Abstract: An optical disk drive and a digital servo method for the optical disk drive includes controlling functions of the optical disk drive with a microprocessor. Low-pass filtered and gain-adjusted versions of photodetector output signals resulting from an illumination of an optical disk are received. Versions of the photodetector signals are digitized to produce digital signals. A focus control signal is determined through at least one servo algorithm executed by a digital signal processor based on a focus error determined from the digital signals. Alternatively, a tracking control signal is determined through at least one servo algorithm executed by the digital signal processor based on a tracking error determined from the digital signals. The digital signal processor has a specialized structure and arrangement for processing digital signals at a higher speed than the microprocessor.

Abstract: A digital servo method for an optical disk drive includes receiving low-pass filtered and gain-adjusted versions of photodetector output signals resulting from an illumination of an optical disk. Versions of the photodetector signals are digitized to produce digital signals. A focus control signal is determined through at least one servo algorithm in a digital signal processor based on a focus error determined from the digital signals. Alternatively, a tracking control signal is determined through at least one servo algorithm in the digital signal processor based on a tracking error determined from the digital signals. An optical disk drive includes an analog-to-digital converter configured to convert low-pass filtered and gain-adjusted versions of photodetector output signals into at least one digital signal and the digital signal processor.

Abstract: Embodiments of the present disclosure provide a method of self-servo writing, the method comprising actions of positionally tracking a selected timing track of a data storage disk, wherein the selected timing track has one or more timing segments; synchronizing an angular position signal to rotation of the data storage disk based on at least one of the one or more timing segments of the selected timing track; specifying servo sector positions relative to the synchronized angular position signal; writing servo sectors to the data storage disk at the specified servo sector positions relative to the synchronized angular position signal; detecting one or more positional errors in timing segments of a next timing track of the data storage disk based at least in part on the synchronized angular position signal; and accounting for the detected one or more positional errors in writing subsequent servo tracks. Other embodiments are also described.

Abstract: A system and method of calibrating optical measuring equipment includes optically measuring discrete objects of a first known predictable pattern from a calibration apparatus, wherein the first known predictable pattern is a bit pattern. A recording surface optical reader is calibrated based on the optically measuring. Using the first known predictable pattern, contamination is filtered from the results of the optically measuring.

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 analog-to-digital converter includes a feedback loop that receives a wobble signal having a wobble signal frequency. The feedback loop includes a comparator that receives the wobble signal through a first resistive component at a first comparator input and outputs a first output signal having either a high output or a low output. The feedback loop also includes a sampling component that samples the first output signal at a sampling frequency and outputs a second output signal and a first integrator component that receives the second output signal and outputs a third output signal. The third output signal tracks the wobble signal due to feedback action in the feedback loop. Finally, the analog-to-digital converter further includes a final discrete integrator component that integrates the second output signal to provide a digital representation of the wobble signal.

Abstract: A recording medium is provided with: a guide layer on which a guide track or tracks are formed; and a plurality of recording layers, wherein a same mark group is formed in a same rotational phase position of each of a plurality of guide tracks which are included in a beam spot of guide laser light, the mark group including a pair of record marks which are shifted by a predetermined distance toward a right side and a left side, respectively, from a track center.

Abstract: A reproducing device includes a light generation and emission unit that obtains signal light as reflection light, which reflects recording signals of a land and a groove, by irradiating an optical recording medium with light and generates reference light so as to emit the signal light and the reference light in a superposed manner, a detection optical system that generates a first combination of signal light and reference light, a second combination of signal light and reference light, a third combination of signal light and reference light, and a fourth combination of signal light and reference light respectively, a light receiving unit in which the first to fourth combinations of signal light and reference light are respectively received by first to fourth light receiving elements, and a reproduction unit that reproduces the recording signals of the land and the groove on the basis of first to fourth light receiving signals.

Abstract: There is provided an recording apparatus including a light irradiation unit, a reference-plane tracking control unit, a recording unit that executes recording on the recording medium by independently modulating first and second recording beams when the recording beams radiated by the first and second objective lenses are designated as the first and second recording beams, respectively, a recording-layer tracking control unit that performs tracking control of the first objective lens based on reflected light of a first servo beam and tracking control of the second objective lens based on reflected light of a second servo beam when the servo beam radiated by the first objective lens is designated as the first servo beam and the servo beam radiated by the second objective lens is designated as the second servo beam, and a control unit that controls the reference-plane tracking control unit, the recording-layer tracking control unit, and the recording unit.

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: In an optical tape drive having optical heads for writing data in tracks on an optical tape, each track having an off-track threshold, a system and method are disclosed for off-track write prevention. The system includes multiple actuators, each actuator configured to control a position of an associated optical heads. The system also includes a controller configured to determine a position of each of the optical heads relative to an associated track on the optical tape and to prevent, in response to an event causing an optical heads to have a position outside the off-track threshold of the associated track, only that optical head from writing data to the optical tape and to buffer a stream of data for that optical head for later processing.

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: According to one embodiment, in an information recording medium including a plurality of data layers, at least one pre-format area is provided on each of the data layers and is circumferentially divided into a plurality of segments. Management information including data layer identification information for identifying the data layers is recorded in at least one of the segments in each of the data layers, using the marks include BCA marks extending radially uniformly. On adjacent ones of the data layers, the BCA marks associated with the management information are recorded in differently positioned segments which are not opposed to each other.

Abstract: An information recording medium in which bottoms of a guide groove and a pit array formed on a disc substrate are allocated on a same flat plane and shaped in flat. Further, in a transition area from a pit array to a guide groove or from a guide groove to a pit array, the information recording medium is provided with an intermediate area composed of a pit array of which height changes from a height between a bottom and a side of a groove to another height between the bottom and a side of the pit array.

Abstract: When using an optical disc medium that includes pit trains having their widths narrower than a diffraction limit, it is difficult to detect a tracking error signal and take a tracking-servo control while increasing pit density in a direction orthogonal to a pit-train extension direction. Information pit trains are arranged spirally or concentrically and formed in a structure in which their depths are changed periodically at a pitch radially along the optical disc medium, so that the tracking error signal can be obtained by push-pull detection of diffraction light from the structure.

Abstract: The purpose of the present invention is to minimize increase in the number of types of medium control information, and increase in time required for OPC, in association with a greater number of recording layers in a multilayer optical information recording medium. Provided is a multilayer optical information recording medium having two or more recording layers, the multilayer optical information recording medium characterized in that the recording layers are classified into layer groups that are fewer in number than the number of recording layers, each of the layer groups so classified being assigned medium control information that is shared within the layer group, and the medium control information assigned to each layer group being pre-registered in an administrative domain.

Abstract: A machine readable information storage medium, a reproducing method and apparatus which reproduces data from the storage medium, and a recording method and apparatus for recording data on the storage medium. The information storage medium includes a control area which stores within a data structure information usable by the recording or reproducing apparatus to record or reproduce the data on or from the storage medium. The information stored within the data structure includes a version corresponding to a specification, a revision number of recording speed, and an extended part version field.

Abstract: An information recording medium in which bottoms of a guide groove and a pit array formed on a disc substrate are allocated on a same flat plane and shaped in flat. Further, in a transition area from a pit array to a guide groove or from a guide groove to a pit array, the information recording medium is provided with an intermediate area composed of a pit array of which height changes from a height between a bottom and a side of a groove to another height between the bottom and a side of the pit array.

Abstract: An optical information device used with a grooveless multilayer disc including multiple recording layers used to record and reproduce information signals and a guide layer dedicated to detect tracking error signals (TES) can always stably detect the TESs when the distance between the recording layer and guide layer varies due to selection of a target recording layer. For example, a plurality of light spots for detecting the TESs are formed by a holographic grating on the guide layer, but are defocused with respect to each other. The TESs are detected individually from the respective light spots. The TESs are subjected to an addition operation to be a signal for tracking control, thereby extraordinarily increasing the defocus dynamic range of the TESs.

Abstract: A rotary position encoder for determining a rotary position of a shaft includes a rigid substrate having a planar surface and mounted on the shaft to rotate with the shaft; an optical disk having at least a transparent polycarbonate layer and a reflective layer on the transparent polycarbonate layer, affixed to the planar surface of the substrate, the optical disk having a first circumferential track encoded therein having binary data; an optics assembly for interrogating the optical disk and providing an output signal indicative of data received from the interrogation of the optical disk; and a tracking motor for driving the optics assembly radially with respect to the optical disk.

Abstract: A machine readable information storage medium, a reproducing method and apparatus which reproduces data from the storage medium, and a recording method and apparatus for recording data on the storage medium. The information storage medium includes a control area which stores within a data structure information usable by the recording or reproducing apparatus to record or reproduce the data on or from the storage medium. The information stored within the data structure includes a version corresponding to a specification, a revision number of recording speed, and an extended part version field.

Abstract: A machine readable information storage medium, a reproducing method and apparatus which reproduces data from the storage medium, and a recording method and apparatus for recording data on the storage medium. The information storage medium includes a control area which stores within a data structure information usable by the recording or reproducing apparatus to record or reproduce the data on or from the storage medium. The information stored within the data structure includes a version corresponding to a specification, a revision number of recording speed, and an extended part version field.

Abstract: A system and method of calibrating optical measuring equipment includes optically measuring discrete objects of a first known predictable pattern from a calibration apparatus, wherein the first known predictable pattern is a bit pattern. A recording surface optical reader is calibrated based on the optically measuring. Using the first known predictable pattern, contamination is filtered from the results of the optically measuring.

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: A recording apparatus includes: a recording unit to record information by laser irradiation on a recording medium having multiple recording layers where information is recorded, with a track formed in the layers as a continuous recording area and data recorded within a track, and also multiple tracks set to one layer according to recording purpose; and a control unit to determine a sparing destination where information is recorded on a recording position specified according to a recording request, and if sparing processing occurs, as a first priority the next recording address of a track being recorded is selected as a sparing destination, and as a second priority the next recording address of a track overlapped with a track where recording is performed according to the recording request in a layering direction of the layers is selected as a sparing destination, and to cause the recording unit to execute sparing recording.

Abstract: An optical recording medium in which recording is performed by a recording device that is configured such that tracking servo control of recording light is performed by irradiating the recording light and ATS light for an adjacent track servo and by an adjacent track servo based on reflected light of the ATS light, wherein while a recording layer in which a mark is formed according to an irradiation of the recording light is included, a mark row is formed in advance by a pitch that is twice a distance between an irradiation spot of the recording light and an irradiation spot of the ATS light or greater in the recording layer.

Abstract: An optical disk that enables a laser beam to be focused on an object track without making mistakes, an optical disk device, a format processing method, and a recording method. The optical disk shall be configured to has a guiding layer with a physical groove structure containing address information and a single or multiple recording layers with no groove structure, in which the guide areas for recording the address information thereon are formed along a track of the guide layer at fixed intervals in a user data area of each recording layer. An address for the recording layer is generated based on information obtained from the guide layer, and the address for the recording layer is recorded in the guide area.

Abstract: According to one embodiment, a multilayer optical recording medium including a substrate, a guide layer group that is provided on the substrate and has guide layers in which positional information in a radial direction is recorded, and a recording layer group that is provided on the substrate and has recording layers in which information can be recorded. In the recording layer group, positional information of the recording layers associated with the positional information recorded in the guide layers and control information of the optical device where reflected light volumes of the laser beams on the guide layers and the recording layers become maximum at the positions in the radial direction are recorded at the positions in the radial direction of the recording layers.

Abstract: Provided is a recording apparatus including a light irradiation and receiving unit configured to irradiate recording light for performing mark recording to a recording layer and an adjacent servo light for an adjacent track servo onto an optical disc recording medium having the recording layer through a common objective lens, and to receive reflected light from the recording layer of the adjacent servo light, a tracking mechanism configured to drive the objective lens in a tracking direction which is the disc radial direction, a tracking servo signal generation unit configured to obtain a corrected servo error signal as a servo error signal based on a light receiving signal for the adjacent servo light, and to generate a tracking servo signal using the corrected servo error signal, and a tracking driving unit configured to drive the tracking mechanism based on the tracking servo signal.

Abstract: An information recording medium adopting a zone CAV method is provided with: a guide layer in which tracks are formed in advance; and a plurality of recording layers laminated on the guide layer. On the tracks, a plurality of guide areas, each of which has a physical structure for carrying guide information for guidance, are arranged discretely at arrangement intervals of predetermined distance or less which is set in advance in a track direction and are shifted between a plurality of tracks throughout the plurality of tracks which are adjacent to each other in a radial direction. On the tracks, moreover, a plurality of specific areas, each of which has a predetermined pattern, are respectively arranged in a same phase from an inner circumference to an outer circumference in the radial direction such that the predetermined pattern can be detected in a state in which tracking servo is open.

Abstract: An information recording medium in which bottoms of a guide groove and a pit array formed on a disc substrate are allocated on a same flat plane and shaped in flat. Further, in a transition area from a pit array to a guide groove or from a guide groove to a pit array, the information recording medium is provided with an intermediate area composed of a pit array of which height changes from a height between a bottom and a side of a groove to another height between the bottom and a side of the pit array.

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.

Abstract: An optical drive device includes first and second light sources, an objective lens configured to receive a first light emitted from the first light source and a second light emitted from the second light source and to irradiate both the first light and the second light to an optical disc recording medium, a first focus mechanism configured to drive the objective lens in a focus direction, a second focus mechanism configured to change collimation of the second light incident to the objective lens and changing the focusing position of the second light independently of the first light, a first focus servo control unit configured to drive the first focus mechanism, an error signal subtraction unit configured to subtract the first focus error signal from a second focus error signal, and a second focus servo control unit configured to drive the second focus mechanism.

Abstract: An information recording medium in which bottoms of a guide groove and a pit array formed on a disc substrate are allocated on a same flat plane and shaped in flat. Further, in a transition area from a pit array to a guide groove or from a guide groove to a pit array, the information recording medium is provided with an intermediate area composed of a pit array of which height changes from a height between a bottom and a side of a groove to another height between the bottom and a side of the pit array.

Abstract: Efficient recording and reading are achieved in an optical recording medium including servo layers and recording and reading layers. The optical recording medium includes: a first servo layer having a projection and a depression for tracking control that are formed in a first spiral direction; a second servo layer having a projection and a depression for tracking control that are formed in a second spiral direction opposite to the first spiral direction; and a plurality of recording and reading layers having a flat structure with no projection and depression for tracking control. Information is recorded on each of the plurality of recording and reading layers while tracking control is performed using the first servo layer or the second servo layer.

Abstract: A system and method for controlling tracking in a holographic data storage system, including: impinging a beam on a holographic data disc, wherein the beam is reflected from a micro-hologram disposed within the holographic data disc; detecting the reflected beam from the holographic data disc by a multi-element detector; and analyzing a pattern detected by multi-element detector to generate a tracking error signal.

Abstract: A focus search is performed for an optical disc. A focus drive voltage is output for moving an objective lens in a thickness direction of an optical disc. An average value of focus drive voltages is acquired and recorded while the optical disc is rotating at least one time in an in-focus condition in which a laser beam emitted via the objective lens is in focus to a data layer of the optical disc. A closest-position voltage is set based on the average value, the closest-position voltage being a focus drive voltage at which the objective lens is moved closest to the optical disc in a focus search that is performed after the average value has been recorded. The focus search is performed by moving the objective lens between a specific starting position and a position corresponding to the closest-position voltage.

Abstract: An optical disc recording apparatus (10) is provided with a tracking servo (13) for tracking a spiral track of concave and convex marks, an analog signal processor (14) for extracting a reproduction signal corresponding to the concave and convex marks, a digital signal processor (15) for extracting a channel clock synchronized with a channel bit length of the concave and convex marks, and a sub-information recording section (30) for recording sub-information by irradiating laser light based on the tracking to the spiral track. The sub-information recording section (30) records all the sub-information by repeating a process of recording a part of the sub-information by discretely irradiating laser light at a specified interval and with a specified frequency in synchronism with a channel clock by one tracking to form recordable marks on a reflective film a plurality of times.

Abstract: An optical recording and reading method is provided in which the information necessary for recording and reading layers is quickly acquired to reduce the seek time during reading and recording. The optical recording and reading method is used for an optical recording medium that includes a plurality of recording and reading layers and a servo layer. Information is recorded on or read from the recording and reading layers by irradiating them with a recording and reading beam while the servo layer is irradiated with a servo beam to perform tracking control. When information is recorded on the recording and reading layers, control information necessary for subsequent recording and reading to be performed on the recording and reading layers is recorded on the servo layer 18. When the subsequent recording or reading is performed, the control information on the servo layer is consulted, and then the recording or reading is performed on the recording and reading layers.

Abstract: An optical disk apparatus and a method of performing a lead-in process with respect to an optical disk thereof includes a feature where an optical pickup unit reads out information recorded on a file system area of the storage area of the optical disk, and performs a lead-in process using the read-out file system if information recorded on a lead-in area of a storage area of the optical disk cannot be read out. Further, the optical disk apparatus may perform the lead-in process with respect to the optical disk even if there is a defect in the lead-in area.

Abstract: An information recording medium (100) is provided with (i) a first information recording area wherein a first track for reproducing first information based on a first track pitch is formed by a laser beam, and (ii) a second information recording area wherein a second track for reproducing second information based on a second track pitch different from the first track pitch is formed by a laser beam. The groove shape of the first track is different from the groove shape of the second track.

Abstract: An information recording medium in which bottoms of a guide groove and a pit array formed on a disc substrate are allocated on a same flat plane and shaped in flat. Further, in a transition area from a pit array to a guide groove or from a guide groove to a pit array, the information recording medium is provided with an intermediate area composed of a pit array of which height changes from a height between a bottom and a side of a groove to another height between the bottom and a side of the pit array.

Abstract: An optical information device used with a grooveless multilayer disc including multiple recording layers used to record and reproduce information signals and a guide layer dedicated to detect tracking error signals (TES) can always stably detect the TESs when the distance between the recording layer and guide layer varies due to selection of a target recording layer. For example, a plurality of light spots for detecting the TESs are formed by a holographic grating on the guide layer, but are defocused with respect to each other. The TESs are detected individually from the respective light spots. The TESs are subjected to an addition operation to be a signal for tracking control, thereby extraordinary increasing the defocus dynamic range of the TESs.

Abstract: An optical disc drive according to the present invention includes an optical pickup and a writing control section for instructing the optical pickup to record a mark, representing the information to be written, on the optical disc. In recording the mark on the optical disc, the writing control section instructs the optical pickup to irradiate the same area on the optical disc with a light beam a plurality of times so that the mark is recorded in that repeatedly irradiated area.

Abstract: An information reproducing apparatus has a medium with a linear tracking mark extending in a scanning direction and a linear data mark extending in a direction orthogonal to the scanning direction. A light control unit irradiates the data mark with a first near-field light polarized in the scanning direction and irradiates the tracking mark with a second near-field light polarized in the direction orthogonal to the scanning direction. A detector detects light scattered by the data mark and the tracking mark irradiated with the first near-field light and the second near-field light, respectively. A signal processing unit processes a first output signal from the detector corresponding to the detected light scattered by the data mark and processes a second output signal from the detector corresponding to the detected light scattered by the tracking mark.

Abstract: Disclosed herein is a misjudgment correction circuit, including, an edge detection section configured to detect, in a binarized full addition signal obtained by adding first and second signals of the same or opposite polarity, edges at which the logic value of the binarized signal changes, a push-pull signal acquisition section configured to acquire a binarized push-pull signal obtained by subtracting the second signal from the first signal, a majority decision calculation section configured to acquire, in chronologic order, a plurality of logic values of the push-pull signal between the two adjacent edges so as to determine, by a majority decision, the more numerous of the two logic values, and a wave correction section configured to correct the push-pull signal between the edges to the more numerous logic value determined by the majority decision calculation section.

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: An optical disc drive according to the present invention writes information on an optical disc, which includes a substrate on which a number of pre-pits have been formed on its tracks and a recording film that is supported on the substrate. The optical disc drive includes a writing control section for instructing an optical pickup to record marks on the tracks by irradiating the recording film with a writing light beam. In accordance with information that defines, on the tracks, recordable areas Aa1 through Aa4 where the marks are recordable and pre-pit reading areas Ab1 through Ab4 where no marks are recordable, the writing control section controls the optical pickup so that the marks are recorded on at least some of the recordable areas. On the tracks on which the marks are recorded, each recordable area is shorter than any of the pre-pit reading areas.

Abstract: An optical disc reader comprising a controller that controls a read operation to read data recorded on an optical disc and a counter that counts the number of zero crossings in a tracking error signal. Between the completion of focusing operation and the start of tracking operation, the controller determines whether or not the light beam is properly focused on a data recording layer in the optical disc based on the number of zero crossings in the tracking error signal counted by the counter. If it is determined that the light beam is not properly focused, the controller causes the focusing operation to be performed again. Otherwise, if it is determined that the light beam is properly focused on the data recording layer, the controller causes the tracking operation to be performed and then starts the read operation.

Abstract: A control apparatus is provided for controlling an access means for accessing a recording medium containing at least one area so that the access means accesses the at least one area. The apparatus comprises a means for determining whether or not at least one first recorded area storing data is included in the at least one area, and a means for controlling the access means. When it is determined that the at least one first recorded area is included in the at least one area, the control means controls the access means based on a result of accessing the at least one first recorded area.