Abstract: Disclosed herein are a disc recording medium, a recording apparatus and a playback apparatus, more concretely, the present invention provides a disc recording medium wherein a circular track is created in advance to be used for recording data as a groove or a land, said track is wobbled to contain approximately fixed number of wobbling periods as counted in a longitudinal direction of said track, and said track includes rotational-angle marks each showing a predetermined rotational angular position on said disc recording medium. As a result, the precision and the reliability of recording can be attained.

Abstract: An optical disc system for recoding data onto an optical disc while the optical disc is rotating at a constant angular velocity. The optical disc system includes a PLL for extracting a carrier frequency of a wobble signal outputted from an optical pick-up, a channel synthesizer electrically connected to the PLL for generating a channel clock according to the carrier frequency and a rotating factor of a spindle motor, a data encoder for encoding inputted data according to the channel clock, and a driving circuit for controlling the optical pick-up to record data onto the optical disc according to the encoded data.

Abstract: A recording/reproducing apparatus for a domain-wall-displacement magneto-optical recording medium with good format efficiency, capable of providing a good reproduction signal and securing a maximum recording region for a user is provided which comprises a recording circuit that starts recording of an information in a data region at a predetermined timing with a detection signal obtained in the preformat region being used as a reference, and a reproducing circuit that starts reproducing of the information recorded in the data region at a timing earlier than the predetermined timing with the detection signal being used-as a reference.

Abstract: A reproduction method for reproducing BCA data for optical discs using the defect signal. The reproduction method for reproducing BCA data includes the steps of: generating a defect signal as a BCA signal by detecting an RF signal of the BCA; generating a BCA data bit stream by sampling the BCA signal according to a sampling clock; and decoding the BCA data bit stream to generate BCA data. Because the defect signal is utilized as the BCA signal of the invention, no additional BCA signal extracting device is needed.

Abstract: A data reading apparatus, capable of reducing the recording field of a header portion, generates a read clock signal based on the average rotational speed and recording density of a disk. Delay circuits generate first and second delay clock signals of different phases. Three ID reading apparatuses operate in accordance with the read clock signal and the first and second delay clock signals to read address information at different timings. A selector circuit selects the best read address and error detection result from the read addresses and error detection results for the read addresses.

Abstract: A system and method are disclosed for reading a multilevel signal from an optical disc. The method includes reading a raw analog data signal from a disc using an optical detector and adjusting the amplitude of the raw analog data signal. A timing signal is recovered from the amplitude adjusted analog data signal and correction is made for amplitude modulation of the raw analog data signal by processing the raw analog data signal and the timing signal.

Abstract: An optical recording medium for accurately deriving the address information or the disc rotation control information despite narrow track pitch and for recording signals to a high density, and a method and apparatus for recording and/or reproducing such optical recording medium. The optical recording medium has a wobbled groove and pits formed at a pre-set interval in an area between turns of the wobbled groove. The recording/reproducing method includes controlling rotation of the optical recording medium by a wobbled signal from the groove and detecting the position on the optical recording medium of a recording signal by pit signals detected from the pits. The recording/reproducing apparatus includes a detection device for detecting the wobbled signal from the groove and a detection device for detecting pit signals from the pits.

Abstract: An optical disc recording and reproducing apparatus for recording and reproducing data in and from an optical disc by the use of the optical disc as a recording medium, comprises analog processing means including a binarization unit for subjecting a signal read from the optical disc to binarization and a servo unit for controlling recording and reproducing a signal in and from the optical disc; synchronous clock generating means for generating a synchronous clock signal which is synchronized with the signal read from the optical disc; address detecting means for detecting address information indicating a physical position on the optical disc based on the signal read from the optical disc, and outputting a signal indicating the address information and a signal indicating that the address has been detected when the address information has been detected; a sector counter for holding a sector count value of a sector as a recording unit on the optical disc, and updating the sector count value according to the sync

Abstract: An optical reproducing method using an optical medium having an aligned prepit portion straddled on a plurality of tracks in a radius direction. The prepit portion includes a first and second prepit portion divided in a track direction with a gap therebetween and with a synchronous information prepit of the respective first and second prepit portion being arranged on a boundary of the respective tracks. The synchronous information prepit and the first and second prepit portion is arranged at every two-track pitch in the radius direction and at opposite boundaries of the same track. An optical spot is irradiated on the optical medium, a reflected beam is detected from the optical medium, and information on the optical medium is reproduced by using a signal obtained by the reflected beam.

Abstract: An optical reproducing method using an optical medium having a disk-like substrate with plural levels associated with grooves, and a plurality of zones. Each track is divided into a plurality of recording and radially adjacent recording units of a respective zone are delimited by a pair of radial lines joined to form a central angle at an apex proximate to a center of the disk-like substrate. The grooves are wobbled in the radial direction of the disk-like substrate with a length of each recording unit being an integer multiple of a cycle of the wobble, and the integer multiple being the same for the different zones. An optical spot is irradiated on the optical medium, a reflected beam from the optical medium is detected, and information on the optical medium is reproduced by using a signal obtained by the reflected beam.

Abstract: An optical information reproducing method for reproducing information recorded at at least one mark on an optical information medium. The method includes irradiating a laser to the optical information medium, detecting a reflected beam reflected from the optical information medium, and reproducing information recorded on the optical information medium from an output signal of a detector which detects the reflected beam. The step of reproducing information is changed in dependence upon a length of the mark of the optical information medium.

Abstract: An information recording medium for recording main information and auxiliary information is provided. The auxiliary information is recorded on the information recording medium in a manner that edge positions of the pits or the recording marks indicating the main information are shifted either in a phase advancing direction or in a phase delaying direction along the track direction. A predetermined frequency is used to determine whether the edge position is shifted in the phase advancing direction or in the phase delaying direction in order to record the auxiliary information. The predetermined frequency is substantially consistently lower than ½of a reference frequency of a recording clock for creating the pits or the recording marks and is higher than a response frequency of a PLL for generating a reproduction clock for reproducing the main information.

Abstract: A radio frequency ripple zero crossing signal calibration method for an optical disk reader undergoing a track following to track seeking transition is disclosed. The method utilizes sampling to obtain radio frequency ripple peak level during a track seeking operation and radio frequency ripple DC level during a track following operation and using their differences as a calibrated value. Through the calibrated value, the radio frequency ripple zero crossing slice level is modified so that a correct radio frequency ripple zero crossing signal is obtained during a track following to track seeking transition. In a track following to seeking transition, this arrangement prevents distortion of the radio frequency ripple signal and corresponding drift in the radio frequency zero crossing signal that may lead to errors in computing moving speed and counting tracks of the pickup head. Hence, search capacity of the optical disk reader is improved and the pickup head is better controlled.

Abstract: A data recording speed control apparatus and method for recording a data on an optical recording medium are disclosed.

Abstract: The present invention relates to a recording and/or reproduction apparatus and a program suitable for use to record or reproduce data onto or from an optical disk having two recording layers on one side thereof.

Abstract: An information storage medium according to an embodiment of this invention includes a wobbled groove having a wobble period modulated by multi-frequency shift keying corresponding to playback control information.

Abstract: A tracking error signal generating apparatus having an inexpensive and simple configuration for a disc-shaped information recording medium driven in conformity with a given system, such as the CAV system, CLV system or ZCLV system, is provided.

Abstract: A data reproduction system, which determines reproduced data based on comparison results of path metrics calculated in accordance with a Viterbi algorithm based on branch metrics calculated from expected values and a sampled value of a readout signal, includes an expected value setting unit for variably setting the expected values used for a calculation of the branch metrics in order to perform a Viterbi detection process without being easily affected by the transient response, offset variation, phase error and nonlinear torsion component of the readout signal. The readout signal is obtained from a recording medium on which data is recorded in accordance with a recording signal of a partial response waveform, the expected values are determined by the partial response waveform, and the sampled value is obtained by sampling the readout signal at a predetermined frequency.

Abstract: A data recording and reproducing method for an optical disk data storage system to record data compressed at different data compression rate according to an operator's specification, and to reproduce the recorded data by decompressing. According to the operator's indication, the data is recorded at certain data compression rate in indicated area. The information of the data compression rate and the recorded area is stored as a table of contents (TOC) data. The TOC data is reproduced and stored in a memory after the optical disk is loaded. The recorded data is reproduced by selecting a decoding circuit to decompress the data. The decoding circuit is selected by referring the TOC data to identify data compression rate of the recorded data. Also the TOC data is referred to identify read-in and read-out region of the recorded data. The position of a pick-up when the data recording is started and ended, is recorded as the TOC data to provide random access capability for the data reproduction.

Abstract: A digitizer for use in a measurement system. The digitizer acquires data from an external source, and includes a static random access memory (SRAM) which stores a scan list comprising entries specifying digitizer operations such as switch time, settle time, measure time, looping, and mathematical operation specifications such as scaling, adding, and averaging specifications. The looping specification may include instructions to repeatedly execute one or more entries in the scan list. The digitizer includes a programmable logic element (e.g. an FPGA) coupled to the SRAM which accesses and executes the scan list to acquire analog signals from the source. The digitizer may include an analog-to-digital converter to convert the analog signals to digital signals, as well as a multiplexer to read the analog signals from multiple channels, a signal conditioner to modify the analog signals from the multiplexer, and an amplifier to amplify the analog signals from the signal conditioner.

Abstract: A slicing apparatus for slicing a pre-pit signal is disclosed. The slicing apparatus utilizes a reference signal with a dynamical voltage to slice a pre-pit signal. The slicing apparatus includes a peak detector, a low-pass filter, a calculating unit, and a comparator. The peak detector detects the peak value of the pre-pit signal to generate a peak signal. The low-pass filter filters out the high-frequency components of the pre-pit signal to generate a DC signal. The calculating unit sums up the peak signal and the DC signal, and then divides the sum value by a predetermined value, so as to generate the reference signal. The comparator compares the pre-pit signal with the reference signal to generate an output signal. Accordingly, even though the amplitude of the pre-pit signal is not always the same, the voltage of the reference signal may also be dynamically adjusted to make the comparator generate a correct output signal.

Abstract: An optical disk device which performs data recording and reproduction with regard to an optical disk on which pre-pit information for specifying an address is formed. An optical disk is irradiated with a laser beam and return light from the optical disk is detected by two photodetectors which are disposed in the radial direction. After the levels of two signals from the photodetectors are limited, a difference between these signals is calculated. Due to the limitation of the levels, noise during the recording power period is removed so that pre-pit information during the reproducing power period, namely during the space period, is extracted. Further, by calculating a difference between the two signals from the photodetectors, pre-pit information during the recording power period is extracted.

Abstract: An optical disk apparatus for driving an optical disk on which a groove wobble corresponding to a signal acquired from frequency modulation of biphase modulated address information, and a mark for representing phase information placed inside the wobble are preformatted, and having the biphase bit count “a” (“a” is a natural number) between two of the adjacent marks, and the channel bit count “n” (“n” is a natural number) between two of the adjacent marks. The apparatus includes first clock signal production means for generating a first clock signal utilizing an “n” frequency multiple of the reproduction signal of the clock mark, wobble signal reproduction means for reproducing from the optical disk a wobble signal corresponding to the groove wobble, and frequency demodulation means for acquiring the address information by frequency demodulation of the wobble signal.

Abstract: A storage medium is provided having a relatively large number of relatively small servo sectors. The storage medium includes a plurality of tracks. Each track includes a plurality of data sectors and a plurality of servo sectors. Each servo sector includes a plurality of servo marks and a synchronization gap. A plurality of first servo sectors includes a synchronization gap having a first length and a plurality of second servo sectors includes a synchronization gap having a second length. The first length is different from the second length, whereby, an unsynchronized reading device may recognize the longer synchronization gap and synchronize to the servo sector and a synchronized reading device may remain synchronized by recognizing the shorter synchronization gap.

Abstract: A method for extracting binary data conveyed by an incident signal is provided in which the binary data is coded in the form of a pulsatile signal whose pulses have variable lengths which are multiples of a base pulse length 1T. The incident signal may include a succession of transitions whose spacings are representative of the lengths of the pulses. The method may include an initialization phase in which the value of a base distance corresponding to the base pulse length is determined from the contents of the incident signal, and an extraction phase in which a set of reference values corresponding respectively to various multiples of the determined base distance is formulated. For a calculated current distance, the values of the data corresponding to this current distance may be determined from a comparison between the reference values and a current corrected distance.

Abstract: Method of recording control signals on a removable optically readable disc like recording device comprising recording control data representing the physical structure of an optically readable disc. The control data set either being a standardized set of control data corresponding to the record carrier or either being a non-standardized set of control data deviating form the standardized set of control data signals. Preferably the non-standardized set of control data relates to different values for the number of information layers present on the record carrier or the type of record carrier being of the read-only type, recordable or rewritable type. Preferably a user may select the non-standardized set of control data by selecting a corresponding type of playback and/or recording apparatus.

Abstract: An optical disc system includes a photo detector circuit of an optical disc drive and a signal processing system. The photo detector circuit is configured to generate at least one information-carrying signal from an optical disc assembly. The signal processing system is coupled to the photo detector circuit to obtain from the at least one information-carrying signal both operational information used to operate the optical disc system and data indicative of presence and/or characteristics of an investigational feature associated with the optical disc assembly. Methods and discs for imaging a biological or medical investigational feature are also provided.

Abstract: This optical receiving device for discriminating and recovering a data signal, which results from converting an optical signal input through a dispersion equalizer into an electrical signal and amplifying it to a pre-determined amplitude, by using a clock and data recovery circuit for discriminating a data signal at the decision point controlled to achieve the optimum position controls the dispersion characteristics of a dispersion equalizer so that the error count in the recovered data signal by using a clock and data recovery circuit will be minimized by controlling the eye pattern of the data signal which has been amplified to a pre-determined amplitude.

Abstract: Disclosed is a disk-like recording medium, a disk recording apparatus and a disk recording method, and a disk playback apparatus and a disk playback method. Disk ID is recorded over a circle of a burst cutting area on an optical disk. The circle is divided into n blocks, each of the blocks is divided into m frames, and ID information is recorded in each of the frames with k channel bits.

Abstract: An optical disc recording and reproducing apparatus for recording and reproducing data in and from an optical disc by the use of the optical disc as a recording medium, comprises analog processing means including a binarization unit for subjecting a signal read from the optical disc to binarization and a servo unit for controlling recording and reproducing a signal in and from the optical disc; synchronous clock generating means for generating a synchronous clock signal which is synchronized with the signal read from the optical disc; address detecting means for detecting address information indicating a physical position on the optical disc based on the signal read from the optical disc, and outputting a signal indicating the address information and a signal indicating that the address has been detected when the address information has been detected; a sector counter for holding a sector count value of a sector as a recording unit on the optical disc, and updating the sector count value according to the sync

Abstract: A PLL (phase-locked loop) circuit is configured with a phase-error detection circuit comprises the following: a provisional judge circuit for provisionally judging a data signal being input to an A/D converter into three levels of 1, 0, and −1; a pattern detector which, among data signals being input in accordance with a result of the provisional judgment, checks a transition pattern ranging from a data signal that precedes one clock cycle to the actually present data signal, and then, when a specific pattern is detected, instructs a selector to select output data from the A/D converter; and the selector which, in compliance with instruction from the pattern detector, selects phase-error data from data signals output from the A/D converter, and then converts the selected phase-error data into an electric current before externally delivering it as an error-current.

Abstract: A laser waveform generation function is provided in a laser driving waveform generator 2 near a laser 3. A recording clock generator 9 is included in the laser driving waveform generator 2 to generate a clock with a frequency higher than that of a synchronizing clock 202. This allows a recording laser current (waveform) to be generated without transmission of a high frequency signal from the modulator 6. Further, because the synchronizing clock 202 is stopped upon a reproduction operation including reproduction operation in an ID unit, undesired effects on a reproduction operation such as ID reproduction can be reduced. Because the response speed of the recording clock generator 9 can be changed, a high precision clock can be generated. Thus, a high-precision recording laser current (waveform) can be generated.

Abstract: In a data reproducing apparatus, a monitor edge sample value is generated based on a second sample value at a trailing edge of the reproduction signal and a change amount of the monitor edge sample value is generated as an offset amount in a first processing part. Then, the offset amount is supplied to a second processing part where the second sample value is obtained by sampling the reproduction signal at the trailing edge. Then, the second processing part restores data based on the reproduction signal and the offset amount.

Abstract: An optical information recording medium according to the present invention includes at least one groove track and at least one land track allowing information to be recorded on or reproduced from the groove track and the land track, the groove track and the land track adjoining each other. The optical information recording medium further includes: an identification signal region including a pre-pit array, the pre-pit array indicating identification information concerning the groove track and the land track; and a servo control region disposed ahead of the identification signal region along the groove track and the land track, the servo control region including wobble pits positioned so as to shift to opposite sides of a center line of either the groove track or the land track.

Abstract: A circuit in an optical read/write device for protecting synchronizing patterns is proposed. The protection circuit utilizes a clock with constant frequency as a reference clock. The circuit for protecting synchronizing patterns of this present invention includes a SYNC detector, a frame period counter, a valid-frame-period judgment unit, a frame period memory, a window generator, a real SYNC judgment unit, a SYNC lock judgment unit, and a SYNC signal generator. The circuit counts the pulse number of a reference clock with constant frequency for each frame to get a constant frame period. Then, the circuit can correctly interpolate the lost frame SYNC signal immediately by counting the reference clock, when the disk is defected.

Abstract: To provide an asymmetry correcting circuit capable of canceling an asymmetry simultaneously with quantization in an ADC and utilizing the dynamic range of the ADC effectively, and also to provide an information reproducing apparatus using such a correcting circuit.

Abstract: A data restoring apparatus of an optical disk reproducing system restores data recorded on an optical disk from an RF signal read from the optical disk.

Abstract: The invention relates to a device for CD reproduction with variable speed or direction, in particular devices compatible with a CD player, such as, for example, DVD players which are likewise suitable for the playback of CDs, or corresponding CD-ROM drives. The invention is based on the fact that the data or information read from the CD are read into a buffer memory at a rate which, as a rule, is higher than is required for real-time reproduction. Data read into the buffer memory (RAM) in a continuous sequence are then used for CD reproduction with variable speed by means of subsampling or oversampling. For the purpose of reverse reproduction, groups of subcode words are successively read from the buffer memory by changing the order within the groups and are reproduced as a continuous reproduction data stream.

Abstract: An waveform equalizer equalizes the signal reproduced from an optical disc to remove reproduction waveform distortion with a frequency characteristic controlled. A binary coder and a PLL circuit generate a bit clock. An a/d converter a/d-converts the equalized signal in response to the bit clock. A Viterbi decoder including metric operation decodes the output of the a/d converter in response to the bit clock to output a bit stream. The metric operation generates a metric operation result from an output of the a/d-converter and prediction data. The Viterbi decoder Viterbi-decodes the output of the a/d converter through the metric operation according to prediction data. An operating circuit operates an equalizing error from the output of a/d converter and a waveform equalizing target. A coefficient generator controls the frequency characteristic according to the equalizing error to minimize the equalizing error.

Abstract: In a digital recorded data reproduction which applies PRML signal processing, it is an object to enhance a reproduction signal quality and a playability for an abnormal signal by an offset correction and a phase,-interpolation-type digital phase-locked loop.

Abstract: A disk player for recording or reproducing recording information to a recording disk by emitting a light beam onto the recording disk. The recording disk has a recording track for recording the recording information, a guide track for guiding the light beam to the recording track, and a prepit which is pre-formed on the guiding track and which serves as control information for controlling a recording operation or a reproduction operation of the disk player.

Abstract: Apparatus for reproducing information from a record carrier include a read head for reading marks representing the information, from a track on the disc shaped record carrier so as to provide an analog read signal. An A/D converter converts the analog read signal to a digital read signal with a specific clock frequency, in response to a control signal. A bit recovery unit retrieves a sequence of bits from the digital read signal, with a specific bit frequency. A generator unit derives the control signal, and includes a generator for deriving the specific bit frequency, and a velocity deriving unit for deriving from the digital read signal, the control signal which indicates the relative velocity of the read head with respect to the marks, so as to generate the specific clock frequency such that approximately N samples per bit are supplied by the A/D converter, irrespective of the relative velocity of the read head with respect to the marks.

Abstract: An optical information reproducing method for reproducing information recorded at at least one mark on an optical information medium. The method includes irradiating a laser to the optical information medium, detecting a reflected beam reflected from the optical information medium, and reproducing information recorded on the optical information medium from an output signal of a detector which detects the reflected beam. The step of reproducing information is changed in dependence upon a length of the mark of the optical information medium.

Abstract: A DVD-Audio which includes a data zone for storing data to be reproduced and an information zone for storing information on the data to be reproduced. The information zone includes directories of a video title set (VIDEO_TS) and an audio title set (AUDIO_TS). The AUDIO_TS directory includes information on an audio manager (AMG) having information on audio titles. The data zone includes the audio titles each having an audio title set information (ATSI) followed by a plurality of contiguous audio objects (AOBs). The ATSI includes a plurality of audio stream attributes each having an audio coding mode, first to third quantization bit numbers, first to third sampling frequencies and decoding algorithm information relating to the number of audio channels. Each of the AOBs includes a plurality of audio packs recorded with audio data corresponding to the decoding algorithm stored in the audio stream attribute.

Abstract: An optical disc drive for reading encoded information, such as on a CD, CD-R, or DVD, is modified to read biological or chemical investigational features from a disc. The modifications can include software changes or the addition of hardware desirably without the need to modify the disc drive electronics.

Abstract: An interface circuit that is suitable for use in a recording system and a system for manufacturing optical disks, which is provided with this interface circuit, have an analog-side interface circuit 100A and a digital-side interface circuit 100B, these interface circuits being optically linked, either acoustically, or electromagnetically, so as to enable mutual transmitting and receiving of a digital signal therebetween. The interface circuits 100A and 100B, which serve as a receiving side with respect to the other sides, detect the logic of the digital signal with a timing that does not include the jitter component that is included in the transmitted digital signal, the detected digital signal logic being used as the basis for generating a new digital signal.

Abstract: This invention resolves the limitations of the binary data encoding and storage system by encoding multi-valued meaning to data elements prior to the recording and storing of these multi-valued data elements based on a plurality of quantities in a memory point. In order to make a single memory point suitable to record multi-valued data elements, where each value has a special meaning in a particular recording, quantities of magnetism or light, like its intensity, shape, etc., are digitized or analogized so that each of the quantities can be recorded and extracted. The invention additionally includes systems and methods for using multi-valued data elements, including wireless transmission.

Abstract: An information reproducing apparatus in which the compressed information read from a disc is written to the memory, the written compressed information is read out in the order of writing and is supplied to an expansion device to obtain reproduced information. Writing of the compressed information to the memory is stopped when the amount of compressed information written to the memory increases to a first predetermined amount and writing of the compressed information to the memory is restarted when the amount of compressed information written decreases to a second predetermined amount which is smaller than the first predetermined amount and which is an amount corresponding to the compression ratio of the compressed information. The rotation speed of a spindle motor during a writing interruption period is lower than that during a writing period.

Abstract: An optical disc drive usable with discs to which data is continuously recorded and discs having a sector format can quickly resume playback signal output after passing imperfection causing potential reading errors, and plays disc with few read errors. A detection signal generator detects DC level fluctuation in the playback signal read from the disc and generates a detection signal tracking the DC level fluctuation. A selector selects a detection signal or a null signal without valid polarity based on the detection signal generated by the detection signal generator and input to the selector. A clamping unit performs a clamping process to suppress DC level fluctuation in the playback signal based on the detection signal when the selection unit selects the detection signal, and does not perform the clamping process when the selection unit selects the null signal. A signal processor performs specific signal processes based on clamping unit output.

Abstract: A composite signal in which pre-pit signal components are piggypacked onto frequency components of wobbling, is extracted from an optical recording medium. The composite signal is binarized, so that pre-pit signals are generated. The pre-pit signals pass through a first gate when the gate is open. The gate is periodically opened only in a period during which the amplitude of the wobbling becomes a maximum one. The number of the pre-pit signals passing through the gate is counted, so that a binarizing level for generating the pre-pit signal is set based on the relationship between the counted number per a reference time and a predetermined reference number.