Abstract: An information recording method and device for recording information by irradiating an optical information recording medium with an energy beam includes forming a first recording mark by irradiation of a monopulse-shaped energy beam having at least a first power level and a second power level that is higher than the first power level, and forming a space succeeding the first recording mark with a write strategy having a downward pulse of a third power level that is lower than the first power level on a backside of a midpoint of the space.

Abstract: The present invention provides an optical information recording apparatus and method capable of effectively determining appropriate recording parameters in a short time with favorable efficiency, when recording information onto an optical disk having different information recording conditions and information recording characteristics. An information recording condition or an information recording characteristic of an optical disk 1 is identified, and a recording pulse position is corrected at a correction accuracy according to the identifies information recording condition or information recording characteristic, such that a recording mark is formed in a predetermined position.

Abstract: A method and apparatus for writing data to an optical storage medium are disclosed. A write signal indicating power levels of a laser diode is generated by encoding and decoding codewords. The codewords are generated and decoded according to a Successive State Change Criterion (SSCC) or SSCC II proposed by the present invention. By doing so, toggling (i.e. state changing) times occurring in channels transferring the codewords can be significantly reduced to avoid the problems of pulse distortion and disappearance in high frequency transmission. Alternatively, toggles appearing in the respective channels can be spread to avoid interference between the channels. Further, a phase adjustment device for adjusting a phase of each codeword is disclosed.

Abstract: To provide a recording and reproducing method for dye-based recordable DVD media, including: recording a mark of the shortest length on a dye-containing recording layer of a dye-based recordable DVD medium using single pulse whose front edge is energized; recording marks other than the shortest thereon using single pulse whose front and rear edges are energized for a given duration, the power of the front edge of pulse being equal to that of the front edge of pulse for the shortest mark, the power of the rear edge of pulse being equal to that of the rear edge of pulse for the shortest mark; and reproducing recorded information using a reproduction beam, wherein the irradiation intensity of cooling pulse provided after the rear edge of pulse upon mark recording is 0.1 mW or less for a given duration, and the recording linear velocity is 42 m/s or more.

Abstract: In a method for adjusting a write strategy, data is written into the optical disc according to a first write strategy in forms of a first type of data storage structures with variable lengths and a second type of data storage structures with variable lengths. A plurality of the first type of data storage structures corresponding to a specified reference length are located, and the recording lengths thereof are operated with the specified reference length to obtain a first averaged deviation. A plurality of the second type of data storage structures formed next to the first type of data storage structures are located, and the recording lengths thereof are operated with respective reference lengths to obtain a second averaged deviation. A parameter of the first write strategy is adjusted so as to generate a second write strategy for subsequently writing data into the optical disc.

Abstract: A test-write method for accurately and quickly determining recording conditions, and an apparatus suitable therefor. In a 2T-based strategy, recording pulse conditions are determined by separately test-writing an even-number length mark and an odd-number length mark, and then the relative positions of the even-number length mark and the odd-number length mark at the recording pulse start time are adjusted.

Abstract: A method of recording data on a double-layer optical recording medium having a recording layer with high light transmittance is provided. A laser beam is modulated to emit a pulse series of laser including a write pulse of a write power and a cooling pulse of a bottom power, so as to encode and write data to be recorded as recording marks of a length nT along a track of the recording layer, where n is an integer and T is one clock cycle. An nT recording mark is formed using (n?1) write pulse(s), and when forming a recording mark of 4 T or longer, a cooling pulse with a pulse width of 0.8 T to 2 T is inserted before the last write pulse. Recording marks are thereby accurately formed without heat interference between consecutive recording marks and cross erase between recording marks of adjacent tracks.

Abstract: A recording condition on a media is optimized by introducing a new evaluation index. An apparatus for optical information recording and reproducing includes: a measurement means for recording codes including a specific code in a medium for optical information recording and reproducing, reproducing the codes from the medium for optical information recording and reproducing, and measuring, from a reproduced signal of the codes, a peak value of amplitude of a reproduced signal related to the specific code, the peak value being a maximum value or a minimum value of the amplitude of the reproduced signal related to the specific code; a statistic calculation means for calculating preset statistic by using a plurality of peak values at the same or different recording places, the plurality of peak value having been obtained by the measurement means; and a condition decision means for deciding at least one of a recording laser power condition and a recording pulse condition by using the statistic.

Abstract: It is an object of certain inventive aspects to provide a recording condition closer to an optimum even for a medium unknown to a drive, and more particularly, to provide means for obtaining a preferable recording condition even for a high-speed recording in which conducting a test recording is difficult. In order to accomplish the object, a power and a phase of a recording pulse are simultaneously corrected at predetermined timing, depending on a recording speed or a recording position such as an inner or outer circumference. For instance, a phase shift ?Phase generated due to a continuing recording from an inner circumference to an outer circumference at ×2 speed is corrected simultaneously with a correction of a power shift at the timing when a recording speed is changed from ×2 to ×4. For the other recording speed, in the same manner as above, a power and a phase shift are simultaneously corrected at every time when a recording speed is changed.

Abstract: A method for recording information on an optical recording medium in which a laser beam modulated into one or a plurality of write pulses with one or a plurality of write powers in accordance with target data to be written is projected onto a recording layer of the optical recording medium to form a record mark. During recording the information on the optical recording medium, a data level and a weight index are assigned to each channel bit in reference data trains before and after the target data. Recording compensation of the target data is carried out in accordance with the sum totals of the products of the data level and the weight index in the reference data trains, so that it is possible to easily carry out high a real recording by writing fine mark/space trains.

Abstract: To provide a method of recording information to an optical recording medium comprising recording a mark of time length nT (n: natural number of 3 or more, T: clock cycle) in an optical recording medium capable of supporting different recording speeds and having constant information line density, and irradiating the optical recording medium, the optical recording medium irradiated with light of alternating m1 heating pulses of power Pw and m1 cooling pulses of power Pc (where m1 is a natural number smaller than n) provided v<v0 (where v is a scanning speed and v0 is a scanning speed unique to each optical recording medium), the optical recording medium irradiated with light of alternating m2 heating pulses of power Pw and m2 cooling pulses of power Pc (where m2 is a natural number smaller than n) provided v?v0, wherein the condition n/m1?n/m2 is satisfied.

Abstract: An optical recording and reproducing apparatus includes a recording-pulse-shift setting unit that shifts a front edge and a rear edge of a recording pulse and sets a write strategy of the recording pulse, an mark-edge-position evaluating unit that detects a front edge and a rear edge of a mark formed and detects a front mark edge position error and a rear mark edge position error, an assuming unit that assumes that the front mark edge position error is represented by a first linear function and assumes that the rear mark edge position error is represented by a second linear function, a sensitivity calculating unit that executes test recording and calculates sensitivities, and a write-strategy calculating unit that calculates a write strategy of the recording pulse on the basis of the sensitivities.

Abstract: An optical recording system and method. A radiation source provides a radiation beam writing marks separated by spaces on a rewritable optical disc. A pulse generator generates a recording pulse signal based on a preset data signal to drive the radiation source, wherein the recording pulse signal comprises a cooling pulse, and wherein the preset data signal corresponds to a mark and space of equal length and is recorded onto the rewritable optical disc in terms of a written mark and space. A pulse controller determines a final width for the cooling pulse according to a difference between lengths of the written mark and the written space.

Abstract: A method and apparatus to record data on an optical recording medium include generating a recording waveform having an erase pattern comprising a multi-pulse having a high level which is higher than an erase power level and a low level which is lower than the erase power level. A power level of a leading one of the multi-pulse of the erase pattern and a power level between an end of the erase pattern and a start point of a leading pulse of a recording pattern are controlled to be the low level and the high level, respectively, the high level and the high level, respectively, the high level and the low level, respectively, or the low level and the low level, respectively.

Abstract: It is an object of the present invention to improve a margin to meet good recording quality by conducting a realtime correction of a recording condition of a medium with different recording characteristics for inner and outer circumferences. To accomplish the object, control factors for power and a pulse width are independently detected and corrected using an mT pulse having a length of m?T as a pulse for power control and an nT pulse having a length of n?T as a pulse for pulse width control; more specifically, power correction for mT pulse and pulse width correction for nT pulse are conducted in realtime, wherein a recording pulse stream including the mT pulse and nT pulse is irradiated onto a medium by a recording laser beam as well as pits and spaces formed by irradiation of the recording pulse stream are reproduced by a reproducing laser beam to detect the effects of power and pulse width variations independently.

Abstract: An information recording method of recording information with a high degree of accuracy on a semitransparent recording layer, which is subjected to severe thermal interference, of a multilayered recording medium. A downward pulse is applied to the back half portion of a prescribed space in the waveform of an energy beam used for irradiation when the space is formed. Thereby good recording performance is obtained.

Abstract: The present invention enables a recording condition closer to an optimum to be obtained even for media unknown to a drive. The present invention provides a method that is especially effective for the case where it is applied to a code identification scheme, such as PRML in which code identification is performed on the basis of information on the amplitude of an RF signal. A condition for a recording pulse comprised of a top pulse, an intermediate pulse and a last pulse is configured in a predetermined order, that is, a reference condition is first determined by a test recording involving an examination of recording quality and changes in conditions for a power and a pulse width, then a condition for the last pulse is determined by a test recording using the reference condition, and subsequently a condition for the intermediate pulse is determined using the reference condition and the last pulse.

Abstract: A recording apparatus generates a first pulse (EQEFM signal) in accordance with recording data such as an EFM signal. A second pulse (first overdrive pulse) to be combined with substantially the leading edge of the first pulse is generated. A third pulse (end overdrive pulse) to be combined with substantially the trailing edge of the first pulse is generated. The first, second, and third pulses are combined to synthesize a driving pulse, and the driving pulse is supplied to a laser unit. At least one of the first, second, and third pulses is controlled so that one of the level and the pulse duration thereof is varied in accordance with the length of formed pits and lands.

Abstract: A read out means reads out, from a multisession type optical disk which has been loaded, identification information which indicates its type, and a recommended write strategy pulse width. A calculation means, when a decision means has decided that the multisession type optical disk is of an unknown type, calculates a compensated pulse width based upon the value of the difference between the average value of the intrinsic write strategy pulse widths which are stored by a strategy storage means in correspondence with the identification information, and the recommended write strategy pulse width which has been read out by the read out means. And a recording means performs recording of data with laser light which has been modulated to the compensated pulse width as calculated by the calculation means.

Abstract: A rewritable optical recording medium includes a substrate and a phase-change type recording layer. A portion in a crystalline state corresponds to an unrecorded or erased state, and a portion in an amorphous state correspond to a recorded state, to record EFM modulated information by forming amorphous marks by irradiating the recording layer with a recording laser beam, and the recording is carried out by irradiating a recording laser beam having a wavelength of about 780 nm through an optical system having a numerical aperture NA of 0.5 or 0.55, at 24-times velocity or 32-times velocity of the reference velocity.

Abstract: A method of generating a recording pulse train in accordance with a NRZI signal for recording information to a recording medium by irradiating a pulse chain including a first pulse, a middle pulse chain, a last pulse and a negative pulse following the last pulse, including adjusting an average power of the first pulse to a designated peak power level, adjusting an average power of the middle pulse chain to a designated peak power level, adjusting an average power of the last pulse to a designated power level, adjusting an average power of the negative pulse to a designated power level that is lower than the peak power level, and controlling a leading edge of the first pulse of the recording pulse train to start with a variable lapse of time from a leading edge of the NRZI signal, with a duration of the first pulse being fixed.

Abstract: The present invention provides a recording pulse generating apparatus capable of forming a recording pit having a proper shape even at the time of ultra-high-speed recording of, for example, 8×recording or higher. A recording controller 10 for generating recording pulse signals having lengths corresponding to ten kinds of lengths of pits formed at the time of recording information has a recording controller 10 for generating the recording pulse signals so that the amplitude of a recording pulse signal corresponding to a pit having a length of 4T changes from a first amplitude to a second amplitude, and generating the recording pulse signals so that the amplitude of a recording pulse signal corresponding to a pit having a length of 5T or longer changes from a third amplitude to a fourth amplitude and further changes to a fifth amplitude.

Abstract: An information-recording method includes the steps of moving a light beam at a selected linear velocity relative to the information-recording medium; controlling the light beam to generate a multi-pulse having at least three power levels of a first power level Ph, a second power level P1 which is lower than the first power level, and a third power level Pm which is intermediate therebetween, the multi-pulse being repeatedly modulated between the first power level Ph and the third power level Pm; adjusting the third power level Pm in response to the selected linear velocity; and recording the information by irradiating the information-recording medium with the controlled light beam. Recording compatibility can be secured for information-recording apparatuses different in recording linear velocity and laser source characteristic.

Abstract: When a space region shorter than the radius of a beam spot is formed, pre-heating with an assist pulse is not performed, and an off pulse pattern is fixed at a base power level. When a space region longer than the radius of the beam spot and shorter than the diameter of the beam spot is formed, an assist pulse is applied to the end of the space region to be formed. The length of the assist pulse is made greater, the longer the space region to be formed. Further, when a space region longer than the diameter of the beam spot is formed, an assist pulse is applied to the end of the space region to be formed, and the length of the assist pulse is kept constant regardless of the length of the space region to be formed.

Abstract: The present invention provides a recording pulse generating apparatus capable of forming a recording pit having a proper shape even at the time of ultra-high-speed recording of, for example, 8× recording or higher. A recording controller 10 for generating recording pulse signals having lengths corresponding to ten kinds of lengths of pits formed at the time of recording information has a recording controller 10 for generating the recording pulse signals so that the amplitude of a recording pulse signal corresponding to a pit having a length of 4T changes from a first amplitude to a second amplitude, and generating the recording pulse signals so that the amplitude of a recording pulse signal corresponding to a pit having a length of 5T or longer changes from a third amplitude to a fourth amplitude and further changes to a fifth amplitude.

Abstract: An optical disc device includes means for recording and reproducing information using a reference write strategy or an alternative write strategy in which pulse widths of 3T, 4T and 5-14T marks are individually varied, when the information is recorded using 1T strategy. The device also includes means for measuring a length of each of the marks, and memory for storing the measured length of each of the marks and a theoretical length of each of the marks. The device further includes means for computing inherent contractile rates of the marks; and means for computing a variation rate of the inherent contractile rate of each of the marks when pulse widths of 3T, 4T and 5-14T marks are individually varied and obtaining a variance of each of the marks. The optical disc device sets the write strategy such that the variance is minimized.

Abstract: A recording/reproduction method is provided, which comprises the steps of generating a binary signal by converting a reproduction signal to a binary form, generating a synchronization signal using the binary signal, the synchronization signal being in synchronization with a clock signal, measuring a time interval between the binary signal and the synchronization signal and measuring an edge shift amount between the time interval and a clock time interval specified by the clock signal, and changing a parameter of a recording pulse based on the edge shift amount.

Abstract: It is an object of the present invention to provide a method for recording data in an optical recording medium which can record data in a write-once type optical recording medium at a high linear recording velocity using a laser beam having a low recording power.

Abstract: The recording method for an optical recording medium with a laminated structure with a ROM layer, from which data having been recorded beforehand can be read out, and a RAM layer, from which data is read out and in which data is recordable, includes: emitting laser light that has two or more pulses per record unit of a RAM record mark, which is recorded as data on the RAM layer, thereby recording the RAM record mark.

Abstract: The optical data recording method comprising the steps of: modulating data to be recorded, to generate a plurality of recording modulation codes; and emitting a pulse-like light beam to an optical disc, so that a plurality of recording marks and spaces which have lengths corresponding to the plurality of recording modulation codes are formed on the optical disc. In the optical data recording method, at least two of the plurality of recording marks comprises: a first pulse which is disposed at a front and forms a leading edge of the recording mark, a last pulse which is disposed at a backend and forms a trailing edge of the recording mark, and a multi-pulse train which is disposed between the first pulse and the last pulse and forms a center of the recording mark. The multi-pulse train has a pulse period longer than T which represents a reference period of the recording modulation code.

Abstract: A light source driving unit includes a modulating signal generating section generating modulating signals based on driving waveform generating information of a light source, a current source selecting section selecting one or more currents output from current sources based on the modulating signals, a light source driving section generating a current having multi-levels based on the one or more currents selected and supplying the generated current to the light source to drive the light source so that light in multi-levels is generated from the light source, and a cancelling section adding a signal error amount which cancels differences in amounts of signal delays generated between the modulating signal generating section and the light source driving section at a stage prior to the current source selecting section.

Abstract: A first trial write process obtains an optimum recording power of a test pattern even with respect to data having different rules for the recording waveforms corresponding n type data length sets, and a second trial write process using this optimum recording power obtains optimum pulse width or optimum pulse edge position separately for each data length set. Based on the optimum recording power and optimum recording waveform obtained by these trial write processes, recording operation is performed so as to form all the data lengths with satisfactory accuracy, thereby making it possible to obtain a proper reproduced signal.

Abstract: A method of and apparatus for recording data on an optical recording medium form a mark or a space by using a recording waveform having an erase pattern containing a multi-pulse. The method and the apparatus prevent distortion of the mark or the space and improve a mark shape such that a recording/reproducing characteristic of the optical recording medium is improved.

Abstract: A recording pulse for driving a laser is formed so that a length of a recorded mark on a recording medium corresponds to a recording code length of data; the recording pulse is formed as a recording pulse train having pulse heights corresponding to a plurality of power levels including a recording power and an erasure power; the recording pulse train is composed of a plurality of pulses including a multi-pulse and a trailing pulse; and the recording medium at a plurality kinds of linear velocities is irradiated with laser light based on the recording pulse to form the mark. When linear velocities v1 and v2 are in a relationship that v1<v2, the following formulas are satisfied: (TL1/Tw1)<(TL2/Tw2), and ((TM2/Tw2)/(TM1/Tw1))<((TL2/Tw2)/(TL1/Tw1)), where Tw1, Tw2: channel dock periods at the linear velocities v1, v2, TL1, TL2: trailing pulse widths at the linear velocities v1, v2, TM1, TM2: multi-pulse widths at the linear velocities v1, v2.

Abstract: According to the invention, a record mark is formed by: using one ON-pulse pattern and one ON-pulse pattern following it when the record mark to be formed is shorter than a specified length X (nT<X); and using two ON-pulse patterns and two ON-pulse patterns respectively following them when the record mark to be formed is longer than the specified length X (nT>X). This makes is possible to secure a heat amount per unit time sufficiently in forming a short record mark even when a targeted recording linear velocity is high. Also, an unwanted heat pocket becomes hard to arise in the record layer even when a sufficient heat amount per unit time is secured in forming a long record mark. Therefore, it becomes possible to form a record mark having a good shape even when data is recorded at a high linear velocity.

Abstract: An optical disk recording method includes the steps of: providing a multi-pulse chain from a recording wave; independently changing the pulse rise timing and pulse fall timing (pulse width) of the first pulse in the multi-pulse chain in accordance with a preceding space length and a recording mark length; changing the pulse rise timing and pulse fall timing (pulse width) in accordance with a following space length and the recording mark length in a predetermined timing or in independence; and in relation to the smallest mark recorded by irradiation with mono pulse, changing the rise timing in accordance with the preceding space length and the recording mark length and the fall timing (pulse width) in accordance with the following space length and recording mark length, compensating various optical disks different in recording material without change of the fundamental waveform.

Abstract: A method is provided for producing a data storage medium by recording disc information on the data storage medium.

Abstract: An optical disc device measures lengths of each mark and each land recorded using a reference write strategy and an alternative write strategy in which at least one parameter is varied in two or more combinations of marks and lands. A deviation value of each of the marks and lands is computed by shifting the write strategy on the basis of the lengths. Inherent contractile rates of all marks and lands are computed from the computed deviation value and the probability of occurrence of each of the marks and lands. A variance of the deviations by the combination of each of the marks and lands is computed from the computed deviation value. The write strategy is set using the computed inherent contractile rates such that the computed variance is minimized.

Abstract: An optical disk recording method includes the steps of: providing a multi-pulse chain from a recording wave; independently changing the pulse rise timing and pulse fall timing (pulse width) of the first pulse in the multi-pulse chain in accordance with a preceding space length and a recording mark length; changing the pulse rise timing and pulse fall timing (pulse width) in accordance with a following space length and the recording mark length in a predetermined timing or in independence; and in relation to the smallest mark recorded by irradiation with mono pulse, changing the rise timing in accordance with the preceding space length and the recording mark length and the fall timing (pulse width) in accordance with the following space length and recording mark length, compensating various optical disks different in recording material without change of the fundamental waveform.

Abstract: A data storage medium is provided on which data is to be recorded by modulating the data to generate a plurality of recording modulation codes and irradiating a pulse-like light beam to the data storage medium, so that a plurality of recording marks and spaces which have lengths corresponding to the plurality of recording modulation codes are formed on the data storage medium. The data storage medium comprises a disc information area that includes a region on which at least one of an irradiation information of the light beam to form the recording marks and a constitution information of the recording mark is to be recorded. At least two of the plurality of recording marks are formed by the light beam emitted according to a recording pulse train.

Abstract: A method is provided for producing a data storage medium by recording disc information on the data storage medium.

Abstract: A data storage medium is provided on which data is to be recorded by modulating the data to generate a plurality of recording modulation codes and irradiating a pulse-like light beam to the data storage medium, so that a plurality of recording marks and spaces which have lengths corresponding to the plurality of recording modulation codes are formed on the data storage medium. At least two of the plurality of recording marks are formed by the light beam emitted according to a recording pulse train. The recording pulse train comprising a first pulse which is disposed at a front and forms a leading edge of the recording mark, a last pulse which is disposed at a backend and forms a trailing edge of the recording mark, and a multi-pulse train which is disposed between the first pulse and the last pulse and forms a center of the recording mark. The multi-pulse train has a pulse period longer than T which represents a reference period of the recording modulation code.

Abstract: An optical (disc) driving system including the DLL based multiphase clock generator circuit capable of generating 32 different phases from input clock having a frequency of 800 MHz or greater. The multiphase clock generator includes on a delay locked loop (DLL) having a frequency divider for outputting an N-divided clock to a first set of M voltage-controlled delay cells within a feedback loop, and further including an identical set of M voltage-controlled delay cells outside of the feedback loop for delaying the undivided clock and for outputting M multiphase clocks. An optical driver circuit of an optical driving system and a method for implementing a write-strategy for preventing “overlapping” of marks written on adjacent grooves on an optical disc. The circuit and method produce multiple write-strategy waveforms (channels) switching at a high resolution (e.g., T/32) in the Gigahertz frequency range.

Abstract: The present invention relates to an optical disk device for recording or reproducing information on or from an optical information recording medium by forming marks and spaces. The device includes a jitter value measurement unit, a measurement unit, measured value memory, theoretical length memory, a deviation value calculation unit, a flexibility amount calculation unit, a correction value calculation unit, and a jitter value calculation unit. The measurement unit measures the lengths of marks and spaces using a varied reference write strategy. The deviation value calculation unit calculates the deviation values of the marks and the spaces. The flexibility amount calculation unit calculates the amounts of intrinsic flexibility of all marks and spaces. The correction value calculation unit calculates a correction value for the reference write strategy. The jitter value calculation unit calculates a jitter value.

Abstract: The optical data recording method comprising the steps of: modulating data to be recorded, to generate a plurality of recording modulation codes; and emitting a pulse-like light beam to an optical disc, so that a plurality of recording marks and spaces which have lengths corresponding to the plurality of recording modulation codes are formed on the optical disc. In the optical data recording method, at least two of the plurality of recording marks comprises: a first pulse which is disposed at a front and forms a leading edge of the recording mark, a last pulse which is disposed at a backend and forms a trailing edge of the recording mark, and a multi-pulse train which is disposed between the first pulse and the last pulse and forms a center of the recording mark. The multi-pulse train has a pulse period longer than T which represents a reference period of the recording modulation code.

Abstract: An optical disk recording method includes the steps of: providing a multi-pulse chain from a recording wave; independently changing the pulse rise timing and pulse fall timing (pulse width) of the first pulse in the multi-pulse chain in accordance with a preceding space length and a recording mark length; changing the pulse rise timing and pulse fall timing (pulse width) in accordance with a following space length and the recording mark length in a predetermined timing or in independence; and in relation to the smallest mark recorded by irradiation with mono pulse, changing the rise timing in accordance with the preceding space length and the recording mark length and the fall timing (pulse width) in accordance with the following space length and recording mark length, compensating various optical disks different in recording material without change of the fundamental waveform.

Abstract: In an optical recording method used when information is recorded in a phase-change recording layer of a large-capacity rewritable optical recording medium such as a DVD-RW, one block pulse is used as a recording pulse for forming one recording mark when a recording velocity is higher than a recording linear velocity at which the rewritable optical recording medium can be rewritten, whereas a pulse train comprised of a plurality of short pulses is used as the recording pulse for forming one recording pulse when the recording velocity is within recording linear velocities at which the rewritable optical recording medium can be rewritten, whereby high-velocity recording is realized.

Abstract: A recording method of recording information in a dye-based write-once digital versatile disc (DVD) containing a substrate having a wobbled guide groove and a recording layer containing an organic dye. Recording is performed by irradiating the DVD with three kinds of single light pulses. Each single pulse contains a recording area to record a mark and a cooling area having a light quantity not greater than 0.1 mW for a predetermined time. When the mark having a shortest length is formed, the DVD is irradiated with a first single light pulse. When the mark having a second shortest length is formed, the DVD is irradiated with a second single light pulse. When the mark having a third shortest length or longer is formed, the DVD is irradiated with a third single light pulse.

Abstract: An information-recording method includes the steps of moving a light beam at a selected linear velocity relative to the information-recording medium; controlling the light beam to generate a multi-pulse having at least three power levels of a first power level Ph, a second power level Pl which is lower than the first power level, and a third power level Pm which is intermediate therebetween, the multi-pulse being repeatedly modulated between the first power level Ph and the third power level Pm; adjusting the third power level Pm in response to the selected linear velocity; and recording the information by irradiating the information-recording medium with the controlled light beam. Recording compatibility can be secured for information-recording apparatuses different in recording linear velocity and laser source characteristic.

Abstract: A write signal control circuit in an optical disk drive for adjusting the duty cycle of the write signals by a duty cycle adjusting unit. The write signal control circuit includes a write signal generator for converting an EFM signal into the write signals according to the write strategy waveform generating rules, a duty cycle adjusting unit for adjusting the duty cycle of each write signal according to adjusting parameters and for outputting adjusted write signals, and a duty cycle detector for detecting the duty cycle of each adjusted write signal and outputting a respective duty cycle control signal. The duty cycle adjusting unit further receives the duty cycle control signal to adapt the adjusting parameters.