Abstract: Disc data accessing in current disc drives is time consuming to the user and generally inefficient. The optical disc evaluation method and access apparatus for evaluating compatibility between a disc and a disc drive described herein was created and designed to increase efficiency during disc accessing. The optical disc access apparatus comprises of a receiver and an optical disc scoring unit. The receiver is configured for retrieving a reflected signal from a disc while the optical disc scoring unit is configured for generating information in response to the reflected signal. The resulting information indicates the compatibility between the disc and disc drive.

Abstract: A method of recording data onto an optical disk uses a write strategy that corresponds to the recording features of the optical disk. The method detects a track pitch or storage capacity of a recording medium, adjusts a write strategy according to the detected track pitch or storage capacity wherein the write strategy has been chosen to correspond to the manufacturer of the recording medium, and records input data onto the recording medium using the adjusted write strategy. Accordingly, data quality during later reproduction is improved even though it is recorded onto a non-standard disk that is larger in capacity than the standard.

Abstract: An information storage medium according to an aspect of this invention has an information storage area for storing information, and a wobbled track which is used to guide a light beam on the information storage area, and is wobbled in correspondence with a frequency, a phase of which is modulated at predetermined timings to reflect predetermined information. The wobbled track is formed so that an evaluation result based on the frequency characteristics of a squared reproduction signal obtained by squaring a reproduction signal corresponding to the wobbled track, obtained from the reflected light of a light beam with which the wobbled track is irradiated, meets a predetermined evaluation measure.

Abstract: The present invention relates to a method of maintaining an optimal writing power for various recording modes during data recording onto a recording medium. The present method checks a recording speed at a recording position, reads a write strategy set for the checked recording speed, detects a reflected level while recording data with the read write strategy, and changes a level reference for ROPC according to the detected level. Accordingly, a writing power can be kept most optimal even though a recording speed changes during data recording, thereby improving the quality of reproduced signals.

Abstract: A laser diode drive control apparatus and method in an optical storage medium recording/reproducing system.

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 double-sided optical disc, such as a DVD-18 disc, is formed with data tracks on each layer. The tracks on one side are oriented along one spiral while the tracks on the other side are oriented along a different spiral, the two spirals being oriented in opposite directions as viewed normally from the respective sides. This allows data to be read by a player seamlessly from either side of the disc without changing the direction of rotation of the disc while the data is being read. The player determines whether a newly inserted disc is oriented properly and, if necessary, the direction of the disc rotation is reversed.

Abstract: Provided is an optical disc device for reading a signal recorded on an optical disc medium, which detects surface reflection at a surface of the optical disc medium, a fake signal generated based on the surface reflection, and light reflected by a data recording layer of the optical disc medium while an objective lens is moved relative to the surface of the optical disc medium, and discriminates a type of the optical disc medium based on a ratio of a first time period between an instant when the surface reflection is detected and an instant when the fake signal is detected, and a second time period between the instant when the surface reflection is detected and an instant when light reflected by the data recording layer is detected.

Abstract: A method of determining a type of a disc for a disc system to record/reproduce a plurality of recordable discs having different track pitches, including detecting a plurality of signals for determination while moving an objective lens up or down and simultaneously making the objective lens vibrate in a radial direction of the disc, and determining the types of the discs having different track pitches by using the detected signals for determination.

Abstract: An apparatus includes a multiple detecting unit having n detectors, and a controller which selects one of the n detectors and controls the selected detector to output a binary signal. In the apparatus, a plurality of detectors are used to detect a signal read from an optical storage medium, and the optimum detector is selected in consideration of a quality of the signal and detection conditions, thereby increasing the efficiency of a signal reproduction. The apparatus can selectively compensate for disturbance of a signal where data from the optical storage medium is reproduced. The apparatus may control a run length of the signal to be 3T.

Abstract: The amount of light reflected from a disk is detected, and it is determined according to the amount of reflected light whether the disk is a recordable disk or a rewritable disk. The disk is controlled according to the result of determination such that it is rotated at a constant angular velocity (CAV) or at a constant linear velocity (CLV) and recording is executed. Further, rotation driving control of the disk is selected according to factors other than the type of the disk, such as according to whether random recording is allowed or not, according to a recording state in the disk, according to whether an alternative area is provided or not, according to a recording start position, or according to whether initialization is required or not. CLV control or CAV control is appropriately selected for a disk at recording to suppress a reduction in accessibility and a reduction in data transmission rate.

Abstract: The amount of light reflected from a disk is detected, and it is determined according to the amount of reflected light whether the disk is a recordable disk or a rewritable disk. The disk is controlled according to the result of determination such that it is rotated at a constant angular velocity (CAV) or at a constant linear velocity (CLV) and recording is executed. Further, rotation driving control of the disk is selected according to factors other than the type of the disk, such as according to whether random recording is allowed or not, according to a recording state in the disk, according to whether an alternative area is provided or not, according to a recording start position, or according to whether initialization is required or not. CLV control or CAV control is appropriately selected for a disk at recording to suppress a reduction in accessibility and a reduction in data transmission rate.

Abstract: The amount of light reflected from a disk is detected, and it is determined according to the amount of reflected light whether the disk is a recordable disk or a rewritable disk. The disk is controlled according to the result of determination such that it is rotated at a constant angular velocity (CAV) or at a constant linear velocity (CLV) and recording is executed. Further, rotation driving control of the disk is selected according to factors other than the type of the disk, such as according to whether random recording is allowed or not, according to a recording state in the disk, according to whether an alternative area is provided or not, according to a recording start position, or according to whether initialization is required or not. CLV control or CAV control is appropriately selected for a disk at recording to suppress a reduction in accessibility and a reduction in data transmission rate.

Abstract: An apparatus and method to accurately discriminate an optical disc type in an optical disc system which records and/or reproduces data to and/or from high density optical discs and low density optical discs includes irradiating a laser beam onto a given one of the optical discs, measuring a track error signal generated from light reflected by the given optical disc, comparing a level of the track error signal with a predetermined reference value, and discriminating a type of the given optical disc according to a comparison result.

Abstract: An optical disk driving apparatus includes a control computer, and the optical disk driving apparatus acquires a wobble signal. The control computer calculates an average period of a binarized wobble signal and a variance of the period of the binarized wobble signal. The control computer determines whether the calculated average period satisfies the specifications of DVD-R or DVD-RW and determines whether the calculated variance is below a predetermined level.

Abstract: A tracking error signal calculating unit (221) detects a tracking error signal of light with respect to a mark recorded on a wobbled groove in a focused-on state from the light reflected back from the wobbled groove. A pull-in signal calculating unit (225) detects a total light volume signal PI of the mark, recorded on the wobbled groove, from the reflected light. A D-flipflop discriminating circuit (244) compares the phase of a binary coded version of a tracking error signal TE detected by the tracking error signal calculating unit to the phase of a binary coded version of the total light volume signal PI as detected by the pull-in signal calculating unit to discriminate the sorts of the optical discs having the same outer shape and the same optical system but differing in the UTOC recording system.

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: An optical disk unit of this invention includes a defocus detecting system for detecting a defocus of an objective lens, a thickness unevenness detecting system for detecting a thickness unevenness of a transparent resin layer provided nearest the objective lens of a recording medium, and a thickness unevenness correcting mechanism for changing the focusing characteristic of light impinging upon the objective lens based on a change in the thickness of the transparent resin layer detected by the thickness detecting system.

Abstract: Four types of optical systems, a polarization optical system including an objective lens having a high numerical aperture, a polarization optical system including an objective lens having a low numerical aperture, a non-polarization optical system including an objective lens having a high numerical aperture and a non-polarization optical system including an objective lens having a low numerical aperture, are selectively used at the time of irradiating light from a semiconductor laser on a target disk for measurement, and the in-plane birefringence characteristic and perpendicular birefringence characteristic of the target disk are separately acquired based on the amounts of received light obtained by measuring reflected light from the target disk by a photosensor.

Abstract: The invention related to a laser diode power control apparatus in an optical drive capable of driving an optical media by high-speed, which uses a fine-tuning pulse to provide a recording pulse type suitable for high-density optical media. The laser diode power control apparatus includes a pulse generating unit, a control unit, and a transmitting unit. The pulse generating unit generates a recording pulse for each channel. The control unit controls the pulse generating unit by determining whether to apply a fine-tuning pulse to the recording pulse for each channel based on the type of the optical medium and the driving speed of the optical drive for the optical medium. The transmitting unit transmits a power level for each channel according to the recording pulse output from the pulse generating unit.

Abstract: A data processor compatible for use with a CD and a DVD includes a first modulation circuit for modulating recording data for recording on a CD to generate first modulated data. A second modulation circuit modulates recording data for recording on a DVD to generate second modulated data. A write signal generation circuit generates a first write signal, which is written to the CD, from the first modulated data, and a second write signal, which is written to the DVD, from the second modulated data. The write signal generation circuit is commonly used for the CD and the DVD to reduce the circuit area of the data processor.

Abstract: The astigmatic aberration in an optical system is to be adjusted. Specifically, in an optical disc device on which can be selectively loaded a first optical disc having a first index of double refraction or a second optical disc having a second index of double refraction larger than said first index of double refraction, and which includes a liquid crystal device 31 between a light source 11 and an objective lens 15 converging a light beam radiated from said light source on the optical disc 2 loaded on the optical disc device, the voltage applied to the liquid crystal device 31 is adjusted to correct the coma aberration or the astigmatic aberration for the first disc or the second disc, respectively.

Abstract: In a method for optically recording information in a system including a recording and reading device that includes a strategy part for conducting a strategy when optically recording information and an information processing apparatus that includes a strategy information storing part storing the strategy information for operating the strategy part, the strategy information for operating the strategy part of the recording and reading device is read from the strategy information storing part of the information processing apparatus and the strategy information is transmitted to the recording and reading device.

Abstract: A BCA (Burst Cutting Area) code including a unique disk code indicating the type of a disk is written in a BCA code area of the disk. If the disk is mounted into the optical disk player, the optical disk player reads data written in the BCA code area, extracts the disk code contained in the read data, and confirms the type of the disk corresponding to the extracted disk code by retrieving a disk code table in which disk codes corresponding to the types of disks are mapped.

Abstract: A data recording medium has plural recording areas. The recording medium includes a first recording area for recording data allocated with address data, a second recording area for recording data having allocated address data different from the address data allocated to the data recorded in the first recording area, and identification data recorded in the second recording area for discriminating the first and second recording areas from each other.

Abstract: An optical recording system includes a laser light source that provides an incident recording light signal for recording information on an optical recording medium, an optical detector for detecting a reflected write pulse from the optical recording medium, and a light source controller for controlling recording laser beam power of the laser light source according to a mark formation effectiveness signal generated by a signal generating device. The signal generating device includes an analog peak value detector for detecting a peak value of the reflected write pulse from the optical detector, at least one sample-hold circuit for sampling the reflected write pulse to obtain at least one amplitude value, and a processor for generating the mark formation effectiveness signal according to the peak value and the amplitude value.

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: 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 BCA (Burst Cutting Area) code including a unique disk code indicating the type of a disk is written in a BCA code area of the disk. If the disk is mounted into the optical disk player, the optical disk player reads data written in the BCA code area, extracts the disk code contained in the read data, and confirms the type of the disk corresponding to the extracted disk code by retrieving a disk code table in which disk codes corresponding to the types of disks are mapped.

Abstract: A disc drive apparatus is provided which determines a recording medium enabling type and recordability for various types of discs. The discs are housed in a cartridge and each cartridge has at least a first and second detection hole formed therein. The second detection hole (H1) is variably opened and closed by an opening/closing device, and the first detection hole (H0) is in an open state at all times. The disc drive apparatus determines the disc type using a light signal reflected from the loaded recording medium. The disc drive apparatus also determines disc determining parameters (for example, recordability of a disc) based on information received about the disc type and the open/closed state of one or more detection holes formed in the cartridge.

Abstract: The present invention relates to an optical disk device and can be applied to, for example, a reproduction system of a phase-change-type optical disk device handling high density recording in order to improve the detection accuracy of specific patterns, such as a synchronizing pattern, without increasing the redundancy of the format. A specific pattern is detected by using NRZI data D1R that is obtained by signal processing of a reproduction signal DRF, and has been NRAI-modulated from pulse-position-modulated data D2R.

Abstract: An apparatus and a method of determining an optimal writing power for an aged writable disk after checking whether a writable disk is aged or not, are discussed. The apparatus and method according to an embodiment read signals written on a writable disk, judge whether or not the writable disk is aged based on a signal characteristic, e.g., a level difference between the read signals before and after an equalization and jitter of the read signals, and conduct an OPC for the writable disk to obtain a precise optimal writing power if the disk is judged to be aged. The precise optimal writing power can prevent deterioration of reproduction characteristic of recorded data even though an aged writable disk is used.

Abstract: A storage medium initializing method includes the steps of detecting a mode corresponding to a recording format to be loaded on a storage medium; and initializing the storage medium according to the mode detected in the detecting step. A recording and reproducing method and apparatus are configured to detect a type of storage medium loaded onto the apparatus and adjust the recording and reproducing processes accordingly.

Abstract: A method and an apparatus for identifying the type of an optical recording medium are provided. The method includes detecting a surface reflected signal SS and a writable-surface reflected signal SR of an optical recording medium while performing a focus search using a first optical system, counting a time difference DTS between a high peak and a low peak of the surface reflected signal SS, counting a time difference DTR between the high peak of the surface reflected signal and a high peak of the writable-surface reflected signal SR, obtaining DT by substituting DTR and DTS into the following equation: DT = ( DT R ) a ( DT S ) b ? ? ( a - b ? 1 2 ) and comparing DT with a reference time T, and driving the first optical system if DT is greater than T and driving a second optical system if DT is not greater than T.

Abstract: An optical disc drive for processing multiple types of optical discs, of which information storage layers have different depths, includes: a light source; a lens for forming a beam spot; a photodetector for outputting a reflected light signal; a spherical aberration generator for generating a minimum spherical aberration when the beam spot is at a reference depth; a focus drive signal generator for moving the beam spot perpendicularly to the information storage layer of a loaded disc by controlling a position of the lens; a light quantity detector for generating a light quantity signal on receiving a reflected light signal every time the beam spot is moved; and a type recognizer for recognizing the type of the loaded disc by estimating the depth of the information storage layer according to a degree of symmetry of the waveform of the light quantity signal.

Abstract: A method and an apparatus for driving an optical recording medium for recording and/or reproducing various information for the optical recording medium, in which the output power ratio of the light source may be reduced for recording and reproduction, for optical recording media of different sorts, or for respective recording surfaces of a multi-layered optical recording medium, so that optimum characteristics may be realized even with use of an easy-to-fabricate light source or a light source with a smaller light output rating.

Abstract: A type of disc is judged at high reliability irrespective of a presence of information record or magnitude of disc eccentricity. A reproduction apparatus judges the type of an optical disc to reproduce information recorded on tracks of the optical disc. The disc is classified as a type of read-only optical discs whose tracks are formed with pits and as a type of recordable optical discs whose tracks are formed with wobbling grooves. The apparatus includes a motor which rotates the optical disc, a head which irradiates the tracks of the optical disc rotated by the motor with an optical beam and outputs two detection signals corresponding to reflected light from the optical disc, and a controller which judges the type of the optical disc according to changes of a period of a specific signal contained in a push-pull signal generated from the two detection signals by varying a rotating speed of the motor.

Abstract: An optical disc apparatus includes a memory, a control circuit, a motor, a spindle, and a pickup head. When determining the type of optical disc, the optical disc apparatus moves a focusing lens at a constant velocity. A first duration is measured that indicates how much time it takes for the moving focal point of a laser shining through the focusing lens to pass through a first layer of the optical disc. A second duration is also measured that indicates how much time it takes for the moving focal point to move from the first layer to a second layer of the optical disc. A ratio of the second duration to the first duration indicates optical disc type.

Abstract: An information recording apparatus is capable of recording data and management information of an information recording medium in a plurality of data recording formats. Typically, a DVD+RW is considered to be a DVD+R disk, when data and management information of the DVD+R are recorded on the DVD+RW disk in the data recording format for the DVD+R disk, such as the sequential writing method and the multi-session writing method.

Abstract: An optical disk unit of this invention includes a defocus detecting system for detecting a defocus of an objective lens, a thickness unevenness detecting system for detecting a thickness unevenness of a transparent resin layer provided nearest the objective lens of a recording medium, and a thickness unevenness correcting mechanism for changing the focusing characteristic of light impinging upon the objective lens based on a change in the thickness of the transparent resin layer detected by the thickness detecting system.

Abstract: The present invention offers an optical disk determination circuit that can improve the stability of the operation to detect the peak (pulse signal) of the received light signal, and that can improve the stability of the optical disk determination operation. When determining the type of optical disk corresponding to the depth from the surface of the plane on which a light beam is irradiated to the data recording layer, light is irradiated while varying the focal position of the light beam at a constant velocity in one direction of the depth direction from the surface of the optical disk. The bottom level of the received light signal corresponding to the intensity of this reflected light is clamped at a specified level by the bottom clamp circuit 43. The received light signal with the bottom level clamped is compared with a specified reference voltage Vref by the comparator 45, and the received light signal peak (pulse signal) is detected corresponding to the results of this comparison.

Abstract: An optical recording/reproducing apparatus and method to determine a type of disk including a photodetector divided into at least two light receiving sections in a radial direction. A radial subtractor generates a radial push-pull signal from a difference between light receiving signals from a disk and received by the at least two light receiving sections, where the disk includes one of a first disk and a second disk. An upper envelope detector detects an upper envelope signal from the radial push-pull signal and a lower envelope detector detects a lower envelope signal from the radial push-pull signal. A phase comparator detects a phase difference between the upper envelope signal and the lower envelope signal. A type of disk determiner distinguishes the first disk from the second disk according to a magnitude of the phase difference and outputting a signal indicative thereof, where the second disk includes a density higher than the first 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: The amount of light reflected from a disk is detected, and it is determined according to the amount of reflected light whether the disk is a recordable disk or a rewritable disk. The disk is controlled according to the result of determination such that it is rotated at a constant angular velocity (CAV) or at a constant linear velocity (CLV) and recording is executed. Further, rotation driving control of the disk is selected according to factors other than the type of the disk, such as according to whether random recording is allowed or not, according to a recording state in the disk, according to whether an alternative area is provided or not, according to a recording start position, or according to whether initialization is required or not. CLV control or CAV control is appropriately selected for a disk at recording to suppress a reduction in accessibility and a reduction in data transmission rate.

Abstract: A method and device for determining the presence or absence of a disk and/or a disk size without using FG signals, are provided. The method includes placing a pickup at a first zone on the optical recording medium, the first zone located between an outer radius of a first recording medium type and an outer radius of a second recording medium type, where the outer radius of the second recording medium type is larger than the outer radius of the first recording medium type; detecting a reflected signal based on a returned beam from the first zone of the optical recording medium; and determining at least one of a size and an absence of the optical recording medium based on the detected reflected signal. Therefore, an FG sensor that is provided in a general disk device can be eliminated, thereby reducing the size and cost of a disk device.

Abstract: An optical disc apparatus for recording, reproducing or erasing an information signal by converging a light flux onto a recording layer through a transparent substrate. The apparatus includes one or a plurality of optical heads having a plurality of objective lenses whose aberrations have respectively been corrected for a plurality of disc substrates of different thicknesses, a cartridge for enclosing the optical disc, a discrimination hole which is formed on the cartridge, and a sensor for detecting the opening/closing state of the discrimination hole and for generating a discrimination signal. In accordance with the result of the discrimination as to the thickness of the loaded optical disc, the objective lens, in which the occurrence of the aberration is smallest, is used, so that the information signal can preferably be recorded, reproduced or erased onto/from the optical discs having different substrate thicknesses.

Abstract: An optical disc apparatus for recording, reproducing or erasing an information signal by converging a light flux onto a recording layer through a transparent substrate. The apparatus includes one or a plurality of optical heads having a plurality of objective lenses whose aberrations have respectively been corrected for a plurality of disc substrates of different thicknesses, a cartridge for enclosing the optical disc, a discrimination hole which is formed on the cartridge, and a sensor for detecting the opening/closing state of the discrimination hole and for generating a discrimination signal. In accordance with the result of the discrimination as to the thickness of the loaded optical disc, the objective lens, in which the occurrence of the aberration is smallest, is used, so that the information signal can preferably be recorded, reproduced or erased onto/from the optical discs having different substrate thicknesses.

Abstract: An optical disc apparatus for recording, reproducing or erasing an information signal by converging a light flux onto a recording layer through a transparent substrate. The apparatus includes one or a plurality of optical heads having a plurality of objective lenses whose aberations have respectivley been corrected for a plurality of disc substrates of different thicknesses, a cartridge for enclosing the optical disc, a discrimination hole which is formed on the cartridge, and a sensor for detecting the opening/ closing state of the discrimination hole and for generating a discrimination signal. In accordance with the result of the discrimination as to the thickness of the loaded optical disc, the objective lens, in which the occurrence of the aberration is smallest, is used, so that the information signal can preferably be recorded, reproduced or erased onto/from the optical discs having different substrate thicknesses.

Abstract: An optical disc apparatus for recording, reproducing or erasing an information signal by converging a light flux onto a recording layer through a transparent substrate. The apparatus includes one or a plurality of optical heads having a plurality of objective lenses whose aberrations have respectively been corrected for a plurality of disc substrates of different thicknesses, a cartridge for enclosing the optical disc, a discrimination hole which is formed on the cartridge, and a sensor for detecting the opening/closing state of the discrimination hole and for generating a discrimination signal. In accordance with the result of the discrimination as to the thickness of the loaded optical disc, the objective lens, in which the occurrence of the aberration is smallest, is used, so that the information signal can preferably be recorded, reproduced or erased onto/from the optical discs having different substrate thicknesses.

Abstract: An optical disc apparatus for recording, reproducing or erasing an information signal by converging a light flux onto a recording layer through a transparent substrate. The apparatus includes one or a plurality of optical heads having a plurality of objective lenses whose aberrations have respectively been corrected for a plurality of disc substrates of different thicknesses, a cartridge for enclosing the optical disc, a discrimination hole which is formed on the cartridge, and a sensor for detecting the opening/closing state of the discrimination hole and for generating a discrimination signal. In accordance with the result of the discrimination as to the thickness of the loaded optical disc, the objective lens, in which the occurrence of the aberration is smallest, is used, so that the information signal can preferably be recorded, reproduced or erased onto/from the optical discs having different substrate thicknesses.