Abstract: A system, for tuning a plurality of write strategy parameters of an optical storage device, includes: a run-length limited (RLL) meter for detecting a plurality of lengths, each length corresponding to a pit or a land on an optical storage medium accessed by the optical storage device; and a calculation module coupled to the RLL meter for performing calculations according to the lengths to generate a plurality of calculation results; wherein the write strategy parameters are tuned according to the calculation results.

Abstract: A method of recording and reproducing information in a phase-change optical recording medium by irradiation of an electromagnetic wave for recording, reproducing and/or rewriting information is proposed, wherein when information is recorded in the phase-change optical recording medium by modulating an input signal and conducting pulse width modulation recording, a recording pulse string for recording and rewriting is a continuous electromagnetic wave, and a recording pulse string for recording and rewriting, after the modulation of the input signal, is an electromagnetic wave pulse string having a front-pulse portion fp, a multi-pulse portion mp with a total pulse duration period T and a duty ratio y, and an off-pulse portion op, wherein the duty ratio y is decreased as a recording linear velocity for the phase-change optical recording medium is increased, whereby multi-speed recording or CAV (constant angular velocity) recording is carried out.

Abstract: A method for recording information on a super-resolution optical recording medium is directed to a reproducing laser beam which moves during the reproduction of the super-resolution optical recording medium from a recording mark/space train smaller than the resolution limit to a recording mark, or mark/space train larger than or equal to the resolution limit. A pulse train employed by the method for forming a recording mark larger than or equal to the resolution limit immediately after a smaller space than the resolution limit of a reproduction optical system includes at least a first ON pulse T1 of recording power followed by a first OFF pulse and second ON pulses T21 and T22 in that order. The first OFF pulse includes an OFF pulse Pc of cooling power and an OFF pulse Pm of middle power in that order.

Abstract: The present invention provides a recording method for a phase-change optical recording medium. The recording method of the present invention contains the step of irradiating an electromagnetic wave having a multipulse pattern so as to perform recording on a phase-change optical recording medium containing a phase-change recording layer. This method is characterised in that a starting time of a front pulse of the multipulse pattern delays 0.5T to 1.25T from a starting point of the first reference clock relative to the recording mark, where T is a reference clock of the multipulse pattern.

Abstract: A digital signal recording disc has a first area storing an audio title set. The audio title set has data representing audio information and data representing a still picture. The audio title set is void of a pack of data for playback control. The first area also stores information for managing the audio title set. The digital signal recording disc is void of a second area storing a video title set and information for managing the video title set.

Abstract: A digital signal recording disc has a first area storing an audio title set. The audio title set has data representing audio information and data representing a still picture. The audio title set is void of a pack of data for playback control. The first area also stores information for managing the audio title set. The digital signal recording disc is void of a second area storing a video title set and information for managing the video title set.

Abstract: If data is recorded using a disc with deviating characteristics and a recorder with deviating characteristics, data will not be appropriately recorded, and errors will occur in the read signal. Standard recording pulse parameters specifying recording pulse positions for plural possible mark length and space length combinations are read from a writable optical disc, these standard recording pulse parameters are then used for test writing, the standard recording pulse parameters are changed uniformly or individually, a best recording pulse parameter is thus obtained, and jitter can be reduced.

Abstract: A laser driver drives a laser diode by producing a write strategy, that is, a recording waveform from a recording clock and a modulated signal. In one embodiment, a laser driver produces the waveform of a driving signal, which is used to drive a laser diode, using a record data signal that represents record data to be recorded on a recording medium. The laser driver comprises an internal clock production circuit that produces an internal clock synchronous with the record data signal, and a strobe circuit that strobes the record data signal according to the internal clock.

Abstract: The present invention relates generally to an optical disk device that records and reproduces information on and from an optical recording medium, such as a compact disk or a digital versatile disk. The optical disk device includes a measurement means and a calculation means.

Abstract: An optical disc recording method is provided for superimposing sub information by displacing edges of one or more optically-readable recording marks by a minute amount on the basis of a binary sequence code, when recording main information by forming said one or more recording marks, the optical disc recording method including a sequence generation step of generating a first binary sequence code and a second binary sequence code that is different from the first binary sequence code; a first displacement step of displacing one of the edges according to the first binary sequence code; and a second displacement step of displacing another of the edges according to the second binary sequence code.

Abstract: An adaptive writing method of a high-density optical recording apparatus and a circuit thereof. The circuit includes a discriminator for discriminating a magnitude of a present mark of input NRZI data and magnitudes of leading and/or trailing spaces of the input NRZI data, a generator for controlling the waveform of a write pulse in accordance with the magnitude of the present mark of the input NRZI data and the magnitudes of the leading and/or trailing spaces of the input NRZI data to generate an adaptive write pulse, and a driver for driving a light source by converting the adaptive write pulse into a current signal in accordance with driving power levels for respective channels of the adaptive write pulse. The widths of the first and/or last pulses of the write pulse waveform are varied in accordance with the magnitude of the present mark of input NRZI data and the magnitude of the leading and/or trailing spaces, thereby minimizing jitter to enhance system reliability and performance.

Abstract: A method is provided for recording data in a write-once type optical recording medium which can record data by forming a recording mark having a desired length and reduce jitter of a reproduced signal. The method comprises determining a pulse train pattern so that a level of a pulse is switched from the level corresponding to the level of the recording power Pw to the level corresponding to the level of the bottom power Pb in accordance with the length of a blank region to be formed immediately after formation of a first recording mark and the length of a second recording mark formed subsequent to the formation of the first recording mark.

Abstract: The present invention provides a device and method for an optical disc such as a DVD which can keep proper edge position of a recording pulse to record data of high quality without depending on a fluctuation in a supply voltage and a fluctuation in a temperature. The optical disc device according to the present invention comprises a laser driver for driving a laser to record data on an optical disc, a recording pulse generator for generating a recording pulse signal by using a predetermined delay circuit, to control the switching of the laser power of the laser driver, a delay amount measuring section for measuring the delay amount of a delay circuit in the recording pulse generator, and a recording pulse position correction section for correcting the predetermined edge position of the recording pulse based on the result of the measurement.

Abstract: In the disclosed pulse shape modulation method, an amplitude modulation gain for a reproduced signal from an information recording medium that makes the jitter of the reproduced signal become the minimum is specified. Then, it is determined whether the amplitude modulation gain corresponding to the minimum jitter resides within a prescribed range. If the amplitude modulation gain corresponding to the minimum jitter is outside the prescribed range, the pulse shape of the pulsed laser beam is modulated.

Abstract: An adaptive writing method of a high-density optical recording apparatus and a circuit thereof. The circuit includes a discriminator for discriminating a magnitude of a present mark of input NRZI data and magnitudes of leading and/or trailing spaces of the input NRZI data, a generator for controlling the waveform of a write pulse in accordance with the magnitude of the present mark of the input NRZI data and the magnitudes of the leading and/or trailing spaces of the input NRZI data to generate an adaptive write pulse, and a driver for driving a light source by converting the adaptive write pulse into a current signal in accordance with driving power levels for respective channels of the adaptive write pulse. The widths of the first and/or last pulses of the write pulse waveform are varied in accordance with the magnitude of the present mark of input NRZI data and the magnitude of the leading and/or trailing spaces, thereby minimizing jitter to enhance system reliability and performance.

Abstract: A write pulse generating apparatus includes a control unit which provides information on an optical recording medium type and information on a recording speed factor, and a control signal generating unit which determines a multi-pulse type which is to be generated in a multi-pulse interval based on the information recording medium type and recording speed factor. The generating unit generates a signal for controlling the light emitting device driving unit to generate a write pulse having the determined multi-pulse type. A control unit sets the level of the write pulse for up to an entire interval of a write mark and/or a write space according to the optical recording medium type and the recording speed factor.

Abstract: The present invention provides a device and method for an optical disc such as a DVD which can keep proper edge position of a recording pulse to record data of high quality without depending on a fluctuation in a supply voltage and a fluctuation in a temperature. The optical disc device according to the present invention comprises a laser driver for driving a laser to record data on an optical disc, a recording pulse generator for generating a recording pulse signal by using a predetermined delay circuit, to control the switching of the laser power of the laser driver, a delay amount measuring section for measuring the delay amount of a delay circuit in the recording pulse generator, and a recording pulse position correction section for correcting the predetermined edge position of the recording pulse based on the result of the measurement.

Abstract: The present invention provides a device and method for an optical disc such as a DVD which can keep proper edge position of a recording pulse to record data of high quality without depending on a fluctuation in a supply voltage and a fluctuation in a temperature. The optical disc device according to the present invention comprises a laser driver for driving a laser to record data on an optical disc, a recording pulse generator for generating a recording pulse signal by using a predetermined delay circuit, to control the switching of the laser power of the laser driver, a delay amount measuring section for measuring the delay amount of a delay circuit in the recording pulse generator, and a recording pulse position correction section for correcting the predetermined edge position of the recording pulse based on the result of the measurement.

Abstract: The present invention provides a device and method for an optical disc such as a DVD which can keep proper edge position of a recording pulse to record data of high quality without depending on a fluctuation in a supply voltage and a fluctuation in a temperature. The optical disc device according to the present invention comprises a laser driver for driving a laser to record data on an optical disc, a recording pulse generator for generating a recording pulse signal by using a predetermined delay circuit, to control the switching of the laser power of the laser driver, a delay amount measuring section for measuring the delay amount of a delay circuit in the recording pulse generator, and a recording pulse position correction section for correcting the predetermined edge position of the recording pulse based on the result of the measurement.

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 ½ of 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: An information recording technique for forming a recording mark with a multi-pulse sequence, which is increased by one pulse with an irradiation power Pw for every increase of 2T in a temporal length nT of the recording mark is provided. Particularly, this technique realizes a recording strategy that is simple in its configuration but is capable of improving the consistency of mark shapes in forming the recording marks when the value n of the temporal length nT is an odd number. More specifically, when n is an odd number and n?7, a period from the fall of a first pulse to the fall of a second pulse is set to 2.5T and a period corresponding to a last pulse is set to (2+?1o) T where the value of ?1o is optimized within a range of 0<?1o?1.

Abstract: A recording/producing device for writing data on a recording medium, or reading data from the recording medium, wherein data matching a recording pattern so specified as to include a plurality of mutually different sets of mark lengths and space lengths is written on the recording medium, and the data is then read to generate data signals. An edge shift detector uses data signals to measure the edge shift amount of a mark formed on a recording medium for each set of a mark length and a space length. A record controller sets a recording parameter for each set of a mark length and a space length based on the measured edge shift amount.

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: The present invention provides a binarization device that realizes reproduction with a low error rate, even where optimum recording conditions such as recording power have not been set in the recording device, or where optimum recording has not been carried out for the reproducing device. The binarization device includes a binarization unit, a slice level setting unit, and a weight adding function. The binarization unit binarizes a reproduction signal obtained by reproducing information recorded by mark length recording on a recording medium to output high-level signals and low-level signals based on a slice level. The slice level setting unit calculates the average value of the high-level signals output from the binarization unit, and determines the slice level from the average value. The determined slice level is set to the binarization unit. Either the binarization unit or the slice level setting unit adds a predetermined weight to each signal having a short high-level time among the high-level signals.

Abstract: An optical carrier is written with a mark representing recorded data, by a sequence of radiation pulses. Additional power levels are introduced in between the cooling power level and the erase power level during the cooling period. This results in a reduced jitter of the written marks.

Abstract: An optical record carrier recording method forms pits and lands by directing a radiation beam (12) onto a recording surface (21) of an optical record carrier (20). The radiation beam for each pit to be recorded is set to at least one write power level (Pw) capable of forming a pit during a write power irradiation period (31) and, for each land between the pits, to at least one bottom power level (P0) incapable of forming a pit during a bottom power irradiation period (51).

Abstract: A laser diode (LD) driver and method of compensating for a bias driving potential of an LD driver according to a change in a power level of a laser signal from an LD in a recording mode include storing the bias driving potential, detecting a change in a bias power level in the laser signal, and compensating the bias driving potential according to the detected change in the bias power level.

Abstract: A record carrier has substantially parallel tracks having first variations of a first physical parameter and second variations of a second physical parameter of the track. The first variations represent information recorded on the record carrier, this information being recoverable by a controllable type of data processing. A modulation pattern of the second variations represents a code for controlling the type of data processing. In respect of a code track that includes the modulation pattern, the modulation pattern in the left neighboring track is aligned to the modulation pattern in the right neighboring track. Thereby crosstalk due to the second variations is decreased, and at least two tracks have the same modulation pattern. The playback device has a demodulator (50) and a control unit (56) for retrieving the code from at least two tracks.

Abstract: An optical recording method for recording mark length-modulated information on a recording medium by using a plurality of recording mark lengths. The optical recording method comprises the steps of: when a time length of one recording mark is denoted nT (T is a reference clock period equal to or less than 25 ns, and n is a natural number equal to or more than 2), (i) dividing the time length of the recording mark nT into ?1T, ?1T, ?1T, ?2T, ?2T, . . .

Abstract: Recording information is disclosed in which an information recording medium is irradiated with a recording energy beam that is power-modulated into at least a record power level and a record-ready power level lower than the record power level. The information is recorded on the recording medium in the form of length and interval of a mark portion. When forming a mark portion of a predetermined length, the radiation energy of the energy beam is increased as compared with when forming a mark portion of a different length before or after the first pulse of an energy beam pulse train including at least a pulse for forming the mark portion.

Abstract: A plurality type of adjustment data groups are stored in a memory for each of a plurality of adjustment items for adjusting a record signal waveform. The adjustment data group for each adjustment item is selected in accordance with identification information preset in accordance with a disk type and a record velocity magnification factor. The selected adjustment data groups are combined to form a record strategy. The record signal waveform is adjusted in accordance with the formed record strategy to record the record signal in an optical disk. It is possible to reduce the amount of adjustment data for the record signal waveform to be stored in the memory.

Abstract: A multi-value data recording and reproducing device is provided that can accurately eliminate interference among codes through waveform equalization when reproducing information from a reproduction signal having levels multi-valued through modulation of the areas of recording marks on an optical information recording medium. This multi-value data recording and reproducing device is embodied by a multi-value data detecting circuit that varies the sizes of the recording marks in accordance with multi-value data (0, 1, 2, . . . , (m?1): m being an integer of 3 or greater) on the optical information recording medium, and detects the multi-value data through predetermined signal processing on signals obtained by scanning the recording marks with an optical spot.

Abstract: Disclosed are an information recording method and an optical disk unit that maintain a good jitter even when a line velocity is variable in a mark edge system. In the case where an erasing power when erasing a record mark at a linear velocity v1 is Pe1(mW), a recording power when forming the record mark at the linear velocity v1 is Pw1(mW), an erasing power when erasing the record mark at a linear velocity v2 faster than v1 is Pe2(mW), and a power when forming the record mark at the linear velocity v2 is Pw2(mW), a relationship of Pw1/Pe1>Pw2/Pe2 is satisfied.

Abstract: A method for recording information is disclosed in which an information recording medium is irradiated with a recording energy beam power-modulated into at least a record power level and a record-ready power level lower than the record power level. When forming a mark portion of a predetermined length, the radiation energy of the energy beam is increased as compared with when forming a mark portion of a different length before or after the first pulse of an energy beam pulse train including at least a pulse for forming the mark portion. Also, only in the case where the energy beam is modulated by the power lower in power level than the record-ready power level after the last pulse of the energy beam pulse train including at least one pulse for forming a mark portion and the mark portion is followed by a space portion of a predetermined length, the particular radiation energy of low power level is reduced as compared with when the mark portion is followed by a space potion of a different length.

Abstract: A method of recording information in which each recording mark is formed in a recording medium, by irradiating a pulse chain of an energy beam including a first pulse, a middle pulse chain, a last pulse and a negative pulse following the last pulse. The adjusting average power of the first middle, last and negative pulses to designated power levels of the first, middle, last and negative pulses recorded in a control data zone.

Abstract: A method, for tuning a plurality of write strategy parameters of an optical storage device, includes: detecting a plurality of lengths, each length corresponding to a pit or a land on an optical storage medium accessed by the optical storage device; performing calculations according to the lengths and a plurality of data set types to generate a plurality of calculation results respectively corresponding to the data set types, each of the data set types corresponding to a combination of at least a specific target pit length and a specific target land length or a combination of at least a specific target land length and a specific target pit length, the combination corresponding to a specific write strategy parameter; and utilizing the calculation results for tuning the write strategy parameters corresponding to the data set types, respectively.

Abstract: A method for recording data in an optical recording medium according to present invention is constituted so that data are recorded in an optical recording medium including a light transmission layer and two recording layers by projecting a laser beam whose power is pulse-like modulated between a recording power and a bottom power lower than the recording power onto the optical recording medium from a side of the light transmission layer and forming recording marks having different lengths in the recording layers and that when a recording mark having a longer length than that of the shortest recording mark is to be formed in the recording layers by modulating the power of a laser beam using a single pulse, a time of raising the power of the laser beam to the recording power is delayed relative to a time of raising the power of the laser beam to the recording power when the shortest recording mark is to be formed.

Abstract: A disc apparatus is designed for recording a signal on an optical disc by irradiating an optical beam according to a strategy which is stepwise updated by a given step amount. In the disc apparatus, a detector successively detects a linear velocity of the optical disc relative to the optical beam in realtime basis. A strategy generator operates every time the detector detects the linear velocity of the optical disc for successively generating the strategy according to the detected linear velocity. A storage has a plurality of storage areas, each being capable of memorizing the strategy successively generated by the strategy generator. A write controller rewrites one of the storage areas every time the strategy is generated until the strategy is updated by a given step amount and then rewrites another of the storage areas every time the strategy is generated while leaving said one storage area to hold the updated strategy, thereby updating the strategy through the plurality of the storage areas.

Abstract: An opical disc recording method, comprises the steps of: a) forming a record signal in accordance with input information; b) generating a recording laser beam modulated with the record signal; c) controlling a laser radiation time at a record power for a 16× or higher write-speed to be (n+K)T for a pit length nT, where n=three to eleven, K is a constant (0?K?1.6), and T is a unit time corresponding to a pit length or a land length at a write-speed; and d) radiating the recording laser beam alternately at the recording power for the controlled radiating time to form pits and at a non-recording power to form lands toward a record surface of a recordable optical disc.

Abstract: Software is securely distributed with limited usage rights. The software may be an executable program and/or one or more data files such as image or multimedia data files. The software includes an access control object which prevents at least some usage of the software without use of a first access control code. The first access control code is produced based on selected information characteristic of the user's computer system. The access control code is produced in a server computer to which the user directs a request for the access control code. The user makes a payment to receive the access control code, which is then downloaded to the user's computer system.

Abstract: Methods and systems for write compensation for optimizing the performance of a data storage or communication channel are disclosed. In one embodiment, a method comprises determining channel sensitivity to modifications in write signal parameters, detecting systematic errors in a read signal recovered from data written with a first set of write parameters, and adjusting the write signal parameters by an amount determined from the channel sensitivity such that the systematic errors are reduced when data are written with the adjusted write parameters.

Abstract: An ATIP (absolute time in pre-groove) bit data generator free from an uneven duty cycle. The ATIP bit data generator includes an analog processor, a high-frequency clock generator, a first decoder, a sync pattern detector, and a second decoder. The analog processor receives a signal generated from an optical pickup, and further processes the signal to generate an ATIP FM signal. The high-frequency clock generator provides a high-frequency clock using the ATIP FM signal as a reference signal. The first decoder receives the ATIP FM signal and the high-frequency clock and generates bi-phase data. The sync pattern detector receives the bi-phase data and the high-frequency clock, and generates a sync indication signal. The second decoder counts the pulse number of the high-frequency clock for each counting cycle, and the counting cycle includes a plurality of half periods of the ATIP FM signal.

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 bit-accurate optical drive determines an address of a data block stored on a disc (the address being determined from a wobble that is embossed in the disc), and synthesizes header information for the block. When the block is read from the disc, recovered (actual) header information is compared to the synthesized header information to determine a phase difference, if any. Recovered user data is phase-shifted by the phase difference.

Abstract: A record carrier has a servo track (4) indicating an information track (9) intended for recording information blocks. The servo track (4) has a periodic variation of a physical parameter at a predetermined frequency and modulated parts for encoding position information at regular intervals. The modulated parts start with a bit sync element and are of a data type having a data bit element, or of a word sync type having a word sync element. The word sync element and the data bit element are modulated according to a same predetermined type of modulation of the periodic variation. The effective strength of a modulated element is the number of periodic variations that are substantially different and available for detection of that element. The effective strength of the word sync element and of the data bit element are equal.

Abstract: A method of compensating for tilt and/or defocus and an apparatus therefor. The apparatus has a tilt and/or defocus detector detecting the tilt and/or defocus of an optical recording medium, and a recording compensator compensating a write pulse having a predetermined recording pattern using a predetermined system with respect to the detected tilt and/or defocus. The apparatus both adjusts write power with respect to the detected defocus, shifts the recording pattern with respect to the detected tilt, adjusts a power level and/or write time required for recording, and records a recording mark having a desired size (length and width). The apparatus is useful in compensating for tilt and/or defocus in a high-density optical system.

Abstract: A system and method are disclosed for compensating during a data writing process for a transformation of input data by an optical disc data storage channel. A write strategy matrix is derived that maps a plurality of input sequences to a plurality of write strategy parameters. The input sequences each include a plurality of input data elements. When an input sequence is received, the write strategy matrix is used to determine in selected write strategy parameter that corresponds to the input sequence.

Abstract: In an optical disk recording device for projecting a recording light beam onto an optical disk to form 3T-11T pits in a land of the optical disk, timing to sample and hold a reflected light detection signal for tracking servo control is delayed behind timing to sample and hold the reflected light detection signal for wobble signal detection. Further, a sample-and-hold time period of the reflected light detection signal for tracking servo control is set to be shorter than a sample-and-hold time period of the reflected light detection signal for wobble signal detection. Such arrangements permit appropriate recording, even at high recording speeds, irrespective of residual optical axis deviations.

Abstract: A recording medium which has a zone or zones storing lookup tables comprising an edge shift value of leading and trailing recording pulses.

Abstract: A shortest mark 108 is recorded with a single recording pulse. A long mark 125 is recorded with a two-stage pulse including a first-part pulse and a second-part pulse. In the case where each of positions 115 and 118 of front edges of the recording pulses is determined based on a relationship between a length of a space immediately before a mark and that of the mark itself so as to properly position the front edges of reproduced waveforms of all the mark lengths and each of positions of rear edges of the recording pulses of all the mark lengths is fixed so as to satisfy a prescribed relative relationship with an edge of a recording clock, power 122 of a recording pulse 101 of the shortest mark is determined so as to realize a proper rear edge position 112 of the reproduced waveform of the shortest mark and power 124 of a second-part pulse 104 is determined for each mark length so as to realize a proper rear edge position 123 of the reproduced waveform of the long mark.