Abstract: A method by which, in an optical disk recording and reproducing device, the time required for a test recording performed prior to an actual information recording can be reduced according to characteristics of an optical disk. A random pattern signal is transmitted from a random pattern signal generating circuit 3 and recorded on a test track on an optical disk 1, and a bit error rate of a reproduction signal is measured. Only when a value of the bit error rate is not less than a fixed value, test pattern signals are transmitted from a test pattern signal generating circuit 4 and recorded. An edge timing of a reproduction signal is measured by an edge timing detecting circuit 13. Based on a result of the measurement, edge positions of a front-end pulse and a back-end pulse are corrected.

Abstract: A PRML detector includes a waveform equalizer for equalizing a waveform of a reproduction signal obtained by reproducing marks and non-marks recorded on a recording medium, and a decoder for generating binary-coded data of the reproduction signal based on the waveform equalized by the waveform equalizer. The decoder outputs a temporary data string which is obtained before the binary-coded data is obtained. The waveform equalizer includes an equalizer that includes a delay element that delays propagation of the reproduction signal, a plurality of multipliers that multiply predetermined coefficients by the reproduction signal and the delayed signal from the delay element, and an adder that adds outputs from the plurality of multipliers.

Abstract: A waveform equalizer for equalizing a waveform of a reproduction signal. A delay element delays a propagation of the reproduction signal. A plurality of multipliers multiply predetermined coefficients by the reproduction signal and the delayed propagation reproduction signal. A detector detects an asymmetry of the reproduction signal arising from physical profiles of each of the marks and the non-marks, and outputs a detection signal representing an amount of asymmetry. A discriminator outputs a discrimination signal in response to a discrimination of the marks and the non-marks. A calculator calculates a first coefficient multiplied by the reproduction signal of the marks based on the outputted detection signal, and calculates a second coefficient multiplied by the reproduction signal of the non-marks. A selector selects either the first or second coefficient, based upon the outputted discriminating signal.

Abstract: Defects of a hard disk drive servo pattern stamper are detected by comparing a scattered light beam pattern against the known servo pattern. A magnetic field is applied to stamper and the beam is linearly polarized. Variations in the physical offset of the beam, its scatter, are indicative of physical defects. Variations in the Kerr rotation of scattered beam are indicative of magnetic defects.

Abstract: A defect detecting circuit generates a defect detection signal when the level of a sum signal obtained from an optical sensor in an optical pickup is lower than a predetermined level, and a gate circuit responds to the defect detection signal to set the level of a fine clock mark signal to zero, that is a difference signal obtained from the optical sensor in the optical pickup. A fine clock mark is thus distinguished from any defect such as scratch and a correct fine clock mark signal is accordingly generated. Alternatively, the value of a sum signal, which indicates the total amount of reflected light output from the optical pickup, is compared with a predetermined threshold. When the period in which the value of the sum signal is smaller than the threshold lasts for a predetermined threshold time period, it is determined that focus of an objective lens deviates from an optical disk and accordingly focus servo control is stopped.

Abstract: A disk reproducing apparatus and a disk reproducing method which permit continuous reproduction of data of the RTR type without interruption and without affecting real time reproduction. A defective block list with defective blocks and alternative blocks registered linked to each other by the types of defective blocks has been acquired beforehand from a recording medium and when there arises need to read a defective block, its alternative block is read out and forwarded to a reproduction requester. Here, reading control means identifies the type of defective blocks registered on the defective block list and controls the reading according to the identification results.

Abstract: An optical information storage medium includes a lead-in area, a user data zone in which user data is recorded, and a lead-out area. Write protection information is recorded in at least one of the lead-in area and the lead-out area, together with defect management information. Information is recorded and/or reproduced according to the defect management information and the write protection information. The write protection information indicates a size of a write protected area differentiated from a plurality of sizes of write protected areas of the optical information storage medium.

Abstract: A method for real time recording and playback of data to and from an optical recording medium, and a method for managing a file thereof is disclosed. In the present invention, the host controls real time data writing by providing a signal requesting for information on a defective area to the device for recording/playback of data to/from an optical disk before providing a write command. Accordingly, the write command is generated such that data is not written on the defective areas, based upon the returned information on the defective area. Alternatively, the host may first provide a write command to the device for recording/playback of data to/from an optical disk, upon which information on defective areas is returned. Thus, the host generates and provides a new write command such that data is not written on a defective area based upon the returned information on the defective area.

Abstract: A recording method for use by an apparatus and/or which is encoded on a computer readable medium includes selecting a defect management on mode or a defect management off mode that indicates whether defect management is to be performed or not while data is recorded in the recording medium, recording the data in the recording medium while defect management is performed on the recording medium, if the defect management on mode is selected, and recording the data in the recording medium without defect management, if the defect management off mode is selected.

Abstract: A waveform equalizer for equalizing a waveform of a reproduction signal. A delay element delays a propagation of the reproduction signal. A plurality of multipliers multiply predetermined coefficients by the reproduction signal and the delayed propagation reproduction signal. A detector detects an asymmetry of the reproduction signal arising from physical profiles of each of the marks and the non-marks, and outputs a detection signal representing an amount of asymmetry. A discriminator outputs a discrimination signal in response to a discrimination of the marks and the non-marks. A calculator calculates a first coefficient multiplied by the reproduction signal of the marks based on the outputted detection signal, and calculates a second coefficient multiplied by the reproduction signal of the non-marks. A selector selects either the first or second coefficient, based upon the outputted discriminating signal.

Abstract: A recording medium having a spare area for defect management and the management information of the spare area, a spare area allocation method, and a defect management method. When a primary spare area is allocated for slipping replacement and linear replacement upon initialization, and a remaining portion of the primary spare area after slipping replacement and allocated for linear replacement after initialization are insufficient, a supplementary spare area is allocated. The sizes of the primary and supplementary spare areas are determined by the number of defects generated upon initialization. The information on the sizes of the spare areas, and the remainder state information representing the degree of use of the spare areas, are recorded, so that the spare areas can be efficiently managed.

Abstract: Even with an asymmetric reproduction waveform, or under the noisy environment, an accurate equalizing error is found and temporary judgment value for adaptively controlling the coefficient of FIR filter is accurately outputted. A waveform equalizer for equalizing a waveform of a reproduction signal obtained by reproducing marks and non-marks recorded on a recording medium is provided. The equalizer includes: a detector which detects asymmetry of the reproduction signal arising from physical profiles of the marks and non-marks and outputs a detection signal representing asymmetric amount; a discriminator which discriminates the marks and non-marks based on the reproduction signal to output a discriminated signal; and a selector which calculates a first and second coefficient multiplied by the reproduction signal of the marks and non-marks based on the detection signal, which are different. The selector selects one of the first and second coefficients based on the discriminating signal.

Abstract: A data compensating method and apparatus for compensating a block from which data cannot be read due to the presence of a scratch or dust when reproducing an optical disk are provided. The data compensating method includes the steps of: (a) setting a first block region for storing a block of data currently being reproduced and a second block region for storing the previous block of data, and reproducing the disk according to a read command; (b) determining the type of data block from a header in a sought block when the number of seek operations is greater than a predetermined value in reproducing the disk in step (a); (c) substituting an address of a block of data in the second block region, corresponding to a data block determined in step (b), for an address requested by a host; and (d) transmitting to the host the block of data in the second block region substituted in step (c).

Abstract: In a recording and reproducing apparatus for a disc-shaped recording medium, and a defect substitution method for a disc-shaped recording medium, whether reproduction of recorded data is good is determined by sector unit and not by product code unit, defective sector discrimination is performed by sector unit, and only sectors determined defective are alternately recorded, when using a recording format in which data that is error detection and correction coded with a product code is segmented and recorded to a plurality of sectors.

Abstract: A defect area management method of an optical recording medium is disclosed. The present method is capable of managing a defective areas by storing information of defective blocks in the user block upon formatting as well as information of defective replacement blocks by extension of the user area by slipping.

Abstract: A method for detecting a defective sector on a recording medium in a method for recording and/or reproducing data for the signal recording medium. A read gate is opened to reproduce data from a data field at a pre-set timing derived from a timing reference signal obtained on detecting a servo timing mark recorded in a servo field. If the timing reference signal has not been detected with success, the read gate is opened at a timing obtained based on a detection signal of a previously detected servo timing mark to reproduce the data from the data field. In detecting the defective sector, the state of deviation between the timing of opening the read gate and the data field is detected to detect the defective sector of the disc.

Abstract: A recording medium for storing defect management information to record real time data, a defect managing method therefor, and a method of recording real time data. The recording medium stores information representing use or non-use of linear replacement defect management in which a defective area on the recording medium is replaced with the spare area, in order to record real time data. While maintaining compatibility between the defect managing method and a defect managing method based on a current DVD-RAM standard, i.e., while allowing a report of the fact that there are blocks which have not been linearly replaced, linear replacement is not performed when real time data is recorded. Thus, real time data can be recorded and reproduced.

Abstract: Method for formatting, and managing a defective area of, a rewritable optical recording medium when a secondary defect list (SDL) is converted into a primary defect list (PDL) without certification by converting only sector numbers of first sectors of the defective blocks listed on the SDL into the PDL. If the defective sector thus listed of the PDL is encountered during writing/reading thereafter, a block (=16 sectors) containing the defective sector is subjected to slipping replacement.

Abstract: A recording medium for storing defect management information to record real time data, a defect managing method therefor, and a method of recording real time data. The recording medium stores information representing use or non-use of linear replacement defect management in which a defective area on the recording medium is replaced with the spare area, in order to record real time data. While maintaining compatibility between the defect managing method and a defect managing method based on a current DVD-RAM standard, i.e., while allowing a report of the fact that there are blocks which have not been linearly replaced, linear replacement is not performed when real time data is recorded. Thus, real time data can be recorded and reproduced.

Abstract: A recording medium having a spare area for defect management and the management information of the spare area, a spare area allocation method, and a defect management method,. When a primary spare area is allocated for slipping replacement and linear replacement upon initialization, and a remaining portion of the primary spare area after slipping replacement and allocated for linear replacement after initialization are insufficient, a supplementary spare area is allocated. The sizes of the primary and supplementary spare areas are determined by the number of defects generated upon initialization. The information on the sizes of the spare areas, and the remainder state information representing the degree of use of the spare areas, are recorded, so that the spare areas can be efficiently managed.

Abstract: An optical disc apparatus being able to read and write from and into an optical disc of a wobble groove type or method, a rotation control of a spindle motor is performed including a spindle controller portion and a PWM oscillator generating a clock for use of rotation control, wherein the frequency of the clock for use of rotation control is set to be different from that of a wobble signal or outside an area ±50% of wide capture fluctuation of the wobble signal, thereby providing the optical disc apparatus with which external disturbance on the wobble signal or the like can be reduced and a stabilization of the optical disc apparatus can be obtained.

Abstract: A music reproducing apparatus is provided. The apparatus reproduces music on the basis of music data which includes music information representing music to be reproduced and beat information representing a beat of the music and which is recorded on a recording medium. The music information is divided into a plurality of music information pieces whose time length are equal to each other. The beat information is divided into a plurality of beat information pieces. Each of the beat information pieces includes information for designating one of the music information pieces in which the beat of the music is present.

Abstract: A system and method to compensate for data defects within a magneto-optical computer memory device comprises a data channel coupled to the memory device for receiving and processing data signals, and a detector channel coupled to the data channel for detecting the data defects and then generating corresponding defect-skipping pulses. The data channel responsively uses the defect-skipping pulses to compensate for the data defects and thus maintain reliability of the data signals.