Abstract: An information processing apparatus includes a data processing section configured to generate data that is capable of being played back using general playback control information containing clip information defining the number of playback packets. The data processing section generates a data file in which data containing a number of playback packets, the number matching the defined number of playback packets, is contained as playback data associated with the clip information.

Abstract: A method for evaluating reproduced signal wherein when Euclidean distance is calculated by judging the coincidence between a binary bit array and a predetermined evaluation bit array in the evaluation of the quality of reproduced signal, in a large capacity optical disc system with constraint length equal to or greater than 5, the assumption is made that the continuous 2T count included in a predetermined evaluation bit array is denoted by i and that each evaluation bit array is composed of a main bit array having a bit length of (5+2i) and auxiliary bit arrays added before and after the main bit array; judgment on whether binary bit arrays include the predetermined evaluation bit array, is concentrated on the coincidence judgment of the main bit arrays; and at the same time, the Euclidean distance between the reproduced signal and the target signal corresponding to the evaluation bit array is calculated with respect to each main bit array and the results of such calculations are separated and counted.

Abstract: An information recording apparatus includes a recording access setting section that executes an operation for setting parameters to be applied during a period of time that the recording section executes a recording operation, prior to the recording operation, and a successive recording control section that controls the verification section and the recording section such that a verification operation for recorded data and the recording operation for data to be recorded next are executed successively. The successive recording control section controls the recording access setting section such that the recording access setting section simultaneously executes the setting operation for the recording operation to be executed for the data to be recorded next in the period of time that the verification section executes the verification operation.

Abstract: Provided is a method of obtaining an image of a disc, in which the method obtains an image of an analysis or test result object of a disc by minimizing a difference between the positionings of a magnet of the disc and a magnet of a feeding unit, and an apparatus for driving a disc, wherein the apparatus performs the method. The method includes: fixing a positioning of a disc by using magnetic attraction between a first magnet installed on the disc and a second magnet installed on a feeding unit; minimizing a difference between the positionings of the first and second magnets; and obtaining an image of an analysis or test result object of the disc.

Abstract: It is provided an optical disc drive for playing data from a loaded optical disc medium. A controller of the optical disc drive judges whether the processing command has been received and whether a reset command has been received, measures a time between a reception of the processing command and a reception of the reset command in a case where the processing of the received processing command does not end until the reception of the processing command, determines a processing time limit shorter than the measured time, and in a case where the processing of the received processing command does not end until the decided processing time limit has elapsed after the reception of the processing command, stops the processing of the processing command and notifies that the processing of the processing command has been stopped to the host device.

Abstract: An object of the invention is to prevent damage or performance degradation of an optical component constituting a second optical system, and suppress degradation of the recording/reproducing performance of an optical pickup device. A first laser light source 1 emits a first light beam having a first wavelength. A first optical system 17 guides the first light beam to be emitted from the first laser light source 1 to a first optical disc. A DVD integration unit 11 emits a second light beam having a second wavelength different from the first wavelength. A second optical system 18 guides the second light beam to be emitted from the DVD integration unit 11 to a second optical disc different from the first optical disc in recording density.

Abstract: An optical information reproducing method includes: obtaining information about a wavelength of a reference beam at recording time from a recording medium which stores main information recorded as a pattern corresponding to interference between an information beam and the reference beam and information about the wavelength of the reference beam at the recording time; determining an aiming temperature, which is a temperature of the recording medium suited to reproduce the pattern; determining an aiming incident angle, which is an incident angle of the reference beam at the reproducing time suited to reproduce the pattern; controlling the temperature of the recording medium so that the temperature of the recording medium is generally equal to the aiming temperature; and controlling the incident angle of the reference beam at the reproducing time so that the incident angle of the reference beam at the reproducing time is generally equal to the aiming incident angle.

Abstract: Problems In a recording medium such as DVD, for example, when groups having the same title or the same song and different numbers of channels are recorded, all the groups are reproduced, further, when a DVD author mistakes, contents which are not needed to be reproduced are reproduced. Means for Solving Problems In a case of DVD-Audio, a condition for reproducing a group having at least one track (a group having the longest reproducing time, a group having the largest number of tracks, a group having the largest data capacity) is set, and only the group which matches the condition is reproduced. In a case of DVD-Video, a title can be used instead of the group. In a case of CD, a folder is used instead of the group.

Abstract: An optical recording/reproducing system 1 reads a recorded signal written to a recording track of a recording medium 3 by light. The light is modulated by a drive signal on which a frequency signal is superimposed. The light is scanned along the recording track at a predetermined scan velocity. The optical recording/reproducing system 1 includes a computer 13 and an LD driver 17 that control, based on the scan velocity, a superimposed magnitude of the frequency signal on the drive signal.

Abstract: A method for generating an RFZC signal is disclosed. The method includes the following steps. First, an RF signal is received and the received RF signal is converted into an RF-ENVLP signal. Next, a DC offset of the RF signal is calibrated according to a variation of the RF-ENVLP signal so as to obtain a calibrated RF-ENVLP signal and obtain a gain according to the calibrated RF-ENVLP signal. Then, an RFZC signal is generated according to the calibrated RF-ENVLP signal and the gain.

Abstract: Provided are a method for emulating a separate contents memory unit into an optical disk, an optical disk drive using the same, and an optical disk including a security zone. In the method, when an optical disk processing command from a host is present, whether an optical disk is present in the optical disk drive is judged. When the optical disk is not present in the optical disk drive as a result of the judgment, the contents memory unit is executed as a virtual optical disk. An application stored in the contents memory unit is displayed. The optical disk drive includes an optical disk storage unit, a contents memory unit, and a controller. The optical disk storage unit stores or reproduces contents using an optical disk. The contents memory unit stores contents therein and is executed as a virtual optical disk when the optical disk is not present. The controller controls the optical disk storage unit and the contents memory unit, and controls an access to be made, subject to the contents memory unit.

Abstract: A recording and reproducing apparatus includes a drive unit that reads data from a first medium and a drive unit control unit that controls the drive unit. The apparatus includes a second medium in which the same amount of data as the amount of data recorded in the first medium can be stored, and from or in which data is read or written at a speed higher than a speed at which data is read or written from or in the first medium. The apparatus further includes an input/output unit that inputs a reading request with which predetermined data is read from among data items stored in the first medium or second medium. The apparatus also includes an access control unit which controls the drive unit control unit or a second medium control unit.

Abstract: A method and apparatus for closing a recording range, a method and apparatus for closing a recording medium, a method and apparatus for recording management information, a method and apparatus for recording/reproducing data on/from a recording medium and a recording medium are disclosed. The method of closing a recording medium includes: determining a position in which recognition information is to be recorded; recording valid data located after the determined position into an unrecorded area before the guard area; and recording the recognition information in the determined position. It is possible to reproduce recording media having different versions with compatibility using the recording medium and the method of recording/reproducing the data on/from the recording medium and to reduce a time consumed for closing the recording medium.

Abstract: A recording apparatus includes: a first strategy calculating device (SCD) for calculating a first optimum strategy allowing jitter recorded at a first speed to satisfy a desired condition by adjusting a first standard strategy; a second SCD for calculating a second standard strategy at a second speed by performing clock cycle conversion according to a difference between the first and second speeds on the first standard strategy; a second power calculating device for calculating a second optimum power used at the second speed; a third SCD for calculating a second optimum strategy allowing jitter recorded at the second speed to satisfy a desired condition, by adjusting the second standard strategy; and a fourth SCD for calculating a third optimum strategy at a third speed, based on each of a difference between the first standard and optimum strategies and a difference between the second standard and optimum strategies.

Abstract: The present invention enables audio data to be recorded or played back more easily. LPCM samples from an LPCM sample 301-1 of a first channel to an LPCM sample 304-1 of a fourth channel in audio data are combined in order to generate a GOLS 310-1. An even number of GOLS are combined to generate an audio frame. Header information is added to the audio frame to generate an audio PES packet, which is multiplexed with a video PES packet and recorded onto a recording medium. As a result, the number of bits of the audio frame is an integral multiple of 32. This increases an affinity with a recording and playback apparatus.

Abstract: Systems and methods for block noise detection and filtering are disclosed. One embodiment includes, computing difference magnitudes in pixel values for adjacent pixels in the image. The difference magnitudes can include horizontal difference magnitudes for horizontally adjacent pixels and vertical difference magnitudes for vertically adjacent pixels. One embodiment further includes using normalized sums of the difference magnitudes to determine a set of noise characteristics of the block noise and a set of image characteristics of the image and configuring inputs to the block noise filter using the set of noise and image characteristics.

Abstract: Apparatus characterized as a multi-session data storage medium such as an optical disc, and method for formatting the same. In accordance with various embodiments, a first session is recorded onto the medium with a first set of user data. A second session is subsequently recorded onto the medium with a second set of user data. The second session contactingly abuts the first session without the use of an intervening linking area therebetween. This enhances the data storage capacity of the medium irrespective of the total number of sessions applied thereto. In some embodiments, the first session is described by a first file system and the second session is described by a different, second file system independent of the first file system. The respective file systems may be accessed by different readback systems, such a personal computer (PC) and a gaming system.

Abstract: According to one embodiment, a power management module of a storage device executes a process of stopping rotation of a disk storage medium by selectively using one of a first mode of stopping the rotation of the disk storage medium on condition that a media access command is not received during a predetermined time from last reception of a media access command, and a second mode of stopping the rotation of the disk storage medium on condition that a media access command which causes access to the disk storage medium is not received during a predetermined time from last reception of a media access command which causes access to the disk storage medium. In addition, the power management module executes a process of starting the rotation of the disk storage medium by selectively using one of a third mode and a fourth mode.

Abstract: In an optical disc having a multilayer structure in which recording layers are bonded to each other, the number of times additional writing can be performed is increased. A method for controlling an optical disc device according to the present invention comprises steps of calculating a displacement amount generated when the recording layers are bonded to each other; and identifying the size of a recordable area in a non-usable area predetermined on the recording layer based on the displacement amount.

Abstract: An optical disc is disclosed having a set of primary tracks and a set of alternate tracks. At least some of the primary and alternate tracks are associated. When a CD-DA reader accesses the optical disc, it locates only the primary tracks. By contrast, when a data reader such as a CD-Rom drive accesses the disc, modifications to the Table of Contents (TOC) cause the data reader not to access a given primary track but instead to be directed to its associated alternate track. This alternate track may contain audio (CD-DA) data which may or may not correspond with the CD-DA data in the associated primary track. The alternate tracks may be copy protected, and/or may include compressed (not CD-DA) data which is the subject of digital rights management.

Abstract: An information recording medium comprises a substrate, a second recording layer, a second light transmitting layer, a first recording layer for recording different information from that to be recorded in the second recording layer, and a first light transmitting layer. The second recording layer is formed with a continuous second microscopic pattern of grooves. The first recording layer is formed with a continuous first microscopic pattern of grooves that is different from the second microscopic pattern. Both sidewalls of raised portions of the first and second microscopic patterns are formed with wobbling so as to be parallel with each other. Auxiliary information and a reference clock is recorded on these sidewalls alternately and continuously.

Abstract: There are provided at least a first information storage area 20A and a second information storage area 40A. The first information storage area 20A contains, in advance, an OS or mpeg data. The second information storage area 40A is either write-once or rewriteable and available for writing OS update information or movie correction information. The configuration enables easy backup and restoration of software, content, and various information including update information for use by the software and content with reduced user time and workload.

Abstract: An optical pickup includes: light collecting element for selectively collecting main and sub beams emitted toward an optical disc formed by layering at least first and second recording layers, onto one of first and second recording layers; main and sub light reception elements receiving the main and sub light from the main and sub beams collected from the optical disc and outputting main and sub light signals; tracking error signal generator for generating a tracking error signal according to the sub light signal; noise component calculator for calculating a noise component generated by interference between the sub light and an invalid light attributed to at least one of the applied main and sub beams and received together with the sub light and the sub light from the other of the first and the second recording layer; and noise remover for removing the calculated noise component from the tracking error signal.

Abstract: In a track offset adjusting method of an information recording medium, data are recorded onto first and second tracks of an information recording medium. No data are recorded on at least one of tracks adjacent to each of the first and second tracks. After the data recording onto the first and second tracks, data are recorded onto the third track adjacent to the inner circumferential side of the first track and onto a fourth track adjacent to the outer circumferential side of the second track. Thereafter, reproduction signal qualities of the first and second tracks are calculated on the basis of reproduction signals obtained by reproducing the data recorded on said first and second tracks. The track offset is adjusted on the basis of the reproduction signal qualities of the first and second tracks.

Abstract: The present invention provides a method and apparatus for optical disc writing. The method provided by the present invention comprises steps: acquiring the writing history information of the optical disc, wherein the data storage area of the optical disc is divided into several writing areas by starting address and ending address of each writing in the history information; selecting a writing area from the plurality of writing areas for the current optical disc writing; determining the write strategy for the optical disc adopted by the current writing for writing the optical disc; and updating the writing history information of the optical disc. According to the method provided by the present invention, the appropriate area can be selected to carry out the optical disc writing, so that the life cycle shortening of the optical disc due to the over-usage of partial recording areas will be avoided, furthermore, the appropriate write strategy can be determined to improve the optical disc writing effects.

Abstract: A movement speed of a lens included in an optical pickup is calculated by differentiating a total reflection return light quantity that is detected by emitting laser light and near-field light onto a signal recording surface of a rotationally driven optical disc. On the basis of the calculated movement speed, processing for driving the optical pickup or the lens included in the optical pickup is controlled. For example, in a case where the calculated movement speed exceeds a permissible speed set in advance, retreat processing is performed for moving the optical pickup or the lens included in the optical pickup apart from a surface of the optical disc.

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: An optical disc drive includes: a means (116, 117) for generating a synchronization signal from a wobble read signal having location information configured by a wobbled groove; a timing correction circuit (127) that generates a control signal having a time width TW after a predetermined time length from the synchronization signal; and a DC level correction means (126) for clamping the DC level of an information read signal for the time width of the control signal, to thereby correct the DC level. After an information read signal in a vicinity of a head of a recorded data field is subjected to the DC level correction by using the DC level correction means (126), the signal is reproduced by binarizing means disposed at the successive stage.

Abstract: In a data recording method for a write-once type recording medium capable of pseudo overwrite, it is judged whether data to be recorded in the write-once type recording medium exists. If it is judged that data exists, it is judged that the data is to be recorded from the next writable address (NWA) indicating the boundary between a recorded area and non-recorded area. If it is judged that the data is to be recorded from the next writable address, the data is recorded from the next writable address; and if it is judged that the data is not to be recorded from the next writable address, recording of the data is suspended. While data to be recorded exists, the aforementioned steps are repeated. If no data to be recorded exists, the data whose recording has been suspended is recorded.

Abstract: In a method of head-disk contact detection in a hard disk drive, a Radio Frequency (RF) carrier signal is injected into a slider which is flying above a surface of a disk in a hard disk drive. A modulated version of the RF carrier signal is received from the slider. The modulated version of the RF carrier signal is demodulated to achieve a demodulated signal. A signal spectrum of a range of frequencies in the demodulated signal is monitored for activity indicative of a contact between a head of the slider and the surface of the disk. An occurrence of the contact is determined based upon an occurrence of the activity.

Abstract: In an optical head apparatus and an optical disc apparatus which can reduce influence of interlayer stray light on a differential push-pull signal without making the configuration complicated, Uy=Ty×N1 is satisfied, where Ty denotes a length in the y-direction of one period of an interference fringe which is formed on the photodetector 9 by reflected light of the zero-order diffracted light by an information recording surface other than the access-target information recording surface, reflected light of the positive-first-order diffracted light by the information recording surface other than the access-target information recording surface, and reflected light of the negative-first-order diffracted light by the information recording surface other than the access-target information recording surface, N1 denotes a positive integer, and Uy denotes each length in the y-direction of the divisional light-receiving elements 9e, 9f, 9g, and 9h.

Abstract: An information recording/reproducing apparatus is disclosed which includes: a recording section for recording files to a storage medium; an arranging section for arranging the files into groups by attribute so as to establish allocation of the files on the storage medium; and a controlling section for controlling the recording section so as to record the files to the storage medium based on the allocation established by the arranging section and to record concurrently allocation information reflecting the allocation to a predetermined location on the storage medium.

Abstract: An information storage medium and a recording/reproducing apparatus and method are provided with the ability to extend at least one middle area of an information storage medium comprising two or more recording layers so as to ensure optimal data recording/reproduction. The information storage medium comprises a plurality of recording layers, each including a user data area for recording user data and at least one middle area used by a recording/reproducing apparatus that records/reproduces data on the information storage medium to move among two recording layers, wherein the at least one middle area is extended when the information storage medium is finalized. As a result, when an information storage medium that contains an OPC area for obtaining optimum recording conditions (such as recording power) in an outer circumference thereof is finalized, and if a middle area of the disk is not large enough, the middle area can flexibly be extended.

Abstract: An information storage medium, and a recording/reproducing apparatus and method, the information storage medium including a plurality of recording layers, each layer including a lead-in area or a lead-out area, a data area, a middle area, and a dedicated area, wherein the data area is flexibly allocated according to data capacity to be recorded in each of the recording layers, the middle area is allocated behind the data area, and the dedicated area is allocated behind the middle area. The dedicated area for a special purpose may selectively be allocated in an outer circumferential area of the information storage medium, i.e., an optical disk including a plurality of recording layers. In particular, optical disks in various formats are provided in which dedicated areas for special purposes can selectively be allocated in outer circumferential areas of the optical disks depending on recording characteristics of the optical disks and the outer circumferential areas.

Abstract: An information storage medium and a recording/reproducing apparatus and method are provided with the ability to extend at least one middle area of an information storage medium comprising two or more recording layers so as to ensure optimal data recording/reproduction. The information storage medium comprises a plurality of recording layers, each including a user data area for recording user data and at least one middle area used by a recording/reproducing apparatus that records/reproduces data on the information storage medium to move among two recording layers, wherein the at least one middle area is extended when the information storage medium is finalized. As a result, when an information storage medium that contains an OPC area for obtaining optimum recording conditions (such as recording power) in an outer circumference thereof is finalized, and if a middle area of the disk is not large enough, the middle area can flexibly be extended.

Abstract: A disk device includes a main control unit controlling the operation of a controlled object on the basis of an error signal calculated from a target signal of the controlled object and an observation signal of the controlled object, a repetitive control unit sampling the error signal with a sampling clock pulse to obtain a repetitive signal component generated in synchronization with rotation of the disk medium from the sampled error signal, a sampling clock generation unit generating the sampling clock pulse and resetting a timing at which the sampling clock pulse is generated in accordance with a rotation detecting pulse and a sampling clock limit unit limiting generation of the sampling clock pulse at a timing immediately before generation of the rotation detecting pulse.

Abstract: An optical disc apparatus that reproduces images from an optical disc by reading image data from the optical disc and displaying images based on the image data read from the optical disc. When the optical disc apparatus reproduces images from an optical disc, the apparatus performs a preparation operation for reproduction of images from the optical disc. During the preparation operation, a controller sequentially displays different types of initial images as time passes. For example, the first initial image, which is to be displayed first of the initial images, is an image indicating the type of the optical disc as well as showing the name of the manufacturer of the optical disc apparatus. The second and third initial images are a scenic image and an image showing a message to a user, respectively.

Abstract: An information recording medium according to the present invention includes a track on which a data sequence including a plurality of recording marks and a plurality of spaces provided between the plurality of recording marks is recordable; and a recording condition recording area in which a recording condition for recording the data sequence on the track is recordable.

Abstract: When a method for increasing density by providing a tracking guide such as a land/groove and introducing a plurality of strings of super-resolution pits into one track thereof is applied to a reproduction-dedicated optical disk, there are problems in that the production cost is increased, the structure is complicated, and the space which can be used for a recording pits is narrowed because of the land/groove structure. In the invention, a concept of group tracking is applied. One track is formed by a plurality of pit strings having a size not greater than the optical resolution limit in the radial direction and a size not less than or not greater than the optical resolution limit or only not greater than the optical resolution limit in the tangential direction.

Abstract: An information reproducing apparatus (1) is provided with: a reading device (10) for reading contents data; an operating device (41) constructed to rotate depending on an operation of a user; a detecting device (42) for detecting rotating operation performed on the operating device as operating signal (d); a generating device (22) for generating modulation signal (d?) by adding a predetermined additional signal (d?) vibrating at a fixed frequency or a variable frequency to the operating signal; a reproducing device (15) for reproducing the contents data, while determining reproduction speed and reproduction direction of the contents data on the basis of the modulation signal.

Abstract: A super resolution medium (1) is provided with an information signal region (11) where a content, such as a video or audio content, is recorded and a test read region (12) where reproduction setting value adjustment information is recorded for adjusting a setting value for reproduction. A shortest mark length on a first prepit row formed in the information signal region (11) is shorter than a length of an optical system resolution limit of a playback apparatus. The types of mark lengths, recorded in the test read region (12), on the second prepit row for adjusting the setting value are the same as part or all types of mark lengths on the first prepit row. Further, the second prepit row includes a prepit having a mark length shorter than the length of the optical system resolution limit of the payback apparatus. Still further, each of the first and second prepit rows has at least three types of mark lengths.

Abstract: The invention relates to a method and a device for recording information on a recordable multi-layer DVD disc wherein information is incrementally recorded on the disc such that the area regarded as containing written information on the first information layer is substantially equal to the area regarded as containing written information on the second information layer. However, an area regarded as containing written information may comprise an area where no information is recorded. In this way a recordable disc is produced from which DVD-ROM players can retrieve the recorded information.

Abstract: As a synchronization signal pattern to be added, a pattern is generated (second SYNC pattern), which has a pattern that breaks a maximum run inserted in a pattern excluding a minimum run is used so that intersymbol interference does not occur readily on a high-density disc, and addition processing of a conventional synchronization signal pattern (first SYNC pattern) is switched according to identification information indicating whether or not a high-density disc for generation.

Abstract: According to one embodiment, a frequency characteristic adjusting circuit includes a cutoff range adjusting module and a control signal inputting module. The cutoff range adjusting module is connected to an AC coupling circuit capacitively coupled with a signal transmission path, and allows an output signal from the AC coupling circuit to pass through such that a low cutoff range in the frequency characteristic of the AC coupling circuit varies. The control signal inputting module receives a control signal to control a zero-point frequency based on a numerator polynomial of a transfer function of the cutoff range adjusting module and a pole frequency based on a denominator polynomial of the transfer function. The numerator polynomial is equalized to a denominator polynomial of a transfer function of the AC coupling circuit by the control signal. A cutoff frequency is determined by the pole frequency according to the control signal.

Abstract: The present invention discloses an optical drive and a method for preprocessing a disc readout signal rk of an optical drive on the basis of a set of low-pass filters. The cutoff frequency fC of the filters wk, more particularly, can be set within the optical bandwidth, which improves the Viterbi detection performance in the case of high speed drive operations. Three types of filters are described, in which a Type I shaping filter performs best given a limited hardware cost for the bit detector. Compared to other more advanced noise-whitening techniques, it is only speed dependent and requires little prior knowledge of the channel and noise, thus cheap and easy to design. The invention can be applied in connection with optical disc drives, in particular when high frequency noises are dominant, for example, in the case of high speed operations.

Abstract: A disc playback apparatus includes a decoder 15 for decoding audio files respectively corresponding to different data formats, which are stored in a storage unit, on the basis of a file attribute preset thereto, and for playing back the decoded audio files, and a control unit 16 for determining a file attribute of data read from the storage unit when starting the decoding and playback process on a basis of the file attribute set to the decoder, and for, when the file attribute differs from the file attribute set to the decoder, holding address information about the read data, and, after stopping the reading of subsequent data, changing the setting of the file attribute made for the decoder and then restarting to read the data by using the address information held thereby.

Abstract: According to one embodiment, a medium processor includes a detector, an acquiring module, a storage module, and an output module. The detector detects a data storage medium. The acquiring module acquires a use period that is set as a period during which data recorded on the data storage medium is supposed to be intact. The storage module stores identification information that identifies the data storage medium in association with the use period. The output module outputs the identification information and the use period stored in the storage module in association with each other.

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: Information is recorded on an information recording medium by classifying recording conditions by data pattern, including at least one recording mark and at least one space, of a data stream to be recorded; wherein the classification of the recording conditions by data pattern is performed using a combination of the length of a first recording mark included in the data stream and the length of a first space located adjacently previous or subsequent to the first recording mark, and then further performed using the length of a second recording mark which is not located adjacent to the first recording mark and is located adjacent to the first space.

Abstract: An optical information recording apparatus includes a first optical system that radiates an information beam that carries information onto a recording medium; a second optical system that radiates reference beams onto the recording medium; a radiation position specifying unit that specifies a plurality of recording spots positioned within a radiation range of the reference beams; and an incident angle obtaining unit that specifies an incident angle of the reference beams that is used for recording an i'th interference fringe into a second recording spot adjacent to a first recording spot, as a value obtained by adding a product of 1/(1+m) and an absolute value of a difference between an incident angle of a first reference beam used for recording an i'th interference fringe into the first recording spot and an incident angle of a second reference beam used for recording an (i+1)'th interference fringe into the first recording spot.