of the focus drive signal generation circuit 21 to the focus drive circuit 51 or operates the focus control to output the output of the focus control circuit 6.
- the input to the focus drive circuit 51 is switched.
- the focus control signal is selected by the control operation switch 71, the focus control signal is input to the focus memory processing circuit 23, and the output of the focus memory processing circuit 23 is added to the focus control signal by the adder 72. Input to the focus drive circuit 51.
- the system controller 61 includes a focus control unit 64, a focus error signal measurement unit 65, a spindle control unit 62, a traverse control unit 63, a reproduction data processing unit 66, and the like.
- the focus control unit 64 controls the entire focus control.
- the focus error signal measurement unit 65 measures the amplitude of the focus error signal.
- the spindle control unit 62 performs spindle motor control.
- the traverse control unit 63 performs traverse control.
- the reproduction data processing unit 66 performs a process for generating reproduction data based on the RF signal.
- FIG. 5 shows the configuration of the focus memory processing circuit 23.
- the focus control signal is input to the band pass filter 74 via the memory input switch 73.
- the band pass filter 74 generates a memory input signal obtained by extracting a signal in a desired frequency band included in the focus control signal, and outputs the memory input signal to the memory input control unit 75.
- the frequency band that the band pass filter 74 passes is controlled to a desired band by a filter control signal from the focus control unit 64.
- the memory input controller 75 stores the memory input signal as memory data at a predetermined clock address of the focus driving memory 76 in synchronization with the clock signal.
- the clock signal is a rotation synchronization signal generated by the clock generation unit 80 and multiplied by the FG signal input via the focus control unit 64.
- the clock address makes a round with one rotation of the optical disk 1.
- the memory output control unit 77 Based on the command signal from the phase correction unit 78, the memory output control unit 77 outputs the memory data stored at the designated clock address as a memory output signal.
- the memory output signal is amplified with a desired gain by the amplifier 79 and added to the focus control signal by the adder 72 via the memory output switch 81.
- the gain of the amplifier 79 is controlled to a desired gain by a gain control signal from the focus control unit 64.
- the focus control signal added with the memory output signal is input to the focus drive circuit 51 and converted into a voltage for driving the focus actuator 7.
- the operation of the optical disc apparatus incorporating the focus control apparatus (focus position control apparatus) according to this embodiment configured as described above will be described.
- First, the operation until the operation of the focus control device is started will be briefly described. Each operation is executed based on a command from the system controller 61.
- the traverse motor control circuit 18 drives the traverse motor 14 according to a command from the system controller 61 to move the optical head 3 to a desired radial position.
- the spindle motor control circuit 5 rotationally drives the optical disc 1 at a desired rotation frequency designated by the system controller 61. In this state, the operation of the focus control device is started.
- the objective lens 4 is moved up and down by a drive signal output from the focus drive signal generation circuit 21 in response to a command from the focus control unit 64.
- the focus control circuit 6 is operated by the control operation command at the timing when the focus error signal approaches zero, that is, the focus of the light beam 39 approaches the disk recording surface, and the control operation switch 71 is switched to perform focus control.
- a signal is input to the focus drive circuit 51 (S1).
- the memory input switch 73 is turned on, and the focus control signal passes through the bandpass filter 74 and is input to the memory input control unit 75 (S2).
- the memory input control unit 75 stores the memory input signal as memory data in order from the top clock address of the focus drive memory 76 in synchronization with the clock signal.
- the top clock address is again stored.
- the memory output control unit 77 stores the memory data stored at the designated clock address in memory based on the command signal from the phase correction unit 78 in synchronization with the clock.
- Output is started as an output signal (S4).
- the memory output switch 81 is turned on, the memory output signal is added to the focus control signal via the amplifier 79 (S5), and focus control is executed by the focus control signal to which the memory output signal is added (S6).
- FIG. 7 shows an FG signal, a clock signal, and a focus control signal stored at each clock address of the focus drive memory 76, that is, a memory input signal.
- the clock signal is output at a timing obtained by dividing one rotation of the optical disk 1 into M in synchronization with the FG signal.
- FIG. 8 shows a clock signal indicating timing for storing data in the focus drive memory 76, memory data stored at each clock address of the focus drive memory 76, a clock signal indicating timing for reading memory data from the focus drive memory 76, and The memory data read out in synchronization with the clock signal is shown.
- the memory input signal is stored in the Pth clock address as Pth memory data in synchronization with the Pth clock.
- the memory data stored at the (P + S) th clock address one round before the optical disk 1 is output in synchronization with the Pth clock. That is, the phase is advanced by S clocks with respect to the clock stored one round before and output.
- the number of clocks that advance the phase is specified by the phase correction unit 78.
- the phase is advanced by S clocks to read out, which is caused by the processing time of the memory input control unit 75, the writing processing time to the focus drive memory 76, and the phase delay due to the frequency characteristics of the bandpass filter 74.
- the delay of the memory output signal with respect to the focus control signal to be corrected can be corrected.
- the memory output signal is added to the focus control signal at a timing deviated from the timing at which the memory output signal should be output as the original deviation amount. For this reason, unnecessary disturbance is added to the normal feedback control performed by the focus control circuit 6, and the control residual to be suppressed increases conversely.
- By correcting this delay it is possible to suppress the effects of so-called repetitive control, that is, control residuals that cannot be suppressed by normal feedback control by the focus control circuit 6.
- the adjustment of the delay correction amount which is the greatest feature of the present invention, will be described.
- the adverse effect of this delay increases as the rotational frequency of the disk increases and the bandwidth of the control residual to be suppressed increases.
- the optimum delay correction amount may vary depending on the frequency of the control residual that has not been suppressed by normal feedback control by the focus control circuit 6, that is, the frequency of the control residual to be suppressed.
- FIG. 9 shows temporal changes of the focus control signal and the focus error signal when the memory output signal is not added to the focus control signal (memory output switch off).
- the rotational frequency of the optical disk 1 is about 200 Hz, and the gain intersection is about 6 kHz.
- the optical disk 1 has a surface vibration of the rotational frequency and its higher-order components and local surface vibration due to distortion of the optical disk 1. The case where it exists in the frequency of 10 times is shown.
- the broken line is an ideal focus control signal that can keep the control residual small enough to perform recording and reproduction.
- the normal feedback control cannot follow the surface vibration component of the rotational frequency, and does not follow the high-order local surface vibration at all.
- FIG. 10 to FIG. 14 show temporal changes of the focus control signal and the focus error signal to which the memory output signal is added under the same condition as above (memory output switch on).
- FIG. 15 shows the characteristics of the bandpass filter 74. 10 to 13, the band-pass filter 74 passes the band from the rotational frequency component to the frequency component of local surface shake.
- FIG. 10 shows a case where the phase correction amount S instructed from the phase correction unit 78 is zero. As can be seen from this figure, the rotational frequency component can be suppressed as compared with the case of only the normal focus control in FIG. 9, but a large phase lag occurs in the focus control signal for the higher-order local surface shake component. And it is worse than normal focus control.
- FIG. 11 shows a case where the phase correction amount S is set to 2. In this case, the low frequency components including the rotation frequency can be completely suppressed, but the higher order components are further deteriorated.
- FIG. 12 shows the case where the phase correction amount S is set to 5. In this case, since the phase of the low frequency component of the focus control signal is excessively advanced, there is a control residual of the rotational frequency component, but the high-order control residual can be kept small.
- phase correction amount S is set to 7.
- the phase of the focus control signal is too advanced, and the control residual is completely expanded.
- the phase correction amount S is set to 5 as in FIG. 12, but the characteristics of the bandpass filter 74 are different. That is, low frequency components such as rotational frequency components are blocked, and only high frequency components including local surface vibration frequency components are allowed to pass.
- the low frequency component is not stored in the focus drive memory 76, the low frequency component in which the phase existing in the memory output signal, that is, the focus control signal is excessively advanced does not exist. Therefore, it is possible to prevent the control residual of the rotation frequency component from increasing.
- FIG. 16 summarizes the relationship between the phase correction amount S and the control residual, and shows the change in the maximum value of the amplitude of the focus error signal when the phase correction amount S is changed.
- the vertical axis represents the ratio in decibels based on the maximum amplitude of the focus error signal in the case of only normal focus control.
- the control residual can be minimized by setting the phase correction amount S to 5 under the conditions shown in FIGS. 9 to 13.
- the control residual can be further reduced as compared with the case of FIG.
- the frequency of the phase lag and the magnitude thereof vary depending on the frequency characteristics of the band pass filter 74 and the like.
- the focus control device of the present embodiment the phase of the clock position at the time of reading with respect to the clock position at the time of writing to the focus drive memory 76 can be corrected. Therefore, it is possible to set the optimum phase correction amount S according to the condition and reduce the control residual.
- the frequency band of the memory input signal input to the focus drive memory 76 can be limited by the band pass filter 74, it is possible to prevent an excessive advance of the phase in an unnecessary band caused by the phase correction. As a result, the control residual can always be kept to a minimum in any case.
- FIG. 17 shows the configuration of an optical disc apparatus incorporating the focal position control apparatus according to Embodiment 1 of the present invention.
- the focus position control apparatus according to the present embodiment is obtained by replacing the focus control in the focus position control apparatus according to the first embodiment with tracking control. Only differences from the first embodiment will be described below.
- the objective lens 4 is driven in the radial direction (tracking direction) of the optical disc 1 by a tracking actuator 8 composed of a magnet and a tracking drive coil.
- the tracking error signal generation circuit 53 generates a tracking error signal indicating the shift of the focal position of the light beam 39 with respect to the track formed on the recording surface.
- the tracking control circuit 55 outputs a tracking control signal for causing the light beam 39 emitted from the optical head 3 to follow the track formed on the recording surface.
- the tracking drive circuit 56 controls the voltage to be applied to the tracking drive coil based on the tracking control signal.
- FIG. 4 shows the tracking error signal generation circuit 53.
- TE tracking error
- the tracking control circuit 55 compensates the frequency characteristics of the amplitude and phase of the tracking control signal to be output so that the tracking control has a desired response characteristic and performs a stable operation.
- the output of the tracking control circuit 55 is input to the tracking drive circuit 56 via the control operation switch 87 and the adder 88.
- the tracking actuator 8 is driven by the voltage applied to the tracking drive coil output from the tracking drive circuit 56.
- the tracking drive signal generation circuit 22 pulls the tracking control from a state where the tracking control is not operating, such as when the optical head 3 moves to a different radial position, or changes the focal position of the light beam 39 from one track to another track.
- a so-called track jump is performed, an acceleration drive signal and a deceleration drive signal for the tracking actuator 8 are generated.
- the control operation switch 87 stops the tracking control circuit 55, cuts off its output, inputs the output of the tracking drive signal generation circuit 22 to the tracking drive circuit 56, or operates the tracking control to output the output of the tracking control circuit 55.
- the input to the tracking drive circuit 56 is switched.
- the tracking control signal is selected by the control operation switch 87, the tracking control signal is input to the tracking memory processing circuit 24, and the output of the tracking memory processing circuit 24 is added to the tracking control signal by the adder 88. Input to the tracking drive circuit 56.
- the system controller 61 includes a tracking control unit 67, a tracking error signal measurement unit 68, a spindle control unit 62, a traverse control unit 63, a reproduction data processing unit 66, and the like.
- the tracking control unit 67 controls the entire tracking control.
- the tracking error signal measurement unit 68 measures the amplitude of the tracking error signal.
- FIG. 18 shows the configuration of the tracking memory processing circuit 24.
- the tracking control signal is input to the band pass filter 83 via the memory input switch 134.
- the band pass filter 83 generates a memory input signal obtained by extracting a signal in a desired frequency band included in the tracking control signal, and outputs the memory input signal to the memory input control unit 84.
- the frequency band that the band pass filter 83 passes is controlled to a desired band by a filter control signal from the tracking control unit 67.
- the memory input controller 84 stores the memory input signal as memory data at a predetermined clock address of the tracking drive memory 82 in synchronization with the clock signal.
- the clock signal is a rotation synchronization signal generated by the clock generation unit 80 and multiplied by the FG signal input via the tracking control unit 67.
- the clock address makes a round with one rotation of the optical disk 1.
- the memory output control unit 85 Based on the command signal from the phase correction unit 89, the memory output control unit 85 outputs the memory data stored at the designated clock address as a memory output signal.
- the memory output signal is amplified with a desired gain by the amplifier 86 and added to the tracking control signal by the adder 88 via the memory output switch 133.
- the gain of the amplifier 86 is controlled to a desired gain by a gain control signal from the tracking control unit 67.
- the tracking control signal added with the memory output signal is input to the tracking drive circuit 56 and converted into a voltage for driving the tracking actuator 8.
- the operation of the optical disc apparatus incorporating the tracking control apparatus will be described.
- the operation until the operation of the tracking control device is started will be briefly described.
- Each operation is executed based on a command from the system controller 61.
- the traverse motor control circuit 18 drives the traverse motor 14 according to a command from the system controller 61 to move the optical head 3 to a desired radial position.
- the spindle motor control circuit 5 rotationally drives the optical disc 1 at a desired rotation frequency designated by the system controller 61.
- the operation of the focus control device is started first, and the operation of the tracking control device is started in a state where the focus control is operating.
- the tracking control circuit 55 is operated by a control operation command from the tracking control unit 67 at the timing when the track crossing frequency due to the eccentricity of the track becomes relatively low, and the control operation switch 87 is switched so that the tracking control signal is sent to the tracking drive circuit 56. (S21).
- the memory input switches 134 and 133 are turned on, and the tracking control signal passes through the band filter 83 and is input to the memory input control unit 84 (S22).
- the memory input control unit 84 stores the memory input signal as memory data in order from the head clock address of the tracking drive memory 82 in synchronization with the clock signal. Are repeatedly stored (S23).
- the memory output control unit 85 synchronizes with the clock and stores the memory data stored at the specified clock address in the memory based on the command signal from the phase correction unit 89. Output is started as an output signal (S24). At the same time, the memory output switch 133 is turned on, and the memory output signal is added to the tracking control signal via the amplifier 86 (S25), and tracking control is executed by the tracking control signal added with the memory output signal (S26).
- the details of the operation from when the tracking control signal that has passed through the bandpass filter 83 is input to the memory input control unit 84 (S22) until the memory data is output as the memory output signal (S24) are described in the first embodiment. It is the same as the case of. Further, the surface shake of the rotational frequency component in the focus control described in the first embodiment corresponds to the eccentricity of the track in the tracking control according to the present embodiment. The higher-order local surface shake in the focus control according to the first embodiment corresponds to the eccentricity of the higher-order local track in the tracking control according to the present embodiment.
- the amount of eccentricity of the optical disc 1 to be recorded and reproduced in the tracking control As described above, as in the case of the focus control, the amount of eccentricity of the optical disc 1 to be recorded and reproduced in the tracking control, the presence / absence and the magnitude of high-order local eccentricity, the processing time of the memory input control unit 84, The phase lag frequency and its magnitude differ depending on the write processing time to the tracking drive memory 82 and the frequency characteristics of the band pass filter 83 and the like.
- the tracking control device according to the present embodiment, the phase of the clock position at the time of reading with respect to the clock position at the time of writing to the tracking drive memory 82 can be corrected. Therefore, it is possible to set the optimum phase correction amount S according to the condition and reduce the control residual.
- the frequency band of the memory input signal input to the tracking drive memory 82 can be limited by the band pass filter 83, it is possible to prevent an excessive phase advance in an unnecessary band caused by the phase correction. As a result, the control residual can always be kept to a minimum in any case.
- the focus position control apparatus is configured to obtain the delay correction amount that minimizes the maximum amplitude of the error signal as the optimum phase correction amount S.
- the focus position control device according to the present embodiment is a focus control device
- the configuration of the focal position control device according to the present embodiment and the optical disk device in which the focus position control device is incorporated are the same as those in the first embodiment (see FIGS. 1 and 5).
- the focus error signal measurement unit 65 measures the amplitude of the focus error signal generated by the focus error signal generation circuit 52. Then, the amplitude of the focus error signal is measured while changing the clock number S as the phase correction amount, and the clock number S with the smallest amplitude is determined.
- the focus error signal measurement unit 65 measures the maximum amplitude of the focus error signal during one rotation of the disk, and the amplitude. Is stored as V (0) (S104).
- the phase correction unit 78 sets the current output correction amount S by adding 1 to the memory output control unit 77 (S106). In this state, the focus error signal measuring unit 65 measures the maximum amplitude of the focus error signal during one rotation of the disk, and stores the amplitude as V (1).
- the phase correction amount S is increased by 1 and the measurement of the maximum amplitude of the focus error signal is repeated while confirming whether a predetermined number of measurements have been completed (S103).
- the phase correction amount S when the measured maximum amplitude becomes the smallest is obtained and set as the optimum phase correction amount S to complete (S107).
- phase correction amount S is obtained and set as the optimum phase correction amount S to complete (S107).
- the focus position control device minimizes the focus error signal regardless of the magnitude of the phase delay amount of the clock position when writing to the memory and when reading.
- An optimum phase correction amount that can be suppressed can be obtained, and in any case, a focal position control device having stable control characteristics can be realized.
- the present embodiment can be modified to the focal position control device that performs the tracking control shown in the second embodiment. That is, the tracking error signal is measured instead of the focus error signal, and the phase correction amount S that minimizes the maximum amplitude of the tracking error signal is determined.
- the optimum phase correction amount that can minimize the tracking error signal can be obtained regardless of the magnitude of the phase lag amount of the clock position between the time of writing to the memory and the time of reading.
- a focal position control device having stable control characteristics can be realized.
- the focal position control apparatus is configured to obtain a delay correction amount that minimizes the reproduction jitter obtained from the RF signal as the optimum phase correction amount S.
- the focus position control device according to the present embodiment is a focus control device
- the configuration of the focal position control device according to the present embodiment and the optical disk device in which it is incorporated are the same as those in the first embodiment (see FIG. 1).
- the reproduction data processing unit 66 measures reproduction jitter based on the RF signal generated by the RF signal generation circuit 54.
- FIG. 21 shows a configuration of the focus memory circuit 23 in the focus position control apparatus according to the present embodiment.
- the measured reproduction jitter value is sent to the focus control unit 64, and its magnitude is determined.
- the reproduction jitter is measured while changing the clock number S as the phase correction amount, and the clock number S with the smallest reproduction jitter is determined.
- the reproduction data processing unit 66 measures the reproduction jitter from the RF signal, and sets the magnitude as J (0).
- the data is sent to the focus control unit 64 and stored in the focus control unit 64 (S204).
- the phase correction unit 78 sets the memory output control unit 77 by adding 1 to the current phase correction amount S (S206).
- the reproduction data processing unit 66 measures the reproduction jitter and stores the amplitude as J (1).
- the phase correction amount S is increased by 1 and the reproduction jitter measurement is repeated while confirming whether a predetermined number of measurements have been completed (S203). When the predetermined number of measurements are completed, the phase correction amount S when the measured reproduction jitter is minimized is obtained and set as the optimum phase correction amount S (S207).
- FIG. 23 shows a change in reproduction jitter when the phase correction amount S is changed.
- there is a phase correction amount that minimizes the reproduction jitter and there is a tendency that the reproduction jitter deteriorates regardless of which phase correction amount is minimized. Therefore, even if the phase correction amount is too large, even if the phase correction amount is changed in the direction opposite to the optimal direction, only the reproduction jitter increases, the optimal point cannot be found, and focus control can become unstable. There is sex. Therefore, even when the measurement has not reached the predetermined number of times, if the reproduction jitter exceeds the predetermined limit value, the measurement is interrupted there (S205), and the reproduction jitter is the smallest among the measurements measured so far. The phase correction amount S at that time is obtained and set as the optimum phase correction amount S to complete (S207).
- the reproduction characteristics are the best regardless of the magnitude of the phase delay amount of the clock position between the time of writing to the memory and the time of reading.
- An optimal phase correction amount that is favorable can be obtained, and an optical disc apparatus having stable reproduction characteristics can be realized in any case.
- the focal position control apparatus is configured to obtain the delay correction amount that maximizes the amplitude of the RF signal as the optimum phase correction amount S.
- the focus position control device according to the present embodiment is a focus control device
- the configuration of the focal position control device according to the present embodiment and the optical disk device in which it is incorporated are the same as those in the fourth embodiment (see FIGS. 1 and 21).
- the difference from the fourth embodiment is that the amplitude of the RF signal is measured instead of the reproduction jitter. That is, the amplitude value of the RF signal measured by the reproduction data processing unit 66 is sent to the focus control unit 64.
- the focus control unit 64 determines the magnitude of the amplitude of the RF signal. Then, the amplitude of the RF signal is measured while changing the clock number S as the phase correction amount, and the clock number S at which the amplitude of the RF signal is maximized is determined.
- the reproduction data processing unit 66 measures the amplitude of the RF signal, and sets the magnitude as R (0) to focus. The data is sent to the control unit 64 and stored in the focus control unit 64 (S304). Next, in response to a command from the focus control unit 64, the phase correction unit 78 sets the memory output control unit 77 by adding 1 to the current phase correction amount S (S306). In this state, the reproduction data processing unit 66 measures the amplitude of the RF signal and stores the amplitude as R (1).
- the phase correction amount S is increased by 1 and the measurement of the RF signal amplitude is repeated while confirming whether a predetermined number of measurements have been completed (S303).
- the phase correction amount S when the measured RF signal has the largest amplitude is obtained and set as the optimum phase correction amount S (307).
- the measurement is interrupted (S305). Then, the phase correction amount S when the amplitude of the RF signal is maximized is obtained from those measured so far, and is set as the optimum phase correction amount S to be completed (S307).
- the reproduction characteristics are the best regardless of the magnitude of the phase delay amount of the clock position between the time of writing to the memory and the time of reading.
- An optimal phase correction amount that is favorable can be obtained, and an optical disc apparatus having stable reproduction characteristics can be realized in any case.
- Embodiment 6 The focus position control apparatus according to Embodiment 6 of the present invention outputs a memory output signal even when normal focus control or tracking control is stopped, and adds it to the drive signal output by the tracking drive signal generation circuit 22. Then, the focus actuator 7 and the tracking actuator 8 are driven to cause the focal position of the light beam 39 to follow surface deflection and eccentricity. With this configuration, it is possible to stabilize the focus jump, tracking jump, and the focus control and tracking control pull-in operations after movement between tracks.
- the focus position control of the focus position control apparatus according to the present embodiment is tracking control will be described as an example.
- the configuration of the focal position control apparatus according to the present embodiment is the same as that of the second embodiment (see FIGS. 17 and 18).
- the memory data stored in the tracking drive memory 82 is output as a memory output signal.
- the memory output signal is added to the tracking control signal with the memory output switch 133 turned on, and the tracking control signal obtained by adding the memory output signal is used.
- the phase correction amount S is set to a value at which the maximum amplitude of the tracking error signal is the smallest or a value at which the reproduction characteristic is the best.
- This phase correction amount is set as a phase correction amount C (S401).
- the control operation switch 87 is switched to the tracking drive signal generation circuit 22 side, and the tracking control operation is stopped (S402).
- the memory input switches 134 and 133 are turned off, and the update of the memory data in the tracking drive memory 82 is stopped (S403).
- the phase correction unit 89 switches the phase correction amount from the previously set phase correction amount C to the phase correction amount D according to the command of the tracking control unit 67 (S404).
- the phase correction amount D is a value at which the control residual in the low frequency band including the rotation frequency is the smallest.
- the memory output switch 133 remains on, and the stored memory data is added to the drive signal by the adder 88 as a memory output signal and input to the tracking drive circuit 56 (S405).
- the tracking actuator 8 is driven by the drive signal to which the memory output signal is added, and the focal position of the light beam 39 is maintained following the eccentricity of the track (S406). Thereafter, the movement of the optical head 3 in the radial direction by the seek operation is completed, and the tracking control pull-in is started (S407).
- tracking control pull-in can be stabilized by performing the timing when the track crossing frequency is relatively low due to the eccentricity of the track.
- the tracking actuator 8 is driven by the memory output signal most suitable for following the eccentricity from the time when the seek operation is started, the time when the movement of the optical head 3 is completed and the start of tracking control is started.
- the track crossing frequency of the light beam 39 is low. Therefore, stable pull-in is possible immediately.
- the control operation switch 87 is switched to the tracking control circuit 55 side (S408).
- the phase correction unit 89 returns the phase correction amount from the phase correction amount D set so far to the phase correction amount C according to the command of the tracking control unit 67.
- the memory input switch 134 is turned on, and writing to the tracking drive memory 82 is resumed (S401).
- the phase correction amount is set to a value that minimizes the maximum amplitude of the tracking error signal, for example, the phase so that a high-order frequency component can be sufficiently suppressed as shown in FIG. Set the correction amount to 5. While tracking control is stopped, there is no need to suppress higher-order frequency components, so the phase correction amount is set to 2 so that the rotational frequency components can be suppressed as shown in FIG.
- FIG. 26 shows a drive signal when the phase correction amount is set to 5 which is a suitable value during the tracking control operation even when the tracking control is stopped.
- the phase of the rotation frequency component has advanced too much, and the follow-up performance with respect to eccentricity deteriorates.
- FIG. 27 shows a track crossing signal of the light beam 39 in this case.
- FIG. 28 since the phase correction amount is switched from 5 to 2 when the tracking control is stopped, the phase of the rotation frequency component is optimized, and the followability to the eccentricity is improved.
- FIG. 29 shows a track crossing signal of the light beam 39 in this case. The track crossing frequency in FIG. 29 is lower than that in FIG.
- stable tracking control can be drawn, and not only the recording / reproducing characteristics can be improved, but also the access speed can be increased by stabilizing and shortening the seek operation. realizable.
- the same effect as described above can be obtained with respect to the surface shake of the optical disc 1. That is, the focus position of the light beam 39 can follow the surface shake even during the focus jump, and the focus control pull-in after the focus jump can be stabilized.
- the focal position control apparatus has a low-frequency drive memory and a high-frequency drive memory individually, and can individually optimize the respective phase correction amounts. Further, unnecessary frequency components of the memory input signal are blocked by a band pass filter provided individually.
- the basic configuration of the focal position control device according to the present embodiment and the optical disk device in which the focus position control device is incorporated are the same as those in the first embodiment (see FIG. 1).
- FIG. 30 shows a configuration of the focus memory processing circuit 23 in the focus position control apparatus according to the present embodiment.
- the focus control signal is input to each of the bandpass filters 126 and 176 via the memory input switch 73.
- the band pass filter 126 passes only low frequency components including the rotation frequency of the focus control signal, generates a memory input signal, and outputs the memory input signal to the memory input control unit 138.
- the band-pass filter 176 passes only high frequency components such as a local surface vibration frequency of the focus control signal, generates a memory input signal obtained by extracting a signal in a desired frequency band, generates a memory input signal,
- the data is output to the memory input control unit 188.
- the frequency band that the band-pass filters 126 and 176 pass can be controlled to a desired band by a filter control signal from the focus control unit 64.
- the memory input control units 138 and 188 store each memory input signal as memory data at a predetermined clock address of the focus drive memories 121 and 171 in synchronization with the common clock signal.
- the clock signal is a rotation synchronization signal generated by the clock generation unit 80 and multiplied by the FG signal input via the focus control unit 64.
- the clock address makes a round with one rotation of the optical disk 1.
- the memory output control units 136 and 186 output the memory data stored in the designated clock addresses as respective memory output signals based on the command signals sent from the phase correction unit 122, respectively. These memory output signals are amplified with desired gains by the amplifier 128 and the amplifier 178, respectively, and added to the focus control signal by the adder 72 via the memory output switches 131 and 181.
- the gains of the amplifiers 128 and 178 are each controlled to a desired gain by a gain control signal from the focus control unit 64.
- the focus control signal to which these memory output signals are added is input to the focus drive circuit 51 and converted into a voltage for driving the focus actuator 7.
- the operation until the operation of the focus control apparatus is the same as in the first embodiment. is there.
- Each operation is executed based on a command from the system controller 61.
- the traverse motor control circuit 18 drives the traverse motor 14 according to a command from the system controller 61 to move the optical head 3 to a desired radial position.
- the spindle motor control circuit 5 rotationally drives the optical disc 1 at a desired rotation frequency designated by the system controller 61. In this state, the operation of the focus control device is started.
- the objective lens 4 is moved up and down by a drive signal output from the focus drive signal generation circuit 21 in response to a command from the focus control unit 64.
- the focus control circuit 6 is operated by the control operation command at the timing when the focus error signal approaches zero, that is, the focus of the light beam 39 approaches the disk recording surface, and the control operation switch 71 is switched to perform focus control.
- a signal is input to the focus drive circuit 51 (S501).
- the memory input switch 73 is turned on, and the focus control signal passes through the band filters 126 and 176 and is input to the memory input control units 138 and 188, respectively (S502).
- the memory input control units 138 and 188 store each memory input signal as memory data in order from the leading clock address of the focus drive memories 121 and 171 in synchronization with the clock signal, and when the optical disk 1 rotates once from the start of storage. Further, it is repeatedly stored from the head clock address (S503).
- the memory output control units 136 and 186 are synchronized with the clock and each memory stored at the designated clock address based on the command signal from the phase correction unit 122. Output is started using the data as each memory output signal (S504).
- the memory output switches 131 and 181 are turned on, and the memory output signals are added to the focus control signal via the amplifier 128 and the amplifier 178, respectively (S505), and the focus control is performed by the focus control signal obtained by adding these memory output signals. Is executed (S506).
- each memory input signal is input to each of the memory input control units 138 and 188 (S502) until each memory data is output as each memory output signal (S504) is the same as in the first embodiment. It is.
- a feature of the present embodiment is that the bandpass filter, the focus drive memory, the memory output control unit, the amplifier, and the memory output switch are high for low frequency components including rotational frequency components and high frequency components of local surface vibration. Two frequency components are provided, and the phase correction amount S is different between the two frequency components.
- FIG. 32 shows the gain characteristics of the bandpass filters 126 and 176.
- the band pass filter 126 passes only low frequency components including the rotation frequency of the focus control signal.
- the band pass filter 176 passes only high frequency components such as a local surface shake frequency of the focus control signal.
- FIG. 33 shows the memory output signal when the memory input signal that has passed through the bandpass filter 126 is stored in the focus drive memory 121 and the phase correction amount S is set to 2 so that the phase lag in the band near the rotation frequency can be corrected.
- the time change of the focus control signal to which is added is shown. As can be seen from this figure, the frequency component of local surface vibration is not included, and the phase delay of the rotational frequency component is almost eliminated.
- the memory input signal that has passed through the bandpass filter 176 is stored in the focus drive memory 171 and the phase correction amount S is set to 5 so that the phase lag in the band near the frequency of local surface vibration can be corrected.
- the time change of the focus control signal to which the memory output signal is added is shown.
- FIG. 35 shows a focus control signal obtained by adding two memory output signals and a focus error signal at that time.
- the phase delay is eliminated in both the rotational frequency component and the higher-order frequency component, and the amplitude of the focus error signal is also kept small.
- the phase residual of the rotation frequency component of the focus control signal and the phase delay of the higher-order frequency component hardly occur, so the control residual is very small. It can be suppressed.
- the focal position control apparatus according to the sixth embodiment when the focal position control is stopped, only the memory output switch 131 is turned on, and the memory output signal from the memory output control unit 136 is added to the drive signal. Then, a large suppression rate can be obtained in a low frequency band, and the focus position control can be stably pulled in. Therefore, not only the recording / reproduction characteristics of the optical disc apparatus can be improved, but also the access speed can be increased by stabilizing and shortening the seek operation.
- the focal position control apparatus has a low-frequency memory output control unit and a high-frequency memory output control unit individually for one drive memory, and each phase correction amount. Are individually optimized, and an unnecessary frequency component of each memory output signal is blocked by a band-pass filter provided individually.
- the basic configuration of the focal position control device according to the present embodiment and the optical disk device in which the focus position control device is incorporated are the same as those in the first embodiment (see FIG. 1).
- FIG. 36 shows a configuration of the focus memory processing circuit 23 in the focus position control apparatus according to the present embodiment.
- the focus control signal is input to the memory input control unit 75 via the memory input switch 73.
- the memory input controller 75 stores the memory input signal as memory data at a predetermined clock address of the focus driving memory 76 in synchronization with the clock signal.
- the clock signal is a rotation synchronization signal generated by the clock generation unit 80 and multiplied by the FG signal input via the focus control unit 64.
- the clock address makes a round with one rotation of the optical disk 1.
- the memory output control units 137 and 187 output the memory data stored at the designated clock addresses as the respective memory output signals based on the command signals sent from the phase correction unit 123, respectively.
- bandpass filters 127 and 177 These memory output signals are input to bandpass filters 127 and 177, respectively.
- the band pass filter 127 passes only a low frequency component including the rotation frequency of the memory output signal from the memory output control unit 137 and inputs the low frequency component to the amplifier 129.
- the band pass fill 177 passes only high frequency components such as local surface vibration frequency of the memory output signal from the memory output control unit 187 and inputs the high frequency component to the amplifier 179.
- the frequency band that the band-pass filters 127 and 177 pass can be controlled to a desired band by a filter control signal from the focus control unit 64.
- These memory output signals are amplified with desired gains by the amplifiers 129 and 179, respectively, and added to the focus control signal by the adder 72 via the memory output switches 132 and 182, respectively.
- the gains of the amplifiers 129 and 179 are controlled to a desired gain by a gain control signal from the focus control unit 64.
- the focus control signal to which these memory output signals are added is input to the focus drive circuit 51 and converted into a voltage for driving the focus actuator 7.
- the operation until the operation of the focus control apparatus is the same as in the first embodiment. is there.
- Each operation is executed based on a command from the system controller 61.
- the traverse motor control circuit 18 drives the traverse motor 14 according to a command from the system controller 61 to move the optical head 3 to a desired radial position.
- the spindle motor control circuit 5 rotationally drives the optical disc 1 at a desired rotation frequency designated by the system controller 61. In this state, the operation of the focus control device is started.
- the objective lens 4 is moved up and down by a drive signal output from the focus drive signal generation circuit 21 in response to a command from the focus control unit 64.
- the focus control circuit 6 is operated by the control operation command at the timing when the focus error signal approaches zero, that is, the focus of the light beam 39 approaches the disk recording surface, and the control operation switch 71 is switched to perform focus control.
- a signal is input to the focus drive circuit 51 (S601).
- the memory input switch 73 is turned on, and the focus control signal is input to the memory input control unit 75 (S602).
- the memory input control unit 75 stores the memory input signal as memory data in order from the top clock address of the focus drive memory 76 in synchronization with the clock signal.
- the top clock address is again stored.
- the memory output control units 137 and 187 are synchronized with the clock, and are stored in the respective clock addresses specified based on the command signal from the phase correction unit 123. Output is started using each data as a memory output signal (S604).
- the memory output switches 132 and 182 are turned on, and these memory output signals are amplified by the amplifiers 129 and 179 through the band-pass filters 127 and 177, respectively, and added to the focus control signal (S605). Then, focus control is executed by a focus control signal to which these memory output signals are added (S606).
- the detailed operation from when the memory input signal is input to the memory input control unit 75 (S602) until the memory data is output as each memory output signal (S604) is the same as in the first embodiment.
- the feature of this embodiment is that the memory output control unit, the bandpass filter, the amplifier, and the memory output switch are for low frequency components including rotational frequency components and for high frequency components including local surface vibration frequency components. Two are provided, and the phase correction amount S is different between the two.
- the memory output control units 137 and 187 read the memory data from the clock address corrected by a predetermined phase correction amount set from the phase correction unit 123, respectively.
- the phase correction amount S set in the memory output control unit 137 is set to 2 so that the phase delay in the band near the rotation frequency can be corrected.
- the memory output signal read with the phase correction amount set in this way has a phase delay in the frequency band of local surface vibration (see FIG. 11).
- the phase correction amount S set in the memory output control unit 187 is set to 5 so that the phase delay in the band near the frequency of local surface vibration can be corrected.
- the memory output signal read with the phase correction amount set in this way has an excessively advanced phase in the band near the rotation frequency (see FIG. 12). Therefore, if the memory output signal is added to the focus control signal and the focus control is performed as it is, the control residual can be made smaller than the normal focus control, but a sufficient control suppression rate may not be obtained.
- the memory output signals are configured to pass through the band-pass filters 127 and 177, respectively.
- the gain characteristics of the bandpass filters 127 and 177 are the same as those of the bandpass filters 126 and 176 according to Embodiment 7, respectively (see FIG. 32). Similar to the bandpass filter 126, the bandpass filter 127 passes only low frequency components including the rotation frequency of the focus control signal. Similarly to the bandpass filter 176, the bandpass fill 177 passes only high frequency components such as a local surface shake frequency of the focus control signal.
- the frequency band of local surface vibration whose phase is delayed in the memory output signal from the memory output control unit 137 is blocked by the band pass filter 127. Further, the band around the rotation frequency whose phase has advanced too much in the memory output signal from the memory output control unit 187 is blocked by the band pass fill 177.
- the phase in the frequency band to be suppressed is optimized by each memory output signal, and unnecessary frequency components other than the frequency band to be suppressed can be removed. As a result, it is possible to accurately follow low frequency components due to surface vibrations and high frequency components due to local surface vibrations, and the control residual can be sufficiently reduced. .
- the phase residual of the rotation frequency component of the focus control signal and the phase delay of the higher-order frequency component hardly occur, so the control residual is very small.
- a focus position control device that can be suppressed can be realized.
- the focal position control apparatus according to the sixth embodiment when the focal position control is stopped, only the memory output switch 132 is turned on, and the memory output signal from the memory output control unit 137 is added to the drive signal. Then, a large suppression rate can be obtained in a low frequency band, and the focus position control can be stably pulled in. Therefore, not only the recording / reproduction characteristics of the optical disc apparatus can be improved, but also the access speed can be increased by stabilizing and shortening the seek operation.
- the focal position control apparatus can be applied to an optical disk apparatus that records and reproduces information by irradiating an optical disk with a light beam.
- Focus control circuit control means 7 Focus actuator (drive means) 8 Tracking actuator (drive means) 21 Focus drive signal generation circuit (control means) 22 Tracking drive signal generation circuit (control means) 52 Focus error signal generation circuit (error signal generation means) 53 Tracking error signal generation circuit (error signal generation means) 55 Tracking control circuit (control means) 65 Focus error signal measuring unit (reproduction signal measuring means) 66 Reproduction data processing unit (reproduction signal measuring means) 68 Tracking error signal measuring unit (reproduction signal measuring means) 72 Adder (addition means) 74 Band pass filter (filter means) 76 Focus drive memory (storage means) 77 Memory output controller (stored data output means) 78 Phase corrector (phase corrector) 80 Clock generator (rotation synchronization signal generator) 82 Tracking drive memory (memory means) 83 Band pass filter (filter means) 85 Memory output controller (stored data output means) 88 Adder (addition means) 89 Phase correction unit (phase correction means) 121 Focus drive memory (first storage means) 122 Phase correction unit
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Abstract
Description
図1は、本発明の実施の形態1に係る焦点位置制御装置を組み込んだ光ディスク装置の構成を示す。光ディスク1はスピンドルモータ2によって回転駆動される。スピンドルモータ2の回転周波数はスピンドルモータ制御回路5によってコントロールされる。スピンドルモータ制御回路5は、システムコントローラ61のスピンドルコントロール部62から指定された回転周波数で光ディスク1を回転させる。このとき、スピンドルモータ制御回路5は、スピンドルモータ2から出力される回転同期信号からFG信号を生成し、そのFG信号により回転周波数を検出しながら、スピンドルモータ2の回転周波数を制御する。光学ヘッド3は光ビーム39を光ディスク1の記録面に集光してデータの記録又は再生を行う。記録すべきデータは図示しない記録信号処理回路で記録信号に変換されて光学ヘッド3に送られる。光ディスク1から読み取った再生信号は再生信号処理回路19で処理され、データ再生信号であるRF信号、フォーカスエラー信号、トラッキングエラー信号などの信号が生成される。
図17は、本発明の実施の形態1に係る焦点位置制御装置を組み込んだ光ディスク装置の構成を示す。本実施形態に係る焦点位置制御装置は、実施の形態1に係る焦点位置制御装置におけるフォーカス制御をトラッキング制御に置き換えたものである。以下、実施の形態1と異なる点についてのみ説明する。
本発明の実施の形態3に係る焦点位置制御装置は、最適な位相補正量Sとしてエラー信号の最大振幅が最も小さくなる遅延補正量を求めるように構成したものである。以下、本実施形態に係る焦点位置制御装置がフォーカス制御装置である場合を例にして説明する。本実施形態に係る焦点位置制御装置及びそれが組み込まれた光ディスク装置の構成は実施の形態1と同様である(図1、図5参照)。フォーカスエラー信号測定部65はフォーカスエラー信号生成回路52で生成されたフォーカスエラー信号の振幅を測定する。そして位相補正量としてのクロック数Sを変化させながら、フォーカスエラー信号の振幅を測定し、その振幅が最も小さくなるクロック数Sを決定する。
本発明の実施の形態4に係る焦点位置制御装置は、最適な位相補正量SとしてRF信号から得られる再生ジッタが最も小さくなる遅延補正量を求めるように構成したものである。以下、本実施形態に係る焦点位置制御装置がフォーカス制御装置である場合を例にして説明する。本実施形態に係る焦点位置制御装置及びそれが組み込まれた光ディスク装置の構成は実施の形態1と同様である(図1参照)。再生データ処理部66はRF信号生成回路54で生成されたRF信号に基づき、再生ジッタを測定する。図21は、本実施形態に係る焦点位置制御装置におけるフォーカスメモリ回路23の構成を示す。測定した再生ジッタ値はフォーカスコントロール部64に送られ、その大きさが判断される。そして位相補正量としてのクロック数Sを変化させながら、再生ジッタを測定し、再生ジッタが最も小さくなるクロック数Sを決定する。
本発明の実施の形態5に係る焦点位置制御装置は、最適な位相補正量SとしてRF信号の振幅が最も大きくなる遅延補正量を求めるように構成したものである。以下、本実施形態に係る焦点位置制御装置がフォーカス制御装置である場合を例にして説明する。本実施形態に係る焦点位置制御装置及びそれが組み込まれた光ディスク装置の構成は実施の形態4と同様である(図1、図21参照)。実施の形態4と異なるのは、再生ジッタの代わりにRF信号の振幅を測定するという点である。すなわち、再生データ処理部66において測定されたRF信号の振幅値はフォーカスコントロール部64に送られる。フォーカスコントロール部64はRF信号の振幅の大きさを判断する。そして位相補正量としてのクロック数Sを変化させながら、RF信号の振幅を測定し、RF信号の振幅が最も大きくなるクロック数Sを決定する。
本発明の実施の形態6に係る焦点位置制御装置は、通常のフォーカス制御やトラッキング制御が停止されている際にもメモリ出力信号を出力し、トラッキング駆動信号生成回路22が出力する駆動信号に加算してフォーカスアクチュエータ7やトラッキングアクチュエータ8を駆動し、光ビーム39の焦点位置を面振れや偏心に追従させるものである。この構成によりフォーカスジャンプ、トラッキングジャンプ、及びトラック間移動後のフォーカス制御、トラッキング制御の引き込み動作を安定化させることができる。以下、本実施形態に係る焦点位置制御装置の焦点位置制御がトラッキング制御である場合を例にして説明する。本実施形態に係る焦点位置制御装置の構成は実施の形態2の構成と同様である(図17、図18参照)。
本発明の実施の形態7に係る焦点位置制御装置は、低周波数用の駆動メモリと高周波数用の駆動メモリを個別に有し、それぞれの位相補正量を個別に最適化できるものである。さらにメモリ入力信号は個別に設けられたバンドパスフィルタによって不要な周波数成分が遮断される。本実施形態に係る焦点位置制御装置及びそれが組み込まれた光ディスク装置の基本構成は実施の形態1と同様である(図1参照)。
本発明の実施の形態8に係る焦点位置制御装置は、一つの駆動メモリに対して低周波数用のメモリ出力制御部と高周波数用のメモリ出力制御部を個別に有し、それぞれの位相補正量を個別に最適化し、さらに個別に設けられたバンドパスフィルタによってそれぞれのメモリ出力信号の不要な周波数成分を遮断するものである。本実施形態に係る焦点位置制御装置及びそれが組み込まれた光ディスク装置の基本構成は実施の形態1と同様である(図1参照)。
6 フォーカス制御回路(制御手段)
7 フォーカスアクチュエータ(駆動手段)
8 トラッキングアクチュエータ(駆動手段)
21 フォーカス駆動信号生成回路(制御手段)
22 トラッキング駆動信号生成回路(制御手段)
52 フォーカスエラー信号生成回路(エラー信号生成手段)
53 トラッキングエラー信号生成回路(エラー信号生成手段)
55 トラッキング制御回路(制御手段)
65 フォーカスエラー信号測定部(再生信号計測手段)
66 再生データ処理部(再生信号計測手段)
68 トラッキングエラー信号測定部(再生信号計測手段)
72 加算器(加算手段)
74 バンドパスフィルタ(フィルタ手段)
76 フォーカス駆動メモリ(記憶手段)
77 メモリ出力制御部(記憶データ出力手段)
78 位相補正部(位相補正手段)
80 クロック生成部(回転同期信号生成手段)
82 トラッキング駆動メモリ(記憶手段)
83 バンドパスフィルタ(フィルタ手段)
85 メモリ出力制御部(記憶データ出力手段)
88 加算器(加算手段)
89 位相補正部(位相補正手段)
121 フォーカス駆動メモリ(第1の記憶手段)
122 位相補正部(位相補正手段)
123 位相補正部(位相補正手段)
126 バンドパスフィルタ(第1のフィルタ手段)
127 バンドパスフィルタ(第1のフィルタ手段)
136 メモリ出力制御部(第1の記憶データ出力手段)
137 メモリ出力制御部(第1の記憶データ出力手段)
171 フォーカス駆動メモリ(第2の記憶手段)
176 バンドパスフィルタ(第2のフィルタ手段)
177 バンドパスフィルタ(第2のフィルタ手段)
186 メモリ出力制御部(第2の記憶データ出力手段)
187 メモリ出力制御部(第2の記憶データ出力手段)
Claims (26)
- 記録面にトラックが設けられた光ディスクに光ビームを照射してデータを記録し、又は再生する光学ヘッドからの出力信号に基づき、前記光ビームの焦点位置の所望の位置からのずれ量を示すエラー信号を生成するエラー信号生成手段と、
前記エラー信号に基づき、前記光ビームの焦点位置を所望の位置に制御するための制御信号を生成する制御手段と、
前記光ディスクの回転に同期したクロック信号を生成する回転同期信号生成手段と、
前記制御信号を、前記クロック信号に同期し、かつ、前記光ディスクの1回転で一巡するクロックアドレスに、記憶データとして順次格納するための記憶手段と、
前記クロック信号に同期して前記記憶手段に格納された前記記憶データを順次読み出す記憶データ出力手段と、
前記記憶データ出力手段が前記記憶手段から前記記憶データを読み出す際に、格納に係るクロックアドレスと読み出しに係るクロックアドレスとの位相を補正する位相補正手段と、
前記記憶データ出力手段の出力信号を前記制御信号に加算する加算手段と、を具備し、
前記位相補正手段は、前記エラー信号に基づく前記光学ヘッドの駆動が行われている場合及び行われていない場合のいずれにおいても前記位相を補正するものであり、
前記エラー信号に基づく前記光学ヘッドの駆動が行われていない場合、前記記憶手段への前記制御信号の入力を遮断する
ことを特徴とする焦点位置制御装置。 - 請求項1に記載の焦点位置制御装置において、
前記位相補正手段は、前記エラー信号に基づく前記光学ヘッドの駆動が行われている場合、前記エラー信号の所望の周波数成分を抑制するように前記位相を補正する
ことを特徴とする焦点位置制御装置。 - 請求項2に記載の焦点位置制御装置において、
前記位相補正手段は、前記エラー信号に基づく前記光学ヘッドの駆動が行われている場合、前記エラー信号が最大となる周波数成分を抑制するように前記位相を補正する
ことを特徴とする焦点位置制御装置。 - 請求項1に記載の焦点位置制御装置において、
前記制御信号における所定の帯域の周波数成分を抽出するフィルタ手段を具備し、
前記記憶手段は、前記フィルタ手段によってフィルタリング処理された制御信号を格納する
ことを特徴とする焦点位置制御装置。 - 請求項1に記載の焦点位置制御装置において、
前記光学ヘッドの出力信号に基づく再生信号の振幅を計測する再生信号計測手段を具備し、
前記位相補正手段は、前記エラー信号に基づく前記光学ヘッドの駆動が行われている場合、前記再生信号の振幅が最大となるように前記位相を補正する
ことを特徴とする焦点位置制御装置。 - 請求項1に記載の焦点位置制御装置において、
前記光学ヘッドの出力信号に基づく再生信号のジッタを計測する再生信号計測手段を具備し、
前記位相補正手段は、前記エラー信号に基づく前記光学ヘッドの駆動が行われている場合、前記再生信号のジッタが最小となるように前記位相を補正する
ことを特徴とする焦点位置制御装置。 - 請求項1に記載の焦点位置制御装置において、
前記位相補正手段は、前記エラー信号に基づく前記光学ヘッドの駆動が行われていない場合、前記位相を、前記光学ヘッドの駆動が行われていたときの前記エラー信号における前記光ディスクの回転周波数成分を抑制する値に補正する
ことを特徴とする焦点位置制御装置。 - 記録面にトラックが設けられた光ディスクに光ビームを照射してデータを記録し、又は再生する光学ヘッドからの出力信号に基づき、前記光ビームの焦点位置の所望の位置からのずれ量を示すエラー信号を生成するエラー信号生成手段と、
前記エラー信号に基づき、前記光ビームの焦点位置を所望の位置に制御するための制御信号を生成する制御手段と、
前記光ディスクの回転に同期したクロック信号を生成する回転同期信号生成手段と、
前記制御信号を、前記クロック信号に同期し、かつ、前記光ディスクの1回転で一巡するクロックアドレスに、記憶データとして順次格納するための第1及び第2の記憶手段と、
前記クロック信号に同期して前記第1及び第2の記憶手段に格納された前記記憶データをそれぞれ順次読み出す第1及び第2の記憶データ出力手段と、
前記第1及び第2の記憶データ出力手段がそれぞれ前記第1及び第2の記憶手段から前記記憶データを読み出す際に、格納に係るクロックアドレスと読み出しに係るクロックアドレスとの位相をそれぞれ補正する位相補正手段と、
前記第1及び第2の記憶データ出力手段の出力信号を前記制御信号に加算する加算手段と、を具備する
ことを特徴とする焦点位置制御装置。 - 請求項8に記載の焦点位置制御装置において、
前記位相補正手段は、前記エラー信号の所望の周波数成分を抑制するように前記位相を補正する
ことを特徴とする焦点位置制御装置。 - 請求項8に記載の焦点位置制御装置において、
前記制御信号における所定の帯域の周波数成分を抽出する第1及び第2のフィルタ手段を具備し、
前記第1及び第2の記憶手段は、それぞれ、前記第1及び第2のフィルタ手段によってフィルタリング処理された制御信号を格納する
ことを特徴とする焦点位置制御装置。 - 請求項10に記載の焦点位置制御装置において、
前記第1及び第2のフィルタ手段の少なくとも一つは、前記制御信号における前記光ディスクの回転周波数成分を抽出する
ことを特徴とする焦点位置制御装置。 - 請求項8に記載の焦点位置制御装置において、
前記位相補正手段は、前記エラー信号に基づく前記光学ヘッドの駆動が行われている場合及び行われていない場合のいずれにおいても前記位相を補正するものであり、
前記第1及び前記第2の記憶データ出力手段の少なくとも一つは、前記エラー信号に基づく前記光学ヘッドの駆動が行われていない場合においても動作するものであり、
前記エラー信号に基づく前記光学ヘッドの駆動が行われていない場合、前記第1及び第2の記憶手段への前記制御信号の入力を遮断する
ことを特徴とする焦点位置制御装置。 - 請求項12に記載の焦点位置制御装置において、
前記位相補正手段は、前記エラー信号に基づく前記光学ヘッドの駆動が行われていない場合、前記位相を、前記光学ヘッドの駆動が行われていたときの前記エラー信号における前記光ディスクの回転周波数成分を抑制する値に補正する
ことを特徴とする焦点位置制御装置。 - 記録面にトラックが設けられた光ディスクに光ビームを照射してデータを記録し、又は再生する光学ヘッドからの出力信号に基づき、前記光ビームの焦点位置の所望の位置からのずれ量を示すエラー信号を生成するエラー信号生成手段と、
前記エラー信号に基づき、前記光ビームの焦点位置を所望の位置に制御するための制御信号を生成する制御手段と、
前記光ディスクの回転に同期したクロック信号を生成する回転同期信号生成手段と、
前記制御信号を、前記クロック信号に同期し、かつ、前記光ディスクの1回転で一巡するクロックアドレスに、記憶データとして順次格納するための記憶手段と、
前記クロック信号に同期して前記記憶手段に格納された前記記憶データを順次読み出す第1及び第2の記憶データ出力手段と、
前記第1及び第2の記憶データ出力手段が前記記憶手段から前記記憶データを読み出す際に、格納に係るクロックアドレスと読み出しに係るクロックアドレスとの位相をそれぞれ補正する位相補正手段と、
前記第1及び第2の記憶データ出力手段の出力信号を前記制御信号に加算する加算手段と、を具備する
ことを特徴とする焦点位置制御装置。 - 請求項14に記載の焦点位置制御装置において、
前記位相補正手段は、前記エラー信号の所望の周波数成分を抑制するように前記位相を補正する
ことを特徴とする焦点位置制御装置。 - 請求項14に記載の焦点位置制御装置において、
前記第1及び第2の記憶データ出力手段のそれぞれの出力信号における所定の帯域の周波数成分を抽出する第1及び第2のフィルタ手段を具備し、
前記加算手段は、前記第1及び第2のフィルタ手段によってフィルタリング処理された後の前記第1及び第2の記憶データ出力手段の出力信号を前記制御信号に加算する
ことを特徴とする焦点位置制御装置。 - 請求項16に記載の焦点位置制御装置において、
前記第1及び第2のフィルタ手段の少なくとも一つは、前記第1及び第2の記憶データ出力手段の出力信号における前記光ディスクの回転周波数成分を抽出する
ことを特徴とする焦点位置制御装置。 - 請求項14に記載の焦点位置制御装置において、
前記位相補正手段は、前記エラー信号に基づく前記光学ヘッドの駆動が行われている場合及び行われていない場合のいずれにおいても前記位相を補正するものであり、
前記第1及び前記第2の記憶データ出力手段の少なくとも一つは、前記エラー信号に基づく前記光学ヘッドの駆動が行われていない場合においても動作するものであり、
前記エラー信号に基づく前記光学ヘッドの駆動が行われていない場合、前記記憶手段への前記制御信号の入力を遮断する
ことを特徴とする焦点位置制御装置。 - 請求項18に記載の焦点位置制御装置において、
前記位相補正手段は、前記エラー信号に基づく前記光学ヘッドの駆動が行われていない場合、前記位相を、前記光学ヘッドの駆動が行われていたときの前記エラー信号における前記光ディスクの回転周波数成分を抑制する値に補正する
ことを特徴とする焦点位置制御装置。 - 請求項1の焦点位置制御装置において、
前記エラー信号は、前記光ビームの焦点の前記記録面からのずれを示すフォーカスエラー信号及び前記光ビームの焦点の前記トラックからのずれを示すトラッキングエラー信号の少なくとも一方であり、
前記制御信号は、前記フォーカスエラー信号に基づき前記光ビームの焦点を前記記録面に合わせるためのフォーカス制御信号及び前記トラッキングエラー信号に基づき前記光ビームを前記トラックに追従させるためのトラッキング制御信号の少なくとも一方である
ことを特徴とする焦点位置制御装置。 - 請求項8の焦点位置制御装置において、
前記エラー信号は、前記光ビームの焦点の前記記録面からのずれを示すフォーカスエラー信号及び前記光ビームの焦点の前記トラックからのずれを示すトラッキングエラー信号の少なくとも一方であり、
前記制御信号は、前記フォーカスエラー信号に基づき前記光ビームの焦点を前記記録面に合わせるためのフォーカス制御信号及び前記トラッキングエラー信号に基づき前記光ビームを前記トラックに追従させるためのトラッキング制御信号の少なくとも一方である
ことを特徴とする焦点位置制御装置。 - 請求項14の焦点位置制御装置において、
前記エラー信号は、前記光ビームの焦点の前記記録面からのずれを示すフォーカスエラー信号及び前記光ビームの焦点の前記トラックからのずれを示すトラッキングエラー信号の少なくとも一方であり、
前記制御信号は、前記フォーカスエラー信号に基づき前記光ビームの焦点を前記記録面に合わせるためのフォーカス制御信号及び前記トラッキングエラー信号に基づき前記光ビームを前記トラックに追従させるためのトラッキング制御信号の少なくとも一方である
ことを特徴とする焦点位置制御装置。 - 請求項1に記載の焦点位置制御装置と、
光ディスクの記録面に光ビームを照射し、前記焦点位置制御装置によって前記光ビームの焦点位置が制御される光学ヘッドと、
前記光学ヘッドを駆動する駆動手段と、を具備する
ことを特徴とする光ディスク装置。 - 請求項8に記載の焦点位置制御装置と、
光ディスクの記録面に光ビームを照射し、前記焦点位置制御装置によって前記光ビームの焦点位置が制御される光学ヘッドと、
前記光学ヘッドを駆動する駆動手段と、を具備する
ことを特徴とする光ディスク装置。 - 請求項14に記載の焦点位置制御装置と、
光ディスクの記録面に光ビームを照射し、前記焦点位置制御装置によって前記光ビームの焦点位置が制御される光学ヘッドと、
前記光学ヘッドを駆動する駆動手段と、を具備する
ことを特徴とする光ディスク装置。 - 記録面にトラックが設けられた光ディスクに光ビームを照射してデータを記録し、又は再生する光学ヘッドからの出力信号に基づき、前記光ビームの焦点位置の所望の位置からのずれ量を示すエラー信号を生成するステップと、
前記エラー信号に基づき、前記光ビームの焦点位置を所望の位置に制御するための制御信号を生成するステップと、
前記光ディスクの回転に同期したクロック信号を生成するステップと、
前記制御信号を、前記クロック信号に同期し、かつ、前記光ディスクの1回転で一巡するクロックアドレスに、記憶データとして順次格納するステップと、
前記クロック信号に同期して前記格納された記憶データを順次読み出すステップと、
前記格納された記憶データを読み出す際に、格納に係るクロックアドレスと読み出しに係るクロックアドレスとの位相を補正するステップと、
前記読み出された記憶データを前記制御信号に加算し、当該加算結果に基づいて前記光ビームの焦点位置を制御するステップと、
前記エラー信号に基づく前記光学ヘッドの駆動が行われていない場合、前記制御信号を前記記憶データとして格納するのを停止するステップと、を具備する
ことを特徴とする焦点位置制御方法。
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CN2009801224238A CN102067213A (zh) | 2008-06-20 | 2009-06-19 | 焦点位置控制装置和具有其的光盘装置以及焦点位置控制方法 |
US12/970,521 US20110085427A1 (en) | 2008-06-20 | 2010-12-16 | Focus position control apparatus, optical disc apparatus using the same, and focus position control method |
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JPS62143237A (ja) * | 1985-12-18 | 1987-06-26 | Toshiba Corp | 光デイスク装置 |
JP2000207750A (ja) * | 1999-01-08 | 2000-07-28 | Sony Corp | ディスクドライブ装置 |
JP2001118271A (ja) * | 1999-10-20 | 2001-04-27 | Hitachi Ltd | 面ぶれ補正制御方法および偏心補正制御方法およびこれらを用いた光ディスク装置 |
JP2006302424A (ja) * | 2005-04-21 | 2006-11-02 | Toshiba Corp | 光ヘッド装置 |
WO2007094387A1 (ja) * | 2006-02-15 | 2007-08-23 | Matsushita Electric Industrial Co., Ltd. | 周回メモリ、及びディスク装置 |
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US4907214A (en) * | 1985-12-18 | 1990-03-06 | Kabushiki Kaisha Toshiba | Eccentricity correction apparatus for an optical disk device |
JP2563648B2 (ja) * | 1990-06-18 | 1996-12-11 | 松下電器産業株式会社 | 光学式記録再生装置 |
CN1075222C (zh) * | 1995-07-27 | 2001-11-21 | 松下电器产业株式会社 | 光盘装置 |
JP3559209B2 (ja) * | 1998-12-24 | 2004-08-25 | 富士通株式会社 | 記憶装置 |
JP4265874B2 (ja) * | 2000-07-10 | 2009-05-20 | 富士通株式会社 | デイスク装置及びトラック追従制御方法 |
WO2003009290A1 (en) * | 2001-07-17 | 2003-01-30 | Fujitsu Limited | Head follow-up control method, head follow-up control device, and storage device comprising the same |
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- 2009-06-19 WO PCT/JP2009/002803 patent/WO2009154003A1/ja active Application Filing
- 2009-06-19 CN CN2009801224238A patent/CN102067213A/zh active Pending
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JPS62143237A (ja) * | 1985-12-18 | 1987-06-26 | Toshiba Corp | 光デイスク装置 |
JP2000207750A (ja) * | 1999-01-08 | 2000-07-28 | Sony Corp | ディスクドライブ装置 |
JP2001118271A (ja) * | 1999-10-20 | 2001-04-27 | Hitachi Ltd | 面ぶれ補正制御方法および偏心補正制御方法およびこれらを用いた光ディスク装置 |
JP2006302424A (ja) * | 2005-04-21 | 2006-11-02 | Toshiba Corp | 光ヘッド装置 |
WO2007094387A1 (ja) * | 2006-02-15 | 2007-08-23 | Matsushita Electric Industrial Co., Ltd. | 周回メモリ、及びディスク装置 |
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