Abstract: Various illustrative aspects are directed to a data storage device, comprising one or more disks; an actuator mechanism configured to position one or more heads proximate to one or more disk surfaces of the one or more disks; and one or more processing devices, comprising an actuator mechanism control system configured for controlling the actuator mechanism. The processing devices are configured to: apply coefficients for a multi-rate notch filter to a servo control loop; measure a multi-rate error rejection transfer function; determine whether a peak of the multi-rate error rejection transfer function is greater than a multi-rate error rejection transfer function threshold; and modify, responsively to determining that the peak of the multi-rate error rejection transfer function is not greater than the multi-rate error rejection transfer function threshold, the parameters of the multi-rate notch filter based at least in part on the peak of the multi-rate error rejection transfer function.

Abstract: An in-plane photonic device is provided for transmission of an optical signal across a gap, in particular an in-plane photonic device for use in a photonic integrated circuit with one or more in-plane crossings of electrical connections and photonic waveguides. One embodiment relates to an in-plane photonic device for use in a photonic integrated circuit with in-plane crossings of electrical connections and photonic waveguides, including: at least one input optical waveguide; and at least one output optical waveguide; wherein the at least one input optical waveguide and the at least one output optical waveguides are positioned such that a gap between them separates the input and the output optical waveguide(s), and wherein the input and the output optical waveguides are configured for optical mode matching across the gap, such that an optical signal can be transmitted from the input optical waveguide to the output optical waveguide across the gap.

Abstract: Provided are a single-photon source device and a single-photon source system including same. The single-photon source device includes a substrate, a straight waveguide extending in a first direction on the substrate, a first coupling layer which is provided on the straight waveguide and has a first point defect, at least one first electrode which is adjacent to the first point defect and provided on the first coupling layer, a ring waveguide which is adjacent to the straight waveguide and provided on the substrate, and at least one second electrode provided on the ring waveguide.

Abstract: According to one embodiment, a magnetic disk device includes a rotatable disk-shaped recording medium, a magnetic head including a write head having a main magnetic pole that applies a recording magnetic field to the recording medium, an assist element that assists magnetic recording by the main magnetic pole, and a plurality of thermal actuators that control a head gradient with respect to the recording medium, and a controller which includes a detection unit configured to detect deterioration of the magnetic head, and changes a head gradient of the magnetic head by the thermal actuator according to the detected deterioration.

Abstract: A delay circuit with multiple dependencies on various environmental parameters is disclosed. The delay circuit is configured to receive an input signal. The delay circuit includes a first circuit configured to generate a first amount of delay, wherein the first amount of delay has a direct relationship to a first environmental parameter. The delay circuit also includes a second circuit configured to generate a second amount of delay such that the second amount of delay has an inverse relationship to a second environmental parameter. The delay circuit is configured to generate a delayed output signal based on the first and second amounts of delay generated by the first and second circuits.

Abstract: Certain aspects of the present disclosure provide techniques for reporting beam-strength related Type-II channel state information (CSI) coefficient feedback.

Abstract: A multimodal ultrasound/photoacoustic tumor margin detection system. The system can be comprised of an imaging and system control console, which can include an ultrasound and data acquisition subsystem including an ultrasound transmitter and receiver configured to transmit and receive ultrasonic energy. A host-control computer configured to provide a function generator function and a delay generation function can also be a part of the imaging and system control console.

Abstract: A motor driving circuit for driving a motor is provided. The motor driving circuit includes a plurality of inverter circuits, a driving signal look-up table module, a driving signal generating unit, a duty cycle command detector, and a protection control circuit. The driving signal look-up table module performs a table lookup on an input driving signal to generate a driving waveform pattern signal while outputting a positive period indication signal. The duty cycle command detector generates a first protection start signal when a duty cycle corresponding to the input driving signal changes by more than a predetermined amount of change. The protection control circuit outputs a forced disable signal in a positive period interval in response to receiving the first protection start signal to control the lower bridge switch of one phase of the inverter circuits to be turned off.

Abstract: The invention relates to a drilling device comprising a light source configured to provide a light beam and a diffractive beam propagation device having a substantially planar surface, wherein the light source is configured such that the light beam is incident on the planar surface of the diffractive beam propagation device, and wherein the diffractive beam propagation device is configured to propagate the light beam as one or more propagated beams such that the one or more propagated beams, at least when being integrated over time, surround an area with a substantially circular shape. A use of the drilling device for drilling a hole in a work piece and a method suitable for drilling a hole in a work piece are also provided.

Abstract: A first processing component samples and lossily accumulates statistical activity data by generating at least one data bucket by segmenting a memory window in a memory and providing a map of the segmented memory window; sampling to detect activity in the data bucket and surjectively populating the map with statistical activity data; and responsive to a trigger, passing at least part of a population of the map to a second processing component. The second processing component receives and stores the at least part of the population of the surjective map, compares it with at least one previously stored map population; and on detecting anomalous patterning, performs an “anomaly detected” action.

Abstract: Beamforming channels of a satellite are calibrated using a low power, spread spectrum calibration signal. The power of the calibration signal is below the noise level of a user signal in an active channel, allowing channels to be calibrated while active. When calibrating the transmit side circuitry, a two-stage calibration can be used, first calibrating the output hybrid matrix, then calibrating the whole of the transmit side. To improve performance, the dwell time spend calibrating a channel can be based on the power of the user signal in the channel. A transmit probe can be used to inject a calibration signal into the receive antennae and a receive probe can be used to extract the calibration signal from the transmit antennae. To reduce frequency of calibrations, the calibrations can be based on path-to-path differences. These techniques are also applied to multiport amplifiers (MPAs).

Abstract: An apparatus comprises supply means for changing an amount of light sinusoidally and supplying to a projection means a patterned light signal for sequentially projecting on an object to be measured at least three patterns of patterned light having phase differences; obtainment means for obtaining image data acquired by capturing the object; first generation means for generating a phase image from image data acquired by capturing the object on which the patterned light is sequentially projected; second generation means for generating, based on the phase image, a shape image which indicates a distance between a surface of the object and a viewpoint in the capturing; and correction means for calculating an amount of correction for the shape image from a correspondence between a pixel value of a high-frequency shape image indicating a high-frequency component of the shape image and a pixel value of the phase image.

Abstract: Various embodiments of the present technology may comprise methods and apparatus for actuator control. The methods and apparatus may comprise various circuits and/or systems to generate a feedback signal according to an induced voltage and further generate various signal processing functions to selectively adjust a gain of the feedback signal. The apparatus for actuator control may comprise an induced voltage detection circuit and a feedback control circuit that operate together to generate the feedback signal used to control the actuator.

Abstract: A hydrodynamic torque converter comprising a pump wheel and a turbine wheel mounted to be rotatable about an axis of rotation is disclosed. A fluid in a region between the pump wheel and the turbine wheel is provided wherein a first axial contact surface is formed on the pump wheel and a second axial contact surface is formed on the turbine wheel. A frictional connection between the pump wheel and the turbine wheel can be produced when the pump wheel and the turbine wheel are pressed axially against one another. Moreover, one of the contact surfaces is configured to be flexible in order to lie against the other contact surface under an axial pressure load.

Abstract: Systems, devices, and methods are presented that allow a data channel to adaptively vary a change in a reference voltage used to read data from a solid state memory. The change in the reference voltage may be determined based on a measured error statistic of the solid state memory. A hard decision low density parity check (HLDPC) decoder may be utilized in conjunction with a soft decision low density parity check (SLDPC).

Abstract: Techniques for verifying a magnetic tape are disclosed. The techniques include obtaining a position signal generated by reading a magnetic tape using a stationary tape head. Next, a simulated current for adjusting a position of the tape head to follow a track on the magnetic tape is updated using the position signal. The simulated current is then compared to one or more saturation limits to generate a verification result for a servo pattern on the magnetic tape, wherein the verification result classifies the magnetic tape as usable or unusable. Finally, the verification result is outputted for use in managing subsequent use of the magnetic tape.

Abstract: Techniques for verifying a magnetic tape are disclosed. The techniques include obtaining a position signal generated by reading a magnetic tape using a stationary tape head. Next, a simulated current for adjusting a position of the tape head to follow a track on the magnetic tape is updated using the position signal. The simulated current is then compared to one or more saturation limits to generate a verification result for a servo pattern on the magnetic tape, wherein the verification result classifies the magnetic tape as usable or unusable. Finally, the verification result is outputted for use in managing subsequent use of the magnetic tape.

Abstract: The recording and reproducing apparatus according to the present disclosure includes: a light source; an optical system configured to divide a beam from the light source, and to form a first optical spot and a second optical spot on a recording medium; a recording circuit configured to drive the light source and to modulate a light amount of the light source, and further to record the information on the recording medium by the first optical spot by modulating the light amount of the light source based on information; and an evaluation circuit configured to evaluate the information recorded on the recording medium by reproducing by the second optical spot in a period in which the recording circuit causes the light source to emit the beam at a constant light amount.

Abstract: A system and method for controlling positioning of an optical pickup unit relative to at least one track of an optical data storage medium include an adaptive track position feedback controller that compensates for defocus of an optical beam relative to the optical data storage medium associated with movement across the medium and/or disturbances in distance between a lens of the optical pickup unit relative to the optical data storage medium. A track position feedback controller may include an adaptive term or parameter based on a focus (or defocus) error signal generated by a focus position feedback controller and associated sensors or detectors of a quadrature photodiode integrated circuit (PDIC).

Abstract: Systems and method relating generally to data processing, and more particularly to systems and methods for utilizing multiple data streams for data recovery from a storage device.

Abstract: A laser light generator emits laser light, a frequency of which can be adjusted. A laser light detector bombards an iodine cell with the laser light and photoelectrically converts the laser light that has passed through the iodine cell, then outputs a light output signal. A third order differential lock-in amplifier generates a third order differential signal of the light output signal. A frequency locker causes the laser light generator to change the frequency of the laser light within a predetermined range, detects an amplitude corresponding to a saturated absorption line occurring in the third order differential signal, and causes the frequency of the laser light to stabilize to a predetermined value. An error detector outputs an error signal in a case where the amplitude corresponding to the saturated absorption line occurring in the third order differential signal is greater than a predetermined value.

Abstract: As for a quadruple light receiving unit, in a case where divided regions of A to D as in a DPD scheme is defined, when binarization signals of light reception signals in regions A to D are set as signals A to D, <1> exclusive OR between the signal A without delay and the signal B with delay, <2> exclusive OR between the signal A with delay and the signal C without delay, <3> exclusive OR between the signal B without delay and the signal D with delay, and exclusive OR between the signal B with delay and the signal D without delay are calculated, and a tracking error signal is obtained on the basis of the calculation of (<1>+<3>)?(<2>+<4>). Thus, the above problem can be solved.

Abstract: A wireless media player and a related system and methodology are disclosed. One aspect of the wireless media player system pertains to a virtual connector system, apparatus, and method for the automatic establishment of wireless connectivity with other electronic devices. In one embodiment, the media player device employs the use of integrated Radio Frequency Identification (RFID) technology to exchange communication settings, media capability, and other parameters with an external device that also has integrated RFID technology. The automatic exchange of settings and other information via a proximity-based RFID data exchange allows a media player to quickly establish a secure communication link with another device via a commonly supported wireless protocol such as Ultra Wideband (UWB) or Bluetooth. Another aspect of the media player system pertains to a method of using the captured media capability of the connecting device to customize certain menu options and software parameters in the media player.

Abstract: A wireless media player and a related system and methodology are disclosed. One aspect of the wireless media player system pertains to a virtual connector system, apparatus, and method for the automatic establishment of wireless connectivity with other electronic devices. In one embodiment, the media player device employs the use of integrated Radio Frequency Identification (RFID) technology to exchange communication settings, media capability, and other parameters with an external device that also has integrated RFID technology. The automatic exchange of settings and other information via a proximity-based RFID data exchange allows a media player to quickly establish a secure communication link with another device via a commonly supported wireless protocol such as Ultra Wideband (UWB) or Bluetooth. Another aspect of the media player system pertains to a method of using the captured media capability of the connecting device to customize certain menu options and software parameters in the media player.

Abstract: A wireless media player and a related system and methodology are disclosed. One aspect of the wireless media player system pertains to a virtual connector system, apparatus, and method for the automatic establishment of wireless connectivity with other electronic devices. In one embodiment, the media player device employs the use of integrated Radio Frequency Identification (RFID) technology to exchange communication settings, media capability, and other parameters with an external device that also has integrated RFID technology. The automatic exchange of settings and other information via a proximity-based RFID data exchange allows a media player to quickly establish a secure communication link with another device via a commonly supported wireless protocol such as Ultra Wideband (UWB) or Bluetooth. Another aspect of the media player system pertains to a method of using the captured media capability of the connecting device to customize certain menu options and software parameters in the media player.

Abstract: Provided is an optical disc device including: an optical pickup which includes an objective lens and a receiver unit which receives light reflected off an optical disc; a signal processing unit which generates a main push-pull signal and sub push-pull signals from signals from the receiver unit, and obtains a signal obtained by subtracting the main push-pull signal from the sub push-pull signal multiplied K times, to generate a tracking-error signal; and a control unit which performs a midpoint servo process, an offset process of adding an offset value to a lens-error signal indicating displacement of the objective lens, a stabilization awaiting process of waiting for oscillation of the optical disc to stabilize, a measurement process of measuring the tracking-error signal, and a K value adjusting process of adjusting a value of K in response to a result of the measurement process.

Abstract: A wireless media player and a related system and methodology are disclosed. One aspect of the wireless media player system pertains to a virtual connector system, apparatus, and method for the automatic establishment of wireless connectivity with other electronic devices. In one embodiment, the media player device employs the use of integrated Radio Frequency Identification (RFID) technology to exchange communication settings, media capability, and other parameters with an external device that also has integrated RFID technology. The automatic exchange of settings and other information via a proximity-based RFID data exchange allows a media player to quickly establish a secure communication link with another device via a commonly supported wireless protocol such as Ultra Wideband (UWB) or Bluetooth. Another aspect of the media player system pertains to a method of using the captured media capability of the connecting device to customize certain menu options and software parameters in the media player.

Abstract: An optical disc device and information recording/reading method for an optical disc in which a recording layer is formed through volume recording by aligning recording tracks, which hold information, in a homogenous recording region that does not internally have a layer defining a recording position. The information recording method includes a step in which a first recording layer forming a complex recording layer is formed by forming a recording track while recording information by focusing a main beam at a predetermined depth position in the recording region, and a step in which a second recording layer forming the complex recording layer is formed by forming a recording track while recording information by focusing the main beam at a depth position that is separated from the first recording layer in a depth direction by a depth offset greater than ? of a wavelength of the main beam.

Abstract: An optical information storage medium system is provided. The optical information storage medium system includes an optical pickup, which comprises a photo-detector configured to control light power detected by receiving a portion of light emitted from a light source and obtains an output signal proportional to output light power of the light source from a signal detected by the photo-detector, and a signal processor configured to signal-process the output signal input from the optical pickup. The signal processor includes a sensitivity acquisition unit configured to acquire a sensitivity value of the photo-detector, a gain calculator configured to calculate a target gain value to be used in comparing the sensitivity value of the photo-detector, which is acquired by the sensitivity acquisition unit, with a target sensitivity value to be used by the optical information storage medium system, and a gain adjustment unit.

Abstract: A device is described for generating a control signal for controlling a passenger protection arrangement of a motor vehicle, having a first acceleration sensor for generating a first acceleration signal, having a second acceleration sensor for generating a second acceleration signal, having a first structure-borne noise sensor for generating a first structure-borne noise signal, having a second structure-borne noise sensor for generating a second structure-borne noise signal, and having an evaluation circuit, the evaluation circuit (being configured for generating a combination signal from the first structure-borne noise signal and the second structure-borne noise signal, the evaluation circuit being configured for generating the control signal as a function of the first acceleration signal, the second acceleration signal and the combination signal.

Abstract: An optical disc device includes an optical pickup that causes a laser beam to be incident on an optical disc and detects a reflected beam, an A/D converter that converts into a digital signal a plurality of analog signals obtained from the reflected beam detected by the optical pickup, an error signal generating circuit that generates a servo signal for the optical pickup based on the digital signal converted by the A/D converter, a low-pass filter that removes noise of a specific band included in the servo error signal generated by the error signal generating circuit, a main processor that switches a noise removal band of the low-pass filter based on states of the optical disc, and an actuator that performs servo control for the optical pickup based on the servo error signal from which the noise has been removed by the low-pass filter.

Abstract: There is provided a position control apparatus including a light radiating/receiving unit that performs radiation of laser light for recording and laser light for adjacent track servo onto an optical disc recording medium through a common objective lens, and receives return light of the laser light for the adjacent track servo and the laser light for the reference surface, a tracking mechanism unit that displaces the objective lens, a reference surface tracking error signal generating unit that generates a reference surface tracking error signal, a reference surface tracking servo control unit that controls the tracking mechanism unit, a recording layer tracking error signal generating unit that generates a recording layer tracking error signal, an integrating unit that integrates the recording layer tracking error signal, an offset providing unit that provides an integration output by the integrating unit, and a feedforward control unit that generates a control signal.

Abstract: The optical disc device has a circuit which forms a focus error signal for focus servo control based on reflection light from an optical disc exposed to laser light. Also, the device has a data processing unit which can control by feedback a position to which an objective lens is moved by a focusing actuator based on a 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 for the focusing actuator is switched to a smaller one in comparison to that in feedback control.

Abstract: A wireless media player and a related system and methodology are disclosed. One aspect of the wireless media player system pertains to a virtual connector system, apparatus, and method for the automatic establishment of wireless connectivity with other electronic devices. In one embodiment, the media player device employs the use of integrated Radio Frequency Identification (RFID) technology to exchange communication settings, media capability, and other parameters with an external device that also has integrated RFID technology. The automatic exchange of settings and other information via a proximity-based RFID data exchange allows a media player to quickly establish a secure communication link with another device via a commonly supported wireless protocol such as Ultra Wideband (UWB) or Bluetooth. Another aspect of the media player system pertains to a method of using the captured media capability of the connecting device to customize certain menu options and software parameters in the media player.

Abstract: Provided is an optical recording medium, including a recording target track that is a track on which small record carriers are arranged and on which information recording is performed by modulating the small record carriers through light irradiation; and a wobbling track on which the small record carriers are arranged in a wobbling manner, wherein a single wobbling track is formed to run parallel to a set of a plurality of recording target tracks.

Abstract: An optical disk device includes an optical pickup, and a controller. The optical pickup emits light on an optical disk, and detects return light from the optical disk. The controller performs a focus control based on a focus error signal corresponding to the return light detected by the optical pickup, and performs a tracking control based on a tracking error signal corresponding to the return light detected by the optical pickup. The controller finds a relation of an amount of deviation in a tracking balance of the tracking error signal relative to a change in a focus balance of the focus error signal while the tracking control is stopped prior to reproduction of the optical disk. The controller corrects the deviation in the tracking balance attributable to the change in the focus balance based on the relation while the focus balance is adjusted.

Abstract: An optical disc driving device includes a control circuit 4 for performing a gain adjustment for each of two recording surfaces of a multilayered optical disc 1 on the basis of an FE signal in such a way as to maintain a state in which light is focused onto either of the recording surfaces, to generate a focus servo loop signal, and for generating a focus jump signal for causing either a transition from a state in which the light is focused onto one recording surface to a state in which the light is focused onto the other recording surface, or a transition in the opposite direction from a threshold set up on the basis of an amount of gain adjustment, and a focus actuator driving circuit 5 for performing either a focus jump or an operation of maintaining the state in which the light is focused.

Abstract: An offset correction is automatically determined and routinely updated to reduce or eliminate data retrieval errors that may be caused by low level distortion in optical disc data storage recording, re-recording and retrieval system. An offset control loop is provided for reading information from a modulated wobble signal with which the data is recorded to an optical disc data storage medium to provide detection of an offset and correction of that offset to facilitate implementation of precise timing synchronization and/or encoded information contact in the system. The offset detector measures a wobble signal and mathematically converts detected information regarding the measured wobble signal to an offset correction by integrating the wobble signal over a specific time interval and comparing the integrated value to an expected integrated value. The integration may be performed over at least one period of the sinusoidal wobble signal, and the correction added to the wobble signal.

Abstract: A disc drive includes an optical pickup that emits laser light to a predetermined layer position via an objective lens and detects reflection light of the laser light, a tracking mechanism that drives the objective lens in a tracking direction, a tracking error signal generation unit that generates a tracking error signal, based on a light detecting signal for the reflection light obtained by the optical pickup, a tracking servo control unit that performs a tracking servo control based on the tracking error signal, and a control unit that makes the tracking servo control unit perform tracking servo pull-in on the basis of a frequency measurement result of the tracking error signal and a recording or non-recording determination result based on the light detecting signal.

Abstract: Aspects of the disclosure can provide a method for generating an offset correction signal with a reduced circuit footprint. The method can include converting samples of a wobble signal into digital values having a reduced number of bits, integrating the digital values having the reduced number of bits over a specified time interval to determine an error signal, and generating an offset correction signal based on the determined error signal.

Abstract: An optical disc apparatus includes a focus controller including a first digital filter, tracking controller including a second filter, focus actuator driver, tracking actuator driver, defect detector for detecting a defect on an optical disc, and a system controller for controlling the focus controller, the tracking controller and the defect detector. The system controller holds an input and output of at least one of either the focus controller or the tracking controller on the basis of the output of the defect detector, and sets an initial value in a delay memory of the digital filter of the controller held upon awake of the hold state.

Abstract: An average servo control method is provided. A target level of at least a servo signal is first detected, which is corresponding to a present condition of the optical disc drive. The target level is then compared with a current level of the servo signal, and a average servo loop gain is adjusted based on the comparison result. A target level calibration may be performed before the gain adjustment. The target level calibration analyzes the servo signal to determine a plurality of preset target levels each corresponding to a different condition. The preset target levels and corresponding conditions are stored as a lookup table. In this way, the target level is acquired based on the lookup table and the present condition.

Abstract: There is a need to prevent a possible erroneous detection of an off-track condition during recording to an optical disk. The above need can be addressed by, for example, determining an off-track condition has occurred when a light spot is located at least half-way from the track being recorded toward another track adjacent the track being recorded, and stopping a recording operation. In another example, the above need can be addressed by determining that off-track has occurred based on an output of a first off-track detector which detects that the light spot is off the track based on a wobble signal, an output of a second off-track detector which detects that the light spot is off the track based on a tracking error signal, and an output of a zero-cross detector which detects that the tracking error signal crosses zero based on an output of the tracking error signal.

Abstract: An optical read/write apparatus as an embodiment of the present invention includes: a light-splitting element configured to split a light beam emitted from a light source into multiple light beams including a write beam and a read beam; an optical system configured to converge the write and read beams onto the same track on an optical storage medium; a photodetector including a light receiving element configured to detect the read beam reflected from the optical storage medium and output an electrical signal; and a divider configured to generate a read signal by dividing the signal detected by the light receiving element by a signal that represents a write modulated component and that is obtained by detecting a part of the light beam emitted from the light source.

Abstract: An imaging apparatus that adjusts focus based on frequency components extracted from an image signal is provided. The apparatus includes a 1st order Infinite Impulse Response (IIR)-filter including a plurality of sample delayers having a plurality of line buffers for buffering and delaying a plurality of samples to sequentially read pixels of the image signal through raster scanning and extracting frequency components of the image signal from the read pixels by using the plurality of sample delayers; and a delay sample number controller for controlling the IIR-filter to match the number of horizontal pixels sequentially read from the image signal through raster scanning to the number of the plurality of samples buffered by the plurality of line buffers.

Abstract: Method and device for generating a control voltage for a position actuator of a disk drive system for displacing a lens of a pick-up unit to a given X-position. The actuator is operated by an open loop control system. First, parameters of the control system are calibrated so that the control system produces a control voltage (Va) from an input position signal (Xact_setp). Then, the control voltage is processed in a feed forward system for generating a processed control signal (Va_p) which is fed to the position actuator for displacing said lens to the X-position. A Z-value corresponding to the axial distance of the lens from a calibrated axial position and a temperature of the pick-up unit are measured. The position actuator operates according to the formula: Xdc=Va—p*K(Temp,Z)/(R(Temp)*C(Temp,Z)).

Abstract: A drive apparatus includes a magnet rotor having a plurality of magnetic poles that are magnetized, a stator having a magnetic pole portion that opposes each pole of the magnet rotor, a coil configured to excite the magnetic pole portion, a position detector configured to detect a position of the magnet rotor, a first driver configured to switch an electrification state of the coil in accordance with a preset time interval, a second driver configured to switch an electrification state of the coil in accordance with an output of the position detector, and a controller configured to select the first driver when the output of the position detector is less than a first threshold, and to select the second driver when the output of the position detector is equal to or larger than the first threshold.

Abstract: Laser write parameters in an optical drive are calibrated. A parameter range for the write parameters is set based on a recordable medium, and a number of test runs are recorded on the recordable medium while varying the write parameters. Write performance characteristics over the test runs are measured. Based on the measured performance characteristics, actual write parameters are selected for use in writing actual data.

Abstract: Detection is made as to at least one of a ratio between a tracking error and a focus error, and a duty cycle of an off-track signal with respect to an optical disc. A decision is made as to whether or not the optical disc is playable on the basis of the detected at least one of the ratio and the duty cycle. The ratio is a ratio of the focus error to the tracking error or a ratio of the tracking error to the focus error.

Abstract: A method and apparatus identifying a type of a recordable disc according to whether a land pre-pit (LPP) is formed on the disc. The apparatus includes an RF (radio frequency) amplifier amplifying light reflected by the disc to a predetermined value; an LPP signal detector detecting an LPP (Land Pre-Pit) signal from output signals of the RF amplifier; and a system controller identifying a type of the disc according to whether the LPP signal is detected by the LPP signal detector. Since a disc type is discriminated and operational conditions of a disc drive are adequately set during an early stage of a disc driving period, a lead-in time of a disc can be reduced.