Abstract: A recording medium identification apparatus that emits a light beam onto a recording medium having recording layers, is provided with; a recording-layer-number-judgment device which determines the number of said recording layers on said recording medium based on the reflected light of said light beam that is reflected from said recording medium; a first identification device which identifies that said recording medium is a recording medium that includes two or more said recording layers when said recording medium is determined to have two or more said recording layers; a shape-judgment device which determines the shape of the recording track on said recording layer based on said reflected light when it is determined that the number of said recording layers is one; and a second identification device which further classifies and identifies the type of recording medium that includes one said recording layer based on said determined shape.

Abstract: The length of a format modulation area in an address segment is limited to be 25% of the address-segment length or less, and the position of the format modulation area is selectable two possible positions. Subsequently, where a CLV optical-disk medium is used, wobble modulation areas in adjacent recording tracks do not overlap each other in the radius direction.

Abstract: A recording-medium-identification apparatus that emits a light beam onto a recording medium, is provided with: a light-receiving device which receives said reflected light beam that is reflected from said recording medium; a first extraction device which extracts a specified wobble-frequency signal from said output received-light signal that corresponds to the wobble frequency of the recording tracks on a specified recording medium from among a plurality of types of said recording media; a second extraction device which extracts another wobble-frequency signal from said output received-light signal that corresponds to the wobble frequency of the recording tracks on another recording medium other than the said specified recording medium from among a plurality of types of said recording media; and an identification device which uses at least said specified wobble-frequency signal or said other wobble-frequency signal to identify the type of said recording medium.

Abstract: A method of determining disc track pitch. First, a first frame count of one revolution corresponding to a first position with a first radius to a disc center is counted, and first time information of the first position is read. Then, a second frame count of one revolution corresponding to a second position is counted, and second time information of the second position is read. Then, a second radius corresponding to the second position to the disc center is calculated according to the first frame count, the second frame count and the first radius. A track pitch of the disc is calculated according to the first radius, the second radius, the first time information, the second time information and a linear velocity.

Abstract: An information storage medium that includes a lead-in area, a user data area, and a lead-out area. Information about whether the information storage medium is compatible with a drive following an older version of standards is recorded in at least one of the lead-in and lead-out areas. Accordingly, the recording performance thereof is improved, and a drive following an older version of standards can record data on or reproduce data from a newer version of an information storage medium.

Abstract: An optical disc playback apparatus, which has an optical pickup receiving reflected light from an optical disc, comprises a signal level detector that detects a level of a signal obtained from the reflected light; and a determining circuit that, based on the level, determines which side the optical pickup is located on, an information recording area or an information non-recorded area of the optical disc.

Abstract: An optical disc discrimination apparatus and method which discriminate a type of a disc loaded on a DVD-RAM drive accurately and simply. The optical disc discrimination apparatus includes an RF envelope generator which detects an envelope signal from an RF signal read from a disc loaded in an optical disc recording and/or reproducing apparatus at an off-track state, when only a focusing is accomplished prior to performing a tracking control, an envelope amplitude detector which detects the amplitude of the detected envelope signal, and a disc discriminator which compares the amplitude of the detected envelope signal with predetermined reference level and discriminating whether the disc is a CD, a DVD-ROM, or a DVD-RAM, based on the comparison result. Thus, a type of the disc can be discriminated simply and accurately with a change in the amplitude of the RF signal.

Abstract: An optical disk drive capable of detecting a surface deviation of a disk during a very short period includes an analog-to-digital converter (ADC) converting a focus error signal output from a pickup into digital data, and a central processing unit (CPU) writing an output of the ADC to a memory during one rotation of a motor according to a timing of a pulse signal output from a spindle motor. After that, the CPU reads data written to the memory and obtains a sine curve that minimizes the sum of squares of errors among data by a least square method. The CPU obtains a peak-to-peak value of the obtained sine curve and compares the peak-to-peak value to a predetermined threshold value, thereby determining the existence of the surface deviation of the disk.

Abstract: An off-track duty measurement unit measures off-track detection sensitivity on the basis of an off-track signal, and track cross cycle information that is obtained from a tracking error signal measured by a track cross cycle measurement unit, whereby off-track detection sensitivity can be measured more accurately. Further, an off-track detection sensitivity controller changes the detection sensitivity of an off-track signal detector according to the obtained off-track detection sensitivity, whereby the off-track sensitivity can be kept constant for various kinds of discs, and accordingly, stabilities of off-track detection, track pull-in judgement, and track jumping can be secured.

Abstract: An error signal detection apparatus for an optical recording/reproducing system including a light source emitting a light beam and an objective lens focusing the light beam to form a light spot on a recording medium, the apparatus including: a photodetecting unit dividing at least a part of the light beam passed through the objective lens after being reflected/diffracted from an information stream of the recording medium into light beam portions, and detecting the light beam portions; and a signal processor detecting phase differences between detection signals from the light beam portions to detect a tangential error signal, a defocus error signal, and/or a radial tilt error signal.

Abstract: An optical head having a semiconductor laser and a generation of a plurality of reflected light beams from an optical disk which have polarities of intensity distribution variations which are substantially inverted to each other when a periodic structure of the optical disk crosses at least one focused spot on the disk. An optical detection system splits the plurality of reflected light beams and detects the split reflected light beams. An electrical circuit provides a focus error signal of the at least one focused spot and a tracking error signal from the plurality of reflected light beams. The electrical circuit adds focus error signals provides a difference signal between the focus error signals, amplifies tracking error signals with a gain, and obtains a difference between amplified tracking error.

Abstract: In the case of a method of detecting a signal edge in a signal with temporally successive signal edges, there are performed, after triggering by an interrupt signal (IS) generated in an analog/digital converter (13), detection of a rise-representing rise value between two detected amplitude values with subsequent assessment of the rise value together with detection of signal edge direction information and signal edge occurrence information. Further use of this signal edge information is dependent on an additionally detected and assessed signal strength value, which signal strength value is formed from a sum of further amplitude values.

Abstract: A method of playing copy-controlled compact discs (CCCDs) in PC-based optical disc drives includes forcibly recognizing at least one track in a first session of the optical disc as an audio track. At least one track in the first session is read to playback as audio.

Abstract: When a setup is performed by reproducing conditions corresponding to the first kind of optical disk and a setup is subsequently performed by reproducing conditions corresponding to the second kind of optical disk, the reproducing conditions which succeed to at least a part of the reproducing conditions corresponding to the first kind of optical disk are used as reproducing conditions corresponding to the second kind of optical disk and the setup is performed. When the setup is completed, the reproducing conditions corresponding to the optical disk as a target of the setup are stored. When the same optical disk is set up again, the stored reproducing conditions are used.

Abstract: In an optical disk recording method, a plurality of strategies are stored, which are selectable according to a model of an optical disk, a recording rate and a linear velocity for adjusting a pulse width of a laser drive signal and a power of a laser beam to shape pits. A first strategy and a second strategy are provided for the same model of the optical disk, the same recording rate and the same linear velocity, the first strategy being designed to shorten the pulse width of the laser drive signal and increase the power of the laser beam, thereby decreasing jitters of the recorded information, the second strategy being designed to lengthen the pulse width of the laser drive signal and decrease the power of the laser beam, thereby decreasing crosstalk of the recorded information. The first strategy and the second strategy are alternatively used dependently on conditions of the recording of information.

Abstract: An input signal is quantized into a quantization-resultant signal. The quantization-resultant signal is compressed into a compression-resultant signal. The compression-resultant signal is formatted into a formatting-resultant signal corresponding to a predetermined format for a digital recording disc. The formatting-resultant signal includes segments corresponding to user data areas prescribed in the predetermined format. The compression-resultant signal is placed in the segments of the formatting-resultant signal. The formatting-resultant signal is encoded into an encoding-resultant signal of a CD format. The encoding-resultant signal is recorded on a recording medium.

Abstract: A reproduction signal evaluation method of this invention includes the step of obtaining a reproduction signal from an information recording medium on which digital information is recorded with record marks having different sizes, the step of obtaining the amplitude of a first reproduction signal, of the signals contained in the reproduction signal, which reflects digital information recorded with a record mark having the maximum size, the step of obtaining the amplitude of a second reproduction signal, of the signals contained in the reproduction signal, which reflects digital information recorded with a record mark having the second smallest size, the step of obtaining an evaluation value from the ratio of the amplitudes of the first and second reproduction signals, and the step of evaluating a characteristic of the reproduction signal on the basis of the evaluation value.

Abstract: A compatible optical pickup includes a light source which emits a first light beam having a wavelength for a first recording medium; a twin light source which emits second and third light beams respectively having wavelengths for second and third recording media; a first objective lens which condenses the first light beam to form a light spot for recording and/or reproduction of the first recording medium; a second objective lens which condenses the second and third light beams to form light spots for recording and/or reproduction of the second and third recording media; an actuator which drives the first and second objective lenses; a first photo-detector which receives the first light beam reflected from a recording medium to detect an information signal and/or an error signal; and a second photo-detector which receives the second and third light beams reflected from a recording medium to detect information signals and/or error signals.

Abstract: An optical disk apparatus that is capable of accurately determining a characteristic of an optical disk is disclosed, where the optical disk has recording and/or replaying characteristics that vary under different conditions. Also, a method for determining such characteristic is disclosed. Specifically, the optical disk apparatus, which is adapted to irradiate an optical beam on an optical disk to realize signal recording, replays a signal recorded on the optical disk after a predetermined time period elapses from the time of the recording of the signal, determines a characteristic of the optical disk based on the replayed signal, and controls the signal recording on the optical disk based on the determined characteristic.

Abstract: An optical pickup apparatus includes a first optical system for recording or reproducing signals to or from a first optical recording medium; a second optical system for recording or reproducing signals to or from a second optical recording medium; a holder for accommodating the first optical system and the second optical system on substantially the same plane; a focusing driving device for moving the holder in a first direction parallel to an optical axis of the first optical system and the second optical system; a tracking driving device for rotating the holder in a second direction perpendicular to the optical axis of the first optical system and the second optical system; a switching device for placing the first optical system on an optical path for recording or reproducing signals to or from the first optical recording medium, and for placing the second optical system on the optical path for recording or reproducing signals to or from the second optical recording medium; and a variable distance driving d

Abstract: An optical disk includes a recording region formed on a substrate for recording user data, and a management region formed on the substrate which includes an identification information region for recording disk-specific identification information such as address information (ID), a SYNC code, or an error detection code (EDC). The identification information region in this optical disk has a flat portion (a mirror region) formed by means of sectioning part of a groove or a land in a given step. The disk-specific identification information is recorded on the identification information region inclusive of this mirror region as irreversible record marks. Moreover, a signal of the disk-specific identification information is detected by a laser beam which is servoed on the recording track of this optical disk. Then, a change in the detected signal level of the disk-specific identification information is detected based on a predetermined threshold level.

Abstract: A method, system and computer-readable medium are disclosed, for creating a backup disc of a hybrid disc that allows creation of a copy of a source hybrid disc properly. The method includes a qualification determination step, a loading step and a writing step. The qualification determination step determines whether or not the target optical disc is qualified as the backup disc by comparing the source optical disc to the target optical disc based on information recorded therein. The loading step loads backup information from the source optical disc when the target optical disc is qualified as the backup disc. The writing step writes the backup information in the target optical disc.

Abstract: A recording medium is structured by a recording layer, which is for storing storage data, and an indication layer, which is for indication information used for identifying the storage data, being laminated together. Writing and deletion are possible at the indication layer. A PC generates inputted storage data and indication information for identifying the storage data, and transmits them to a writing/reading device. The writing/reading device writes the storage data and the indication information to the recording medium. The storage data is written at the recording layer, and the indication information is written at the indication layer. The storage data stored at the recording medium can be easily and correctly grasped.

Abstract: A device and method of string a disc-ID on a record carrier. The record carriercomprises tracks. Information is stored on the record carrier. A disc-ID that comprises I groups of disc-ID bits is stored on the record carrier in a scattered way. I comprises at least 1 group. At least one of the I groups of disc-ID bits comprises a plurality of disc-ID bits.

Abstract: During manufacturing of optical disks, mastering equipment inserts marks (“high frequency wobble marks” or“HFWMs”) into the wobble of the groove on optical disks to store data. The presence of a HFWM at a zero crossing of the wobble indicates an active bit and the absence of the HFWM indicates an inactive bit. The zero crossing is, for example, a negative zero crossing. A matched filter is used to detect the shape of the HFWMs. If a HFWM is detected during a wobble cycle, an active bit is saved in a register or a memory. If a HFWM is not detected during a wobble cycle, an inactive bit is saved in a register or a memory. The active and inactive bits may be coded bits that must be decoded to data bits. The data bits include information such as a synchronization mark, a sector identification data, and an error detection code.

Abstract: There is disclosed a management information storage section which detects and stores management information on a folder recorded in a first recording/reproducing device. The management information includes a time that has elapsed from a time when the folder was prepared, the number of contents in the folder, and the like. A specific information storage section stores specific information to specify the folder. The specific information includes an elapse time set value, the number of contents, and the like set by a user. An information comparison section compares the management information stored in the management information storage section with the specific information stored in the specific information storage section. When the management information meets the specific information, the comparison result is provided. A folder state display section notifies the user of the comparison result.

Abstract: A read-only information storage medium includes: a data area which stores user data; a lead-in area; and a lead-out area. A pattern for achieving a purpose is formed in at least one of the lead-in area and the lead-out area.

Abstract: A push-pull signal Spp fetched with tracking open is smoothed to a smoothing signal Spp to remove signal components generated wobbling due to radial runout, and the smoothing signal is binarized to compute an autocorrelation value in the autocorrelation computing circuit 210. This computing is made by multiplying the binarized signal by a signal delayed by the half cycle and sign-negated to compute the integrated value, and the integrated value output signal Dint is generated. A maximum value of the integrated value output signal Dint within a predetermined period of time is computed by the maximum value holding circuit 220 to output a maximum value output signal Dout. Depending on the amplitude of the maximum value signal Dout, the CPU 105 determines whether the recording medium is a writable one or read only one. Wobble determination can be made keeping tracking open, and a type of a recording medium is carried out accurately.

Abstract: An optical disc drive which is capable of easily and reliably recording information onto and/or playing back information recorded on various types of optical discs having different reflectances is disclosed. The optical disc drive has a rotational drive mechanism for rotating the optical disc loaded in the optical disc drive; an optical pick-up which includes an objective lens, an actuator, a laser diode and a split photodiode; an optical pick-up moving mechanism; a control means; an RF amplifier IC; a servo processor; a decoder; a memory; and a casing for housing all these elements. After moving a disc tray to the loaded position, the optical disc forces the objective lens to move in the optical axis direction to generate a focus error signal. Then, after calculating an amplitude of the generated focus error signal, the optical disc drive discriminates the presence or absence of an optical disc and the disc type of the optical disc loaded in the optical disc drive.

Abstract: A method and apparatus for initializing optical recording media is provided that detects the intensity of a reflective light off of an optical recording media and analyzes the initializing condition based on the detected intensity during an initializing process. The light is radiated on a rotating phase-change optical recording medium. The light may be moved in a radial direction of the optical recording medium. The detected intensity of the reflected light may be used to identify crystallized portions and amorphous portions of the optical media. The initialization process can be adaptively controlled to ensure proper initialization. If desired, re-initialization can be limited to those areas detected to be outside of the predetermined parameters.

Abstract: A method of writing data to an optical disc comprising determining a disc category value to be written to an optical disc, and writing, by an optical disc drive, the disc category value to the optical disc, the disc category value written to the optical disc different than a standardized disc category value associated with a disc category type of the optical disc is provided. A computer-readable medium having stored thereon an instruction set to be executed, the instruction set, when executed by a processor, causes the processor to perform a computer method of determining an optical disc category value, and writing, by an optical disc drive, the disc category value to an optical disc, the disc category value written to the optical disc different than a standardized disc category value associated with a disc category type of the optical disc is provided.

Abstract: An information storage medium includes an area in which updated disc-related information and recording-related information updated with a change in at least one of a disc version number and a recording speed is recorded along with existing disc-related information and recording-related information. The existing disc-related information and recording-related information are recorded, and the updated disc-related information and recording-related information is recorded in an area in which the existing disc-related information and recording-related information is recorded. Accordingly, data can be recorded/reproduced on/from a new version of information storage medium even using an existing drive.

Abstract: A method and apparatus renders an optical disk unplayable on a customer's optical disc playback machine. A portion of the information bearing surface of the optical disc or the light reflected therefrom, is altered for data destruction from a predetermined area, i.e., a “Table of Contents” (TOC), in order to make the disc unplayable on the playback machine of the customer.

Abstract: A method for reproducing an optical disc having a plurality of titles. The method is capable of, when an all disc repeat play operation or an all disc successive play operation is performed with respect to a plurality of optical discs loaded in a multi-disc changer, or when an instant play operation is performed in a general optical disc player, omitting a still mode operation of outputting and displaying a title menu picture regarding titles recorded on each disc, and selecting and reproducing any one of the titles with reference to respective playback times of the titles, thereby efficiently preventing the all disc repeat play operation, all disc successive play operation or instant play operation from being interrupted due to the display of the menu picture.

Abstract: A recording medium having at least a lead-in area, a data recording area to which data is recorded, and a lead-out area, wherein the data recording area comprises a first recording area portion to which data that has been encoded with an error correction code is recorded; and a second recording area portion to which at least data that has been encoded with a plurality of types of generation polynomials as error correction codes.

Abstract: A method for discriminating optical media type includes positioning a reading unit of the optical drive at a first position, moving the reading unit to a second position so that a light spot passes over a data layer of the optical media, continuing measuring the reflection of the laser beam to obtain a first time when the reflection is larger than a predetermined reflection, moving the reading unit back to the first position so that the light spot again passes over the data layer of the optical media, continuing measuring the reflection of the laser beam to obtain a second time when the reflection is larger than the predetermined reflection, and calculating the time difference between the second time and the first time and comparing with at least one predetermined time in order to discriminate the type of the optical media.

Abstract: There is provided a disk device including a detector section which generates detection signals according to reflected lights of laser lights emitted on a disk, a removing section which detects detrack components which have failed to detect recording information on the disk from the detection signals and removes and outputs the same from the detection signals, and a processing section which applies a predetermined processing on the basis of signals obtained by removing detrack components from the detection signals, so that erroneous address information on CAPA which has been failed to read or the like can be removed, thereby improving reading accuracy of the disk.

Abstract: When reproducing a multilayer optical disk using a high-numerical-aperture objective, the period of time required before the disk is reproduced is reduced by discriminating recording layers. A spherical aberration signal is detected as a differential signal between focus position fluctuation signals respectively in a central section and in a peripheral section of a reproduced flux of light. A recording layer is discriminated using a quantity of correction of spherical aberration at a zero-crossing point of a level or a spherical aberration signal associated with the differential signal. After adding the spherical aberration for the correction of the discriminated layer, residual spherical aberration is corrected by feedback control using a residual spherical aberration signal.

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 apparatus, method, and medium including computer readable code for discriminating a type of a recording medium using an amplitude of a groove wobble formed on the recording medium. The apparatus includes a radio frequency (RF) amplifier, a wobble amplitude detector, and a system controller. The RF amplifier generates a signal based on light reflected from the recording medium, wobble amplitude detector detects the amplitude of wobble formed on the recording medium based on an output signal of the RF amplifier, and the system controller discriminates a type of the recording medium by comparing the wobble amplitude detected by the wobble amplitude detector with a reference value.

Abstract: A method and apparatus identifying a type of a recordable disc using the reflectivity and RPM (Rotation Per Minute) of the disc. The method includes the operations of detecting an RPM (Rotation Per Minute) of the disc, identifying a first disc type by comparing the RPM with a first reference value, measuring the reflectivity of the disc, and identifying a second disc type between a one-time recordable disc type and a re-recordable disc type by comparing the reflectivity of the disc with a second reference value. Accordingly, the lead-in time of the disc can be reduced.

Abstract: Audio data of 20 bits is separated into first data of upper 16 bits and second data of lower 4 bits. EFM modulation data is formed from the first data. A laser beam is on/off controlled in correspondence to the logic level of channel data obtained by NRZI modulating a serial data train. The first data, therefore, is recorded in a manner similar to the case of a compact disc. Each pit is controlled so as to have a displacement in the right/left direction for the track center in accordance with the second data and the deviated pit is formed. When data is recorded by the displacement of the pit, since a high frequency component of a tracking error signal changes upon reproduction, the second data can be extracted from the tracking error signal.

Abstract: An optical disc recorder and/or player using as a recording medium an optical disc having a plurality of recording layers formed one over another includes an optical pickup having a photodetector to direct a light beam towards any one of the plurality of recording layers and detect a return light beam from a recording layer, and an identifier to compare an output signal from the photodetector with a predetermined reference value and identify, based on a comparison result, which one of the plurality of recording layers formed in the optical disc has focused thereon the light beam from the optical pickup.

Abstract: A local track pitch measuring apparatus is disclosed for an optical disk of the type that stores optically readable information in the form of a spiral or annular pattern defining a plurality of essentially concentric tracks. The apparatus has a laser light source and a drive mechanism which projects a laser beam spot from the laser light source onto a surface of the optical disk and moves the projected laser beam spot radially over a portion of the disk surface across at least some of the tracks. A light detector detects a diffraction or reflection from the projected laser beam spot during its movement. The light detector produces a time variant measurement signal having a periodicity associated with the passages of the moving laser beam spot across respective tracks. A processing device determines a local deviation in the periodicity of the measurement signal and provides an output indicative of a local track pitch for the spiral or annular pattern.

Abstract: A method for discriminating an optical storage medium is disclosed. A predetermined range of the optical storage medium is read after the light source is focused on; and thereby a plurality of data transition points and transition regions defined by an interval of two neighboring points are obtained. Thereafter, the time-consumption for reading the longest transition region is used to determine the type of the currently accessed optical storage medium. Another physical characteristics according to data storage formats, such as the PLL clock frequency or the distance between the reflection layer and the surface layer of the optical storage medium, may be used as references to discriminate the currently accessed optical storage medium.

Abstract: A code judging apparatus is provided with: a detecting device (11) for optically detecting an information code including at least identification information to individually identify a writable record medium (DK), in which record information can be written, from the writable record medium to thereby output an output signal; a moving device (19) for moving the detecting device onto a set area, which is an area on the writable record medium where the information code is supposed to be recorded; and a judging device (19) for judging whether or not the information code is recorded on the writable record medium, in accordance with the output signal outputted from the detecting device moved on the set area.

Abstract: A system controller is provided so as to record the second disk type information having the same content as that of the first disk type information, which is recorded in a DVD-R in advance, in a DVD-R in which the first disk type information is recorded as well as to record the record information in the DVD-R and reproduce the record information only if the first disk type information and the second disk type information have the same contents each other upon reproducing the record information.

Abstract: In a multi-session disc including both audio session and data session, the data session is correctly recognized and accessed. The reproducing apparatus is a reproducing apparatus of a multi-session disc mixing a session of first type recording first data and a session of second type recording second data different from the first data, comprising an optical pickup for accessing the session of first type and the session of second type, a judging unit for judging a type of the session accessed by the optical pickup, and a limiting unit for limiting the session of first type to a reproducible session when the session of second type judged by the judging unit is present at an access position after the session of first type.

Abstract: An information storage medium includes an area in which updated disc-related information and recording-related information updated with a change in at least one of a disc version number and a recording speed is recorded along with existing disc-related information and recording-related information. The existing disc-related information and recording-related information are recorded, and the updated disc-related information and recording-related information is recorded in an area in which the existing disc-related information and recording-related information is recorded. Accordingly, data can be recorded/reproduced on/from a new version of information storage medium even using an existing drive.

Abstract: A laser diode applies a laser beam through a grating, a beam splitter, and an objective to a compact disc. A laser beam reflected by the compact disc is applied through the objective and the beam splitter to a photodiode. The objective has a large numerical aperture of 0.6 in order to be able of play back a digital video disc that has a thin substrate and contains information recorded at a high density. To prevent the photodiode from suffering aberrations caused due to the large numerical aperture of the objective, the photodiode has a relatively small photodetector unit having a normalized detector size ranging from 3 &mgr;m to 16 &mgr;m, for detecting only returning light up to a numerical aperture of 0.3 and not detecting light of greater numerical aperture values.