Abstract: An information reproducing method includes the steps o of reading information from an information medium that is rotated, and determining a rotation velocity of the information medium on the basis of a data transfer rate based on a specification of a read request.

Abstract: A signal processing circuit, which extracts a signal superimposed on a reference signal and having a peak level higher than a level of the reference signal by a value greater than a given value, includes a first pulse generation part generating a first binary signal by binarizing a composite signal of the reference signal and the superimposed signal by using a given slice level, a noise elimination part eliminating noise from the first binary signal by using a cumulative length of time of each of polarities of the first binary signal, a second pulse generation part generating a second binary signal by binarizing the composite signal by using a slice level higher than the level of the reference signal by a value smaller than or equal to the given value, and a gate part outputting the second binary signal based on a signal output from said noise elimination part.

Abstract: There is disclosed an optical recording medium comprising: a transparent resin substrate on which a groove and a land between the grooves disposed adjacent to each other are formed beforehand, wherein recording position information indicating a recording position with respect to an information signal is recorded beforehand on at least one of the groove and land, and a metal reflective film and protective film are successively formed on the groove and land.

Abstract: A calibration of input signal offset in an optical disk drive is presented. The input signal offsets the input signals received from an optical pick-up unit before digitization. In some embodiments, the input signal offset is set such that the digitized input signals are zero when laser power is off. Further, a thermal drift correction is presented.

Abstract: This invention provides a method of acquisition of binary information that has been stored physically in a periodic storage medium. The method, referred to as matrix-method deconvolution (MMD), is useful for use with optical storage media using an optical addressing system that reads and writes binary information in a periodic array of nano-particles. With this MMD method, the density of existing memory systems can be boosted to between 10 and 100 Terabytes of data per cubic centimeter. This matrix-method deconvolution method compensates for the effects of the optical addressing system's point spread function. Prior knowledge of a system's point spread function and inter memory-center spacing is used.

Abstract: A method for protecting a phase lock loop (PLL) in an optical system is disclosed. The disclosed method will determine whether the currently reading data is erroneous and then maintain the frequency currently locked by the PLL circuit when the waveform lengths of the EFM signal in a detecting window contain at least one waveform length longer than 11T and at least one waveform length shorter than 3T. Otherwise, the PLL circuit will adjust the locked frequency according to the waveform length of the detected EFM signal so that the system clock frequency can be adjusted based on the locked one. In addition, when the optical system seeks tracks for reading required data under a constant angular velocity (CAV) modulation mode, the PLL circuit will increase the locked frequency gradually as the pick-up head moves towards the outer tracks of the optical disc, and decrease the locked frequency gradually as the pick-up head moves towards the inner tracks of the optical disc.

Abstract: An optical disc recording/reproducing apparatus detects last position information of already recorded data and information of initial data recordable capacity of an optical disc that is in a state of no further writing by a recording completion process, a calculating device that calculates data recordable capacity of a free space in accordance with the last position information of already recorded data and the information of initial data recordable capacity of the optical disc and records data in the free space after the last position of already recorded data. The optical disc recording/reproducing apparatus scans the area after the last position of the already recorded data, and when the recorded data is found in the area, the data recorded after the last position is read. Data can be recorded to or reproduced from a free space of the optical disc to which the finalizing process has been executed.

Abstract: An optical disk recording method performs recording of data at a variable linear velocity multiplication factor in accordance with a radial position of a irradiation optical beam on an optical disk. The method is carried out by the steps of performing an actual recording with a variable writing power y=ax+b of the irradiation optical beam in accordance with a linear velocity multiplication factor x where the constant a is determined to a fixed value according to a type of the optical disk, performing a test recording before starting the actual recording such that the test recording is carried out with a test linear velocity multiplication factor to obtain an appropriate writing power of the irradiation optical beam, and setting the constant b by solving the function y=ax+b with using the results of the test recording, whereby the actual recording can be performed with an appropriate writing power y calculated based on the function y=ax+b having the set constants a and b.

Abstract: A method of recording and/or reproducing information onto/from an information storage medium includes the step of detecting a time interval between a received command and a subsequent command. The method further includes the step of controlling recording and/or reproducing-speed of information on the basis of the detected time interval between the received command and the subsequent command.

Abstract: A recording medium includes first information selected from a plurality of information patterns and second information selected from another plurality of information patterns for the true-false judgement. A true-false judging device performs a statistic analysis when any coincidence is found between the readout combination of the first and second information and registered combination patterns, to identify an inspected recording medium as a forged product based on the result of the statistic analysis.

Abstract: For an optical disk for which a record strategy is not prepared in a memory and an optical disk which cannot obtain a good signal quality by using the record strategy prepared in the memory, test recording is performed by using all record strategies prepared in the memory or properly adopted record strategies by changing the record power. A record strategy providing a relatively high signal quality is selected to record data in the optical disk. The record strategies for such optical disks can be easily set.

Abstract: In an optical disk, address information, including an address information start mark, is recorded in a header region primarily based on variable-length codes such that, between each pair of nearest bits having a first logic value, at least two and at most seven bits having a second logic value are disposed. The address information start mark is detected based on a first criterion that a combination of pulse widths each defined in association with a nearest pair of bits having the first logic value is present in a pulse sequence, and also based on a second criterion that, when the logic level of the pulse sequence alternates between a first logic level and a second logic level in association with occurrence of bits having the first logic value intermittently disposed among bits having the second logic value, the logic levels of pulses in the pulse sequence coincide with their respective counterparts in the combination of pulse widths.

Abstract: The present invention relates to method and apparatus of recording data onto a disk recording medium in zoned-CLV mode while adjusting recording speed and recording condition adequately at every speed change point between zones. The present invention detects a current recording position while recording data along a track of the disk recording medium, adjusts a recording speed and resets both a write strategy and a base B-level used for running OPC to be suitable for the adjusted recording speed. The present invention can record input data onto a writable disk with the most suitable writing condition at the highest allowable speed.

Abstract: An apparatus for searching for defective address of recording medium includes a recording unit, a converter, and a comparator. The recording unit is configured to record a defect list recorded in an recording medium using physical addresses. The defect list includes defective addresses indicating the addresses of defects present in the recording medium, and the defective addresses are described using physical addresses. The converter is configured to convert a request address received in an access command to the recording medium from a logical address to a physical address. The comparator is configured to compare the defective address in the defect list recorded in the recording unit with the request address that has been converted into the physical address. A defective address present immediately after the request address is searched for on the basis of the comparison result of the comparator.

Abstract: An optical disk apparatus that records data on an optical disk whose linear velocity is not constant. The optical disk apparatus includes an optical pickup that irradiates a laser beam of a recording power on the optical disk, converts light reflected from the optical disk into an electric signal; a detector that detects a level of the reflected light signal; and a controller that controls a recording power such that the reflected light signal level matches a target value set according to the linear velocity. When adjusting the recording power such that the reflected light level matches the target value, the target value is not set to a constant level, but set in accordance with the linear velocity. Target values at different linear velocities differ and, with this configuration, an appropriate target value is set and an appropriate recording power corresponding to the linear velocity is obtained.

Abstract: A calibration of input signal offsets for stray light in an optical disk drive is presented. The input signal offsets can be determined by setting a laser power level, receiving digitized input signals, and setting the input signal offsets so that the digitized input signals are zero. The laser power level can be a read power or a write power. In some embodiments, input signal offsets for both read power and write power are determined and stored.

Abstract: A method for recording data to optical media is provided. Embodiments include receiving a selection of data files to record from a source to a destination optical media, and generating an enumeration of the data files. The enumeration identifies each source file by a source file path node. A location on the destination optical media to record each source file is identified by destination file path node for each data file. Only one occurrence of any source file in the enumeration of data files will be recorded to the destination optical media, and a data tree of files on the destination optical media includes multiple pointers to the same data file.

Abstract: A method for using an optical disc apparatus to record data onto an optical disc in multiple write sessions. The optical disc apparatus includes a delay detection circuit for detecting gaps between data written to the optical disc in successive write sessions. The method includes writing a set of first data to the optical disc, searching for an ending location of the first data, writing a set of test data to the optical disc such that a beginning location of the test data is near the ending location of the first data, using the delay detection circuit to detect a gap between the first data and the test data, and writing a set of second data to the optical disc such that a beginning location of the second data is equal to the beginning location of the test data minus a value contained in the gap.

Abstract: An optimal power calibration (OPC) method calibrates writing power for an optical disc. The optical disc includes a power calibration area, with a plurality of counting units and test blocks. The OPC method includes generating a plurality of first power levels by using an indicated power, selecting a plurality of second power levels from the first power levels, recording test data onto test blocks with the second power levels, reading the test blocks, and generating data signals and first beta values. The method further includes generating estimated optimal power by a calculating algorithm, generating a plurality of third power levels by using the estimated optimal power, recording test data onto test blocks with the third power levels, reading the test blocks, and generating data signals and second beta values. Optimal power is calculated by using the estimated optimal power, the first beta values, and the second beta values.

Abstract: A method of overwriting data in a linking loss area. The method includes the operations of (a) determining whether or not the first sector of a block in which it is desired for data to be recorded is a linking loss area, and if it is determined that the first sector is a linking loss area, reading the previous block; (b) modifying data type identification information of the last sector of the previous block after completing reading the previous block; and (c) recording data in blocks starting from the previous block. According to this method, based on determination of whether or not the first sector of the block in which it is desirable to record data is a linking loss area, data is recorded in the blocks starting from the current block or from the previous block so as to prevent errors in reproducing. By doing so, the method improves error correction effects.

Abstract: A signal can be detected based on a level slice system and detection delay time can be reduced by setting the recording density of a header field in a linear direction lower (coarse) than that of a user data recording field. Further, a signal can be detected based on the level slice system and detection delay time can be reduced by using a mark position form having a large detection margin as an information recording system of the header field. A readout error of a sector number due to a detection error is compensated for by recording address marks AM for attaining byte synchronization of the header field in both of a head portion and tail portion of information recorded in the header field.

Abstract: In a system using a pickup including a bifocal lens which is one lens having two focal points, mere judgment by the number of peaks of a focus error signal does not achieve a clear judgment of the type of an optical disc, especially whether it is a CD or a DVD. Therefore, it is required to perform a judgment based on a difference in recording density of the optical disc. According to the present invention, when detecting a tracking error by the phase difference method, a pulse width limit circuit 35 in a tracking error detecting circuit 7 provides such limitations that a pulse of a width larger than a predetermined pulse width should not appear in a pulse train of a phase error signal. Disc type judgment is then performed for discs having different recording densities, for instance, whether it is a CD or a DVD, based on the phase error signal after the pulse width limitation or that before and after the pulse width limitation.

Abstract: An information editing apparatus for editing recording information already recorded on a write-once recording medium such as DVD-R is provided. In this apparatus, a remaining capacity in the DVD-R is detected. Then, it is determined whether the recording information can be edited or not on the basis of the detected remaining capacity and an amount of information to be recorded in the unrecorded area by editing the recording information. Further, a result of the determination is notified.

Abstract: A reproducing apparatus for reproducing a plurality of information data recorded on a recording medium in accordance with reproduction control data that indicates a reproduction procedure of the plurality of information data, wherein a reproduction order designated by the reproduction control data is changed in accordance with the recording positions of the plurality of information data on the recording medium, the plurality of information data are reproduced in accordance with the changed reproduction order to be written in a memory, the plurality of information data are read out from the memory in the order designated by the reproduction control data, and the content of the reproduction control data is changed in accordance with the changed reproduction order.

Abstract: A reproduction method for a multi-level optical recording medium according to the present invention rotates an optical recording medium, on which recording data has been recorded according to a multi-level recording method which sets several levels for light reflectivity of virtual recording cells, emits a reproduction laser beam towards the optical recording medium, and reproduces the recording data based on an electric signal generated in accordance with a received level of reflected light, the method setting the emission power of the reproduction laser beam in a range of 1.0 mW to 2.5 mW inclusive when the optical recording medium is rotated at a linear velocity in a range of 9 m/s to 25 m/s inclusive. By doing so, it is possible to improve the read accuracy for recording data while suppressing the reproduction deterioration of the optical recording medium to a level where deterioration effectively does not occur.

Abstract: The present invention provides an optical disk with pits and/or bumps which each contain a plurality of facets. Each facet of each pit and/or bump is intended for separate read back as an individual ‘side’ of the optical disk (much as vinyl records had two ‘sides’ for separate playback). The separate ‘sides’ of the optical disk formed by separate facets of each pit and/or bump can be read back either simultaneously or serially, either by a corresponding plurality of laser beams, or by a common laser beam which is positioned to a first orientation with respect to a rotating track to focus on a first set of facets of each pit and/or bump, and then repositioned to focus on a second set of facets of the same set of pits and/or bumps and thus to read a second ‘side’ of the optical disk.

Abstract: A direction sensor in a tracking and focus servo system of an optical disk drive is presented. The direction sensor calculates a direction sum signal and a tracking error signal from side elements of detectors in an optical pick-up unit of the optical disk drive. A first direction can be indicates when the signs of a high-pass filtered sum signal and a high pass filtered tracking error signal are opposite and a second direction opposite the first direction if the signs are the same.

Abstract: A digital servo system for controlling tracking or focus in an optical disk driver is presented. A servo system according to the present invention includes an optical pick-up with detectors providing optical signals, an analog processor receiving the optical signals and providing a digital signal, and digital processors receiving the digital signal and providing a control signal that controls the position of the optical pick-up unit. The digital processor executes an algorithm that calculates an error signal, provides amplification and biasing to the error signal, provides filtering for the error signal, and computes the control signal. The error signal can be the focus error signal or the tracking error signal.

Abstract: An apparatus and method for detecting a wobble signal read from an optical disc. The wobble signal detection apparatus comprises an analog/digital (A/D) converter for A/D-converting an analog wobble signal, read from the optical disc and then band pass filtered, a slope detector for detecting a slope of the A/D-converted wobble signal according to a variation thereof, and a wobble signal detector for detecting a peak point of the A/D-converted wobble signal using the detected wobble signal slope, and detecting/outputting a square-wave wobble signal with a high level or low level transition at the detected peak point. The slope detector calculates variations of data values of the A/D-converted wobble signal sampled within a predetermined period on the basis of predetermined different weights, accumulates the calculated values and detects the slope of the A/D-converted wobble signal on the basis of the accumulated value.

Abstract: A device for and method of reducing intersymbol interference (ISI) and/or crosstalk is disclosed. The ISI and crosstalk reducing device includes an optical detector which divides an optical signal reflected from an optical disk into central and peripheral parts in the tangential direction of the optical disk, and a correcting unit for controlling the gain value of a peripheral detection signal detected by the optical detector and adding the gain-controlled detection signal and a central detection signal to each other to provide an ISI corrected signal. Instead of using the existing waveform equalizer, the device uses a multiple-divided detection signal output from the optical detector to thereby obtain a jitter value of the same level as that obtained when the waveform equalizer is used. Further, in HD-DVD system requiring high density recording, it is possible to reduce crosstalk and ISI at the same time even when the high density recording causes crosstalk or interference between neighboring tracks.

Abstract: A digital signal modulation method selects a modulation strategy to modulate current M sets of data by determining variations in a digital sum value (DSV) corresponding to the modulated data modulated according to a first modulation strategy from M sets of data ahead of the current M sets of data.

Abstract: A data recording method for calculating a digital sum value (DSV) corresponding to a proportion of positive data and negative data included in predetermined data ranges, selecting a resync pattern to be inserted between the data ranges according to the DSV, and inserting the selected resync pattern between the data ranges, has a step of selecting a resync pattern that minimizes differences in DSV between the data ranges.

Abstract: A wobble signal generating apparatus of an optical-electronic system. A first operation unit for generating a reference signal in responsive to a first input signal and a second input signal that are derived from a plurality of light signals reflected from an optical storage medium is provided. The plurality of reflected light signals is used for generating the reference signal even when the optical-electronic system is recording data onto the optical storage medium. A processing unit processes the reference signal to generate the wobble signal.

Abstract: A continuity maintaining part restarts recording of data onto the optical disk after pause of recording occurring due to buffer under-run, in such a manner that continuity with information recorded immediately before the occurrence of the pause occurred is maintained. A counting part counts the number of times of operation of the continuity maintaining part during the recording of the information onto the optical disk. A display part displays the number of times of operation of the continuity maintaining part counted by the counting part.

Abstract: An information recording device is provided. The information recording device includes an end detecting unit, a timing management unit, an encoder, and the like. In a case in which the information recording device writes data having a fixed unit length on a recording medium by dispersing and rearranging the data based on a fixed rule, the end detecting unit detects an end location of data recorded on the recording medium. The timing management unit decides a starting location on the recording medium for dispersing and rearranging data based on the end location. The encoder disperses and rearranges additional data by starting from the starting location, and writes the additional data on the recording medium continuously from the end location.

Abstract: A playback apparatus includes a data source (1) that provides a data stream signal (d0), and a device (2) responsive to the data stream signal. The device forms a first data stream (d1) in a first data format (F1), wherein the first data stream (d1) includes a data field (D1) that is encoded in a second data format (F2). A code converter (3) is responsive to the first data stream (d1), and converts selected parts of the first data stream (d1) to a second data stream (d2) that has data encoded in a third data format (F3). An output decoder (5) forms playback signals from the second data stream (d2). The playback signal may be audio and/or video signals that are presented to the appropriate audio transducer or display device for presentation to a playback apparatus user(s).

Abstract: A lead-out area is recorded and a session is formed each time a file is recorded with the data structure of a disc recorded with the conventional CD-R multi-session method. The latest file structure recorded in the last session is read with a multi-session disc by reading in series the start address of the next session recorded in the lead-in area of each session. This information read in series is dependent upon the number of file write operations, and as the number of writes increases, the slower the latest file structure retrieval process becomes. In a write-once medium in which the file management information and unrecorded area information are update recorded at each recording session, chaining information is recorded at each file write. Furthermore, an area for recording a plurality of continuously recorded chaining information is reserved, and access in the latest chaining information retrieval process is accelerated.

Abstract: A copy-limit pre-recorded CD (Compact Disc) and a copy-limit method protect the data recorded on the pre-recorded CD from copied onto a recordable CD. The pre-recorded CD (Compact Disc) includes a data area of the pre-recorded CD and an indivisible file. The storage capacity of a data area of the recordable CD is Z. The indivisible file is stored in the data area of the pre-recorded CD and has a file size Y which approximately ranges between Z+10 MB and Z+100 MB. The copying action is prohibited to proceed when the indivisible file with a size is larger than the storage capacity of the data area of a recordable CD is determined.

Abstract: Compressed audio data for 5.1 channels stored in a DVD-ROM is read by an AC-3 decoder of a pseudo multi-channel stereo play-back apparatus and, after expansion, stored temporarily in a buffer, channel by channel. Among stored audio data stored in the buffer, audio data for left and right channels and for a front center channel are then subjected to the phase transformation. Audio data for left and right front channels are mixed with the phase transformed audio data by first and second mixing circuits and mixed audio data are converted into analog audio signals by first and second D/A converters. The apparatus is capable of pseudo reproduction of the multi-channel audio signals stored in a recording medium such as a DVD-ROM by two channel play-back.

Abstract: A drive controller is capable of reading information from an optically encoded disk. The drive controller is made to attempt a first read operation from a first area of the optically encoded disk to generate a first data set. If the first read operation is successful, the drive controller then verifies that the first data set conforms to a first data format. A media type descriptor is obtained from the first data set if the first data set conforms to the first data format. A media type descriptor is obtained from a second data set read from a second area of the optically encoded disk if the first data set does not conform to the first data format, or if the first read operation is not successful.

Abstract: In a digital modulation method, digital data is supplied to a conversion table, and the digital data is converted into serial data. The serial data is supplied to a first fixed contact of a selector and is switched to data for a sync pattern from a sync pattern table, the sync pattern being supplied to a second fixed contact. From the selector, 93-data serial data including the 2-data sync pattern at the head thereof is extracted. The serial data is supplied to an exclusive-OR circuit, and the exclusive-OR output is fed back through a delay circuit, thereby generating NRZI data to be recorded. A digital sum value (DSV) of the NRZI data varies in accordance with the selection of conversion tables. The DSV is arbitrarily controlled, and sub-information is inserted by performing the control in a predetermined format.

Abstract: In a disk device, when processing is resumed after replacing the disk or cutting off the power supply, in order to acquire disk-related information in a short period of time and reduce the start-up time, the effectiveness of management information recorded on the disk is judged, the finding of the judgment is stored into a memory means capable of storing even when power supply is off, the management information is read out of some of the recording areas of the disk in advance of a recording or reproducing operation if the stored information on the finding of the judgment indicates effectiveness for the inserted disk.

Abstract: The invention relates to methods and devices for forming marks and lands by applying a radiation beam (32) to a recording surface (301) of an optical record carrier (30). Recording strategies are proposed for recording information at high recording speeds. An intermediate power level (P1, P2) is introduced in between the bottom power level (P0) and the write power level (Pw), its value being dependent on the length of the preceding land (151, 152, 153). A raised write power level (PR1, PR2) is also proposed, its value being dependent on the length of the mark to be recorded (241, 242, 243).

Abstract: The irradiation time and/or the irradiation power of a laser beam is varied to perform multi-level recording on a recording layer in five stages or more. On the recording layer 12 of an optical recording medium 10, defined contiguously are virtual recording cells 40 within a groove 16 along tracks arranged at track pitches of 1 to 1.5 &mgr;m. The time and/or the irradiation irradiation power of the laser beam is modulated in five stages or more corresponding to the information to be recorded on each of the virtual recording cells 40 in order to form recording marks 48A-48G having five stages or more of different sizes and/or optical transmittance. The overall optical reflectivity of each of the virtual recording cells 40 is modulated in multi-stages to vary in five stages or more the entire reflectivity level of the reading laser beam used upon reading in the virtual recording cell including the outside of the recording mark.

Abstract: Provided is a disc drive device that optimally controls a speed for reading RTR-format data, such as video and audio, recorded on a DVD-format disc, thereby enabling real-time playback without interruption. In the disc drive device, information added to each sector is used for determining whether data is RTR-format data. When an error occurs at high-speed reading of RTR-format data and therefore the reading speed is changed to a low speed, the reading speed is so controlled as to be kept at the low speed for reading the following RTR-format data. Thus, for RTR-format data, overhead due to repetitive acceleration and deceleration processes can be avoided, and reading can be carried out without interfering with real-time playback. For normal data, reading can be carried out in a manner similar to that in background art.

Abstract: There are times when an abnormal light emission occurs and damage the medium when updating the setting register of the pulse width or the laser driving current during recording operation in an optical information recording and reproducing device. There are thus provided a plurality of pulse width setting registers for setting the pulse width of the multi-pulse emissions. When updating the pulse width of the multi-pulse, the pulse width setting register is changed and then the recording operation is performed, and at the time to change the pulse width setting register during recording, the generation of recording pulse train is stopped.

Abstract: An optical disc having marks for dispersed addresses that can be easily detected with high precision. A dispersed address comprises synchronization marks, positive marks, and negative marks. Synchronization marks, positive marks, and negative marks are formed along a groove as partial discontinuities or partial modifications in the wobbled groove.

Abstract: A method of optimal power calibration adapted to an optical storage medium such as a rewritable (CD-RW) disk is disclosed. The method takes the advantages of rewritable characteristic defined in the Orange Book to perform a plurality of optimal power calibration (OPC) processes on the power calibration area allocated in inner track and several recording positions on the rewritable disk. The OPC processes write erasable patterns such as the “Sub Q mode 0” pattern define in Orange Book on data written area(s) of the rewritable disk so that these erasable patterns will be overwritten by sequentially recording data. A relation curve, which indicates the relationships between optimal recording powers of a recording position and the distance from the center of the rewritable disk to the recording position, is then established by using the optimal recording powers measured from the aforementioned OPC processes.

Abstract: An optical pick-up head of the present invention includes a semiconductor substrate, a semiconductor laser mounted on the semiconductor substrate, a first photodetector for receiving a laser beam emitted from the semiconductor laser and reflected from an optical storage medium and outputting a current signal in accordance with the light amount of the received laser beam, and a current-voltage conversion circuit for converting the current signal to a voltage signal. The semiconductor laser is supplied with a high-frequency signal for preventing an output from fluctuating due to the laser beam reflected from the optical storage medium, and the photodetector and the current-voltage conversion circuit are formed on the semiconductor substrate.

Abstract: An optical disc recording method to record data on a disc using multiple speeds by dividing a disc region into an inner circumference region and an outer circumference region depending on radii of the disc, setting a multiple recording speed for each region; setting optical recording power in a lead-in region of the inner circumference region and a lead-out region of the outer circumference region, by performing optimum power controls therein; determining in which one of the divided regions data is to be recorded using an address detected from the disc, rotating the disc at the multiple recording speed set for the one region in which the data is to be recorded, and recording the data in the one region using the set optical recording power for the one region.