Abstract: An optical information recording method and a device which can record information with a laser light irradiating direction kept constant even if an information recording surface of an optical information recording medium is inclined and, a recording medium having a program therefor recorded thereon are provided. When performing OPC, a relational expression between a recording power and asymmetry (a standard expression), a relational expression between a differential light intensity value and a recording power (a first detection expression), a relational expression between a recording power and a difference between a differential light intensity value and a reflected light amount ratio (a second detection expression), a relational expression between a reflected light amount ratio and a recording power (a third detection expression), a differential light intensity value with which optimum asymmetry can be obtained, a recording power, a reflected light amount ratio and the like are determined and stored.

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: A method is designed for recording information on an optical disk in the form of a sequence of pits along a track of the optical disk.

Abstract: A drive current supply circuit is provided in which the speed of rise of the drive current to a laser diode is increased. In a drive current supply circuit for supplying drive current I to load 50 connected with the line 1R of two parallel lines 1R and 2R of a first current mirror circuit 1, this drive current supply circuit is provided with a control circuit CONT that controls the current i flowing in the other line 1L in accordance with first control signal ?ø1 and the first control signal ?ø1 comprises a steady DC component øD and a drive signal component ø1 added to the DC component øD when desired.

Abstract: An optical disc recording method comprises the steps of: setting a recording parameter function representing a relationship between a recording velocity for recording data to an optical disc and a parameter for optimally controlling a recording power controlling waveform for controlling a recording power of a light beam irradiated to the optical disc for recording the data; obtaining an optimal value for the parameter by executing a test recording at one recording velocity or at a plurality of recording velocities to a test area of the optical disc before actual data recording to the optical disc; correcting the recording parameter function in accordance with the obtained optimal value for the parameter; deriving the parameter corresponding to a recording velocity from the corrected recording parameter function; and recording the data by irradiating a light beam of the recording power controlling waveform to which the obtained parameter is applied.

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: An optical disk drive includes drive current generation unit for supplying a mark forming semiconductor laser drive current and a space forming semiconductor laser drive current; first high-frequency superimposition unit for superimposing a high-frequency component on the space forming semiconductor laser drive current; and high-frequency superimposition control unit for controlling the first high-frequency superimposition unit to stop the superimposition of the high-frequency component for a predetermined duration prior to a timing at which to switch from the space forming semiconductor laser drive current to the mark forming semiconductor laser drive current, eliminating positional variations on the disk of the mark leading and trailing edges due to the high frequency superimposition.

Abstract: In a method and an apparatus for aberration correction according to the invention, aberration occurring in recording/reproducing information derived from causes such as thickness variation of a substrate, a tilt, a focus error and a tracking error is detected, and the aberration is corrected by correcting these causes.

Abstract: A laser diode drive circuit for an optical disc recording and/or reproducing apparatus includes a plurality of laser diodes to output laser beams having different wavelengths, a switch circuit for selectively connecting a required laser diode from a plurality of laser diodes, a laser diode drive power supply circuit for driving the laser diode selectively connected by the switch circuit, a photodiode for detecting at least part of laser beams emitted from the laser diode to convert a detected part of laser beams into an electrical signal, a plurality of current-to-voltage conversion amplifiers connected to an output of the photodiode and whose conversion resistance values can be adjusted and having differently designed center conversion resistance values and an automatic power control circuit connected to outputs of the current-to-voltage conversion amplifiers to output a feedback signal to the laser diode drive power supply circuit.

Abstract: An optical information recording method records information with respect to an optical information recording medium having a multi-layer structure recording layer formed by a plurality of recording layers each capable of recording information, and carries out an Optimum Power Control (OPC) prior to carrying out the recording. Recording conditions that are used when carrying out the OPC are read from one of the recording layers of the optical information recording medium to which the recording is to be made, where each of the recording layers is recorded with the recording conditions therefor, and the OPC is carried out using the read recording conditions.

Abstract: A high-frequency superposing module for driving a laser diode includes an oscillating circuit and an impedance matching circuit. The impedance matching circuit includes a capacitor connected in series between the emitter of a transistor and the terminal through which a laser-diode drive signal is output; and a capacitor connected in parallel between the drive-signal output terminal and the ground. The oscillating circuit includes an inductor serving as a choke coil connected between the drive-signal output terminal and the collector of the transistor, thus allowing the drive-signal output terminal to serve as a power input terminal for the oscillating circuit.

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, 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: An optical disk device for writing information on an optical disk having an APC part for monitored driving of a laser diode is provided which performs first and second OPCs. An unused partition of a test area and reference power value are read out from the optical disk. APC is turned off if the recording speed exceeds 1×. A first optimum writing power value is obtained by writing on the unused partition by driving the laser diode at a plurality of first test laser power values centered on the reference power value and reading out the information. APC is turned on if the recording speed exceeds 1×. A second optimum writing power value is obtained by writing on a subsequent unused partition by driving the laser diode at a plurality of second test laser power values centered on the first optimum writing power value and reading out the information.

Abstract: A device for recording information on an optical disc so as to improve the recording quality of the information when a recording operation has just started. The recording device includes a luminous element radiating a light for recording information on the optical disc; a radiation intensity controller constantly controlling an intensity of radiation of the light radiated by the luminous element; a constant outputting unit providing a constant energy to the luminous element; a selector selectively selecting one of the outputs of the intensity of radiation controller and the constant outputting unit; wherein, the selector selects the output from the constant outputting unit during a predetermined duration from a starting time of recording the information on the optical disc, and selects the output from the intensity of radiation controller afterward.

Abstract: An information recording device for writing information in a circumferential direction of a disk-type recording medium, with a substantially constant linear density.

Abstract: Data is written on a plurality of data tracks on an optical disk by a plurality of laser beams. The spots illuminated by the beams are spaced apart to prevent thermal interference. The spots are aligned along a line at an angle to the tangent of the data tracks. The angle of the line of spots is determined by an equation using variables that include the track pitch, the minimum distance between spots and the difference in track numbers between tracks being written.

Abstract: A controlling unit 130 of an optical disc recording apparatus judges a failure of a focus servo in accordance with an output signal of a servo circuit 107 When the failure of the focus servo is detected, a laser light irradiating position at the time of the failure is obtained as a standard position and a laser power controlling unit 140 is controlled to pause a control of the laser power based on data to be recorded. Thereafter, the laser power controlling unit 140 and a position of an optical pickup 103 are controlled to restart the control of the laser power based on the data to be recorded from the standard position as a starting position.

Abstract: An optical system of an optical disk recording apparatus irradiates a disk with a main beam for use in writing a data signal onto a disk and a sub-beam succeeding the main beam. When writing a data signal onto the disk, a site on the disk at which a data signal is written by the main beam is subsequently irradiated with the succeeding sub-beam. Light of the succeeding sub-beam reflected from the disk is received by a succeeding light receiving sub-region. A sampling circuit samples a signal at periods when the emission power of the main beam is at the recording level, among output signals from the succeeding light receiving sub-region. Based on the sampled signal at the recording level, a ? value detection circuit and a jitter amount detection circuit obtain a ? value and a jitter amount indicative of the recording state of the data signal recorded on the disk, respectively.

Abstract: A test recording is performed with respect to an optical disc prior to a regular recording, and a ? value for setting a qualitative parameter relating to the level of the recording state within a preferable range is derived from a result of the test recording. Then, the recording velocity at which the derived ? value or the writing laser power value is within the preferable value can be obtained. Therefore, the recording velocity at which the satisfactory recording can be realized with few recording errors can be determined. Further, a relation between a writing laser power value and a ?? value is obtained from the reproduced signal from the test record area, and the writing laser power value is determined considering the ?? value.

Abstract: A method and system for optimizing energy consumption during data read/write operations in a disk-based memory system is provided. The method includes the steps of reading a data clip length, Ls and determining an available energy-optimum recordable track segment.

Abstract: The present invention provides an optical disk device which optimizes recording power level used when recording data. A controller records test data in a test region of an optical disk and evaluates reproduced signal quality of the test data, so as to determine an optimum recording power level Po (OPC). Subsequently, the controller uses reflected light intensity level B obtained when recording data to make adjustments to the optimum recording power level Po, thereby obtaining recording power level P. The recording power level P is adjusted such that Bm/Pn=constant, where m and n are positive rational numbers satisfying m<n. When m=1, the value of n is greater than or equal to 1.5 and no larger than 10.

Abstract: An optical recording medium having a higher improved read accuracy is disclosed. In the case of irradiating a laser beam to an optical recording medium including an optical reflective layer and a recording layer so as to record information therein, in the recording layer, a virtual recording cell having an arbitrary unit length and a unit width perpendicular to the unit length is continuously defined. In the case where the laser beam is irradiated to the virtual recording cell over the entire allowable irradiation time T securable to one virtual recording cell, a reference power of the laser beam is preset so that an optical reflectance of the virtual recording cell can be reduced more than 50% with respect to the initial reflectance.

Abstract: An apparatus for detecting abnormal states which prevents damage to a laser diode or data recorded on a disc and swiftly correcting the abnormal state. An overflow/underflow detector detects whether overflow or underflow of the laser diode occurs, by comparing a laser diode output power control value, which is output from the laser diode output power control circuit, with an overflow setting value and an underflow setting value. A mode switch switches an operation mode of the laser diode output power control circuit from a recording mode to a reproducing mode, in response to the detection result of the overflow/underflow detector.

Abstract: A light source drive which modulates a light source so as to cause the same to emit a light, includes: a superposition current generation part which generates a superposition current approximately corresponding to a charging/discharging current needed for a capacitance occurring in parallel to the light source for a predetermined time period near at least one of a rising-up part and a decaying-down part of a waveform of a drive current for the light source; and an addition/subtraction part which adds to or subtracts from the drive current the superposition current generated by the superposition current generation part.

Abstract: Electric power consumed by a laser diode when an optical disk or magneto-optical disk is played back is reduced. A laser diode control circuit (6) causes the laser diode to emit continuously rather than intermittently, even if a PCK signal is supplied to the laser diode control circuit (6), when an optical display player or magneto-optical disk drive does not yet stabilize and is being pulled into a phase-locked state. When the focus is locked, the player is in a phase-locked state, and the operation is stable, a mode-switching circuit (9) included in the laser diode control circuit (6) switches the mode of operation from continuous operation to intermittent operation according to an FLOCK signal. The frequency of the PCK is multiplied by a frequency multiplier circuit (7), and the pulse width is adjusted by a pulse width-adjusting circuit (8). A laser diode driver circuit (10) produces intermittent current of this adjusted pulse width. The laser diode is started to emit intermittently.

Abstract: An optical disk drive has a pick-up head for emitting laser beams, and an analog front-end circuit controlled by a microprocessor for controlling the operation of the pick-up head. An automatic control method for generating stable laser power of the optical disk drive includes getting a power reference function measured by a fixed quantity of optical disk sample drives, establishing the relationship between the laser power control signal of pick-up head from the analog front-end circuit by the microprocessor, and calculating the difference amount from a feedback signal minus a reference voltage on pick-up head side to generate a first function. When the analog front-end circuit receives this feedback signal, this method will be enabled automatically and adjust the first function of the laser power control signal to approach the reference function so as to adjust the intensity of the laser power generated by the pick-up head.

Abstract: An information recording apparatus that records information with a substantially constant linear density in a circumferential direction of a recording medium having a disk shape, includes variable velocity recording control means, recording power modification means, recording power storage means, and initial recording power value setting means.

Abstract: A power control circuit for an optical information recording device is disclosed. A power sampling signal from a photodiode is transmitted to a peal envelope acquiring circuit and a bottom envelope acquiring circuit and then sampled and held, which is fed-back to a laser diode driving circuit. The laser diode driving circuit alters a driving signal emitted to the laser diode according to the fed-back signal to adjust the power of the optical signal emitted from the laser diode. Therefore, cost is reduced and the power control circuit is particularly suitable for high-speed recordable optical disk drive.

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: An optical information recording medium includes: a substantially disk-shaped substrate; and a recording layer formed on a surface of the substrate for recording, reproducing and erasing information by irradiation with a laser beam. A test recording region for test recording and an information recording region for recording the information at least are arranged on the surface of the substrate. In the test recording region and the information recording region arranged on the surface of the substrate, a test recording track and an information recording track respectively are formed in a spiral-shaped arrangement or in a concentric arrangement. A track pitch of the test recording track is wider than a track pitch of the information recording track.

Abstract: An optical recording power controlling apparatus and method, in which the determination conditions for received Non Return to Zero Inverted (NRZI) data and the varying range of the optical recording power level are set depending on the multiple-speed of recording and the type of an optical medium, and the varying range of the optical recording power level is controlled so that optical recording power provided to a light emitting device is optimal for the multiple-speed of recording and the type of an optical medium. In the optical recording power controlling apparatus, a system control unit sets the discrimination conditions of received data to be recorded and the varying range of the optical recording power level, depending on the multiple-speed of recording and the type of an optical medium.

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: At spin-up of an optical disk 3, gain adjustment and offset adjustment are performed on a servo error signal to obtain a first gain adjustment value and a first offset adjustment value. Based on the first gain adjustment value, a CPU 11 obtains a second gain adjustment value and a second offset adjustment value at data writing on the optical disk 3, and stores them in storage 7. When the reading state of the optical disk 3 shifts to the writing operation, the CPU 11 controls a laser power switching circuit 12 to change the output from an optical pickup 1 and, simultaneously, reads the second offset adjustment value and gain adjustment value stored in the storage 7 and sets them in an offset adjustment unit 5 and a gain adjustment unit 8, respectively.

Abstract: A high-frequency superposition module for an optical pickup that reduces the number of devices, facilitates scale-down and allows an oscillating circuit to be turned off when a power supply for feeding a direct current to a laser diode is turned off and an optical pickup using the high-frequency superposition module. An oscillating circuit for feeding a high frequency to a laser diode comprises at least an active element and passive elements such as capacitors, resistors, and inductors. A power supply for feeding a direct current to the laser diode is also used as a power supply for the oscillating circuit.

Abstract: An optical information recording method including: irradiating a recording medium with laser light, wherein 0 signals having width nT are recorded or rewritten using continuous laser light having a power level Pe, and 1 signals having width nT are recorded or rewritten using a light pulse train having a first pulse portion fp having power Pw and width xT (T: clock time), a multi-pulse portion mp in which a number (n?n?) of high level pulses each having power Pw? and width yT, and, if (n?n?)>1, a low level pulse which has power Pb and width (1?y)T are applied, and an end pulse portion ep having power Pb? and width zT, wherein n and n? are a positive integer (n>n?), and wherein each of Pw and Pw? is greater than Pe, Pe is greater than each of Pb and Pb?, and at least one of x, y and z is in a range as follows: 0.35?x?0.75, 0.30?y?0.55, 0.35?z?0.70.

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

Abstract: An apparatus for and a method of controlling an output of a laser diode in an optical recording/reproducing apparatus. The apparatus includes a sampling circuit sampling a present power value output from the laser diode with a predetermined frequency, an arithmetic unit connected to the sampling circuit, outputting a control power value applied to the laser diode in response to the present power value output from the sampling circuit and a reference power value, and a controller connected to the sampling circuit and the arithmetic unit, generating control signals, which control the operations of the sampling circuit and the arithmetic unit.

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

Abstract: A drive pulse for writing is generated based on a data pulse signal to be recorded, a light source element is driven with this drive pulse to obtain a beam of light, and this beam of light is irradiated onto an optical recording medium to record the data pulse signal on the optical recording medium. When the drive pulse is generated, a write pulse is generated based on the data pulse signal, and compared with a beam intensity signal representing intensity of the beam of light to optimally control a pulse width of the drive pulse.

Abstract: An information storage apparatus includes a mark reading section for reading a mark written on an information storage medium. A recording state changing section is provided for changing a recording state in an adjacent region situated next to a region from which the mark reading section fails to read a mark, so as to reduce cross talk caused by the adjacent region. The mark reading section reads the mark in the failed region again after the recording state changing section changes the recording state in the adjacent region.

Abstract: In a laser-driving device including a high-frequency current generating circuit generating a high-frequency current superimposed on a control current output from a light intensity control circuit for light intensity control, and supplied to a laser diode as a drive current, the high-frequency current generating circuit has a sourcing current source, a sinking current source, current switches connected between the current sources and a drive output terminal respectively, a gated oscillation circuit oscillating with a desired frequency, and switch drive circuits complementarily on/off controlling the current switches by using a drive switching signal obtained by removing a high-frequency component from an output signal of the oscillation circuit.

Abstract: An initialization method for a phase change type optical disc, including the steps of irradiating a laser beam of a predetermined power onto a specimen optical disc, increasing the power of the laser beam with constant rate, detecting a reflectivity of the laser beam reflected from the optical disc in accordance with the increasing laser power, detecting a saturated value of the reflectivity of the laser beam, detecting an optimal power of the laser beam where the reflectivity belongs 70% to 90% of the saturated value, and performing initialization by irradiating the laser beam having thus obtained optimal power onto the optical disc to be initialized which will be initialized with the adjusted laser beam can improve the recording characteristic and erase ratio.

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, apparatus, and medium for erasing information recorded on a rewritable recording medium. The method includes: searching for test result information on a recording power recorded on a recording management area disposed on the recording medium; if corresponding test result information is found, reading in the test result information; and by using a recording power determined according to the read test result, recording a unique pattern on at least part of a user data area of the recording medium where predetermined information is recorded. According to the method, the writing characteristic can be greatly improved.

Abstract: Disclosed are a compatible type optical pick-up device for writing/reading data at a high density and a method for operating the optical pick-up device, thereby allowing the optical pick-up device to be easily assembled and improving optical efficiency. The compatible type optical pick-up device includes a laser beam source for outputting a laser beam having a writing mode power level for writing data from a disk, a collimator lens for collimating the laser beam outputted from the laser beam source, an optical attenuator located on an optical route of the laser beam passing through the collimator lens for attenuating the power of the laser beam, and an objective lens for converging the laser beam, incident thereon, onto the disk.

Abstract: Disclosed herein is a technology that enables stable and high-speed writing and/or reading in an optical disk apparatus. The optical disk apparatus has an optical head that includes a first circuit for driving a laser diode, a second circuit for sampling and holding analog electric signals that are based on reflected laser light from the optical disk, and a third circuit for converting said signals being sampled and held into digital signals. Signals digitized in the optical head are transmitted to the apparatus body side using time-division multiplexing. The first circuit, the second circuit, and the third circuit are constructed on a single substrate or in a single IC.

Abstract: A data recording/reproducing apparatus wherein various data to be used for maintenance are measured, and parameters required for analysis of the maintenance data are prerecorded to realize prediction of the service life of a semiconductor laser and detection of occurrence of any trouble that may be derived therefrom. In this apparatus where data are recorded in and/or reproduced from a recording medium, the internal state of the apparatus is measured, then any abnormal state in the apparatus is detected on the basis of abnormal state decision data, and the detected state is transmitted to an external information processor. The apparatus comprises a means for measuring first data relative to the apparatus; a first memory means for storing second data to make a decision as to an abnormal state of the measured first data; a means for generating third data relative to maintenance of the apparatus on the basis of the first and second data; and an output means for delivering the third data as an output.

Abstract: It is an object of the present invention to provide a method of recording information to an optical recording medium that is suited to achieving high data transfer rates.

Abstract: A laser power control apparatus for controlling the output power of a semiconductor laser used to record and reproduce data in and from a recording medium is provided. The laser power control apparatus includes a controller configured to vary the peak output power level of the semiconductor laser in a stepwise manner, calculate a differential efficiency at each of the varied peak output power levels, and determine a laser driving current based on a relation between the differential efficiency and the peak output power level. In addition, a laser driving unit is configured to drive the semiconductor laser using the laser driving current determined by the controller.