Abstract: The present invention provides a method for adaptively driving a tracking element with mechanical deviation and a driving device using the same. The method comprises the following steps: recording standard moving time and a standard motor current value, supplying driving voltage to a motor for driving a tracking element, detecting a current value of the motor and detecting moving time of the tracking element, and adjusting a driving gain of the motor based on the relation between the current value of the motor and the standard motor current value, and based on the relation between the moving time of the tracking element and the standard moving time of the standard one.

Abstract: A signal processing device for optical disks includes a reflected light process section configured to convert reflected light received by an optical pickup into an electric signal based on a first gain, wherein the optical pickup emits laser light to an optical disk and receives reflected light from the optical disk; a servo signal generation section configured to generate a servo signal by using the electric signal generated by the reflected light process section; a servo signal control section configured to control the servo signal so that a change in the amplitude of the servo signal, in response to an increase or decrease of the amount of the reflected light from the optical disk, is suppressed using an attenuator that attenuates the servo signal generated by the servo signal generation section by a factor of a second gain; and a gain setting section configured to set the first gain to the reflected light process section and the second gain to the servo signal control section substantially simultaneously.

Abstract: In a device for controlling a focus to an optical disc having a land section and a groove section, the control is performed so as to avoid a focus step difference at a land-area/groove-area switching point. When performing write-in or readout of data to an optical disc on which a land area and a groove area are continuously formed, using an optical pickup, there are provided a land learning unit (1) for determining a focus position in the land area, a groove learning unit (2) for determining a focus position in the groove area, and a focus position calculation unit (3) for determining a focus position in an area where the land area and the groove area are switched, and the focus position of the optical pickup is moved so that it is located at the third focus position when the switching signal is inverted according to the switching between the land area and the groove area.

Abstract: An apparatus having switchable servo gains and offsets for an optical disk drive adjusts its gains and offsets through the coupling of a servo signal and a switch with several changeable paths. The servo signals are either designated to undergo signal reduction with respect to a first offset, through the switch and then be output after a first gain unit performed proportional conversion, or designated to undergo signal reduction with respect to a second offset and then be output after a second gain unit performed proportional conversion. The switch is switched on/off in the light of the working status of the pick-up head, for example, seeking or tracking, at a data area or at a blank area, and at a groove area or at a land area, so as to choose different offsets and gains to have the conversion of the servo signals.

Abstract: A method of reducing power dissipation in a variable-gain photo-detector circuit is described. The variable-gain photo-detector circuit has an output to output a main spot signal and at least one side spot signal. The main spot (M) and the side spot (Si or S2) are formed by separating a light beam into a main beam and at least one side beam and focusing the main beam on the main spot (M) and the side beam on at least one side spot (Si or S2) on an optical record carrier The method processes the main spot signal with a first averaging circuit having a first cut-off frequency. The side spot signal is processed with a second averaging circuit having a second cut-off frequency. The second cut-off frequency is lower than the first cut-off frequency. The above technique reduces power dissipation in the variable-gain photo-detector circuit and is useful for all optical devices.

Abstract: A method and a device for fast disc recognition for use in read/write performances when an optical disc is connected to an optical drive, including the provision of a set S of parameters for safe data transfer between the drive and the disc, the direct calibration during a disc recognition step only of those parameters out of said set S in need of a direct calibration, the start of a read/write data transfer sequence after said disc recognition step is finalized and the calibration of the remaining parameters at first after or during one or more data transfer read/write sequences.

Abstract: A signal processing device, even when a steep difference in DC level is included in a signal read from a disc such as a DVD-RAM format, cuts off the DC level and pulls the read signal into an appropriate A/D input level. A steep difference in DC level between a data section and a CAPA section is absorbed by a first offset unit, and an asymmetry which occurs due to variations in the disc manufacturing stage is corrected by a second offset unit. Further, a control signal for operating the two offset units exclusively is generated by a controller, thereby controlling both offset units.

Abstract: A method and apparatus of compensating for misalignment in an optical disk device includes detecting a plurality of focus error signals, comparing the focus error signals, and shifting a position of an optical lens based on the comparison. Alternatively, a one or more of the focus error signals may be compared to a reference signal and a corresponding shift may be performed. When the lens is shifted, an optical spot corresponding to an optical beam reflected from a disk surface is corrected to a position which reduces or eliminates misalignment errors attributable to one or more elements of the pickup.

Abstract: A drive signal generation circuit comprising: a tracking signal output circuit to output a tracking signal based on an error signal indicating a track deviation of laser light output from the optical pickup relative to a track, the tracking signal being a signal for driving a motor to move an optical pickup in a radial direction of an optical disc to reduce the track deviation of the laser light; a stop signal output circuit to output a stop signal for driving the motor to stop moving the optical pickup in the radial direction; and a switch circuit to output the tracking signal as a drive signal for driving the motor when a level of an output signal from the optical pickup is higher than a predetermined level, and to output the stop signal as the drive signal when the level of the output signal is lower than the predetermined level.

Abstract: A method for enhancing the optical initializing operation comprises: sending a radial error signal from an optical pick-up unit to a radial error signal calibration unit; sending the radial error signal from the optical pick-up unit to an offset adjuster; sending a calibrated radial error signal from the radial error signal calibration unit to the offset adjuster and a gain adjuster; sending a radial actuator (RA) signal from the radial error signal calibration unit to activate a radial actuator during an initialization or a period for calculating RE signal calibrating parameters.

Abstract: In an optical element feeding device and an optical pickup unit using the same, in order to make the device compact and light and achieve a stable operation, the device has a main shaft and a sub shaft supporting a movable frame in which an optical element is arranged in such a manner as to be movable in a direction of an optical axis, a stepping motor, a lead screw rotating on the basis of a rotation of the stepping motor, a resin nut engaging with the lead screw and being movable in the direction of the optical axis on the basis of the rotation of the lead screw, and a spring pressing the movable frame in the direction of the optical axis so as to bring the movable frame into contact with the nut, and a cushioning material is provided between the nut and the movable frame so as to connect the nut and the movable frame.

Abstract: Provided is an optical disk device capable of recording and/or reproducing information on optical disks with high reliability; and a method for controlling the optical disk device. The position of an optical lens where the amplitude of a reproduction signal during the period corresponding to a minimum-length recording mark and a space having the same length reaches its maximum is detected; and the detected position is set as a reference position for the objective lens relative to the optical disk, for use in focus control. Also, the position of the objective lens where the result of multiplication of resolution and modulation becomes greatest is detected; and the detected position is set as a reference position for the objective lens relative to the optical disk, for use in focus control.

Abstract: The optical disc device has a circuit 4 which forms a focus error signal FER for focus servo control based on reflection light from an optical disc exposed to laser light. A data processing unit 2 can control by feedback a position to which an objective lens is moved by a focusing actuator 30 based on the focus error signal. In label printing, the data processing unit controls, by feedforward, a position to which the objective lens is moved by the focusing actuator based on control data for label printing. The operation resolution of the focusing actuator in feedforward control is made higher than that in feedback control. Thus, an intended position control accuracy is achieved in feedforward control. For instance, in feedforward control, the gain of the driver circuit 40 for the focusing actuator is switched to a smaller one in comparison to that in feedback control.

Abstract: It is highly precisely determined as to whether or not a laser-irradiated position on an optical disk is positioned within an identification area (BCA) in which identification information is recorded, and the position of the identification information area is efficiently determined. An optical disk apparatus includes an optical pickup for detecting reflected light from an optical disk and generating a light amount signal, and a detecting section for outputting a detection signal which is in accordance with a change in the signal level of the light amount signal, the detection signal indicating that the change has continued for a first predetermined time or longer.

Abstract: A system and method of controlling position of a pick-up head of an optical drive, including manipulating the position of the pick-up head as a primary variable in a cascade control scheme, and manipulating current flowing through the pick-up head as a secondary variable in the cascade control scheme.

Abstract: The present invention provides an optical disk apparatus capable of stably performing a layer jump on an optical disk having plural recording layers and non-uniform interlayer distances. In an optical disk with at least three recording layers and non-uniform interlayer distances between respective recording layers, if a layer jump is carried out from a first recording layer to a second recording layer, a distance from the first recording layer to the second recording layer is obtained and driving voltages set according to the distance are applied to an actuator for the layer jump to carry out the layer jump. At this time, interlayer distances for combinations of the respective recording layers and applied driving voltages thereto are stored in a memory in advance and when necessary, corresponding driving voltages are read out from the memory and are set for the layer jump.

Abstract: Defocus detection device and method capable of detecting a defocus accurately during recording of information to an optical disk having a plurality of recording layers and an optical disk unit using the device and method are provided. A temporal restriction is imposed on defocus detection and besides, in comparison with a level for detection of a first change of a focus error signal developing during a defocus, a level for detection of a successively occurring second change of a polarity inverse to that of the first change is made to be smaller. When the first level is exceeded and thereafter the second level is exceeded within a restricted time, a defocus is detected.

Abstract: A model is derived for write parameters of a laser in an optical drive. A parameter range for the write parameters is set based on a recordable medium. A number of test runs are recorded on the recordable medium while varying the write parameters. Write performance characteristics are measured over the test runs, and a model of write performance as a function of the write parameters is derived. Values for write parameters are selected for use in writing actual data based on the derived model. A first section of user data is written to the data-carrying region of the recordable medium using the selected values. The write performance characteristics of the first section of user data are measured, and the model is updated by including the measurements from the data-carrying region. New values for the write parameters of the laser are selected based on the updated model.

Abstract: A driving apparatus includes: a driving mechanism slider-driving a head including a first optical pickup and a second optical pickup, the first optical pickup and the second optical pickup having a same specification; a calculating mechanism performing predetermined calculation using a first slide-error signal obtained by filtering a signal from the first optical pickup and a second slide-error signal obtained by filtering a signal from the second optical pickup; and an outputting mechanism outputting a signal from the calculating means as a slider control signal for driving the driving mechanism.

Abstract: A gain calibration method for optical storage servo systems in which, plant gain calibration is used by injecting a reference sine wave r into an optical storage servo system, obtaining an effort signal m at the input of the servo plant and an error signal y at the output of the servo plant, using a DFT (Discrete Fourier Transformation) to translate the time domain signals m and y into frequency responses M and Y, calculating a Y-to-M ratio, and using the magnitude of the Y-to-M ratio as the plant gain K of the servo system. The servo system's sensor gain K1 at the outermost layer of a disk may be calibrated by, e.g., the conventional peak-to-peak measurement. Since K=K1·K2, the servo system's actuator gain K2 at the outermost layer of the disk may be obtained. Because the actuator gain K2 is the same for all layers of a disk, the variation of the sensor gain K1 at an inner layer may follow that of the plant gain K at that layer.

Abstract: In servo control within an optical disc apparatus, when iterative learning control is started, the servo characteristics are modified to servo characteristic giving increased gains during a given period of time. Under this condition, the iterative learning control is provided.

Abstract: An optical disk 101 in which information is recorded on a groove track, and an optical disk 107 in which information is recorded on a land track. The optical disk 101 has a control data area 102, and a data recording area 103 in which user data is recorded. The optical disk 107 has a control data area 108, and a data recording area 109 in which user data is recorded. A code for indicating the groove track or the land track onto which a tracking servo control is to be executed is provided both in the control data area 102 of the optical disk 101, and in the control data area 108 of the optical disk 107.

Abstract: An optical disk suppressing the time required for a startup of a recording/playback apparatus from unduly increasing, even when there is (i) one type of disk where information is recorded on a groove track, and (ii) another type of disk where information is recorded on a land track. Both types of optical disks having a control data area, and a data recording area in which user data is recorded. A code for indicating the groove track or the land track onto which tracking servo control is executed is provided in the control data area of both types of optical disks.

Abstract: An optical disk 101 in which information is recorded on a groove track, and an optical disk 107 in which information is recorded on a land track. The optical disk 101 has a control data area 102, and a data recording area 103 in which user data is recorded. The optical disk 107 has a control data area 108, and a data recording area 109 in which user data is recorded. A code for indicating the groove track or the land track onto which a tracking servo control is to be executed is provided both in the control data area 102 of the optical disk 101, and in the control data area 108 of the optical disk 107.

Abstract: Various embodiments of the present invention provide systems and methods for reduced latency feedback in a data processing system. For example, some embodiments provide a data processing system that includes a variable gain amplifier, a processing circuit, a data detector, and an error signal calculation circuit. The variable gain amplifier amplifies a data input signal and provides an amplified signal. The processing circuit generates a signal output corresponding to the amplified signal, and includes a conditional multiplication circuit. The conditional multiplication circuit conditionally multiplies the signal output by a gain correction signal and provides the result as an interim output. The data detector applies a data detection algorithm to the signal output and provides an ideal output. The error signal calculation circuit generates a gain correction signal based at least in part on the interim output and a derivative of the ideal output.

Abstract: An optical disc device that irradiates an optical beam to an optical disc including a recording layer for recording information and a positioning layer provided with a track for identifying a recording position of the information on the recording layer, includes: objective lens that converges a predetermined positioning optical beam to adjust the optical beam to a desired track on the positioning layer and converges an information optical beam that shares an optical axis with the positioning optical beam on the recording layer; moving section that moves the objective lens in a tracking direction which is substantially orthogonal to the track to make a focal point of the positioning optical beam to follow the desired track; a detection section that detects a moving amount of the objective lens to the tracking direction; and correction section that corrects a converging position of the information optical beam in accordance with the moving amount.

Abstract: An optical disk apparatus includes: an optical pickup unit for reading out information recorded on an optical disk; a demodulation circuit for demodulating digital data from an output signal of the optical pickup unit; and a controller for performing a servo control based on the output signal of the optical pickup unit. When performing a focus/tracking control in a recess and a protrusion of a guide groove of the optical disk, the controller obtains a focus control gain difference between the recess and the protrusion by comparing focus offsets with respect to variations in amplitudes of signals from the optical disk for the recess and the protrusion, respectively.

Abstract: A focus-servo control method of an optical disc recording/reproducing apparatus, for recording or reproducing information onto/from an optical disc having a track with a land and a groove, which are formed in a spiral manner on an information recording surface thereof, the optical disc recording/reproducing apparatus including an objective lens, the method comprising steps of: moving an optical spot from the land to the groove or from the groove to the land through a L/G exchange portion therebetween and moving a position of the objective lens from a land position to a groove position by gradually changing a focus offset value for the land to a focus offset value for the groove from a position located before the L/G exchange portion, when the optical spot moves from the land to the groove.

Abstract: In a method for adjusting a focus position for an optical disc, onto/from which in formation is recorded or reproduced, while adjusting the focus position of an optical reproducing means, upon a recording surface of an optical information recording medium having an area where information of the optical information recording medium is recorded in advance, comprising the following steps of: memorizing plural numbers of information relating to focus positions determined appropriately, which can be obtained from the area where the information of the optical information recording medium is recorded in advance; and adjusting the focus position for the optical disc loaded into an apparatus, from at lease one (1) signal relating to the focus position, which can be obtained from the optical disc, with utilizing a relationship between the plural numbers of information relating to the focus positions determined appropriately, memorized in advance, when reproduction of the information is impossible when the optical disc

Abstract: The invention provides an apparatus for controlling servo signal gains of an optical disc drive. The apparatus adjusts the gains of a plurality of servo signals controlling a servo system of the optical disc drive when the optical disk drive encounters an operating state transition. In a first mode, at least one AGC loop of the apparatus compensates the gains of the servo signals with a selectable bandwidth during a specific period after the operating state transition to accelerate the convergence of the servo signals. In a second mode, at least one AGC loop of the apparatus reloads the previously saved convergence values or pre-determined values as the initial values according to the current operating state immediately after the operating state transition to accelerate the convergence of the servo signals.

Abstract: In an optical disc drive that needs an aberration correcting element for correcting spherical aberrations, it takes long time to conduct a processing operation of the aberration correcting element in an interlayer movement of a multilayer disc and a drive initializing operation. In order to eliminate the problem, an optical disc drive using a pickup includes a focus actuator for moving an objective lens in a rotation axis direction of a disc, a tracking actuator for moving the objective lens in a radial direction of the disc, an aberration corrector for correcting aberrations, and a feeder for moving the pickup in the disc radial direction. A control operation of the aberration corrector and a control operation of the feeder are conducted in parallel.

Abstract: An optical pickup apparatus includes a light source, focusing optics, a light detector, a controller, and a drive unit. The drive unit first drives the focusing optics to a specific position on an information recording medium. Light from the light source irradiates the information recording medium via the focusing optics as near-field light. Light reflected off the medium due to total internal reflection is then detected by the light detector, generating a gap error signal as a result. The controller then generates a gap servo signal by conducting a feed-forward control, whereby a push-pull signal in the direction orthogonal to the relative travel direction of the medium is applied to the gap error signal. In so doing, precise control of the gap size between the focusing optics and the information recording medium is achieved for near-field read/write operations.

Abstract: A multi-layered information recording medium used in an information recording/reproducing apparatus applicable to both a single-layer information recording medium and an arbitrary multi-layered information recording medium is provided. The multi-layered information recording medium has a plurality of recording layers, and each of the recording layers has a guiding groove formed at a track pitch defined as a quadratic function of disk thickness (i.e., the distance from the light incident surface) of the associated recording layer. The guiding grooves of the recording layers are formed such that the track pitch of a reference recording layer having a disk thickness closest to that of the single-layer information recording medium is the smallest amongst the multiple recording layers.

Abstract: An apparatus includes a first circuit and a second circuit. The first circuit may be configured to generate status signals and an error signal in response to accessing a storage medium. The error signal provides a first value based on an accuracy of accessing the storage medium. The second circuit may be configured to offset the first value of the error signal to a second value to increase the accuracy of accessing said storage medium. The status signals include one or more of a data signal and a differential signal. In a first mode, an offset signal is generated in response to the data signal. In a second mode, the offset signal is generated in response to the differential signal.

Abstract: A near field optical recording/reproducing apparatus includes a light source, an objective lens to form a spot by focusing light emitted from the light source, a solid immersion lens to generate an evanescent wave by using the spot formed by the objective lens, a photodetector to measure an amplitude of a gap error signal that is totally reflected by the solid immersion lens, and an operating unit to generate a normalized gap error signal by using an amplitude of a driving signal applied to the light source and the amplitude of the gap error signal measured by the photodetector.

Abstract: An apparatus comprising a center error creation circuit and a center error offset injection circuit. The center error creation circuit may be configured to generate a center error signal in response to light from a main laser reflected from a surface of an optical disc. The center error offset injection circuit may be configured to (i) determine a value of the center error signal when a lens in a sled housing is at a mechanical center and (ii) generate an offset signal based upon the value. The center error offset injection circuit generally measures an average value of the center error signal over a predetermined amount of time when a lens suspension which holds the lens in place is in a mechanical equilibrium state.

Abstract: The invention provides an apparatus for controlling servo signal gains of an optical disc drive. The apparatus adjusts the gains of a plurality of servo signals controlling a servo system of the optical disc drive according to a closed-loop mode or a state-reloading mode whenever the optical disk drive encounters an operating state transition. In closed-loop mode, at least one AGC loop of the apparatus compensates the gains of the servo signals with a selectable bandwidth during a specific period after the operating state transition to accelerate the convergence of the servo signals. In state-reloading mode, at least one AGC loop of the apparatus reloads the previously saved convergence values or pre-determined values as the initial values according to the current operating state immediately after the operating state transition to accelerate the convergence of the servo signals.

Abstract: The present invention aims to provide an optical recording method etc. that provides higher efficiency of recording and reproducing and is uninfluenced by the mismatch of optical axes of plural laser lights induced from accident errors of optical recording and optical reproducing apparatuses when carrying out recording or reproducing, or focus control etc. by use of a laser light, high multiple-recording can be carried out, and layer construction of the recording medium itself is simple. For the purpose, an optical recording method etc.

Abstract: An optical disc drive includes: an optical branching element for splitting light from a light source into main and sub-beams; a condenser element for condensing the main and sub-beams; a photodetector section including photodetectors to receive reflected portions of the main and sub-beams, each photodetector having photosensitive areas, each of which outputs a signal representing the intensity of light received there; and a computing section for generating a first focus signal, representing where the focal point of the main beam is located with respect to the storage layer, based on the reflected light of the main beam, and a second focus signal based on the reflected light of the main and sub-beams.

Abstract: An optical disc drive device has an FE signal generator which generates a focus error signal, a TE signal generator which generates a tracking error signal, a return beam detector which detects a return beam reflected by an optical disc after irradiated by an optical pickup to generate a return beam level signal, a return beam gain setting part which sets amplitude adjustment amount of the return beam level signal so that a signal level of the return beam level signal generated by the return beam detector coincides with a predetermined reference level, an FE gain setting part which sets amplitude adjustment amount of the focus error signal in accordance with the signal level of the return beam level signal adjusted by the return beam gain setting part so that a signal amplitude of the focus error signal is constant, and a TE gain setting part which sets amplitude adjustment amount of the tracking error signal in accordance with the signal level of the return beam level signal adjusted by the return beam gain

Abstract: A system for determining groove/land (G/L) switching points of an optical disc is disclosed. The system includes a motor rotating signal generating apparatus, an detection apparatus, and a G/L switching point generating apparatus. The motor rotating signal generating apparatus is for sensing the rotation of a motor to generate a motor rotating signal with a period corresponding to the rotation of the optical disc. Also, the detection apparatus is used for receiving the motor rotating signal and an original G/L switching point signal and utilizing the motor rotating signal and the original G/L switching point signal to determine a location of an reproduced G/L switching point of the optical disc. The G/L switching point generating apparatus is for generating an reproduced G/L switching point signal according to the location of the reproduced G/L switching point determined by the detection apparatus.

Abstract: Before initiation of tracking control, an optical disk device performs an offset amount obtaining operation, in which a difference between a middle value of the amplitude of a tracking error signal and a predetermined reference value is obtained as an offset amount. After the initiation of the tracking control, the optical disk device initiates an attenuation operation, in which an offset amount attenuation section attenuates the offset amount obtained by the offset amount obtaining operation to obtain an attenuated offset amount, while initiating, with an initial value being 0, an estimation operation, in which an observer estimates the offset amount according to a tracking driving signal to obtain an estimated offset amount. The optical disk device corrects the tracking error signal by using the attenuated offset amount obtained by the attenuation operation and the estimated offset amount obtained by the estimation operation.

Abstract: In a signal reproducing device, for securing the stability in the steady state while enhancing the response of automatic gain control, a variable gain amplifier 109 adjusts the amplitude of a reproduction signal outputted from a head amplifier 108. A gain control section 112 increases/decreases the gain in the variable gain amplifier 109 by a predetermined change amount according to the large-small relationship of the comparison result outputted from a comparator 111. The gain change amount control circuit 113 controls the change amount of the gain in the gain control section 112 according to the frequency of inversion of the large-small relationship of the comparison result outputted from the comparator 111.

Abstract: An optical disc drive and a control method thereof are disclosed to prevent unstable servo-control of a pickup module caused by an abnormal control signal, when recording/reproducing/erasing of information on/from an optical disc in the optical disc drive, and in particularly, possible collision between the pickup module and the optical disc, even when the pickup module very closely approaches the surface of the optical disc during recording/reproducing/erasing of information on/from a high density optical disc. The optical disc drive includes a pickup module having an objective lens focusing a laser on the surface of a recording layer of the optical disc, and a servo-controlling unit performing the focus servo-control of the pickup module using a high frequency broadband control and a low frequency broadband control of a focus error signal where the high frequency broadband control is performed prior to the frequency broadband control.

Abstract: A servo accelerator for an optical drive includes input and output (I/O) terminals that receive an input signal from a processor of the optical drive. An error circuit generates an error signal based on a sensed characteristic of a laser beam. A compensation circuit generates a compensation signal based on the input signal and the error signal. A servo output adjusts the sensed characteristic of the laser beam based on the compensation signal.

Abstract: An optical disk reproducing device includes: a signal reproducing section configured to read and decode information recorded on an optical disk by an optical pickup unit, and reproduce the information, wherein the signal reproducing section includes a gain controlled amplifier circuit configured to amplify an radio frequency signal generated from a light receiving element, an automatic gain control circuit configured to control a gain of the gain controlled amplifier circuit, and a signal processing section configured to derive a part of an automatic gain control value generated in the automatic gain control circuit, and generate a control signal for adjusting one of an optical system path and a detection system path for controlling the optical pickup unit.

Abstract: A DSP of the DVD recorder includes a balance value setting portion for determining an appropriate value of a focus balance value ? when information is reproduced from an optical disc so as to record the determined focus balance value ?0 in a balance value storing portion and to set the same in a first amplifier of a focus error signal generating circuit, and a correction executing portion for reading the focus balance value ?0 stored in the balance value storing portion when information is recorded in the optical disc 2 so as to correct the read value to be a focus balance value ?1, which is set in the first amplifier of the focus error signal generating circuit.

Abstract: An optical disk apparatus includes a signal detection unit which detects a signal corresponding to a wobbling guide groove formed on an optical disk, a timing signal generating unit which generates first and second timing signals in accordance with an amplitude level of the signal detected, a photodetector which detects reflective light from the optical disk, and a wobble signal generating unit which outputs as a wobble signal a signal which is amplified with a low gain amount by the first timing signal in a case where an arithmetic signal, which is generated for the wobble signal on the basis of a signal detected by the photodetector, is at a high amplification level, and outputs as the wobble signal a signal which is amplified with a high gain amount by the second timing signal in a case where the arithmetic signal is at a low amplification level.

Abstract: A method for controlling an optical pickup head of an optical processing apparatus is provided. A first lead-lag compensator is disabled and a second lead-lag compensator is enabled when the optical pickup head switches from a following mode to a seeking mode. Then, an initial operating factor of the second lead-lag compensator is determined according to a last input value and a last output value of the first lead-lag compensator. An initial kick force of the actuator in the seeking mode is calculated by realizing the last input value and the last output value of the first lead-lag compensator immediately before the first lead-lag compensator is disabled. Finally, the optical pickup head is actuated to perform a seeking operation with the initial kick force.

Abstract: An optical storage system includes a pickup head for picking up data from a storage medium. Firstly, the maxima of a tracking error signal and runout are obtained in a calibration procedure in a close loop formed by an optical pickup head, a pre-amplifier, a compensator, a band-pass filter and a maximum detector. A calibration factor is then defined and derived by using the obtained maxima and nominal factors of a power amplifier and the optical pickup head of the optical storage system. The path formed by the series-connected band-pass filter and maximum detector is then disabled, while the calculated calibration factor is then stored in the compensator. The optical storage system may operate in a close loop formed by the optical pick head, pre-amplifier, compensator, a power amplifier under a normal operation procedure so that the optical storage system may record or read data onto/from an optical disc under the compensation provided by the calibration factor.