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: 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: It is an optical disk apparatus that comprises: a laser drive device for outputting a test power larger than a prescribed value in a gap section; an optical pickup for forming a beam spot on a disk and detecting reflected light; a focus error detector for detecting position shift between a recording face of the information recording medium and the beam spot; a focus control device for controlling the position shift; and a focus drive device for driving an objective lens in directions far from and close to the disk, wherein, in the gap section, the focus drive device keeps a focus drive output level of right before the laser drive device outputs the test power, and sets a recording power such that the emitted light power becomes the prescribed value.

Abstract: The method for estimating recording power Pow_tilting of a tilting part of a tilting disk is shown based on a power compensation formula: Pow_comp=A*(A*K). After a focus error (FE) signal of the tilting part of the tilting disk is manipulated as a focus servo output (FOO) signal, the parameter A is derived by low-pass filtering the FOO signal. Thereafter, another parameter K is then derived from a reference lookup table by using curve fitting approach based on parameter A such that the power compensation Pow_comp could be estimated by substituting parameters A and K into the above formula. A recording power Pow_tilting of the tilting part of the tilting disk could be estimated by adding a given recording power Piwrtpwr to the power compensation Pow_comp.

Abstract: It is an object of the present invention to provide a method for absorbing individual variance between optical disc devices or optical discs, and for determining the optimal servo adjustment position even with optical discs in which no convex/concave pit string is present. When mounting a disc, servo position adjustment is performed in at least two stages: first servo position adjustment and second servo position adjustment. Also, the second servo position adjustment is performed by recording a predetermined signal after the first servo position adjustment and reproducing the track where the predetermined signal was recorded.

Abstract: The invention relates to a method for optimized tracking of an optical scanner along a track of an optical recording medium, the track having information markings arranged in dense succession, and also having fundamental changes in properties in significantly lower density. The method has the following steps: formation of a track error signal, detection of the occurrence of fundamental changes in properties of the track, formation of an offset value from the comparison of the value of the track error signal that occurs shortly before and shortly after the fundamental change in properties, formation of the track error signal, taking account of the offset value and repetition of the aforementioned steps.

Abstract: In an optical recording medium of the present invention, plural pits which carry main information recorded in a user area and tangential push/pull (T-PP) information required for reproducing the main information recorded in T-PP area are formed. The pit length in a track direction is formed according to the main information, and the pit depth is formed according to the T-PP information, and copyright protection information by digital watermarking is embedded in the main information. Also, if the optical disk by unauthorized copying is loaded, a reproducing apparatus restricts the reproduction thereof.

Abstract: A digital servo system of an optical disk drive with a calibrated inverse non-linearity function is disclosed. A look-up table is determined, for example, with a focus error signal gain corresponding with a focus error signal offset so that the response of the focus servo system is substantially linear. Additionally, the look-up table can include tracking error signal gain, tracking error signal offset, or tracking loop gain parameters corresponding with the focus error signal offset.

Abstract: In a first mode, an R/W channel starts to monitor read information to thereby detect a servo mark contained in servo information, each time a servo controller generates a servo gate pulse. Upon detecting the servo mark, the R/W channel detects, from the read information, position information contained in the servo information and following the servo mark, at a timing determined by the detection timing of the servo mark. When the first mode has been switched to a second mode, the R/W channel detects the servo mark and position information using the synchronous method.

Abstract: A method of generating a composite signal in a closed loop servo signal system of a data recording system used to drive a recording head to any given position within a dynamic range of a servo tracks includes an optical pickup system for generating optical spots focused on a recording medium, the spots separated by equal distances across a track, the optical pickup system receiving a set of reflectances from the spots, a media system for providing the servo tracks responsive to optical spot illumination, an electric system for generating a set of filtered signals from the reflectances and for generating a set of S-curves by pair wise subtraction of the filtered signals, a processing system to generate a composite servo position signal from the S-curves and filtered reflectances, and a servo system for driving the recording head to a desired position by comparing the desired position to a measured position from the composite servo position.

Abstract: An information storage apparatus records, reproduces and/or erases information with respect to a recording medium. The apparatus includes a servo error generation detector for detecting a generation of a servo error based on at least one of servo signals including a focus error signal and a tracking error signal which are derived from output signals of a light receiving element, and a data recording resuming section for temporarily interrupting a data recording with respect to the recording medium, temporarily turning OFF a servo and then turning ON the servo again, to thereafter synchronize recording data to recorded data already recorded on the recording medium, and resume recording of the recording data continuing without a discontinuity to an end of the recorded data recorded immediately before the interruption of the data recording, when the generation of the servo error is detected while recording data on the recording medium.

Abstract: A servo mark detector detects a servo mark from each servo information item detected by the servo detector. A counter measures a time period each time a servo mark is detected, thereby measuring a servo interval. A correction circuit corrects a time period T2 on the basis of the measured servo interval and an ideal servo interval. A determination circuit determines which one of the time period T2 and a time period T2? obtained by correcting the time period T2 should be used. A servo-sector-pulse-generating unit generates a servo sector pulse a time period T1 after the detection of each servo mark, and generates a pseudo servo sector pulse when the time period determined by the determination circuit has elapsed after the detection of each servo mark, if the next servo mark is not detected during the determined time period.

Abstract: A method and apparatus are disclosed for a multi-channel imaging system wherein the beams of light corresponding to each channel can be individually auto-focussed. Individual channel focussing permits image data to be recorded on a surface of variable depth, such as the patterned surfaces of semiconductor wafers and masks. A light source illuminates an array of reflective, deformable, micromachined ribbons and the ribbons reflect the light to form beams for the various channels. An auto-focus detector determines the depth profile of a recording surface and focus data for each channel is fed back to the ribbon array. The focus data for a particular channel is used to control the deformation of a corresponding ribbon and consequently, the focal length of the reflected beam. The individual beams can be modulated with image data by an external modulator or by the ribbon array itself.

Abstract: An optical disk unit, which performs tracking control by generating a tracking error signal based on detection signals of reflected lights of a main light beam for recording and reproduction and sub light beams for tracking, includes a first tracking error generation part generating a first tracking error component from the detection signals of the reflected light of the main light beam of a read-power time or an erase-power time, a second tracking error generation part generating a second tracking error component from the detection signals of the reflected lights of the sub light beams of a write-power time, and a subtraction part obtaining the tracking error signal for a recording time by subtracting the second tracking error component from the first tracking error component.

Abstract: Method and apparatus for controlling the light power of an optical disk system, and optical disk system having the same are provided. The optical disk system includes a microcontroller for controlling the operation of the optical disk system, a light power adjusting apparatus for generating a light quantity control signal for controlling the quantity of light emitted from the optical disk, and an optical pickup device for adjusting the quantity of light emitted from the optical disk in response to the light quantity control signal.

Abstract: An information recording apparatus and a method therefor which can form a beam guide groove in the shape of highly accurate rectangle having abrupt edges. A recording mark is formed by exposing a recording medium with a recording beam having a beam diameter smaller than the beam guide groove, while periodically vibrating the recording beam in a direction perpendicular to a recording track on the recording medium, or in both horizontal and vertical directions of the recording track.

Abstract: An information recording and reproducing apparatus for scanning with a laser beam along an information track on a recording medium. The information recording and reproducing apparatus has a track offset adjustment circuit to perform track offset adjustment during recording and to not perform track offset adjustment during reproduction.

Abstract: An information recording and reproducing apparatus for scanning with a laser beam along an information track on a recording medium. The information recording and reproducing apparatus has a track offset adjustment circuit to perform track offset adjustment during recording and to not perform track offset adjustment during reproduction.

Abstract: A battery pack is detachably provided for a drive main body. When carrying, an interface card and a connector cable are detachably supported and fixed to the drive main body by a holder member, thereby packaging. A power source is supplied from an upper apparatus to a control IC circuit unit of a device via the interface card. Only when both of the power supply from the upper apparatus and the power supply from an external power source unit are detected, the power source from the external power source unit is supplied to a device circuit unit, thereby making the device circuit unit operative.

Abstract: Disclosed is an optical recording and reproducing apparatus comprising a light source directing a light spot toward a recording medium, a detection system detecting light reflected from the recording medium to derive an electrical signal from the reflected light, an information processing circuit modulating the intensity of the light spot according to writing pulses to record information on the recording medium and using the electrical signal to reproduce information from the recording medium, and a tracking servo circuit carrying out tracking servo operation on the basis of the electrical signal and including an extracting circuit connected to a source of extracting pulses having a pulse width at least equal to the writing pulse width so that writing pulse parts contained in the electrical signal are extracted during recording information, whereby a track offset occurring during information recording can be minimized, and the stability of the tracking servo system can be improved.

Abstract: A power control device for controlling a power of a light source of an optical beam directed to an optical medium. The power control device includes a reflected light detector for detecting reflected light from the optical medium when irradiated by an optical beam which is following a track; an arithmetic unit for calculating from the reflected light a transmissivity of light transmitted from a disk surface to a recording layer or an amount of directed light on the recording layer of the medium; and power control means for controlling the power of the light source for emission based on a calculation result produced by the arithmetic unit.