Abstract: An LPP detection unit detects an LPP from a wobble signal. A correction unit obtains a difference set by performing processing of calculating a difference in signal level between an LPP-present sync pattern portion and a non-LPP sync pattern portion having the same polarity, and executes correction on an RF signal at a timing when the LPP is detected, by using the difference set. The LPP-present sync pattern portion is a sync pattern portion obtained when the LPP is detected at the timing of the sync pattern portion positioned at the head of a sync frame of the RF signal. The non-LPP sync pattern portion is a sync pattern portion obtained when no LPP is detected at the timing of the sync pattern portion of the sync frame. In the case of reproducing information recorded on a DVD-R/RW optical disk, the occurrence of errors due to the effect of the LPP can be reduced.

Abstract: A focus jump technique enables focus control on recording layers of a disc in such a manner that its effect is not absorbed by disturbance or a variation in the movement speed of an objective lens. The technique involves monitoring level of a focus error signal and rejecting noise from the error signal. A speed sensor detects movement speed of an objective lens; and a speed control circuit generates a voltage for controlling the objective lens, based on the detected movement speed. Movement speed of the objective lens is detected during focus jump, a corresponding lens drive signal is generated, and an end position is determined from behavior of the error signal immediately before the end of the jump. A focus control is pulled, from a focus point corresponding to one recording layer, into a focus point corresponding to another recording layer forcibly in a stable manner.

Abstract: A technique for investigating differences of composition and structural state of a recording layer of an optical disc along with other defects, such as scratches, contamination, warp and distortion, prior to video recording and for setting up appropriate recording conditions in compliance with this result to thereby perform recording is disclosed. In an optical disc recording device capable of recording information on an optical disc, a region to be investigated is defined based on the video recording reservation contents. Then, investigate and evaluate the disc state which can affect the recording quality in a target disc region to be recorded. Next, based on investigation/evaluation results, perform recording setup, recording speed setup, servo control setup and recording position setup to thereby perform the recording. By appropriately modifying the recording setup on a case-by-case basis, it is possible to achieve high-quality recording.

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: Provided herein are hybrid laser diode drivers (LDDs) that drive a laser diode in response to receiving enable signals from a controller. In accordance with specific embodiments, a hybrid LDD includes a read channel to selectively output a read current, one or more write channel each to selectively output a write current, and an oscillator channel to selectively output an oscillator current. Additionally, in specific embodiments the hybrid LDD includes a state machine that receives the enable signals from the controller, and based on the enable signals, controls timing of the currents output by the read, write and oscillator channels.

Abstract: An information recording/reproducing apparatus including an optical pickup unit for generating an RF signal performs signal processing to acquire, at a restart of recording after a halt of recording, a data ID to be used as a reference for specifying a recording restart position in the recording medium based on the RF signal. The signal processing includes reproduced signal generation processing to generate a reproduced signal based on the RF signal, and data ID acquisition determination processing to determine, at the restart of recording after the halt of recording, whether or not the data ID has been properly acquired, based on the reproduced signal. If it is determined in the data ID acquisition determination step that the data ID has not been properly acquired, a reproduction parameter to be used for generating the reproduced signal in the reproduced signal generation step is adjusted.

Abstract: An optical disc recording method for recording disc information to be used in recording/reproducing control on an optical disc, comprises the following steps of: providing a first disc information unit and a second disc information unit, each having a predetermined data size, in a predetermined management information area of the optical disc; the disc information includes write strategy information; separating the write strategy information into first write strategy information and second write strategy information; recording the first disc information into the first disc information unit; and recording the second disc information into the second disc information unit.

Abstract: A recording device including: an optical head section for irradiating a recording medium with laser to record and reproduce information; a laser driving section for driving the optical head section to output laser; and a control section for, in a process of adjusting recording laser power output from the optical head section, obtaining an evaluation value of a recorded area after a predetermined period of time elapsed since data was recorded as an evaluation value about a reproduction signal during reproduction of the recorded data, and adjusting recording laser power on the basis of the evaluation value after the predetermined period of time elapsed since data was recorded.

Abstract: An optical disc recording apparatus for recording a video object onto an optical disc. A recording area of the optical disc is divided into a plurality of zones which each include a plurality of adjacent tracks. The optical disc recording apparatus includes: a reading unit for reading from the optical disc the sector information showing data assignment for sectors on the optical disc; a recording unit for recording the video object onto the optical disc; and a control unit for controlling the reading unit and the recording unit. The control unit detects at least one series of consecutive unassigned sectors on the optical disc by referring to the read sector information. Each series has a total size greater than a minimum size and is located within a single zone. The minimum size corresponds to a data amount that ensures uninterrupted reproduction of the video object. The control unit also controls the recording unit to record the video object into the detected series.

Abstract: A semiconductor storage device including a memory cell and having a function of refreshing the memory cell, includes a clock generation circuit configured to receive a first clock, generate a second clock based on an inversion of the first clock, and output the second clock. The semiconductor storage device performs operation of the refresh function in synchronization with at least one of the first and second clocks.

Abstract: The present invention aims to provide a reproduced signal evaluation method and a write adjustment method for offering a Blu-ray disc having a large storage capacity with excellent media compatibility. An evaluation index L-SEAT is calculated through signed addition using a Euclidean distance difference calculated from at least one of target signals in which a focused edge is shifted to the right and left, and the quality of the reproduced signal is evaluated based on the evaluation index. Write condition adjustment using the index enables write adjustment not depending on SNR and achieving high adjustment accuracy.

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: According to one embodiment, a disk comprises an area which comprises a plurality of data tracks and is partitioned into a first segment and a plurality of second segments. A controller detects that a segment to be refreshed next is one of the plurality of second segments. The controller saves data stored in the one of the plurality of second segments into the first segment when a segment to be refreshed next is the one of the plurality of second segments.

Abstract: A method and apparatus for determining an optimal writing power for recording data on a recording medium such as an optical disk, are discussed. The method according to an aspect of the present invention includes (a) performing a plurality of OPC operations on a plurality of areas of the recording medium, the plurality of OPC operations being performed in mutually different manners, the plurality of areas being areas within a power calibration area (PCA) allocated in the recording medium; and (b) determining an optimal writing power for recording data on the recording medium based on writing powers detected via the plurality of OPC operations.

Abstract: A DRM disk such as a Blu-ray stores content in a high resolution version for playing by a disk player. The disk also stores the same content in a lower resolution version for playing by a secondary device such as a Playstation Portable (PSP). The disk can be engaged with the disk player and the lower resolution format transferred to the secondary player through a mechanism such as a removable medium (e.g., a Sony Memory Stick®) or a USB connection or other means in accordance with DRM restrictions on the disk.

Abstract: Data storage systems are provided. Data storage systems illustratively include a writing element and a recording medium. In some embodiments, the writing element generates first and second magnetization fields that respectively record first and second magnetization patterns to the recording medium. In some embodiments, the writing element is de-saturated between recording the first and second magnetization patterns.

Abstract: A Spare Area kept unused on a disk is available for use other than spare processing, or Defect Management process, and compatibility of the disk is at least secured between different recording apparatuses. This is implemented by recording a SWP_PAC cluster defined as a new item and by recording address information of used addresses in a PAC or TDDS area.

Abstract: A small size circuit reproducing data with low error rate even when a signal includes a non-linear distortion is desired. In such a circuit, the Viterbi method is performed. In the Viterbi method, branch metrics are calculated based on a difference of a sampled reproduction signal and a predetermined expectation values. Path metrics are calculated from the branch metrics. Paths among the plurality of paths having the calculated path metrics and merging at a same state are compared with one another. Based on the magnitude of the compared path metrics, survivor path is selected. In the circuit, for the path metrics of paths merging at a same state, offset corresponding to a determination result until a merging point is added to the paths for the comparison for determining the survivor path from the plurality of merging paths.

Abstract: A recording apparatus is provided with: a recording device for recording a data pattern onto a recording medium provided with a user data area; a first controlling device for controlling the recording device to record the data pattern for adjusting the recording condition into an area portion which is outer than an end on an outer side of a recording-scheduled area portion and in which the data pattern is scheduled to be recorded; a reading device for reading the data pattern recorded by the control of the first controlling device, thereby obtaining a read signal; a measuring device for measuring jitter of the read signal; an adjusting device for adjusting a recording condition such that the jitter satisfies a desired condition, and a second controlling device for controlling the recording device to start the recording into the recording-scheduled area portion by using the recording condition adjusted by the adjusting device.

Abstract: Disclosed is a method of manufacturing a magnetic recording medium capable of effectively and reliably removing foreign materials on the surface of a magnetic recording medium, preventing a mask layer from remaining on the surface of the magnetic recording medium, and forming the pattern of a magnetic layer with high productivity. The method of manufacturing a magnetic recording medium includes: a step of forming a magnetic layer on a non-magnetic substrate; a step of forming a mask layer on the magnetic layer; a step of patterning the mask layer to form a mask pattern; a step of forming a magnetic recording pattern on the magnetic layer using the mask pattern; a step of burnishing the surface of the mask pattern with an abrasive; and a step of removing the mask pattern.

Abstract: An optical disc recording apparatus (10) is provided with a tracking servo (13) for tracking a spiral track of concave and convex marks, an analog signal processor (14) for extracting a reproduction signal corresponding to the concave and convex marks, a digital signal processor (15) for extracting a channel clock synchronized with a channel bit length of the concave and convex marks, and a sub-information recording section (30) for recording sub-information by irradiating laser light based on the tracking to the spiral track. The sub-information recording section (30) records all the sub-information by repeating a process of recording a part of the sub-information by discretely irradiating laser light at a specified interval and with a specified frequency in synchronism with a channel clock by one tracking to form recordable marks on a reflective film a plurality of times.

Abstract: To prevent the degradation in read access performance to replacement data caused by not selecting appropriate replacement clusters and to suppress the waste of the number of DFL registrations. Attention is paid to the usage direction of a user data area and that of a replacement area, and in the case where one CRD-type DFL registration can be made collectively in the sequential defect management processes, a replacement area of which the usage direction is the same as that of the user data area is selected.

Abstract: An optical disc drive, and a method of driving the optical disc drive are provided. Where the optical disc drive has a connectivity or a compatibility with a host that is incompatible with the optical disc drive, a file system and device information accepted by the host are provided. The host may have a compatibility with limited external medium devices and a specific command set for data exchange. The optical disc drive and the method of driving the optical disc drive may transmit compatible information to the host and select the specific command set accepted by the host, so that the optical disc drive is compatible with the host.

Abstract: Various embodiments of the present invention provide systems and methods for data processing. As an example, a data processing circuit is discussed that includes a summation circuit, a data detector circuit, an error feedback circuit, and an error calculation circuit. The summation circuit subtracts a low frequency offset feedback from an input signal to yield a processing output. The data detector circuit applies a data detection algorithm to a derivative of the processing output and provides an ideal output. The error feedback circuit includes a conditional subtraction circuit that conditionally subtracts an interim low frequency offset correction signal from a delayed version of the derivative of the processing output to yield an interim factor. The error calculation circuit generates an interim low frequency offset correction signal based at least in part on the interim factor and a derivative of the ideal output.

Abstract: An apparatus includes a read/write head disposed on a slider, a control circuit disposed on the slider, and an adjustable delay line disposed on the slider. The adjustable delay line delays transmission of aligned write data to the read/write head by an adjustable delay. The adjustable delay is controlled by the control circuit a function of read synchronization data provided by the read/write head.

Abstract: An optical storage medium playback apparatus includes an optical storage access device, a connection port, and a controller. The optical storage access device is implemented for reading a multimedia content from an optical storage medium. The controller is coupled to the optical storage access device and the connection port, and is implemented for storing a portion of the multimedia content read from the optical storage medium into an external storage via the connection port when the external storage is electrically connected to the connection port, and for accessing the portion of the multimedia content which is stored in the external storage electrically connected to the connection port and performing a playback operation upon data read from the optical storage medium concurrently.

Abstract: If a defective cluster in a spare area is managed with a defect entry, the size of a DFL will increase as the size of the spare area increases with an increase in the number of recording layers stacked in a disc. An information recording medium according to the present invention has pointer information indicating the location of the next available cluster in each spare area, and restricts the direction in which the spare area is used. Also, a defect entry indicating a defective cluster in the spare area is registered with the DFL. Thus, even if the size of the spare area 15 increases, the size of the DFL 21 can be kept relatively small. Furthermore, even after physical reformatting is done, a defective cluster, if any, in the spare area 15 can still be recognized as a defect and the control operation can be performed so that a replacement cluster is not re-allocated to that defective cluster (i.e., the defective cluster is not used).

Abstract: A current gain control system is described and comprises first and second gain blocks respectively associated with the first and second input channels, wherein first and second gain blocks transmit first and second gain signals in response to receiving first and second input signals; first and second converters adapted to be respectively coupled to the first and second gain blocks, the first and second converters operative for setting gains associated with the first and second input channel and for transmitting first and second converted signals in response to receiving the first and second gain signals; and first and second switches for selectively coupling the first and second converters to first and second channel drivers, respectively, wherein the first and second channel drivers transmit channel gain signals in response to receiving the first converted signal, and the channel gain signal allows control of the gain associated with the input channel.

Abstract: An input current channel device is described. This device comprises a first terminal for receiving a reference signal; a second terminal for receiving a first target signal; a pass through device coupled to the first terminal, the pass through device operative for transmitting a delayed reference signal in response to receiving the reference signal; a first combination logic device coupled to the first terminal and the second terminal, the first combination logic device operative for transmitting a first combination logic signal in response to receiving the reference signal and the first target signal; a selection device coupled for receiving the delayed reference signal, the first combination logic signal, and a first synchronization signal, the selection device operative for selectively transmitting a second synchronization signal, and wherein selectively transmitting the second synchronization signal reduces skew between the reference channel and the first target channel.

Abstract: A recording medium having a data structure for managing reproduction of multiple audio streams is discussed. The recording medium according to an embodiment includes a data area storing at least multiple audio streams in at least one portion thereof, the multiple audio streams being multiplexed, each audio stream being a transport stream and stored as one or more packets, each packet having a packet identifier, and the packets of a same audio stream having a same packet identifier, and a management area including management information for managing reproduction of the multiple audio streams.

Abstract: A method of how to perform parallel binary information processing on a hard disk drive with magnetic media is invented. Two or more recording heads synchronously and independently write the binary information in the form of “positive” or “negative” “pulses”. All previous information is erased. Then, the sensors synchronously read the profiles of previously written information. As the result of adding, we obtain the superimposed signals that contain information on logic operations. Such operations can be made in parallel for several independent channels of information and with different groups of binary numbers.

Abstract: In a method for causing data to be written to a non-volatile medium, first data to be encoded and written in a sector of the non-volatile medium as a codeword is transmitted to a write or read/write channel device, and a write gate signal corresponding to the sector is asserted. Asserting the write gate signal indicates to the write or read/write channel device when to write the codeword to the sector. While asserting the write gate signal to cause the codeword to be written, second data to be encoded and written to the non-volatile medium is transmitted to the write or read/write channel device.

Abstract: By referring to a table of reproducing conditions and medium specific parameters, stored in an optical disc or optical disc apparatus and/or generated by the optical disc apparatus, the medium specific parameters to be used for performing reproducing power adjustment are changed in accordance with the reproducing condition to execute reproducing power adjustment.

Abstract: A write once disc allowing management of a data area, includes a lead-in zone, a data area, and a lead-out zone. The write once disc includes a predetermined area storing area allocation information which indicates whether at least one section of the data area is allocated for disc defect management. In the disc and method, area allocation information specifying a structure of the data area is recorded on the disc, thus allowing a recording/reproducing apparatus to recognize the data area structure. Therefore, allocating areas, such as a spare area, for disc defect management other than an area for storing user data, to the data area is possible. The allocation of the areas for disc defect management to the data area enables effective use of the write once disc.

Abstract: A magnetoresistive effect device includes an underlayer, an antiferromagnetic layer, a first ferromagnetic layer, a nonmagnetic layer, and a second ferromagnetic layer which are multilayered in this order on a substrate. The underlayer is formed of a metal nitride, and the antiferromagnetic layer is formed of an antiferromagnetic material including Ir and Mn.

Abstract: Provided is a technology in which a controller for controlling read/write performed to/from an optical disc includes a processor for controlling an interface, a temporary memory unit, a rotation control unit, and an optical control unit. The controller causes the processor to shift to a hibernate state when a predetermined condition is satisfied, and causes the processor to recover from the hibernate state into an active state when the interface receives a first command. The processor receives the first command from the interface, instructs the rotation control unit to drive the optical disc at a predetermined target rotational speed, instructs the optical control unit to perform a processing specified by the first command, transmits a completion notification of the first command to the interface with a delay, receives a second command after transmitting the completion notification of the first command, and executes the processing of the second command.

Abstract: An information reproducing apparatus and method thereof. The information reproducing apparatus includes a storage unit, communication unit, controller, and display unit. The storage unit stores music data and at least one first string of characters corresponding to the music data. The reproducing unit reproduces the music data from the storage unit. The communication unit communicates with an image data storage unit, which stores a plurality of image data each corresponding to at least one second string of characters. The controller controls acquisition of one image data from the image data storage unit via the communication unit. The one image data is acquired based on a comparison between the at least one first string of characters and the plurality of the at least one second string of characters. Further, the display unit is configured to display the acquired image data when the reproducing unit is reproducing the music data.

Abstract: According to one embodiment, an information processor includes an optical disc drive, an acquiring module, a storage module, and a determination module. The acquiring module acquires identification information that uniquely identifies an optical disc loaded in the optical disc drive based on information read from the optical disc. The storage module obtains information related to failure analysis of the optical disc contained in state information indicating reading state or writing state upon reading from or writing to the optical disc, and stores the information related to failure analysis in association with the identification information. The determination module calculates values each indicating a level of failure of the optical disc based on pieces of information related to failure analysis of the optical disc stored until just recently in association with the identification information and, when the values satisfy a predetermined condition, determines that there is a risk of failure in the optical disc.

Abstract: The present invention relates to a drive apparatus (20) for accessing an optical record carrier (10) carrying a time-indicative information (T) and a second ROM mark (M2), comprising: —an access unit (21, 25) for accessing said record carrier (10) for reading data from and/or writing data to said record carrier (10), —a time-information detector (D3) for checking for the presence of time-indicative information (T) and for checking, if time-indicative information (T) is present, whether said time-indicative information (T) indicates a time that lies before a predetermined reference time, —a second ROM mark detector (D2) for checking, if said time-indicative information (T) indicates a time that lies on or after said predetermined reference time, for the presence of said second ROM mark (M2), and—a controlunit (23, 24) for controlling said access unit (21, 25) such that the reading and/or writing of data is inhibited if said time-indicative information (T) indicates a time that lies on or after said predetermin

Abstract: An optical-disc apparatus comprising: a laser-light source; an objective lens; an aberration-correction lens to be moved in an optical-axis direction according to a cover-layer thickness of an optical disc; a stepping motor; a driving unit to generate a driving pulse for the motor; a storage unit to store current-position information of the aberration-correction lens based on the number of the pulse; and a control unit to control the driving unit so that the aberration-correction lens is moved between a first position set in a mechanical-movable range of the aberration-correction lens and a second position set on the objective-lens side relative to the first position, the driving unit being controlled so that the aberration-correction lens is moved to the second position when stop of disc rotation occurs, and is moved to a start position between the first-and-second positions according to the thickness based on the information when the stop is cancelled.

Abstract: An information storage medium has user data areas and additional data areas, and sync patterns to distinguish the additional data areas from the user data areas. The information storage medium includes a user data area in which user data is recorded and an additional data area located in at least one of areas before and after the user data area. Second sync patterns used in the additional data area are different from first sync patterns used in the user data area.

Abstract: Provided are an optical disk drive and an advertisement/service system using the same. The optical disk drive includes an optical disk storage unit, an Internet link storage unit, and a controller. The optical disk storage unit stores or reproduces contents using an optical disk. The Internet link storage unit stores an Internet link in an inside and is executed as a virtual optical disk when the optical disk is not presentpresentontroller controls the optical disk storage unit and the Internet link storage unit, and controlling an access to be made, subject to the Internet link storage unit. The service system using the optical disk drive includes a user terminal, an optical disk service network, and a network connecting the user terminal and the optical disk service network. The user terminal includes an optical disk drive configured to allow an Internet link.

Abstract: According to one embodiment, an information processing system includes a plurality of information processing devices connected to one another and capable of transmitting/receiving data to/from one another. One information processing device includes a determiner configured to determine whether an address level included in a transmission signal transmitted from another information processing device is for specifying the one information processing device based on information on the address level, and a data receiver configured to receive real data included in the received transmission signal when the determiner determines that the address level is for specifying the one information processing device.

Abstract: An object of the invention is to suppress an influence of a wavefront aberration which is generated at the time of correcting a third-order spherical aberration, and realize satisfactory information recording and/or reproducing. A collimator lens 4 corrects a third-order spherical aberration which is generated depending on the thickness of a light transmissive layer from a surface of a first optical information recording medium 30, corresponding to an optimal substrate thickness of a first objective lens 6, to an intended information recording surface, assuming that the light transmissive layer thickness of the first optical information recording medium 30 which minimizes a residual third-order spherical aberration at the time of incidence of parallel light into the first objective lens 6 is defined as the optimal substrate thickness of the first objective lens 6.

Abstract: A recording medium comprising a recording area, the recording area includes a first area and a second area, the first area includes a frame area, the frame area includes an area in which a second synchronization code sequence and at least a portion of data are to be recorded, and the second area includes an area in which a third synchronization code sequence and a fourth synchronization code sequence are to be recorded.

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: This invention allows super-resolution reproduction with which a better bER value is attainable, when information is recorded by a random pattern including a mark length not longer than a resolution limit, by use of a highly versatile signal decoding method. Information is recorded as marks and spaces coded by RLL(1,7) modulation, which each of the marks and spaces have one of a plurality of lengths, and 2 T marks and 2 T spaces of the marks and spaces being formed are shorter than 0.12 ?m. An information recording layer (20) includes a reproduction film (21) and a reflective film (22) which are provided in this order from a side from which reproducing light is incident, which reproduction film is made of (i) zinc oxide, (ii) strontium titanate, (iii) titanium oxide, (iv) cerium oxide, or (v) a material including at least one of the (i) through (iv), and which reflective film is made of tantalum or titanium.

Abstract: An optical disk apparatus according to the present invention generates a divided clock signal by dividing a recording clock signal, and based on the divided clock signal, determines a test emission pattern for test recording which is used for controlling the power of a light beam that is output from an emission section. When the linear velocity at recording changes, the division ratio is adjusted in a direction of reducing a change in frequency of the divided clock signal. In an optical disk apparatus which performs laser power control by conducting a test emission with multipulses in a test area, a good detection accuracy of a multi-pulse average value can be maintained even at high x-speeds.

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.