Abstract: The latency corresponding to a latency-sensitive event-based processor is evaluated to determine whether the latency-sensitive event-based processor (EBP) should be prioritized. If so, constraints on the number of events that the latency-sensitive EBP can process are relaxed and the frequency with which the latency-sensitive EBP can process events is increased. At a next latency evaluation, if the latency-sensitive EBP no longer meets criteria for prioritization, the constraint on the number of events is returned to a nominal level, as is the frequency with which the latency-sensitive EBP can process events.

Abstract: A magnetic disk device includes a control circuit, and a disk unit including a plurality of magnetic disks, a plurality of magnetic heads configured to read or write data from or to the magnetic disks, a first actuator configured to move the magnetic heads, a plurality of second actuators each configured to move the corresponding magnetic head, and a switch circuit configured to connect the control circuit and one of the second actuators. The control circuit is configured to transmit to the disk unit an instruction in which one of the magnetic heads is specified, control one of the second actuators corresponding to the specified magnetic head to move the magnetic head via the switch circuit, and based on a signal from the one of the second actuators, determine whether an error occurs in the one of the second actuators.

Abstract: According to one embodiment, a magnetic disk device includes a disk, a head for writing data to the disk and reading data from the disk, and a controller configured to detect a positioning error of the head as the head is writing the data in a first track of the disk, and change a first threshold value for interrupting the writing based on one or more evaluation values corresponding to a possibility of correcting error data in the first track of the disk. The controller interrupts the writing when detecting the positioning error of the head writing the first track that exceeds the first threshold value.

Abstract: A controller is capable of improving position detection accuracy during the stopping of an actuator, and controlling the actuator with high stability and quick responsiveness during driving. A first position signal corresponding to an amount of relative movement between the actuator and a driven element is output to a filter, and the filter outputs a second position signal generated by attenuating signal components having frequencies except a specific frequency band. Driving and stopping of the actuator are controlled according to the second position signal. As the specific frequency band, a first frequency band is set in the filter during the driving of the actuator, and a second frequency band is set in the filter during the stopping of the actuator. The first frequency band and the second frequency band both include 0 Hz, and the second frequency band is narrower than the first frequency band.

Abstract: An apparatus comprises a ring oscillator comprising a plurality of delay stages connected in cascade and an injection apparatus comprising a plurality of injection devices, wherein the injection devices receive a reference clock from their inputs and outputs of the injection devices are coupled to respective outputs of the delay stages, and wherein each injection device comprises a polarity selection stage having inputs coupled to the reference clock and an adjustable gain stage having inputs coupled to outputs of the polarity selection stage and outputs coupled to outputs of a corresponding delay stage.

Abstract: An envelope tracking (ET) current bias circuit comprises an envelope detection circuit detecting an ET voltage from an input signal; a first voltage/current converting circuit converting a reference voltage into a direct current (DC) current and adjusting the DC current according to a first control signal; a second voltage/current converting circuit converting the ET voltage into an ET current, adjusting the ET current according to a second control signal, and removing a DC offset current from the ET current to provide an offset compensated ET current; and an arithmetic circuit calculating levels of the offset compensated ET current and the DC current to generate an ET bias current.

Abstract: A position control device includes a position detector that detects a position of an object to be controlled; a target generator that outputs a target velocity and a target position of the object to be controlled; a first calculator that calculates a control amount for causing the object to be controlled to track the target position; a second calculator that calculates a control amount for controlling the velocity of the object to be controlled, to be at the target velocity; a control signal output unit that outputs a control signal according to a total control amount obtained by the first and the second calculators; and a storage unit that stores an attitudinal change correction amount. The second calculator acquires the attitudinal change correction amount stored in the storage unit, adds the attitudinal change correction amount to the control amount to correct the control amount, and outputs the corrected control amount.

Abstract: The present invention relates to a filter assembly for a medical image signal and a dynamic decimation method using the same. The filter assembly includes a decimation filter that includes an integer number of multiplier accumulators (MACs), changes a cut-off frequency depending on a bandwidth of the medical image signal received through a dynamic impulse response update, and performs a decimation with respect to the received signal according to a decimation ratio, wherein the decimation filter determines a filter coefficient corresponding to an integer interval so as to up-sample the received medical image signal and supplies the filter coefficient to the MACs.

Abstract: A position detecting device detects the position of a moving body by using first and second detected signals that have voltage values changing in connection with a movement of the moving body. The position detecting device includes a difference computing unit that computes first and second difference values, the first being the difference between a center voltage of the first detected signal and the voltage value of the first detected signal, and the second being the difference between a center voltage of the second detected signal and the voltage value of the second detected signal. A ratio computing unit computes a difference-sum ratio index in accordance with the ratio of the difference value between the absolute values of the first and second difference values and the absolute value of the second difference value to the sum of the absolute values of the first and second difference values.

Abstract: The present invention provides a radiotherapy system that can monitor a target location in real time. The radiotherapy system includes a remote control system operable to actuate a real-time image capturing device to acquire images in real time for monitoring the target location. The system also includes an image registration system that can register the acquired image with an image previously captured for the treatment plan, whereby it can be determined whether the patient's tumor is in the beam's eye view of the treatment plan. By confirming that the tumor is in the range of the beam's eye view, the accuracy of the treatment can be improved, and the irradiated area can be reduced, which makes the radiation treatment safer.

Abstract: A data acquisition system and a method of operating the data acquisition system are disclosed. A zero crossing detector generates a mains cycle start signal in accordance with a power line frequency of a mains power source. An analog-to-digital converter samples a signal provided by a test probe and generates data samples at a sampling rate. A noise replica generator generates noise replicas from the data samples at a replica generation rate, and noise estimates from the noise replicas at the sampling rate, wherein the noise replica generation rate is less than the sampling frequency. A noise removal module removes each noise estimate from a corresponding data sample.

Abstract: A laser apparatus and bio-imaging apparatus are provided, which include: a mode-lock laser unit including a saturable absorber section that applies a bias voltage, a gain section that feeds a gain current, a semiconductor laser that emits laser light, and an external resonator; an optical modulation unit performing amplification modulation on the laser light emitted from the mode-lock laser unit; a reference signal generation unit generating a master clock signal and supplying a signal synchronized with the master clock signal to the gain section of the semiconductor laser; and a driving circuit generating a driving pulse used to drive the optical modulation unit based on the reference signal.

Abstract: Systems and methods are provided for reducing jitter in a write strategy for an optical drive. A pattern on an optical medium is recorded according to a first write strategy. Edge timings corresponding to the pattern recorded on the optical medium are measured, and edge timing sensitivities are determined based at least in part on the measured edge timings. A second write strategy is determined based on the edge timing sensitivities, such that the second write strategy is associated with a second jitter amount less than a first jitter amount associated with the first write strategy.

Abstract: The invention provides a method for adjusting a tracking error signal of an optical disk drive. First, a pickup head control signal is applied to an actuator to move a pickup head. The tracking error signal is then generated while the pickup head moves. The tracking error signal is then sampled and a characteristic value of the tracking error signal is determined. An adjustment signal is then generated according to the characteristic value and a target value. Finally, the tracking error signal is adjusted according to the adjustment signal.

Abstract: An optical disc (120) has a first mark (131) disposed at the center of a track, a second mark (132) disposed away from the center of the track in a tracking direction thereof by a distance b1, and disposed away from the first mark (131) in the direction along the track by a distance L, and a third mark (133) disposed away from the center of the track in the tracking direction opposite to that of the second mark (132) by a distance b2, and disposed away from the first mark (131) in the direction along the track by a distance L2. The second and third marks (132) and (133) generate scattered light depending on the distance between a scattering medium (103) and each of the marks by irradiating the scattering medium (103) in an optical information apparatus with light. The distances b1 and b2 are smaller than 50 nm.

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: The amplitude deviation of a tracking error signal in an optical disk apparatus is reliably corrected by processing signals at low costs. A servo signal generator generates a tracking error signal and a lens error signal from a photodetected signal. A lens error deviation signal memory circuit stores the lens error signal generated at the servo signal generator, and reproduces the one-turn deviation of the lens error signal. A tracking error signal corrector learns an amplitude correcting value for the tracking error signal from the tracking error signal detected in reproducing the one-turn deviation of the lens error signal, and stores the amplitude correcting value in a correcting signal generator.

Abstract: A disk drive is disclosed comprising a head actuated over a disk, wherein a bootstrap spiral track is written on the disk. While servoing on the bootstrap spiral track at least one circular reference track is written on the disk. A velocity profile is adjusted in response to the circular reference track, and a plurality of spiral tracks are written to the disk in response to the velocity profile.

Abstract: A differential phase detector for an optical storage system is set forth. The differential phase detector includes a photodetector circuit arranged to detect light deviations associated with radial errors in the optical storage system. A non-linear equalizer is in communication with the photodetector circuit. The output of the non-linear equalizer is in communication with signal processing circuitry. The signal processing circuitry uses the equalized signals to generate one or more radial error signals.

Abstract: To carry out a track control by compensating for an offset caused by a radial tilt when a track control of a main beam is carried out by detecting tracking information provided at a reference layer of a spatial recording medium by a guide beam, there are formed a first mark pair row aligned with the first mark pairs in a radius direction by a track pitch, and other mark pair row aligned with the second mark pairs in the radius direction by the track pitch. The other mark pair row is arranged in the radius direction by being shifted from the first mark pair row by a prescribed distance. The track control is made to be able to carry out by dispensing with an uncontrollable region by selecting one of plural track error signals generated from the plural mark pairs.

Abstract: A layer-to-layer jumping method according to the present invention includes, after a layer-to-layer jump has been started in a multilayer optical disc, the step ST7 of detecting an S-curve signal from an information layer, which is located shallower than the target information layer of the layer-to-layer jump, with a spherical aberration correction made adaptively to that shallower information layer, and the step ST8 of generating a deceleration signal based on the S-curve signal detected to get the layer-to-layer jump done.

Abstract: A system including a control module, error modules, and a tracking module. The control module: transitions a laser beam between positions on an storage medium; based on a tracking signal, adjusts a speed that the laser beam is transitioned, and while the laser beam is transitioned, increases the speed that the laser beam is transitioned from a first speed to a second speed. The error modules determine a track error of a current position of the laser beam and estimate a depth of a groove. The tracking module: while the speed of the laser beam is equal to the first speed, tracks the current position based on the track error and the depth of the groove; while the speed of the laser beam is equal to the second speed, tracks the current position based on the track error; and generates the tracking signal based on the current position.

Abstract: A position control method of an optical pickup head of an optical disc drive is provided. The optical disc drive has an optical pickup head for reading data from an optical disc and a step index for controlling the movement of the optical pickup head. The position control method includes: calculating a first position information of the optical pickup head according to the step index; reading an address information from the optical disc, calculating a second position information of the optical pickup head according to the address information; determining whether a difference between the first position information and the second position information is greater than a predetermined value; updating the step index when the difference is not greater than the predetermined value; moving the optical pickup head to an initial position when the difference is greater than the predetermined value, and setting the step index as zero.

Abstract: An optical disc apparatus has: a spherical aberration correction unit (7) which corrects the spherical aberration generated in a light spot on a recording layer; a control unit (52) which focuses a light beam on a predetermined recording layer, and shifts the focal point position of the light beam from the current recording layer to another recording layer; and a focus jump control unit (60) which controls correction of spherical aberration and shift of the focal point position based on the interlayer distance between the current recording layer and a recording layer which adjoins in a direction opposite to a direction of shifting the focal point position of the light beam. By this configuration, focus jump is stably executed.

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: A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of spiral tracks. During a seek operation, a demodulation window is opened in response to a window offset during a first revolution of the disk, wherein the demodulation window corresponds to the head approaching a spiral track. A window position error signal (PES) is generated representing a difference between a target framing of the demodulation window around the spiral track crossing and a detected framing of the demodulation window around the spiral track crossing. The window offset is adjusted in response to the first window PES, and the demodulation window is opened in response to the adjusted window offset during a second revolution of the disk.

Abstract: A servo control device includes a plurality of reproduction channels, a plurality of analog/digital (A/D) converters, a servo error detecting circuit that generates a servo error signal, a servo signal processing device that executes predetermined processing for the servo error signal to generate a control signal, and a sampling frequency converter that converts the sampling frequency between the servo error detecting circuit and the servo signal processing device. A first clock is included as a sampling clock of the A/D converters and a processing clock of the servo error detecting circuit. A second clock is included as a processing clock of the servo signal processing device. The sampling frequency converter converts the sampling frequency by processing the servo error signal by the servo error detecting circuit in synchronization with the first clock and processing the signal processed in synchronization with the first clock in synchronization with the second clock.

Abstract: A tracking method executed by an optical disc device. The optical disc device includes an optical head for emitting light to read or write data from or to an optical disc. The tracking method includes steps of: providing a table for listing a plurality of predetermined track classes, and a plurality of tracking errors; calculating the number of tracks between a current track in which the optical head is currently positioned and a target track from or to which the optical head reads or writes data; determining whether the number of tracks reaches a predetermined number; searching the table for the corresponding tracking errors when the number of tracking error reaches a predetermined number; calculating second jumping tracks based on the first jumping tracks and the found tracking errors; and driving the optical head to move to the second jumping tracks for tracking.

Abstract: An optical pickup device includes an astigmatism element which imparts astigmatism to laser light reflected on a disc, a spectral element which changes propagating directions of four light fluxes obtained by dividing a light flux of the laser light reflected on the disc to disperse the four light fluxes from each other, and a photodetector having a sensor group which receives the four light fluxes. The optical pickup device is further provided with a memory which holds a correction value for suppressing a DC component in a tracking error signal resulting from a positional displacement of the spectral element. The tracking error signal is corrected by the correction value to thereby suppress the DC component.

Abstract: In an optical disc device, a way of canceling a lens shift due to an electric offset of an output of a tracking actuator driving circuit is desired. A tracking servo control circuit contains a first operation mode for setting an output current of the tracking actuator driving circuit to generally zero and a second operation mode for supplying a predetermined potential to the input. An average potential of a push-pull signal detected in the first operation mode is acquired. An object lens is moved by a predetermined amount in both radial directions by changing a potential supplied in the second mode to acquire correlative relationship between average potential of a push-pull signal relative to a lens movement amount and the supplied potential. An offset amount is acquired from the potential and the correlative relationship to cancel the offset.

Abstract: A disk drive determines, from eccentric amounts of individual prescribed rotation phases for one round of an optical disk 1, a rotation phase range in which a lens shift amount after tracking pulling-in of an object lens constituting an optical pickup 3 does not exceed a movable range of the object lens in a preset tracking direction, sets the rotation phase range as a tracking pulling-in range, and carries out tracking pulling-in of the optical pickup 3 while the rotation phase of the optical disk 1 is placed within the tracking pulling-in range.

Abstract: A differential phase detector for an optical storage system is set forth. The differential phase detector includes a photodetector circuit arranged to detect light deviations associated with radial errors in the optical storage system. A non-linear equalizer is in communication with the photodetector circuit. The output of the non-linear equalizer is in communication with signal processing circuitry. The signal processing circuitry uses the equalized signals to generate one or more radial error signals.

Abstract: A method and apparatus to control a position in which data is to be recorded on a holographic data recording medium by using interference between a reference light and a signal light, the method including: irradiating the reference light and the signal light on the holographic data recording medium; generating a focus error signal that indicates a distance difference between a first focus corresponding to a focus of the reference light on the holographic data recording medium and a second focus corresponding to a focus of the signal light on the holographic data recording medium, based on information about a reflective signal light generated when the irradiated signal light is reflected from a reflective transmission layer of the holographic data recording medium; and moving the second focus to a position of the first focus, based on the focus error signal.

Abstract: A method and system for obtaining focus optimization in an optical disc system is disclosed. The focus offset of a recording unit is set to a first of a plurality of predetermined values. A HF quality value is measured and stored for the selected focus offset value of the recording unit. The focus offset is then set to a best-known focus offset value. Tracks on the optical media being read are then jumped. The above steps are then repeated for each of the plurality of predetermined focus offset values. The optimal focus setting is then determined from the stored HF quality measurements.

Abstract: A tracking system for a drive includes a beam positioning actuator and a control module. The beam positioning actuator is configured to radially displace a laser beam relative to an optical storage medium. The control module is configured to increase a seek speed of the beam positioning actuator to a predetermined speed based on a seek command signal to move the laser beam to a target position on the optical storage medium. The control module is also configured to reduce the seek speed of the beam positioning actuator from the predetermined speed responsive to the laser beam being radially displaced within a predetermined distance of the target position on the optical storage medium.

Abstract: An optical disk apparatus includes an optical pickup and a signal processor. The optical pickup includes an actuator for driving an objective lens, and a detected light intensity signal output part for outputting a detected light intensity signal to the processor. The signal processor includes a servo signal generator for generating a main push-pull signal and a sub push-pull signal on the basis of the detected light intensity signal supplied from the detected light intensity signal output part, a signal generator for generating a differential push-pull signal and a lens error signal by conducting addition/subtraction on the main push-pull signal and the sub push-pull signal, and a tracking offset correction signal generator which is input with the lens error signal to output a tracking offset correction signal. The differential push-pull signal correction is conducted by conducting addition/subtraction between the differential push-pull signal and the tracking offset correction signal.

Abstract: The invention provides an optical disk drive. The optical disk drive comprises a pickup head, a seek control device, a lens vision characteristic decoder, and an anti lens shift device. The pickup head comprises a sled and a lens for projecting a beam on a disk. The seek control device moves the sled, and shifts the lens with a shift distance relative to an origin at a center of the sled. The equalizer derives a servo signal from a reflection of the beam. The lens vision characteristic decoder obtains a vision characteristic of the lens according to the servo signal and determines a track-on direction according to the vision characteristic. The anti lens shift device triggers the seek control device to perform a track-on process according to the track-on direction.

Abstract: A simple circuit configuration allows an optical disc apparatus to reduce a problem of sound skips occurring due to damage on an optical disc. To this end, an LPF extracts a low-frequency component from a tracking actuator drive signal obtained by a tracking actuator driver. When the optical disc apparatus reads and writes information to and from the optical disc, a sled drive signal supplier outputs a sled pulse signal, as a drive signal for a sled motor, for a set-up predetermined time within each interval of a predetermined length, the sled pulse signal having a level corresponding to a level of the low-frequency component obtained by the LPF. On the other occasions, the sled drive signal supplier outputs the low-frequency component obtained by the LPF as the drive signal for the sled motor.

Abstract: A recording apparatus for an optical disk drive is provided. The recording apparatus includes a driver, a servo signal generator, a filter, and a counter. The driver controls a recording speed of the optical disk drive. The servo signal generator generates at least a servo signal. The filter with a specific bandwidth filters the servo signal to generate a filtered servo signal. The counter generate a count value according to the filtered servo signal and instructs the driver to decrease the recording speed of the optical disk drive when the count value exceeds a trigger value, so as to record with the decreased recording speed.

Abstract: An optical disk device for recording or reproducing an optical disk has: an objective lens for irradiating a laser beam to the optical disk; an actuator for moving the objective lens in the radial direction of the optical disk; and a spindle motor for rotating the optical disk. After the laser beam irradiated to the optical disk passed through a PID portion of the optical disk, the actuator moves the objective lens in the radial direction of the optical disk at a timing corresponding to a rotational speed. Between signals to drive the actuator, an output time of a deceleration signal is set to a predetermined ratio of a time during which an acceleration signal is outputted. While the deceleration signal is outputted, a light spot passes through the PID portion.

Abstract: With a high-density optical disc drive, although it is necessary to correct spherical aberrations which depend on a disc substrate thickness error, operation of an aberrations correction element takes time and therefore easy correction according to a disc radius degrades the operability of the apparatus. The present invention comprises an optical pickup unit including an objective lens and an aberrations correction lens, a focus actuator, a tracking actuator, a aberrations correction motor, a seek motor, an aberrations correction lens control module, a radius information detecting module, and a system control module.

Abstract: Stable interlayer jump is realized by judging whether a signal is a false signal caused by noises, stray light, or interference of an adjacent layer or a true FE signal.

Abstract: A method of recognizing a track pitch of an optical disk, adapted for an optical disk player, is provided. The method includes the steps of driving an optical pickup head to a predetermined position, so that the optical pickup head and the spindle motor are a predetermined distance apart, reading a data sector address, and recognizing the magnitude of the track pitch of the optical disk according to the value of the data sector address.

Abstract: An apparatus for recording and reproducing an information signal on and from an optical disc includes a memory. The information signal is written into the memory. The information signal is read out from the memory. An optical head generates a laser beam in response to the readout information signal, and applies the laser beam to the optical disc to record the readout information signal on the optical disc. A test signal is recorded on a position of the optical disc near a recording position thereof via the optical head during the writing of the information signal into the memory. The test signal is reproduced from the optical disc. The reproduced test signal is evaluated to generate an evaluation result. An intensity of the laser beam is optimized in response to the evaluation result.

Abstract: A position-error-signal calculation circuit (105) calculates a relative position error between a laser-focused-beam spot (103) and an information recording layer (102), and generates a focus error signal (106). A filter (108) amplifies and passes therethrough a signal component in the vicinity of the natural resonance frequency of at least one mode among the natural vibration modes of the optical disc medium (101). A drive amplifier receives through a stabilizing compensator (109) and a D/A converter (110) the focus error signal (106) passed by the filter (108), to drive an objective lens (113), thereby allowing the laser-focused-beam spot (103) to track the information recording layer (102).

Abstract: When a focus error signal (FE signal) is detected with an astigmatic method, a track crossing component leaks into the FE signal. Another detection method for the FE signal would reduce the leaking signal, but is not applicable when the light use efficiency decreases. An optical crosstalk correction amount determination unit (1000) determines a correction amount to correct an output of a tracking error detection unit (120) based on optical crosstalk from a TE signal to an FE signal occurring in reflection light from an optical disc (102) when a spot crosses a track. An output of the tracking error detection unit (120) is multiplied by the determined correction amount, and added to an output of the focus error detection unit (118). A focus control unit (138) executes focus control based on the addition result. This effectively reduces a TE signal component that leaks into the FE signal due to optical crosstalk.

Abstract: A tracking error (TE) signal polarity determining method, comprising: (a) obtaining a wobble related signal and a TE signal from an optical pick-up unit accessing an optical disc; (b) determining an accessing direction; and (c) determining if an original polarity of the TE signal from the optical disc should be changed or not according to the relation between the wobble related signal and the accessing direction.

Abstract: A method and apparatus for eliminating errors in a seek operation on a recording medium are provided. Given a target address on a recording medium, a reading device is moved to seek the target address, and it is determined whether or not a signal is read out at the location to which the reading device has been moved. If the expected signal is not available at that location, by extending a variable frequency range of an oscillator clock of a PLL circuit or by increasing a track gap between the target address and the track to which the reading device jumps initially to seek the target address, the oscillator clock can be phase-synchronized to EFM signal from the recording medium reliably, resulting in reduction of the seek errors.

Abstract: A driving device includes an optical pickup unit that irradiates a disc having a plurality of recording surfaces with a laser beam used for recording or reproducing information, and a generating unit that generates a focus control signal used for controlling a focus state of the laser beam emitted from the optical pickup unit on the basis of a focus error signal. The generating unit includes level detector that detects a level of the focus error signal, an offset generator that generates an offset signal used for performing focus jumping from one of the plurality of recording surfaces to another one of the plurality of recording surfaces in accordance with the focus error signal, and a switcher that switches a polarity of the focus control signal by comparing the level of the focus error signal of the level detector with a threshold value.

Abstract: An optical disk playback device includes a first control means for holding difference information which the first control means generates by, during playback of an optical disk 10, performing a comparison between track start point position information detected and track start point position information acquired with reference to contents information recorded in the above-mentioned optical disk, and a second control means for, when receiving a search request from outside the device, correcting the above-mentioned track start point position information on the basis of the above-mentioned held difference information.