Abstract: An optical disc device is configured to reproduce an optical disc. The optical disc device includes an optical pickup and a driver. The optical pickup has a laser irradiation component that is configured to emit a laser beam to the optical disc for obtaining a return light. The driver is configured to generate a drive signal for driving the laser irradiation component based on a high-frequency signal. The driver is further configured to set an amplitude of the high-frequency signal used while reproducing a test region of the optical disc to be different from an amplitude of the high-frequency signal used while reproducing a data region of the optical disc. The test region of the optical disc is reproduced to acquire a setting signal for a setup of the optical pickup.

Abstract: Provided are a light detecting element, and an optical pick-up device and an optical disc drive including the light detecting element. The light detecting element includes a terminal resistance unit that is provided between an amplification unit and an output port to limit an electric current of the output signal.

Abstract: In an optical recording method, recording parameters (WU) to be used for recording are obtained using recommended recording parameter values (WR) read from an optical recording medium and previously obtained vector information (PC) and approximation coefficients (Ca, Cb) (S24). Writing to the optical recording medium is performed using the obtained recording parameters (S17). The vector information (PC) includes a vector component of the parameters obtained statistically with respect to parameter difference values (DF) between optimal recording parameter values (WO) and the recommended recording parameter values (WR) over a plurality of optical recording media so as to strengthen mutual correlation between the parameters.

Abstract: An optical disk drive system associated with a laser diode is described. The optical disk drive system comprises a current generator for receiving input signals; a current switch coupled to receive timing signals; a current driver coupled to receive output signals from the current switch and the current generator, the current driver further comprising a driver with wave shape control selected from the group consisting of a laser diode read driver and a laser diode write driver, wherein the driver with shape control is operative for transmitting at least one output signal that is a scaled version of at least one of the output signals received from the current generator, wherein the current driver is operative for transmitting at least one output signal driving the laser diode.

Abstract: The present invention provides a non-resonant two-photon absorption recording material containing a non-resonant polymer two-photon absorption compound, and the non-resonant two-photon absorption recording material wherein the main chain of the non-resonant polymer two-photon absorption compound contains at least one member selected from polystyrene, polyacrylate, polymethacrylate, polyester, polyurethane, polyether and polyimide, and also provides an optical information recording medium having a recording layer containing the recording material.

Abstract: A reproducing device includes a light generation and emission unit that obtains signal light as reflection light, which reflects recording signals of a land and a groove, by irradiating an optical recording medium with light and generates reference light so as to emit the signal light and the reference light in a superposed manner, a detection optical system that generates a first combination of signal light and reference light, a second combination of signal light and reference light, a third combination of signal light and reference light, and a fourth combination of signal light and reference light respectively, a light receiving unit in which the first to fourth combinations of signal light and reference light are respectively received by first to fourth light receiving elements, and a reproduction unit that reproduces the recording signals of the land and the groove on the basis of first to fourth light receiving signals.

Abstract: A recording waveform is adjusted based on the fluctuation amount of the mark edge position, focused on that fluctuation of a mark edge position is increased in aged deterioration of a recording signal. Specifically, the recording waveform is adjusted such that a fluctuation amount becomes minimum or a threshold value or less. Then, information is recorded on the optical disc using the recording waveform. Further, provided is a recording medium or an information recording apparatus which stores parameters of the recording waveform.

Abstract: A method for reducing a number of input terminals of an APC circuit is provided, where the APC circuit is arranged to control an optical pickup unit (OPU) within an optical storage device. The method includes: utilizing at least one switching module to ground one of a first and a second input terminals of the APC circuit at a time; and utilizing the switching module to electrically connect an APC front end within the APC circuit to a non-grounded input terminal of the first and the second input terminals, in order to receive a detection signal of a photo diode of the OPU through the non-grounded input terminal at the time. An associated APC circuit is also provided.

Abstract: A reproduction method for reproducing a rewritable and readable optical information storage medium in such a manner that an information recording layer is disclosed. The reproduction method comprising: reading setting information of reproduction laser power for each information recording layer of the rewritable and readable optical information storage medium, the setting information being stored in the rewritable and readable optical information storage medium; and setting, based on the setting information thus read, reproduction laser power for the information recording layer that is closest to a reproduction-laser-incident surface to be not less than 1.0 mW but less than 1.1 mW.

Abstract: Provided are a method of optical writing on a disc and a device adopting the method. The method of optical writing includes initially driving a laser diode (LD) at a preset reference value corresponding to a target output, detecting an actual output power by monitoring light output by the LD, and comparing the actual output power to the target output power. The method further includes compensating the reference value and writing data to the optical disc using the compensated reference value.

Abstract: An optical drive laser diode drive current has a High Frequency Modulation (HFM) signal superimposed to aid optical medium readability. The HFM signal is provided by an HFM oscillator interfaced with the laser diode drive current to provide the HFM signal with a frequency from within a predetermined range. A frequency controller varies the frequency of the HFM signal over time to reduce RF emissions associated with the HFM signal. For instance, the HFM signal frequency is varied in a swept sawtooth or triangle pattern. As another example, the HFM frequency is varied with random selections of frequencies from a predetermined frequency range.

Abstract: Amplitude and frequency of a high-frequency signal superposed on a reproduction laser beam are changed in accordance with a reproduction spot diameter on the surface of the recording layer upon discrimination of an optical disk in initial adjustment after insertion of the optical disk and change of a layer of a multi-layer optical disk. Further, the high-frequency signal is not superposed on the reproduction laser beam until end of the discrimination and change to a target layer upon discrimination of the optical disk and change of a layer of a multi-layer optical disk.

Abstract: An optical disk apparatus has: a laser (14) that outputs light; an optical system that includes an SIL (2) for forming a predetermined sized beam spot on an optical disk (1) using the light from the laser; a detector (26) that detects output power of the laser and generates a laser power detection signal; a laser power control circuit (27) that controls the output power of the laser using the laser power detection signal; a detector (10) that detects a gap length between the optical disk and the SIL and generates a gap detection signal; and a gap control circuit (15) that controls the gap length between the optical disk and the SIL using the gap detection signal. The power control circuit has a gain crossover frequency greater than a gain crossover frequency of the gap control circuit.

Abstract: A device and method for controlling a driving current with respect to an optical source of an optical disc drive are provided. The method includes changing a characteristic of a high frequency component based on a change in the peripheral temperature of on optical pickup device, modulating the driving current using the high frequency component, and applying the modulated driving current to the optical source.

Abstract: An optical disc device is configured to reproduce an optical disc. The optical disc device includes an optical pickup and a driver. The optical pickup has a laser irradiation component that is configured to emit a laser beam to the optical disc for obtaining a return light. The driver is configured to generate a drive signal for driving the laser irradiation component based on a high-frequency signal. The driver is further configured to set an amplitude of the high-frequency signal used while reproducing a test region of the optical disc to be different from an amplitude of the high-frequency signal used while reproducing a data region of the optical disc. The test region of the optical disc is reproduced to acquire a setting signal for a setup of the optical pickup.

Abstract: A reproducing device includes: a laser light irradiating section; a correction coefficient information retaining section; a correction coefficient obtaining section; a laser power setting section; and a driving signal outputting section.

Abstract: Disclosed is an improved DRAW technique for writing data on an optical storage medium and reading the data in parallel. In obtaining the optical power of a first light source 1, writing user data is temporarily suspended to write non-user data with a second light source 2 turned OFF.

Abstract: An improvement to an optical recording apparatus is provided for adapting the apparatus for an optical recording format using multiple modulation levels. The improvement includes an electro-optic modulator (EOM) added between a light source and a first modulator, to regulate a power of the light beam supplied to the first modulator. A modulation interface is adapted to output a power control signal to the EOM, and the EOM regulates the power of the light beam supplied to the first modulator to a power level corresponding to the power control signal. The apparatus is further adapted to supply a formatted data signal directly from a formatter to the first modulator, without going through the modulation interface.

Abstract: Various embodiments of the present invention provide single-ended and differential current drivers for heat assisted magnetic recording and other applications. For example, a current driver is disclosed that includes an upper output terminal and lower output terminal, a number of current switches operable to selectively contribute electrical currents through the upper and lower output terminals, a control input for each of the current switches operable to control the electrical currents, and a voltage supply operable to establish a voltage across the upper and output terminals.

Abstract: With a large capacity of an optical disk and high-speed recording, a frequency of a recording signal is increased and a pulse width is narrowed. In the case that a laser is driven by a signal having the short pulse width, unfortunately the high-speed recording is hardly performed to an optical disk when a rise time and a fall time of the optical pulse are lengthened. During user data recording, a bottom driving current is set to a second bottom driving current value that is a current value of a threshold or less, so that the rise time and the fall time of the optical pulse can be shortened to perform the high-speed recording of the optical disk.

Abstract: An optical disk drive system associated with a laser diode is described. The optical disk drive system comprises a current generator for receiving input signals; a current switch coupled to receive timing signals; a current driver coupled to receive output signals from the current switch and the current generator, the current driver further comprising a driver with wave shape control selected from the group consisting of a laser diode read driver and a laser diode write driver, wherein the driver with shape control is operative for transmitting at least one output signal that is a scaled version of at least one of the output signals received from the current generator, wherein the current driver is operative for transmitting at least one output signal driving the laser diode.

Abstract: An apparatus and associated method is presently disclosed for a control circuitry capable of managing a heat source used in data storage applications. Various embodiments of the present invention are generally directed to a heat source directed at a data storage medium with a synchronization signal and a serial interface that are each selectively activated via a demultiplexed write gate signal. The selective activation allows for pulsed operation of the heat source resulting in reduced duty cycle and temperature during a write operation.

Abstract: An optical disc device includes an optical source for emitting an optical beam, an incident intensity control circuit for controlling an intensity of the optical beam emitted from the optical source, an objective lens for focusing the optical beam on an optical disc, an optical detector for receiving the optical beam reflected from the optical disc, and a servo signal generation circuit for generating a focus error signal from the optical detector, by this configuration, the optical beam is varied once to a third optical beam intensity to be present in between a first optical beam intensity and a second optical beam intensity when varying from the first optical beam intensity up to the second optical beam intensity different from the first optical beam intensity, and the incident intensity control circuit is controlled such that the variation of focus error signal is not exceeded over a predetermined range.

Abstract: The invention relates to recording methods for recording information on a dual layer recordable disk, and to corresponding recording devices. In one such method and recording device the OPC-area is variably located on a layer of the disk. In a preferred embodiment the OPC-area is located relative close to the radius where the data stream switches from the first layer to the second layer. This reduced additional time required for jumping to a fixed OPC-area. Furthermore, in another such method and device the information to be recorded is equally divided over both layers of the dual layer disc. This avoids additional time required for finalization.

Abstract: A reproduction method for reproducing a rewritable and readable optical information storage medium in such a manner that an information recording layer is disclosed. The reproduction method comprising: reading setting information of reproduction laser power for each information recording layer of the rewritable and readable optical information storage medium, the setting information being stored in the rewritable and readable optical information storage medium; and setting, based on the setting information thus read, reproduction laser power for the information recording layer that is closest to a reproduction-laser-incident surface to be not less than 1.0 mW but less than 1.1 mW.

Abstract: When the power of the write pulse is taken as the peak power and the power of the bottom pulse is taken as the bottom power, the power setting device (114) sets the power of each pulse in the recording pulse train such that the peak power PwN of the Nth information layer which is closest to the light entry surface of the optical recording medium (11), the bottom power PbN of the Nth information layer, the peak power PwM of the Mth information layer (where M is an integer such that N>M?1), and the bottom power PbM of the Mth information layer satisfy the following formula: PbN/PwN>PbM/PwM.

Abstract: An optical information record/playback device of the present invention includes: a light source; a current driver for supplying current to the light source; an optical system for condensing light from the light source onto a recording medium; a monitoring section for monitoring light emission power of the light source; a current driver control section for controlling output current of the current driver; and an arithmetic/control section for controlling an operation of the current driver control section. Before recording information, the arithmetic/control section sequentially conducts a first test light-emission to cause the light source to emit light by using a closed loop circuit and a second test light-emission to cause the light source to emit light by using an open loop circuit, and compares first and second sampling values, which are respectively obtained by sampling the outputs of the monitoring section during the first and second test light-emissions.

Abstract: A controller for a laser driver includes a parameter generation module, a timing encoding module, and a pulse generation module. The parameter generation module is configured to, for each mark contained in a bit stream, generate a set of timing parameters based on defining characteristics of the bit stream. The defining characteristics include length of the mark and at least one of (i) a length of a leading space prior to the mark and (ii) a length of a following space subsequent to the mark. The timing encoding module is configured to determine a plurality of pulse defining parameters based on the set of timing parameters. The pulse generation module is configured to create a plurality of pulses based on the plurality of pulse defining parameters, combine the plurality of pulses into a plurality of enable signals, and output the plurality of enable signals to the laser driver.

Abstract: When ld0 denotes an initial optical path length that is a length of an optical path, along which the signal light travels, as converted using a refractive index in vacuum, lm0 denotes an initial optical path length that is a length of an optical path, along which the reference light travels, as converted using a refractive index in vacuum, ?l denotes a fluctuation width of a difference in optical path lengths between the signal light and the reference light as converted using a refractive index in vacuum, ?0 denotes a central oscillation wavelength of the wavelength-variable laser, and ?? denotes an oscillation wavelength variable range of the wavelength-variable laser, then an initial optical path difference |ld0?lm0| satisfies |ld0?lm0|>(?l/??)?0.

Abstract: An optical disc apparatus includes: a light source; a power detection portion that detects optical power of light emitted from the light source; a temperature detection portion that detects an ambient temperature of the power detection portion; a storage portion in which information relating to a temperature drift characteristic of the power detection portion is stored; and a control portion that controls the optical power while performing a temperature correction relating to the power detection portion by using the information stored in the storage portion. In the optical disc apparatus, the information stored in the storage portion is updated.

Abstract: A recording device that records information in an optical recording medium includes: a self excited oscillation semiconductor laser including a saturable absorber section to apply a bias voltage and a gain section to inject a gain current, and also emitting a laser light to record the information in the optical recording medium; a reference signal generation unit generating a master clock signal and also supplying an injection signal synchronized with the master clock signal to the gain section of the self excited oscillation semiconductor laser; and a recording signal generation unit generating a recording signal based upon the master clock signal and also applying the recording signal to the saturable absorber section of the self excited oscillation semiconductor laser as the bias voltage.

Abstract: The present invention can control output of pulses from a semiconductor laser. In the present invention, a short-pulse light source (1) applies a laser drive voltage (DJ) having a pulse-shaped drive voltage pulse (DJw) to a semiconductor laser (3), thereby causing the semiconductor laser (3) to emit specific output light (LAp), as laser light (LL), having a pulse-shaped specific peak (APK) and a specific slope (ASP), an emission intensity of the specific slope (ASP) being lower than an emission intensity of the specific peak (APK). The short-pulse light source (1) controls a voltage pulse half-width (Thalf), which is a pulse width of the drive voltage pulse (DJw), by setting a pulse width (Ws) of a set pulse (SLs), thereby adjusting a ratio between the specific peak (APK) and the specific slope (ASP).

Abstract: A method and an apparatus for reading data from or writing data to an optical recording medium is described, the data being stored as marks having different lengths. Marks having a length below the limit of diffraction at a first wavelength are read or written with the first wavelength, whereas marks having a length above the limit of diffraction at the first wavelength are read or written with a second wavelength larger than the first wavelength.

Abstract: A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of data tracks defined by servo sectors. The head comprises a laser operable to heat the disk while writing data to the disk and a fly height actuator operable to adjust a fly height of the head over the disk. When the head approaches a target data sector of a write command, the fly height of the actuator adjusts the fly height of the head to a target pre-heat fly height during a pre-heat interval. After the pre-heat interval and during a pre-laser interval, the fly height actuator increases the fly height of the head. After the pre-laser interval, a power applied to the laser is increased to heat the disk, wherein the pre-laser interval compensates for a protrusion transient of the head toward the disk due to increasing the power applied to the laser.

Abstract: A disk drive is disclosed comprising a disk comprising a plurality of data tracks, wherein each data track comprises a plurality of data sectors. A head is actuated over the disk, wherein the head comprises a laser operable to heat the disk while writing data to the disk. When a write command is received to write data to a target data sector of a target data track, the head is positioned over the target data track. When the head reaches the target data sector, a power applied to the laser is increased to above a steady state value to compensate for a high fly height of the head. The power applied to the laser is decreased toward the steady state value while writing at least part of the data to the target data sector.

Abstract: A high frequency modulator is described. It comprises: a first converter for receiving a constant current signal and transmitting a first converted signal; an adder coupled the first converter and operative for transmitting a summed signal in response to receiving the first converted signal and selectively receiving a triangular signal; a first oscillator coupled to the adder for receiving the summed signal, the first oscillator operative for transmitting a time varying current signal; a second converter coupled to the first oscillator for receiving the time varying current signal and operative for transmitting a second converted signal; and an output device selectively coupled to the second converter and operative for transmitting an output signal in response to receiving either the second converted signal or an offset signal.

Abstract: An optical head 200 comprises: a light source 101 that emits a light beam; an objective lens 105 that condenses, in the form of converging light, the light beam emitted by the light source 101, onto an information recording medium; a cylindrical lens 115 onto which a reflected light beam that is reflected by the information recording medium is incident, and which generates astigmatism for forming a focus error signal; a light detector 120 that receives the reflected light beam passing through the cylindrical lens 115; and a holder 130 that holds the cylindrical lens 115 and the light detector 120. The holder 130 has a first main face and a second main face that extend in directions that intersect the optical axis of the reflected light beam. The cylindrical lens 115 is bonded to the first main face and the light detector 120 is bonded to the second main face.

Abstract: In an optical information storage medium reproduction apparatus (10) for reproducing an optical information storage medium including a plurality of information recording layers each including a recording mark having a length shorter than an optical system resolution limit, reproduction laser power for reading an information recording layer closest to a reproduction-laser-incident surface of the optical information storage medium is set to be lower than reproduction laser power for reading an information recording layer farthest from the reproduction-laser-incident surface but not lower than minimum reproduction laser power that satisfies a reproduction signal characteristic that the optical information storage medium reproduction apparatus (10) requires.

Abstract: In an optical information storage medium reproduction apparatus (10) for reproducing an optical information storage medium including a plurality of information recording layers each including a recording mark having a length shorter than an optical system resolution limit, reproduction laser power for reading an information recording layer closest to a reproduction-laser-incident surface of the optical information storage medium is set to be lower than reproduction laser power for reading an information recording layer farthest from the reproduction-laser-incident surface but not lower than minimum reproduction laser power that satisfies a reproduction signal characteristic that the optical information storage medium reproduction apparatus (10) requires.

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: According to one embodiment, an optical disk device includes types of semiconductor laser diodes configured to emit laser light of different wavelengths, an output control circuit configured to control light output of each semiconductor laser diode, and a composite power source configured to generate voltages required for driving the types of semiconductor laser diodes and operating the output control circuit from a single power source voltage and to selectively output the generated voltages. The composite power source includes an input port to input an external control signal at a time of voltage selection and is configured to change the output voltage stepwise in response to the control signal.

Abstract: A recording apparatus for recording information on an optical recording medium includes a mode-locked laser unit that includes a semiconductor laser emitting a laser beam for recording the information on the optical recording medium, and an external resonator, an optical modulation unit that amplifies and modulates the laser beam emitted from the mode-locked laser unit, a recording signal generation unit that generates a recording signal based on a reference signal from a drive of the optical recording medium, and a modulation unit that generates a modulation signal for driving the optical modulation unit by latching the recording signal using a laser clock generated by an oscillation pulse of the laser beam emitted from the mode-locked laser unit.

Abstract: A circuit for preventing destruction of a semiconductor laser element of an optical disc device comprises a light-emission-directing circuit part for outputting a light-emission-directing signal for directing the semiconductor laser element to emit light; a voltage-monitoring circuit part for monitoring a light-emitting voltage and, when a judgment is made that the light-emitting voltage is normal, outputting a light-emission-permitting signal for permitting the semiconductor laser element to emit light, the light-emitting voltage being supplied from a power source for the semiconductor laser element to an optical-output-controlling circuit part in order to cause the semiconductor laser element to emit light; and a light-emission-permitting circuit part for using the optical-output-controlling circuit part to cause the semiconductor laser element to emit light only when the light-emission-directing signal and the light-emission-permitting signal are inputted.

Abstract: In an optical information storage medium reproduction apparatus (10) for reproducing an optical information storage medium including a plurality of information recording layers each including a recording mark having a length shorter than an optical system resolution limit, reproduction laser power for reading an information recording layer closest to a reproduction-laser-incident surface of the optical information storage medium is set to be lower than reproduction laser power for reading an information recording layer farthest from the reproduction-laser-incident surface but not lower than minimum reproduction laser power that satisfies a reproduction signal characteristic that the optical information storage medium reproduction apparatus (10) requires.

Abstract: Aspects of the disclosure provide a method for power calibration. The method includes writing, using a power configuration, a second pattern over a first pattern on a rewritable storage medium. The first pattern includes at least a first symbol and a second symbol while the second pattern does not include the second symbol. Thus, the second symbol in the first pattern is erased according to the power configuration. Then, the method includes reading the rewritable storage medium to measure remaining amplitude of the second symbol in the first pattern.

Abstract: An optical-pickup apparatus configured to prevent noise caused by return light by superposing a high-frequency signal, generated from a high-frequency signal generation circuit, on a driving signal to be supplied to a laser diode, the optical-pickup apparatus includes: a high-frequency superimposition integrated circuit including the high-frequency signal generation circuit; first wiring connected between an anode of the laser diode and the high-frequency superimposition integrated circuit; and second wiring connected between a cathode of the laser diode and the high-frequency-superimposition integrated circuit, the laser diode and the high-frequency superimposition integrated circuit mounted on a circuit board, the first wiring and the second wiring arranged, for the most part, in a region where the laser diode is arranged, the second wiring configured to pass through between an anode terminal of the laser diode and an anode terminal of a monitor diode.

Abstract: An optical disc recording method of determining a disc address when write and read operations are performed for an optical disc during recording power calibration in an optical disc recording apparatus having at least two optical head units including first and second optical head units is disclosed. The method includes: determining a first recording power calibration start address, which is an address at which the first optical head unit starts calibration of the recording power, from a power calibration area provided in advance as an area used to calibrate the recording power; and determining an address obtained by adding a range of the power calibration area used to calibrate the recording power to the first recording power calibration start address as a second recording power calibration start address, which is an address at which the second optical head unit starts calibration of the recording power.

Abstract: An optical information recording reproduction apparatus includes: a first light beam source; a second light beam source emitting a beam with a wavelength shorter than that of the first light beam source; and an object lens condensing the beams from the first and second light beam sources to an optical information recording medium. When information is recorded in the optical information recording medium, a recording beam is emitted from the first light beam source and a beam used to generate a signal for controlling a position of the object lens is emitted from the second light beam source. When the information of the optical information recording medium is reproduced, a reproduction beam is emitted from the second light beam source.

Abstract: According to one embodiment, a write-once type information storage medium comprises an organic dye based recording material having sensitivity at a wavelength of 405 nm and at a recording wavelength in the range of 600 nm to 700 nm, wherein, when absorbance of a maximum absorption wavelength in the vicinity of 405 nm is defined as 1, the absorbance is 5% or more at any wavelength in the range of 600 nm to 700 nm.

Abstract: According to a method for setting the laser beam power applied to reproduce information recorded on an optical disc, information recorded in a region on the optical disc is reproduced using three or more test reproduction powers (S22B), the number of reproductions until the degradation of the quality of the reproduced signal reaches a prescribed value is determined as the degradation number of reproductions (S22F), the relation between the test reproduction power and the degradation number of reproductions is approximated by a curve, and a reproduction power restricting the degradation of the reproduced signal quality to a predetermined amount or less over a certain guaranteed number of reproductions is determined (S25F). In optical reproduction from an optical disc on which information is recorded, the optimum power of irradiation for reproduction can be set, and degradation of the information due to the reproducing light can be prevented.