Abstract: According to one embodiment, an optical recording medium is provided in which interlayer crosstalk is low and in which stable and high-quality recording characteristics can be obtained. To this end, an optical recording medium comprises a first recording part which includes a first recording layer and a first light reflecting layer and which is disposed on a side closer to a light receiving surface, and a second recording part which includes a second recording layer and a second light reflecting layer and which is disposed on a side farther from the light receiving surface, the first recording part and the second recording part being stacked, wherein the thickness of the second light reflecting layer is larger than the thickness of the first light reflecting layer.

Abstract: According to one embodiment, an optical recording medium is provided in which interlayer crosstalk is low and in which stable and high-quality recording characteristics can be obtained. To this end, an optical recording medium comprises a first recording part which includes a first recording layer and a first light reflecting layer and which is disposed on a side closer to a light receiving surface, and a second recording part which includes a second recording layer and a second light reflecting layer and which is disposed on a side farther from the light receiving surface, the first recording part and the second recording part being stacked, wherein the thickness of the second light reflecting layer is larger than the thickness of the first light reflecting layer.

Abstract: The present invention is to realize a proper inner zone layout in an optical disk having at least three layers. A test area is provided in the inner zone (inner circumference side area) in each of recording layers. The test areas of each layer are so disposed as to be prevented from overlapping with each other in the layer direction. Furthermore, the number of management information recording/reproduction areas overlapping with the test area in the layer direction at a position closer to the laser-incident surface than this test area is set equal to or smaller than one in each test area of each recording layer. The management information recording/reproduction areas are each so disposed as to be prevented from overlapping with the test areas in the respective recording layers in the layer direction on the disk substrate side of the test areas.

Abstract: According to one embodiment, an optical recording medium is provided in which interlayer crosstalk is low and in which stable and high-quality recording characteristics can be obtained. To this end, an optical recording medium comprises a first recording part which includes a first recording layer and a first light reflecting layer and which is disposed on a side closer to a light receiving surface, and a second recording part which includes a second recording layer and a second light reflecting layer and which is disposed on a side farther from the light receiving surface, the first recording part and the second recording part being stacked, wherein the thickness of the second light reflecting layer is larger than the thickness of the first light reflecting layer.

Abstract: According to one embodiment, an optical recording medium is provided in which interlayer crosstalk is low and in which stable and high-quality recording characteristics can be obtained. To this end, an optical recording medium comprises a first recording part which includes a first recording layer and a first light reflecting layer and which is disposed on a side closer to a light receiving surface, and a second recording part which includes a second recording layer and a second light reflecting layer and which is disposed on a side farther from the light receiving surface, the first recording part and the second recording part being stacked, wherein the thickness of the second light reflecting layer is larger than the thickness of the first light reflecting layer.

Abstract: According to one embodiment, an optical recording medium is provided in which interlayer crosstalk is low and in which stable and high-quality recording characteristics can be obtained. To this end, an optical recording medium comprises a first recording part which includes a first recording layer and a first light reflecting layer and which is disposed on a side closer to a light receiving surface, and a second recording part which includes a second recording layer and a second light reflecting layer and which is disposed on a side farther from the light receiving surface, the first recording part and the second recording part being stacked, wherein the thickness of the second light reflecting layer is larger than the thickness of the first light reflecting layer.

Abstract: In an optical disk apparatus, the same signal path is used to both reduce an interchannel phase shift in write strategy signals and also to perform the actual writing to the disk. The optical disk apparatus includes a laser diode, a laser diode driver, and a semiconductor integrated circuit. The semiconductor integrated circuit includes a write strategy circuit and a control unit for controlling the operation of the write strategy circuit. Information collection for interchannel delay adjustment is performed through the use of the same signal path as that used for transmitting pulse signals from a pulse generation circuit to the laser diode driver for actual writing to an optical disk. Based thereon, an interchannel delay amount for applying laser light to the optical disk is set, thereby reducing the interchannel phase shift in the write strategy signals.

Abstract: The time required for starting up drives in a storage device mounted with both hard disk drives and solid state drives is shortened. A storage controller of the storage device identifies the type (HDD/SSD) of the mounted drives before starting up the drives. The storage controller thereafter performs staggered spinup to the HDDs in several batches. After the startup of HDDs is complete, the storage controller collectively starts up the SSDs. The storage controller determines the drive startup processing based on a pre-set drive startup policy such as reduction of the peak current reduction or shortening of the startup time, and the drive type identification result.

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

Abstract: An optical recording/reproducing system 1 reads, based on a predetermined reproduction clock, information associated with a recording track of a recording medium by irradiating frequency light. The frequency light is scanned at a predetermined scan velocity. The optical recording/reproducing system includes a computer 13, a DSP 49, and a LD driver that modulate light by a drive signal on which a frequency signal is superimposed to thereby output the frequency light, and synchronizes a frequency of the frequency signal with a frequency of the reproduction clock according to the scan velocity.

Abstract: An apparatus and method for determining the power consumption of one or more disk arrays are described. Power consumption information for various hardware components of the array, especially that for the disk drives since these consume more than 90% of the required power, are stored in a static data table in a database which may be controller firmware. Through inspection of this table and the chosen state of the individual disk drives as directed by a controller, one may determine the power use of the array.

Abstract: A data recording/reproducing system (1) reads a recording signal written on a recording track of a recording medium (3), by using light, which is modulated by a drive signal wherein a frequency signal is superposed for scanning the signal along the recording track at a prescribed scanning speed. Then, the system reproduces the read signal as data. The data recording/reproducing system is provided with a computer (13) for controlling the superposition frequency of the frequency signal for the drive signal corresponding to the scanning speed, and an LD driver (17).

Abstract: A multi-layered high-density recording medium and an optical power adjusting method for use with the same. Control information is pre-recorded in a specific area of at least a specific recording layer among the multiple recording layers, wherein the control information and includes each reference power information for respective recording layers. The method includes: (a) reading control information from a specific area of the recording medium, wherein the control information includes each reference power information for respective recording layers and is pre-recorded in the specific area of at least a specific recording layer among the multi recording layers; (b) adjusting a power value to be used for at least one of a recording operation and a reproducing operation at a target recording layer, by referring to the read control information; and (c) performing at least one of the recording and reproducing operations based on the adjusted power value.

Abstract: An information recording apparatus (2) is for forming a record mark corresponding to a recording signal by applying a laser beam to a recording medium, and is provided with: a light source (21) for emitting the laser beam; and a signal generating device (22) for generating a recording pulse signal for driving the light source on the basis of the recording signal, the recording pulse signal includes a mark period and a space period, a level of the recording pulse signal corresponds to a recording power by which waveform distortion is greater than or equal to an upper limit (L) or is less than or equal to a lower limit (?L) of an amplitude limit value on a limit equalizer (15), in the mark period corresponding to a long mark.

Abstract: An optical recording/reproducing device which minimizes the number of home-in operations to move a pickup to a predetermined reference position of an inner circumference of a disc, and a method of controlling the same. The optical recording/reproducing device includes a pickup to record or reproduce information on or from a disc, a pickup movement motor to move the pickup along the disc, a main power supply controller to detect whether power is initially supplied to the optical recording/reproducing device so as to output a home-in control signal, and a drive controller to perform a home-in operation to move the pickup to a predetermined reference position of the disc, only when power is initially supplied according to the home-in control signal of the main power supply controller. Since the home-in operation is performed only when power is initially supplied to the optical recording/reproducing device, the number of home-in operations is minimized.

Abstract: The present techniques provide methods and systems reading a data bit of interest on an optical data disc with a reduced error rate. The data bit estimation may be improved by reducing deterministic noise resulting from an optical reader system and/or the optical data disc. The reader may adjust the position of a detector to detect light scattered from the disc based on parameters of known noise sources. In one embodiment, the detector may be moved vertically in relation to the data bit of interest on the optical disc. In another embodiment, more than one detector may be used to detect light scattered from a data bit of interest. In embodiments, the positioning of the detector(s) may be based on system or disc parameters, and the detected scatterings may provide a data reading, improved for an optical return from a present micro-hologram.

Abstract: A write strategy for use in recording is determined from recommended write strategy parameters recorded on an optical disk (160) and the characteristics of the optical recording device used in recording; a recommended asymmetry value is determined from the difference between the numerical aperture NA1 of the objective lens, which is a recording condition of the recommended asymmetry value recorded on the optical disk (160) and the numerical aperture NA2 of the objective lens (150) of the optical recording device used in recording, and recording is carried out on the optical disk (160) according to the write strategy and asymmetry value thus determined. Optimal recording can be carried out even on an optical disk for which the optimal write strategy information has not been determined in advance, without the need to store write strategy information suitable for each and every optical disk.

Abstract: A method and apparatus for recording data on an optical disk calculates an optical power at a first recording speed, compares the calculated optical power to a predetermined value, and then determines whether to apply the first recording speed based on a result of the comparison. The optical power at the first recording speed is calculated based on a reference optical power and a measured optical power, and the predetermined value may correspond to the maximum allowable power of a laser pickup. The method and apparatus may be used to control the speeding, timing, and/power of a data recording operation, as well as to compensate for temperature variations and/or power margins of one or more circuits in an optical disk device.

Abstract: An automatic power control system, an automatic power control method, a down sampling circuit and a down sampling method. The automatic power control system is incorporated in an optical disc drive comprising a laser diode for receiving a control signal to generate a laser beam; and a photodetector for detecting the laser beam to generate an analog input signal. The automatic power control system comprises an analog-to-digital converter, a down sampling circuit, a comparator, and a digital-to-analog converter. The analog-to-digital converter converts the analog input signal to digital data. The down sampling circuit, coupled to the analog-to-digital converter, comprises a down sampler, a counter, and a controller. The down sampler receives a predetermined amount of digital data to generate representation data. The counter, coupled to the down sampler, calculates the amount of digital data, and resets the down sampler when the amount equals or exceeds the predetermined count.

Abstract: An information recording/reproducing device which can record or reproduce the predetermined information quickly and properly is proposed. An information recording/reproducing device 10 detects recording condition of an area in radial direction of an optical medium 2 using the rotation angle in a layer 0 as a standard when recording given data in a layer 1 of the optical medium 2 and on the basis of the detection result, controls power of laser beam irradiated on the layer 1 to record or reproduce given recording data.

Abstract: In order to ensure recording quality while suppressing the adverse effects due to performance variations among apparatuses and disc radial positions on an optical disc, an optical disc apparatus according to the present invention performs, at the time of data recording, the steps of: acquiring a jitter value and ? value from a reproduced signal based on laser light reflected from the optical disc in relation to a disc radial position; learning a ? value when the acquired jitter value is a minimum as a target ? value; and, if a jitter value acquired thereafter is larger than the minimum jitter value by a preset reference value or above, correcting recording power based on the magnitude relation and the difference between the ? value associated with the acquired jitter value and the target ? value or performing trial record processing.

Abstract: Methods and devices are described for writing to an optical record carrier, in which a mark representing recorded data is written in a phase-change layer of a record carrier by a sequence of radiation pulses. A rear heating pulse is introduced after a last write pulse and a front heating pulse is introduced before the first write pulse. The power level of the front heating pulse and the power level of the rear heating pulse may be dependent on the length of the mark to be recorded and on properties of the record carrier. The method results in a reduced jitter of the marks written, especially when writing at high recording speeds.

Abstract: In an optical disk apparatus, by obtaining the temperature in the vicinity of a laser in the apparatus, the power source voltage of the laser driver is controlled such that power consumed by the headroom of the laser driver is reduced to the maximum extent without deteriorating the current drive characteristic of the headroom when the temperature becomes higher. The laser driving current of the laser driver is monitored to control the power source of the laser driver such that the power consumed by the headroom is possibly reduced while maintaining the current drive characteristic of the headroom for the monitored current.

Abstract: An optical disk writing apparatus enhances writing accuracy by writing first data (e.g., test data) that encodes a first writing strategy within first patterns on an optical disk, in response to a first writing signal. A reproducing signal is generated in response to reading the first data from the optical disk. Variations between leading and trailing edges of the first writing signal and leading and trailing edges of the reproducing signal are detected. A correction value is determined using a jitter evaluation function to evaluate the detected variations. From these operations, a second writing strategy is determined using the correction value to modify the first writing strategy. Thereafter, second data (e.g., actual data) is written, which encodes the second writing strategy within second patterns on the optical disk.

Abstract: A method and apparatus for manufacturing an optical disk master and an optical disk, including measuring the reflectance of laser light at each of a plurality of radius positions by applying the laser light to an optical disk master-forming substrate provided with an inorganic resist layer, the laser light having a non-recording laser power smaller than a recording sensitivity of the inorganic resist layer, producing recording power control data indicating recording laser powers in accordance with the radius positions of the optical disk master-forming substrate by using the reflectances measured, forming an exposure pattern on the inorganic resist layer by applying the laser light to the optical disk master-forming substrate on the basis of the recording power control data while the recording power is varied in accordance with the radius positions, and developing the inorganic resist layer provided with the exposure pattern so as to prepare an uneven pattern.

Abstract: In an optical disc having N (N is an integer larger than or equal to 3) information recording layers of rewritable or recordable type, each of the information recording layers includes an test area to adjust conditions for recording and reproduction and the test areas are arranged so that the radial positions thereof overlap those of other layers. Recording test is performed only to an area smaller than or equal to 1/N of the test area of each layer and any other area is always unrecorded (write inhibited).

Abstract: In a super-resolution optical disk for the purpose of achieving an increase in the density of recording data by reproducing a recording mark smaller than optical resolution, the optimum reproduction power needs to be determined since the quality of a super-resolution reproduced signal strongly depends on the reproduction laser power. However, since the track error signal required for tracking servo also depends on the reproduction power, there is a need for a method for determining the reproduction power taking into account both the stabilization of tracking servo and a quality improvement of the reproduction signal. The reproduction power is changed under conditions with focusing servo applied but without application of tracking servo. Thereby, a cross track signal is detected to identify a reproduction power region that leads to quality improvement of both a reproduction signal and a track error signal.

Abstract: Provided is an optical disk apparatus which optimizes a frequency of a high frequency superimposing operation upon reproduction so that good reproduction performance is realized in a wide irradiation power range of a laser power. The optical disk apparatus includes: a semiconductor laser device; an optical disk discrimination circuit for performing laser discrimination; a driver device including a drive circuit for supplying direct drive current to the semiconductor laser device and a high frequency superimposing circuit for superimposing high frequency current on the drive current; and a high frequency superimposing variable circuit for changing a frequency of the high frequency current in which when information is reproduced, the high frequency superimposing variable circuit sets the frequency of the high frequency current for reproducing a multi-layer disk to be higher than the frequency of the high frequency current for reproducing a single-layer disk.

Abstract: An apparatus for recording and reproducing an information signal on and from an optical disc includes a memory. The information signal is written into the memory. The information signal is read out from the memory. An optical head generates a laser beam in response to the readout information signal, and applies the laser beam to the optical disc to record the readout information signal on the optical disc. A test signal is recorded on a position of the optical disc near a recording position thereof via the optical head during the writing of the information signal into the memory. The test signal is reproduced from the optical disc. The reproduced test signal is evaluated to generate an evaluation result. An intensity of the laser beam is optimized in response to the evaluation result.

Abstract: When recording or reading an optical disc having plural data recording layers, which data recording layer the light spot is focused on is detected to improve playback signal quality and signals written to the layer on which the light spot is focused are read more reliably. A convergent lens converges the laser beam on the optical disc, and a focus controller controls the focal point of the laser beam on the data layer. A tracking controller positions and tracks the focal point of the laser beam converged by the convergent lens on a track of the optical disc. A photodetector detects the reflected laser beam from the disc. A convergence detector then detects the convergence state of the laser beam emitted to the plural data recording layers. Based on output from the convergence detector, the laser driver is controlled to separately set beam power appropriately for each of the plural data layers of the disc during playback.

Abstract: The invention relates to the field of the optical recording of information on a medium, such as an optical disc. To read an optical disc in super-resolution mode, a procedure for optimizing the power of the read laser beam is implemented. This optimization is based on the observation that a correlation exists between the power allowing the disc to be read without risk in super-resolution mode and the reflectivity of the sensitive layer containing the information. The reflectivity of the optical disc is measured for several power levels of the read laser, a critical power is determined on the basis of the reflectivity measurements made, and a read power sufficiently above the critical power, so as to be well outside a range of power levels entailing risks, is selected according to the critical power.

Abstract: A writing current circuit (42) supplies a controlled electrical current to a laser diode (34) for recording data swiftly onto a DVD (16). A plurality of current sources (62) in the writing current circuit (42) supply electrical current to the laser diode (34). Each current source (62) respectively receives a single output signal from a current control register (52) included in the writing current circuit (42) which activates or deactivates the current source (62) for supplying a particular quantity of electrical current to the laser diode (34). In each current source (62), electrical current flows to the laser diode (34) through a MOSFET output transistor (142) connected in series with the laser diode (34). Each current source's MOSFET output transistor (142) has a gate insulating layer which is thinner than the gate insulating layer conventionally used for a MOSFET output transistor (142) that is energized by the electrical potential the it applied to the writing current circuit (42).

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

Abstract: 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: According to one embodiment, an optical disk device includes a laser light source that emits laser light to be applied to an optical disk, an automatic power control circuit that controls a laser output of the laser light source, and a control processor that performs a setting data transmission process for the automatic power control circuit. The automatic power control circuit includes an operation setting module that makes an operation setting according to setting data obtained in the setting data transmission process of the control processor and a condition determining module that determines whether an operation setting permission condition containing the number of clocks during a transmission period of the setting data is adequate, and inhibits the operation setting of the operation setting module when the operation setting permission condition is not adequate.

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: 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: 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: [PROBLEMS] To provide an optical information reproducing device capable of performing excellent super resolution reproduction at all times without complicating the hardware structure. [MEANS FOR SOLVING PROBLEMS] An optical information reproducing device (10) irradiates a laser beam to an optical information recording medium (16) in which effective spot size of the irradiated laser beam changes in accordance with intensity of the laser beam and reproduces information. The optical information reproducing device (10) includes: an asymmetry detection unit (13) as asymmetry detection device for obtaining asymmetry from a reproduction signal obtained by reproducing the information; and a laser power adjusting unit (14) as laser power adjusting device for controlling the laser beam intensity according to the asymmetry obtained by the asymmetry detection unit (13).

Abstract: Provided are a method of controlling a recording operation in an optical disc drive to improve recording quality and an optical disc drive employing the method. The method includes setting recording power and parameters related to the generation of recording pulses by successively performing an optimum power controlling (OPC) process for adjusting recording power and an optimum write strategy (WST) tuning control (OWC) process for adjusting parameters related to the generation of recording pulses. The method also includes performing data recording based on the set recording power and the set parameters related to the generation of recording pulses.

Abstract: An information recording medium according to the present invention includes at least three information recording layers. If the readout power of a laser beam in reading information from an information recording layer L(n) is identified by Pw(n), and if the readout power of the laser beam in reading information from an information recording layer L(n+a) is identified by Pw(n+a), then a base thickness between the information recording layers is determined so that the intensity of the light when the information recording layer L(n+a) is irradiated with a laser beam having the readout power Pw(n) becomes equal to or lower than that of the light when the information recording layer L(n+a) is irradiated with a laser beam having the readout power Pw(n+a).

Abstract: A data readout method is disclosed that is able to read data from an optical disk capable of super resolution readout with high accuracy. The data readout method allows reading data recorded in an optical disk by irradiating a laser beam onto the optical disk. The method includes the steps of varying a light emission power level of the laser beam while the laser beam is irradiated onto the optical disk, and acquiring a reflectivity of the optical disk corresponding to each light emission power level; calculating a second derivative of a curve representing correlation between the reflectivity and the light emission power with respect to the light emission power; calculating an extreme value of the second derivative; and calculating an optimum readout power level for super resolution readout based on the extreme value.

Abstract: An apparatus for controlling discrete data in a disk overwrite area or a power calibration area comprises a signal-processing unit, an address-processing unit, a control signal-processing unit, a clock recovery circuit, a signal-processing unit parameter control unit, and a clock recovery circuit parameter control unit, wherein the control signal-processing unit uses a message produced by a data on the disc to determine the control signals such as hold, load, or increasing bandwidth for holding, loading, and increasing the bandwidth of the parameters for processing the related circuits (such as the circuit of the signal-processing unit or the clock recovery circuit) of the discrete data produced between the two data clusters, so as to increase the convergent speed of the circuits for assuring the accuracy of reading data.

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: According to one embodiment, a recording/reproduction apparatus includes a power source controller. The power source controller includes a determination unit, a stand-by mode execution unit, and a pause mode execution unit. The determination unit determines whether or not an event associated with at least one of recording and reproduction of the information signal occurs at start-up time. The stand-by mode execution unit executes a stand-by mode in which the power level of each of the encoder, the decoder, the recording medium, and the plurality of signal processors is controlled to be lower than a predetermined level. The pause mode execution unit executes a pause mode in which the power to each of the encoder, the decoder, the recording medium, and the plurality of signal processors is turned off, and the power level of the process controller is controlled to be lower than the predetermined level.

Abstract: Directed to freely adjusting an emission period of a semiconductor laser. In the present invention, pulsed light serving as pulse-shaped laser light (LL) is emitted from a semiconductor laser (3), and a laser drive voltage (DJ) that is generated on the basis of a pulse signal (SL) and that has pulse-shaped drive voltage pulses (DJw) is applied to the semiconductor laser (3). At this time, a short-pulse light source (51) varies a voltage period (TV) corresponding to an interval between the drive voltage pulses (DJw), thereby varying a set period (TS) corresponding to an interval between generated signal pulses (SLw) in the pulse signal (SL).

Abstract: Each layer includes a data recording area and a test writing area divided into a plurality of small areas, wherein the small areas of the test writing area are recorded in advance so that other each layer can make a combination of recorded and unrecorded states with respect to the small area, where OPC is carried out, in a layer where OPC is carried out. Moreover, OPC is carried out to each small area, where a combination of recorded/unrecorded states of other each layer differs from each other, to thereby calculate, as the optimum power, an average value of the result of each OPC or a central value of the dispersion thereof.

Abstract: Medium recording and reproduction apparatus and method can prevent prohibition of disc recording due to the fact that laser power calibration area becomes unusable by studying a management information update method during data recording. When usable capacity of the laser power calibration area is monitored and the capacity is reduced, management information area to be currently updated is changed to another layer.

Abstract: When setting a recording power for use in recording optical information on a DVD-R, by using any one of sectors provided on the DVD-R as a PCA, whether a predetermined special detected signal is detected or not in the sectors is checked (Step S2), a non-used sector where no special detected signal is detected, of the sectors, is retrieved, based on the check result (Step S3), a mark signal for obtaining the special detected signal is recorded in the retrieved non-used sector (Step S5), a setting signal for setting a recording power is recorded in the non-used sector excluding the area where at least the mark signal is recorded (Step S6), and the recorded setting signal is optically detected to set the recording power (Step S13).