Abstract: An optical drive tracking control method allowing an optical drive to select a first tracking error detecting method or a second tracking error detecting method to generate tracking error signals when reading a CD is provided. First of all, a CD is read and the first tracking error detecting method is used to generate a first tracking error signal. Next, determine if the first tracking error signal is correct or not: if yes, continue to use the first tracking error detecting method, otherwise, change to the second tracking error detecting method. Of which, the first tracking error detecting method can be the three-beam method or the differential push pull method (DPP method), while the second tracking error detecting method can be the differential phase detection method (DPD method).

Abstract: Marks with curved edges are used in data patterns and sensed with proximity recording. Circular, elliptical, and oval marks are examples of marks with curved edges that can be used in the present invention. The marks with curved edges are used to define data patterns (e.g. position error signal patterns) as a function of radius. If the marks with curved edges have been recorded longitudinally, an amplitude of a read back signal, such as a peak amplitude, is determined in order to generate a position error signal. If the marks with curved edges have been recorded vertically, an area under the curve of the read back signal is determined in order to generate a position error signal.

Abstract: A recording and/or reproducing apparatus for an optical disc having a pit area where data has been recorded and also having a grooved area where data is to be recorded includes an optical pickup, an error signal generating unit, a shift signal generating unit and a servo controller. The optical pickup includes an objective lens for converging a light beam on a signal surface of the optical disc, a photodetector for receiving the light beam reflected from the signal surface and an actuator for moving the objective lens in a direction perpendicular to its optical axis. The shift signal generating unit is responsive to the output signal of the photodetector to generate a lens shift signal corresponding to the amount of shift of the objective lens from its neutral position. The servo controller drives the actuator based on the lens shift signal or the error signal to move the objective lens along the radial direction of the optical disc.

Abstract: A track discrimination signal can be generated without requiring the use of a large number of parts or a complex device configuration even when an optical recording medium adapted to the “land/groove recording system” such as a “DVD-RAM” is used. A main light spot is and auxiliary light spots are formed on an optical disc for signal recording and signal reproduction. The auxiliary light spots have respective distances different from that of the main light spot relative to an objective lens and formed at a position expressed by SPn/2, where S is the absolute value of the distance relative to the main spot in the normal direction of the recording tracks formed on the signal recording surface relative to the man spot, P is the track pitch and n is an integer.

Abstract: A method of selecting laser beam in an optical disk drive is disclosed. A first laser beam (such as CD laser beam) is used to read an optical disk and generate a first testing result. Whether the first testing result is normal is then determined. The first laser beam is used to read data from the optical disk if the first testing result is normal, and a second laser beam (such as DVD laser beam) is, in stead, used to read data from the optical disk if the first testing result is abnormal.

Abstract: A method, apparatus, and computer readable medium controlling a servo of a recording and/or reproducing apparatus, using a detected header field signal. An optical recording and/or reproducing apparatus includes a playback signal detector that detects a playback signal and a track error signal from information recorded on a DVD-RAM disc, as picked up by a pickup. A header field signal detecting circuit detects a header field signal by comparing a sampled playback signal for a signal representing the presence of a header field with a reference level and holding the comparison result for a predetermined period of time to generate the header field signal. Accordingly, a tracking servo can be stably controlled by using a tracking driving signal that is not affected by the presence of a header. Also, in a seek mode, the track error signal can be held based on the header field signal to generate a track count signal that is similarly not affected by the header.

Abstract: A reference pattern on the non-data side (or label side) of an optical data storage disc enables optical disc devices to register a position of a laser to an absolute radial location on the disc's non-data side. The absolute radial location serves as a reference track to which that all radial positioning can be referenced.

Abstract: An optical disc and an optical disc drive for the optical disc are provided which are suitable for recording data with a high density. The optical disc D uses both lands and grooves as recording tracks. Each of the tracks consists of one address segment and forty five data segments. The address segment is wobbled at one side thereof. Each of the data segments is a DC groove. The address segment records an address information including a sync signal, frame address, track address and CRC, a tilt pattern and a clock mark. The clock mark is adapted to reflect laser beam in one amount before the mark and in another amount after the mark. The tilt pattern has a different track pitch from those in other areas. The data segments record data magneto-optically.

Abstract: An apparatus for holding digital data. The apparatus includes a medium in which a plurality of dimples are spaced for tracking by a playing apparatus. Each dimple includes a plurality of facets, and each facet represents a data bit. Because the location of each dimple is predetermined, a tracking assembly can use the dimple locations for tracking purposes. Thus there is no need to reserve bits for tracking purposes, and more data can be stored in a given space on a given medium than with previously developed high-density digital storage media.

Abstract: An aberration detecting method of the present invention is arranged such that a light beam, having passed through an optical convergence system provided in an optical pickup device, illuminates a flat section of an optical disk, and using the light beam which has been reflected, and the aberration occurring in the two-element objective lens is detected.

Abstract: Conventionally, as in the case of switching between a DVD-R and a DVD-RAM, when the method of record mark arrangement in a track is changed, the physical format of the disk is also changed. This makes it difficult to ensure compatibility between pieces of data recorded by a plurality of different methods of record mark arrangement. According to the present invention, sector address data and block address data are recorded in each sector by using wobbling or deformation of a recording groove. Then, depending on which address is used, sector data structure is modified, thereby making it possible to select an address data detection and a data structure on a disk in a single physical format depending on the purpose.

Abstract: A recording and/or reproducing apparatus for an optical disc in which the loop gain variation in tracking servo control can be suppressed to cause the illuminated laser light to follow correctly the recording track center. An optical disc recording/reproducing device 1 detects a traversing signal generated when the laser light traverses a track at the time of tracking servo pull-in and sets the amplification degree of a GCA 4 so that the push-pull signals will be at a predetermined level. The optical disc recording/reproducing device 1 holds the amplitude of the wobbling signals on memory as an initial setting value. On starting the recording or reproduction, the optical disc recording/reproducing device 1 monitors the amplitudes of the wobbling signals during the recording or reproduction to compare the amplitudes to the initial setting value.

Abstract: An optical disc recording and reproducing apparatus is provided. The apparatus detects the level of a focus error signal output from an optical pickup and a peak of the focus error signal occurred before the focus is obtained while an objective lens of the optical pickup moves in the focusing direction, discriminates a type of the loaded optical disc based on a first reference level or a second reference level, and actuates a focus servo before the objective lens moving in the focusing direction reaches a focalized position. Thus, a read only disc or a recordable disc can be rapidly reproduced.

Abstract: An optical information recording medium according to the present invention includes at least one groove track and at least one land track allowing information to be recorded on or reproduced from the groove track and the land track, the groove track and the land track adjoining each other. The optical information recording medium further includes: an identification signal region including a pre-pit array, the pre-pit array indicating identification information concerning the groove track and the land track; and a servo control region disposed ahead of the identification signal region along the groove track and the land track, the servo control region including wobble pits positioned so as to shift to opposite sides of a center line of either the groove track or the land track.

Abstract: An optical disc (1) is provided with: a disc substrate (110); an information track (102, G) formed on the disc substrate spirally or coaxially around a center of the disc substrate, on which an information signal including a physical sector number is to be recorded; and a guide track (102, L) adjacent to the information track and formed on the disc substrate spirally or coaxially around the center, on which a guide signal including address information is to be recorded, wherein a readable emboss area, in which the information signal is recorded by an emboss pit, and an unreadable emboss area, in which an unreadable emboss pit to disable writing and reading the information signal, are formed on the information track, and the guide signal is not recorded on the guide track corresponding to the readable emboss area and the guide signal is recorded on the guide track corresponding to the unreadable emboss area.

Abstract: An optical record carrier is described comprising a track for carrying data encoded in optical marks. A parameter of the track has a periodic variation for generating a varying signal when scanning the track, for example a variation of the center of a pre-groove usually called wobble. The track further comprises reference elements, e.g. headers, interrupting the periodic variation. The phase of the periodic variation after the reference elements is indicative of a property of the record carrier for controlling the scanning of the record carrier in dependence of said property. In particular the phase may indicate whether or not the bottom of the pre-groove is closer to the scanning beam entry side of the disc. Further a scanning device is described comprising a detector for detecting said phase based on the varying signal. The device adapts its scanning control means to the indicated property.

Abstract: An optical information recording and reproducing apparatus for recording and reproducing an information signal on/from both concave portions and convex portions of guide grooves formed on a recording medium is disclosed.

Abstract: An optical detector for detecting at least three optical beams reflected by an optical information recording medium and outputting an electric signal, the optical detector having three light receiving areas each of which receives a respective one of the three optical beams and each of which has four light receiving surfaces, twelve signal lines to transmit an electric signal obtained on respective ones of the four light receiving surfaces of the three light receiving areas, selected ones of the twelve signal lines connected to the four light receiving surfaces of different ones of the three light receiving areas being joined together within the optical detector, and less than nine signal output lines formed by joining the selected ones of the twelve signal lines extend from the optical detector to a signal processing circuit.

Abstract: A method of detecting a servo error, an apparatus therefor, a disk which maintains quantity of a servo error signal, a method of controlling a servo of an apparatus for recording data on and reproducing data from a disk, a method of detecting the tracking error, and a method of detecting tilt error of the apparatus. The apparatus for recording data on and reproducing data from the disk in which a recording area is divided into sectors, each sector has a header for indicating an address, each header has a first header and a second header which are recorded to deviate from the center of the track in opposite directions, and the first header and the second header have address areas in which the addresses of sectors are recorded and synchronous signal areas in which synchronous signals for detecting the address signals recorded in the address area are recorded.

Abstract: An object of the present invention is to provide an optical head apparatus which are capable of detecting correctly a radial tilt of an optical recording medium, without allowing offsets in radial tilt signals, even when an objective lens is shifted in a radial direction. A beam emitted from a semiconductor laser is divided into 0th order main beam and ±1st order sub beams. The three beams are shifted in the radial direction of the disc. The three beams reflected from the disc are diffracted by a holographic element, and are received by a photo detector. With respect to the main beam and the sub beams, a radial tilt of the disc is detected on the basis of a difference between intensities of the main and sub beams diffracted from a plurality of regions of the holographic element.

Abstract: An optical information storage medium includes a lead-in area, a lead-out area, and a user data area between the lead-in and lead-out areas and in which user data is recorded. Pits are formed in the lead-in area, the user data area, and the lead-out area, and a track pitch in all or a portion of the lead-in area is different from a track pitch in the remaining area of the optical information storage medium.

Abstract: In one embodiment, a holographic data storage medium includes a substrate, a holographic recording material, and an optically detectable tracking pattern on the medium. The substrate may have first and second substrate portions. The holographic recording material may be a photopolymer, and the medium may have a sandwiched construction, where the holographic recording material is sandwiched between the first and second substrate portions. The optically detectable tracking pattern may be replicated on at least one of the substrate portions. Alternatively, the optically detectable tracking pattern may be recorded as a holographic grating in the holographic recording material. The tracking pattern may facilitate the ability to pinpoint the location of the holographic bit maps on the holographic medium to within a fraction of a micron.

Abstract: An optical disc recording apparatus can draw an image by radially vibrating a laser beam under stable focus control. A pickup radiates the laser beam onto the optical disc rotated by a spindle motor. A focus servo controller maintains a constant spot diameter of the laser beam on the optical disc by detecting a return light of the laser beam reflected back from the optical disc. An irradiation position controller operates when the pickup opposes a label face of the optical disc for controlling an irradiation trajectory of the laser beam to vibrate in a radial direction of the optical disc while the laser beam runs along circumferential zones defined on a coloring layer of the label face. A modulating section modulates an intensity of the laser beam for forming dots along the circumferential zones so as to draw the image.

Abstract: A method for optical data recording and readout includes scanning a blank region of an optical recording medium while recording a data band including a plurality of adjacent data tracks; synchronizing the recording on all tracks to a common data clock; and simultaneously recording control tracks with the band of data tracks, each control track having a well-defined track center and a repetitive pattern of marks that is synchronized to the data clock. The method further includes optically sensing the cross-scan positions and clock offsets of at least one control track on either side of the data band; interpolating between the control track cross-scan positions to predict the cross-scan positions of each data track and compensate for magnification errors; interpolating between the control track clock offsets to predict the clock offset of each data track and compensate for skew errors; and simultaneously reading and decoding information recorded on all tracks of the data band.

Abstract: A circuit for recovering the timing reference signal includes a superheterodyne phase locked loop. The recovery circuit avoids the need for a phase linear filter with a large percentage bandwidth and allows placement of the filter at a point in the recovery circuit where the center frequency to be passed is substantially fixed. The recovery circuit thus constructed further allows the bandwidth of the filter to be narrower and tailored to match the modulation characteristics of the timing recovery signal. This further results in a better signal-to-noise ratio into a limiter and phase detector, improving the performance of the phase locked loop.

Abstract: An apparatus for generating linear patterns of light comprises a light source emitting a first light beam. An anamorphic system is positioned downstream of the light source and is adapted to receive the first light beam of the light source for concentrating the first light beam such that the first light beam would project a first linear pattern on a far field. A diffractive optical element is positioned downstream of the anamorphic system for receiving and diffusing the first light beam of the anamorphic system a plurality of second light beams. The plurality of second light beams overlap one another at least partially so as to project a second linear pattern on the far field of altered intensity with respect to the first linear pattern.

Abstract: A recording information reproducing apparatus is disclosed for performing a searching operation. The recording information reproducing apparatus according to the invention is for reproducing recording information from a recording disc on which information data has been divided and recorded into a plurality of concentric zones. The apparatus selects a suitable one of a tracking servo by a sampled servo system and a tracking servo by a continuous servo system in accordance with a zone for reading information data.

Abstract: A recording/reproducing apparatus is configured to displace near-field light for recording or reproduction and tracking illumination light toward an outer periphery of a recording pit when an off-track state toward the outer periphery occurs. The amount of reflected tracking illumination light increases since the reflectivity of an outer peripheral track band is higher than that of a recording region and that of an inner peripheral track band. The near-field light and the tracking illumination light are displaced toward an inner periphery of a recording pit when an off-track state toward the inner periphery occurs. The amount of reflected tracking illumination light decreases since the reflectivity of the inner peripheral track band is lower than that of the recording region and that of the outer peripheral track band. The single tracking illumination light is required for tracking control.

Abstract: In an optical disc recording medium having formed thereon a first pit train and a second pit train, these pit trains are formed to be different in pit depth from each other and meet following two relations: Y ≥   ⁢ 0.5 ⁢ M + 73.0411 - 1098.4938 ⁢   ⁢ ( X - 0.5 ⁢ K ) +   ⁢ 6584.

Abstract: The disclosed device is directed towards an optical data storage system. The optical data storage system comprises an optical medium including a servo plane and at least one data plane. A first laser is positioned to generate a servo laser beam and address the servo plane with a first servo focus spot. A second laser is positioned to generate a read-write laser beam and address the data plane with a second read-write focus spot. A first servo system is associated with the first laser and is configured to provide focus and tracking error correction according to servo information associated with the servo plane. A second servo system is associated with the second laser and is configured to provide focus and tracking error correction according to servo information associated with the data plane.

Abstract: In an initial operation of an optical disc apparatus for reading out information data recorded in the innermost data recording area on the optical disc, a main processor judges whether periods between adjoining two pits are normal or not from signals outputted from an optical pickup. When the periods of the pits are normal, a light beam emitted from the optical pickup is on the present data recording track, and the information data is read out from the optical disc. Alternatively, when the periods of the pits are abnormal, the optical pickup is moved inwardly with sensing the periods of the pits and judges whether the periods are normal or not. When the periods of the pits become normal, the light beam is precisely tracked on the present data recording track, and reproduces the information data from the optical disc.

Abstract: An optical record carrier is described comprising a track for carrying data encoded in optical marks. A parameter of the track has a periodic variation for generating a varying signal when scanning the track, for example a variation of the center of a pre-groove usually called wobble. The track further comprises reference elements, e.g. headers, interrupting the periodic variation. The phase of the periodic variation after the reference elements is indicative of a property of the record carrier for controlling the scanning of the record carrier in dependence of said property. In particular the phase may indicate whether or not the bottom of the pre-groove is closer to the scanning beam entry side of the disc. Further a scanning device is described comprising a detector for detecting said phase based on the varying signal. The device adapts its scanning control means to the indicated property.

Abstract: An optical information recording and reproducing apparatus for recording and reproducing an information signal on/from both concave portions and convex portions of guide grooves formed on a recording medium is disclosed.

Abstract: An image forming apparatus includes: a spindle motor (130) for rotating an optical disk (200); an optical pick-up (100) for applying laser light to the optical disk which moves in a radial direction of the optical disk; a stepping motor (140) for transporting the optical pick-up in the radial direction by a predetermined distance every time the optical disk is rotated plural times; a tracking actuator for actuating a position of laser light irradiated from the optical pick-up; a servo circuit (138) for controlling the tracking actuator in such a manner that irradiation loci of the laser light is made different from each other every time the optical disk is rotated plural times; and a data converter (160) for defining intensity of the laser light in accordance with gradation of dots to be arrayed and a total rotation time of the optical disk.

Abstract: A processing method of a master for optical disk by a laser processing to form grooves, prepit groups on a groove track and prepit groups on a land track in a high quality and in a good balance. On an optical course of a laser beam for forming the prepit groups, an optical deflector is provided. Also, the laser beam is positioned to shoot on the center of the groove track and the land track. The deflector deflects the laser beam in the same amount of deflection to the opposite direction to form each of the prepit groups. Further, a difference in diffraction efficiencies by a difference in the deflection directions is corrected by controlling the laser power independently from each other.

Abstract: An optical disk has a servo area composed of a synchronous pit and guard pits provided on each track and a data area composed of data pits. In recording and reproducing digital data on and from the optical disk, a beam spot of laser beam is traced on centerlines between adjacent two tracks. In the tracking of this case, a reflected light is changed due to a tracking error with an arrangement of the synchronous pit and the guard pits on an odd track and an arrangement of the synchronous pit and the guard pits on an even track. A tracking servo is made by comparing output levels of the reflected light changed before and after this synchronous pit.

Abstract: In a track-following method in a DVD-RAM disc, CAPA detection is avoided during the track-following process, and a track-following operation is stably made from a high-speed state using adaptive deceleration pulses. In order to avoid CAPA detection during the track-following process, a CAPA is detected from a tracking error signal using a high-pass filter, and the track-following start timing is set within 0.4 ms after the detection of the CAPA. The pulse width of the adaptive deceleration pulses to a lens actuator is variable so that the tracking error signal follows a standard tracking error signal. The zero-crossing point of the tracking error signal after the detection of the CAPA is set as the track-following start timing, and tracking-servo is started after an adaptive brake process for varying the deceleration pulse width based on the difference between the tracking error signal and standard tracking error (TE) signal.

Abstract: An optical reproducing apparatus that uses a hologram laser module and is applicable to a DVD Multi drive, wherein five sub spots of light in total that are most suitable to perform the differential push-pull tracking both for DVD-RAM and for DVD-R/RW are irradiated on the disk, respectively, and influence of several sub spots that are unnecessary in recording and reproducing a disk is canceled out by calculation, to realize an optical head that is compatible with the DVD Multi drive using a hologram laser module, and thereby providing a small-size, high-performance optical reproducing apparatus.

Abstract: The optical disk recording apparatus of this invention includes: a first detection section for detecting a ID address cycle based on a timing of detection of an ID section of an optical disk; a second detection section for detecting a wobble cycle based on a wobble clock; and a state determination section for determining a state of the wobble clock based on the ID address cycle and the wobble cycle.

Abstract: A tracking control circuit includes a light receiving element divided in at least four sections. Of these, a group of divided light receiving sections located on a diagonal line obtains a first differential signal. A group of divided light receiving sections located on another diagonal line obtains a second differential signal. In accordance with the phase difference between the first and second differential signals, a tracking error signal is generated to make tracking control on a wobbled information recording track.

Abstract: An optical pickup is provided which is constructed from a single optical integrated device adapted to write data to, and/or read data from, more than one type of optical disc such as CD, DVD and the like. The optical integrated device includes means for selectively providing as output a result of the light detection by one of a plurality of light detecting elements. This selective output means makes it unnecessary to provide added terminals at the optical integrated device. There is also provided an optical disc drive using the optical pickup.

Abstract: An optical recording medium driving apparatus which can obtain a tracking error signal necessary for an accurate track count. An optical recording medium driving apparatus for recording and/or reproducing data in/from an optical recording medium, where information can be recorded in plural tracks formed by land portions and groove portions provided between the land portions, based on a light emitted to the tracks. The apparatus includes a detector for detecting a position of the emitted light, a peak-hold circuit for holding a peak of a position detected signal outputted from the detector so as to output the position detected signal, a bottom-hold circuit for holding a bottom of the position detected signal so as to output the position detected signal, and a switching circuit for switching signals based on the output signals from the peak-hold circuit and bottom-hold circuit so as to output either signal.

Abstract: There is provided an objective lens drive for driving an objective lens to optically read information recorded on a rotative driven disc. An objective lens holding member (2) is held by four first metal wires (61) on a relay holding member (71), and the relay holding member (71) is held by four second metal wires (62) on a fixing part (72). The acceleration sensitivity which acts on the objective holding member (2) in different disc rotation frequency bands is increased. The disc rotation frequency bands correspond to different resonance frequency bands created by each of a first free oscillation system, the main part of which is the first metal wires (61), and a second free oscillation system, the main part of which is the second metal wires (62). Thereby, the light spot's following sensitivity to the displacement of an information recording, track can be increased in at least two disc rotation frequency bands.

Abstract: A method of elimination of interference created on CDR/W run-out motors on sledge servers, especially for the elimination of interference created by the run-out of the combination of CDR/W spindle motor on track-seeing servers, where a general evaluating device is provided linking the controller output of the data access module driven by the sledge server motor and the final track signal output, including a speed evaluating device and a run-out evaluating device that may have access to the run-out factor of the CDR/W motor and the CD in the data access module for evaluation of the elimination function of the speed and the run-out tolerance, so that the run-out evaluating device could emit run-out compensation signals for amplification by a relay amplifier and the spindle motor synchronized signal before a negative feedback calculation by playing the final output signal of the module, with access to a play control signal for the elimination of run-out to the CDR/W sledge server, so that the CD may be read, wri

Abstract: A recording disc and recorded information reproducing apparatus and method for immediately starting reproduction of information when a push-pull based tracking control is employed to reproduce recorded information from the recording disc. The recording disc comprises an information data area for recording recording marks which carry information data in columns, and a control data area for recording identification information indicative of a recording pattern of the recording marks in the information data area.

Abstract: An optical disc 1 has spiral grooves GR formed on a data recording surface thereof and in which information is written to, and read from, both a land between the grooves and the grooves as tracks. Each track has a plurality of address areas AR1 and user areas AR2 formed thereon, and each of the address areas AR1 has embossed pits for a groove header GRH and embossed pits for a land header LH. Each of the address areas AR1 has provided in a leading part thereof a header mark area HM formed from a mirror finished surface. That is, this optical disc is of an on-land/in-groove recording type. An offset taking place in a tracking error signal and focus error signal is removed to accurately control the tracking and focus of an optical head.

Abstract: A magnetic tape has a guide track for optically obtaining a tracking signal and an independent information track for storing information. The magnetic tape is partitioned into different kinds of zones. The guide tracks are provided with grooves or pits serving as tracking marks, and the tracking marks are selectively located in the zones depending on the kind of zone. Thus, the track spacing of the guide tracks in each zone can be increased, so that a tracking control can be performed for a high density recording medium without reducing the spot size of the light.

Abstract: A disklike storage medium on which information is recorded at higher density by reducing the redundancy of the address part and a tracking method using the medium are disclosed. The disklike storage medium where a track is divided into areas and address data is recorded in the areas is so adapted that an error detecting code for identifying the data common to adjacent tracks out of the address data is added to the common data. Thus, a data synchronization processing performed when the address data is reproduced is realized without any special synchronization pattern.

Abstract: An optical pick-up device for optically recording and/or reproducing information on an information record medium having plural record layers and guide tracking layers in the depth direction is disclosed.

Abstract: An information recording disk having a structure that a ring-shaped recording region is divided into a plurality of concentric, annular blocks, each of the blocks is divided in a circumferential direction into a plurality of equal sectors, and a recording track and a pit train for generating a header signal are previously formed in the recording region so that the recording density of a block increases as the block is nearer to the outer circumference of the recording region, in comparison with constant angular velocity type, is disclosed in which disk the recording region has a portion where blocks are pre-formatted so that the pit pitch of the header-signal generating pit train formed on the innermost recording track of the outer one of two adjacent blocks is greater than the pit pitch of the header-signal generating pit train formed on the innermost recording track of the inner block.