Abstract: In a conventional multilayer optical disc, management information needs to be retrieved from the control area of its reference layer to find how many information layers there are in the optical disc. A multilayer optical disc according to the present invention has multiple information layers that are stacked one upon the other. The information layers include at least one layer on which layer number information, indicating its own place in the multiple information layers, and information about the total number of information layers included are both stored.

Abstract: An optical pickup device corresponding to a plurality of media is provided. The optical pickup device includes a light emitting system and a light receiving system including a plurality of light sources and a light transmission system shared by the light emitting system and the light receiving system, configured to irradiate light on a medium, and receive light reflected from the medium. The light transmission system irradiates light from the light emitting system to be appropriately focused on the medium, receives light reflected from the medium, and transports light to the light receiving system. The light transmission system includes one beam splitter corresponding to the light emitting system and the light receiving system and a position-changing collimating lens shared to correspond to a plurality of media. The position-changing collimating lens is disposed between the beam splitter and the medium, the position being controlled according to optical characteristics of the media.

Abstract: A recorded area is reproduced during a suspension of a recording operation; when degradation of the recorded signal is detected (S4, S5) by the signal quality detection means (16), a tilt adjustment is performed in the recorded area, the signal quality of the recorded signal is detected after the tilt adjustment (S6), and if it is still degraded, a recording parameter is altered (step S7). The need to obtain tilt adjustment values for tilt corrections at a plurality of radial positions in advance is eliminated, resulting in reduced apparatus overhead and better recording quality.

Abstract: The invention relates to a master device which can be used in a method for producing a recording medium, a substantially spirally or concentrically running main track structure and at least one substantially spirally or concentrically running secondary track structure being formed on the master device, the secondary track structure being arranged on at least one side of the main track structure, the secondary track structure having discontinuities varying an optically detectable surface texture of the recording medium in such a way that at least first auxiliary information is represented on the recording medium.

Abstract: An optical pickup device includes an astigmatism element which imparts astigmatism to laser light reflected on a disc, a spectral element which changes propagating directions of four light fluxes obtained by dividing a light flux of the laser light reflected on the disc to disperse the four light fluxes from each other, and a photodetector having a sensor group which receives the four light fluxes. The optical pickup device is further provided with a memory which holds a correction value for suppressing a DC component in a tracking error signal resulting from a positional displacement of the spectral element. The tracking error signal is corrected by the correction value to thereby suppress the DC component.

Abstract: According to the present invention, multiple space bitmaps (SBMs #0 and #1 30) are provided for the user data area of each recording layer. A disc management structure update unit including one of those space bitmaps and a disc definition structure (TDDS 32) and having a size of one block is written on a management information area (TDMA 17). As a result, data including the disc definition structure (TDDS 32) can always be arranged in the first block at the top of the management information area (TDMA 17).

Abstract: An optical disk reproducing device includes: a signal reproducing section configured to read and decode information recorded on an optical disk by an optical pickup unit, and reproduce the information, wherein the signal reproducing section includes a gain controlled amplifier circuit configured to amplify an radio frequency signal generated from a light receiving element, an automatic gain control circuit configured to control a gain of the gain controlled amplifier circuit, and a signal processing section configured to derive a part of an automatic gain control value generated in the automatic gain control circuit, and generate a control signal for adjusting one of an optical system path and a detection system path for controlling the optical pickup unit.

Abstract: A method of managing data in an optical disc apparatus is provided. The type of a loaded disc is checked, and data corresponding to the checked disc type is read from a compressed file, decompressed and stored in a memory of the optical disc apparatus. Recording-related data respectively corresponding to disc types, manufacturers, and recording speeds are separately compressed in the compressed file. Identification information about the disc types, manufacturers, and recording speeds and information on positions at which the recording-related data about the disc types, manufacturers, and recording speeds are stored may be included in the head of the compressed file. The compressed file may include separately compressed servo data, and information on the position at which the servo data is stored may be included in the head of the compressed file. Accordingly, the optical disc manufacturing cost can be decreased and a data loading time can be reduced.

Abstract: Universal multimedia distribution, storage, and playback systems, devices, and methods are disclosed herein. A media distribution kiosk located at a retail establishment provides a user with access to a multitude of different forms of digital multimedia that may be purchased and downloaded onto a portable media transporter device. The portable media transporter device may then be inserted into a media storage and playback device that is capable of transcoding and storing the media on a hard disk drive. Additionally, the media storage and playback device is capable of transcoding, storing, and playing information residing on various other media formats such as DVD (movies, audio, gaming software), CD, and memory cards. Digital rights management (DRM) security measures employed at the kiosk and at the transporter and storage/playback devices ensure the integrity of the media transferred to the user.

Abstract: An optical-disc writer writes extrinsic data to an optical disc. Extrinsic data can be written as (i) embedded marks (e.g., pits and lands) located outside the conventional readable area of a disc and/or (ii) alternative marks, such as surface marks located on a surface of the disc. In an optical-disc player having a disc-reading subsystem and a read controller, the disc-reading subsystem reads and relays the extrinsic data to the read controller, which controls the operations of the player based on the extrinsic data. For example, the writer prints extrinsic data, e.g., a barcode, on the surface of a software installation disc. The disc is inserted in the player and installation is commenced. The read controller instructs the disc-reading subsystem to read the extrinsic information. If the read controller determines that the extrinsic data was successfully read, then installation proceeds; otherwise, installation is halted.

Abstract: An oscillation circuit includes: n ring oscillators each formed from m delay elements connected annularly, m being an integer equal to or greater than 2, n being an integer equal to or greater than 2; and a phase coupled ring.

Abstract: In optical recording and/or reproduction using an SIL optical system that performs a tilt servo using light for recording and/or reproduction, the SIL and an optical recording medium have a high probability of colliding with each other before the tilt servo is started. To prevent the collision, an optical recording/reproduction method performs a gap servo that controls a gap between a surface of an optical recording medium and a bottom surface of an SIL using reflected light that is generated from light traveling from the bottom surface of the SIL and reflecting on the optical recording medium, a focus servo that controls a distance between a focal point of the light and the bottom surface of the SIL, and a tilt servo that controls a tilt of the bottom surface of the SIL relative to the surface of the optical recording medium using the reflected light.

Abstract: An optical information recording and reproducing method for recording or reproducing information by irradiating pulsed laser diode light from a laser diode (LD) light source in which the resistance value of the LD light source is measured in an operating state, the measured LD light source resistance value is compared with a target resistance value, and the LD light source is heated when the LD light source resistance value is higher than the target resistance value, in order to maintain the LD light source resistance at a specified value or less.

Abstract: A write power adjustment method makes it possible to set optimum write power with high precision. Trial writing is conducted by using write power Pw,m (where m is an integer) of a plurality of kinds, and a modulation M,m associated with each write power is calculated. Optimum asymptotic power Pasy-opt is calculated by performing predetermined computation by using reference asymptotic power Pasy-ref and reference write start power Pws-ref which are previously determined for each medium. An evaluated value S,m=M,m×(Pw,m?Pasy-opt) is calculated by using the optimum asymptotic power Pasy-opt. Write power Pw that makes the evaluated value S equal to zero when applying straight line approximation to a relation between the write power Pw,m and the evaluated value S,m is calculated as optimum write start power Pws-opt. And optimum write power Pw-opt is found by performing predetermined computation on the optimum write start power Pws-opt.

Abstract: A method for controlling focus on a label side of a light-scribe disc divides the label side into several zones, finds the maximum SBAD and the corresponding focus volt and spoke during focusing on each zone, approaches a primary focus volt level curve, compensates a predetermined volt to focus on the label side, checks the maximum SBAD and the corresponding focus volt and spoke between the primary focus volt level curve and the compensation volt on each zone, and approaches a calibrating focus volt level curve to reduce errors.

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: An adjusting system for adjusting a tilt of an optical pickup head includes a collimator, a processing device, and a controller. The collimator receives reflected light beams from the optical pickup head and generating images from the reflected light beams. The processing device processes the images and generates an adjust signal. The controller receives the adjust signal and adjusting a position of the optical pickup head based on the adjust signal.

Abstract: According to the present invention, multiple space bitmaps (SBMs #0 and #1 30) are provided for the user data area of each recording layer. A disc management structure update unit including one of those space bitmaps and a disc definition structure (TDDS 32) and having a size of one block is written on a management information area (TDMA 17). As a result, data including the disc definition structure (TDDS 32) can always be arranged in the first block at the top of the management information area (TDMA 17).

Abstract: Information about a variation ratio of the recording power sensitivity, which varies depending on whether another recording layer is recorded or unrecorded, is recorded onto a disc control information area (DI) in advance. Moreover, based on this recording-power-sensitivity variation information, recording-power compensation is performed. The corresponding recording-power compensation method is classified into three types: (1) type in which the recording is performed by judging the recorded/unrecorded states of another layer, (2) type in which, instead of judging the recorded/unrecorded states of another layer, the recording is performed using an intermediate power of the optimum powers for both of the recorded/unrecorded states, and (3) combination of (1) and (2).

Abstract: A method of storing data includes receiving general purpose (GP) data and special Error Tolerant or Streaming (ETS) data, storing the GP data using a data storage method, and storing the ETS data using a different data storage method which affects the access rate, resilience to errors, data integrity, storage density, or storage capacity. The storage medium, which can include a disk drive, flash memory, or holographic memory, is utilized differently depending on the required Quality of Service in aspects including block size, storage of error correction codes, utilization of error correction codes, storage area density, physical format pattern, storage verification, or reaction to failed storage verification. For disk drives these differences include spacing between tracks; overlap between tracks; spiral track formatting; concentric track formatting, and size of blocks, and for flash memories these differences include levels per cell and number of cells.

Abstract: The method provides a recording of data on a rotating disc by using an electron beam for recording marks along a track on the disc, the electron beam performing a wobble oscillation in a radial direction of the disc with a wobble amplitude for recording at least two tracks in parallel, and modulating the electron beam intensity for recording alternatingly a mark or a fraction of a mark of the first track or the second track. For recording a mark of a defined width, the electron beam is switched on in accordance with the mark width of the marks of each specific track, and is switched off for providing spaces between the marks of each track or a land area separating the marks of the first and second track. The method is used advantageously for recording tracks with a track pitch being below the diffraction limit for manufacturing a master disc for a production of read-only optical discs with a high data density.

Abstract: According to an embodiment, a storage medium includes a transparent resin substrate having a concentric or spiral groove and a recording film formed on the groove on the transparent resin substrate, a recording mark being formed by irradiation of a laser beam, wherein a reproduction durability count in a case where reproduction is continuously carried out by a laser beam is 1,000,000 or more.

Abstract: A disk inspection apparatus for discriminating disks. The disk inspection apparatus has an ECC control section and a comparison section. The ECC control section measures the number of error corrections PIE and the number of error correction failures PIF in a predetermined section of the disk. The comparison section discriminates the disk as a disk with a deterioration in jitter characteristic when the minimum or the average of the PIE exceeds a first threshold value; discriminates the disk as a normal disk when the maximum of the PIF is equal to or smaller than a second threshold and the minimum or the average of the PIE is equal to or smaller than the first threshold value; and discriminates the disk as a scratched disk when the minimum or the average of the PIE is equal to or smaller than the first threshold value and the maximum of the PIF exceeds the second threshold value.

Abstract: Target levels in the PRML method are adaptively set under conditions of simplicity and a low cost. A method of setting a target level for reproduction of an optical information recording medium includes: a step of producing a reproduction signal from reflected light of laser light irradiated to an optical information recording medium; a step of performing waveform equalization processing, which depends on a predetermined partial response characteristic, on the reproduction signal to produce a waveform-equalized reproduction signal; a step of detecting peak levels for marks and spaces of a predetermined number of symbols from the waveform-equalized reproduction signal irrespective of a condition for a symbol adjoining each symbol; and a setting step of determining and setting values of a plurality of target levels, which is employed in Viterbi decoding and is arrayed with non-equal intervals among them, on the basis of a relative relationship among the detected peak levels.

Abstract: An information storage medium according to the present invention has n information storage layers (where n is an integer and n?3), on which data can be written with a laser beam and which are stacked one upon the other. Each of the n storage layers has a test write zone for determining the recording power of the laser beam. When those n layers are counted from the one that is located most distant from the surface of the medium on which the laser beam is incident, there is a bigger radial location difference between the outer peripheral end of the inner one of the test write zones of ith and (i+1)th information storage layers (where i is an integer that satisfies 2?i?n?1) and the inner peripheral end of the other outer test write zone than between the outer peripheral end of the inner one of the test write zones of jth and (j+1)th information storage layers (where j is an integer that satisfies 1?j?i?1) and the inner peripheral end of the other outer test write zone.

Abstract: An optical disc having a region with pre-recorded data and a recordable region, a method of fabricating the disc, a stamper for forming a disc master, and a recording device for use with the disc are disclosed. Data recorded in the recordable region may be used for activation of the disc, providing unique identification or enhancing program content on the disc.

Abstract: An optical recording method for recording information by irradiating an optical disc medium with a modulated write pulse train of laser light variable over a plurality of power levels such that a plurality of marks are formed on the optical disc medium, edge positions of each of the marks and a space between adjacent two of the marks being utilized for recording of the information.

Abstract: An optical recording medium includes a main-information area in which a metal reflection film is formed on a substrate where a row of pits is formed as main data, and a sub-information area in which is recorded medium identification information, which is used to identify the optical recording medium individually, by removing the metal reflection film partially and forming a plurality of reflection-film removed areas. Information is reproduced by irradiating the metal reflection film with a beam of light. In the sub-information area, a row of pits or a guide groove is formed on the substrate, and a track pitch of the row of pits or the guide groove is at least 0.24 ?m wide and at most 0.45 ?m wide.

Abstract: A drive apparatus of the present invention includes a recording/reproduction section and a drive control section. The drive control section performs a process including: determining whether or not replacement management information including a replacement physical address is found in the replacement management information list, the replacement physical address matching the physical address corresponding to the logical address included in the recording instruction, when the replacement management information is not found, as a first time pseudo-overwrite recording for a location indicated by the physical address corresponding to the logical address included in the recording instruction, performing a process; and when the replacement management information is found, as a second time or more pseudo-overwrite recording for a location indicated by the physical address corresponding to the logical address included in the recording instruction, performing a process.

Abstract: A holographic memory storage device that uses a photorefractive crystal for storing data is disclosed. The device uses angle-multiplexing in order to store and retrieve page data and sub page data. MEMS devices are used in order to provide individual sector addressing.

Abstract: When recording/reproducing an optical disc having a recording layer of multi-layer structure, an unwanted optical beam reflected from a recording layer other than a target layer for recording/reproduction is incident on a photodetector to cause an unwanted disturbance component to leak to a detection signal, giving rise to a degradation in the quality of a tracking control signal. In an optical pickup apparatus, for suppression of the degradation, an optical element is mounted having a diffraction area for diffracting part of the optical beam and light receiving planes for sub-optical beams are provided each of which has a light shielding zone or dead zone of a predetermined width on its central sectioning line.

Abstract: An optical information reproducing apparatus includes: an irradiation section irradiating a light beam onto an optical information recording medium, in which holes are formed along a virtual track on a recording medium, along the virtual track; a light receiving section receiving a reflected light beam when the light beam is reflected by the optical information recording medium and sequentially generating a light receiving signal corresponding to the light intensity; a detection section detecting a variation pattern appearing when a signal level of the light receiving signal changes according to the hole; and a code string generating section, when generating a code string corresponding to the signal level, generating a code corresponding to the one hole from the variation pattern if the variation pattern falls within a range and generating a code string, which includes a plurality of codes, from the variation pattern if the variation pattern exceeds the range.

Abstract: The optical disk device includes a generation means and a LC servo means. The generation means generates a lens error signal based on an electrical signal output from a pickup head. After amplifying the lens error signal with a predetermined gain, the generation means outputs the lens error signal. The LC servo means performs lens center servo control based on the lens error signal. The optical disk device further includes a measurement means which measures, before the lens center servo control, a first and a second amplitude values of the lens error signal. The measurement means calculates a current gain based on the first and second amplitude values, the latest gain which is currently set, and a predetermined target amplitude value. Then the measurement means sets the current gain to the generation means.

Abstract: A method for controlling layer changes for an optical disk drive is provided, where a focus of a laserbeam emitted by a pickup head of the optical disk drive is moved from a current data layer of a disk to a target data layer of the disk. First, a position of a collimator lens of the pickup head is adjusted for spherical aberration correction. The objective lens is then lowered to a low position to move the focus of the laserbeam off the surface of the disk. The objective lens is then raised towards the disk. A focusing error signal is generated while the objective lens is being raised. Whether a target S-curve corresponding to the target data layer is present in the focusing error signal is then started to be detected. If the target S-curve is detected, the focus on operation on the target data layer of the disk is successful.

Abstract: A modulation control system for use with a high frequency modulator is described. This system comprises a latch for selectively receiving enable signals, wherein the latch transmits a latched signal in response to receiving at least two of the enable signals; a selection device coupled to the latch for receiving the latched signal, a voltage source, and a terminal for receiving at least one of the enable signals, wherein the selection device transmits a selected signal; and a logic device coupled to the selection device and a terminal for receiving a modulated enable signal, wherein the logic device transmits a synchronized signal for either enabling or disabling the high frequency modulator in response to receiving the selected signal associated with at least one of the enable signals.

Abstract: A laser diode read driver is described. A first transistor operative for producing a first voltage in response to receiving a first current signal. A first resistor is coupled between the first transistor and a low voltage supply. A first transconductor having a first input is coupled to receive the first voltage, wherein the transconductor produces a second current signal in response to differences between signals received on the first input and a second input. A second transistor is coupled to the second input, and operative for producing a third current signal in response to receiving the second current signal. A third transistor is coupled to the second transistor and the second input, the third transistor operative for producing an output current signal in response to receiving the third current signal, wherein the first transistor is scaled to the first transistor by the inverse of a gain factor.

Abstract: An input signal processing system is described. It comprises a first transconductance device having a first input, second input, and an output, wherein the first input is coupled to receive the input signal; a first resistor coupled to a first input of the first transconductance device, wherein the first resistor converts the input current signal to an input voltage signal; a first voltage-current converter coupled to the output, the second input, the resistor, and a low voltage supply, wherein the first voltage-current converter is operative for converting the input voltage signal to a input current signal; and a low pass filter having an input coupled to the voltage converter for filtering noise from the input current signal.

Abstract: A rotation-activated electronic component, preferably a RFID tag mounted on or incorporated in a support that is rotated when read, e.g. a CD or DVD. The RFID tag comprises an antenna, a rotational switch and a component, advantageously a processor. The antenna is adapted to transform received RFID signals to electric energy that powers the component. In a preferred embodiment, the rotational switch is adapted to cut the circuit unless the support does not rotate at or above a certain rotational speed. Supports equipped with the RFID tag of the invention will thus respond only if they rotate sufficiently. This can avoid collisions in case more than one such RFID tag is within communication range of an antenna of a reader. In a preferred embodiment, the information returned by the component is needed for full use of the content on the support.

Abstract: An over current protection device is described. It includes a plurality of input channels for receiving an input signal; a plurality of low pass filters coupled to a first group of the plurality of input channels, wherein each low pass filter is associated with one input channel within the first group of input channels, the plurality of low pass filters operative for removing spikes in associated with the input signal; and a plurality of digital to analog converters coupled to a second group of the plurality of input channels, wherein each digital to analog converter is associated with one low pass filter in the second group of input channels, the digital to analog converters operative for triggering over current protection when a signal received from the associated low pass filter is beyond a preset level, wherein the over current protection device is on chip with the laser diode driver.

Abstract: An optical disk apparatus to record data on an optical disk on which a wobble is formed, the optical disk apparatus including; a detection unit including a BPF which a signal obtained from a reflected light from an optical disk passes, the detection unit to detect a wobble signal from a wobble based on the signal passing the BPF; and a register to store an adjustment value for adjusting the BPF as a register value, so as to adjust the BPF based on each of register values obtained by changing the register value 1 LSB by 1 LSB; acquire an amplitude of the signal passing the BPF, the amplitude corresponding to each of the register values; identify one of the register values for the largest acquired amplitude; and adjust the BPF based on a value obtained by adding 1 LSB to the identified register value when data is recorded.

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

Abstract: In a recording method for recording information on an optical recording medium (500) according to the parameters of a write strategy by repeatedly recording (S23) a certain amount of information onto the optical disc (500) and entering a standby state (S22) in which recording is suspended and data are stored in a buffer memory (190), during an interval while recording is suspended, the information recorded just before is reproduced, the quality of the reproduced signal is measured (S25A), and the write strategy is altered as necessary (S25C) to obtain consistent recording quality. Only one correction is made per suspension period. Consistent recording quality is thus obtained despite changes in the recording position on the optical disc or changes in recording conditions.

Abstract: The present invention relates to a method for performing pre-exposure and curing of a photo-sensitive material for optical data storage, in particular for holographic data storage, and to an apparatus for writing to optical storage media using such method. According to the invention, for pre-exposure and/or curing of an optical storage medium the optical storage medium is illuminated by a coherent light beam emitted by a light source, which is also used for data recording. Pre-exposure and/or curing is performed in one or more exposure steps, in which the coherent light beam carries a data pattern, the exposure dose for each exposure step being smaller than a minimum dose such that the diffraction efficiency of the recorded data pattern is too low to distinguish data from noise.

Abstract: An enhanced write splice for optical recording channels is disclosed. Optical control circuitry locks to previously-written data and determines the estimated write splice location. A training sequence is written to the optical medium at a location based on the estimated write splice location. The phase offset is then estimated by reading the training sequence. A new write splice location may then be calculated compensating for the phase offset estimate. Finally, the new data to be spliced may be written or overwritten to the channel at the new write splice location.

Abstract: The optical storage medium comprises a substrate layer, and a data layer having a mark/space data structure with data arranged in tracks on the substrate layer, wherein between neighboring tracks alternatingly a groove section or a land section without a groove is arranged. The tracks, groove sections and land sections may be arranged by providing a single spiral, two spirals, or four spirals on the optical storage medium. The optical storage medium is in particular an optical disc comprising a nonlinear layer with a super-resolution structure arranged above the data layer.

Abstract: An optical disc device includes: a first searching part which searches a condition where amplitude level of a TE signal is made maximum by changing either one of position of a movable lens and a focus balance value in a state where a focus servo control is performed based on a FE signal; an adjusting line setting part which sets an adjusting line that has an inclination ? which is preliminarily stored in a memory portion and that passes the position of the movable lens and the focus balance value both of which are searched by the first searching part; and a second searching part which changes the position of the movable lens and the focus balance value to plural values on the adjusting line in a state where the focus servo control is performed consecutively to search a condition where the amplitude level of the tracking error signal is made maximum.

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

Abstract: In an optical pickup device 3, a supporting base 18 that has a main-shaft bearing 6a with two concentric round holes to pass a main shaft 7 through is formed out of a synthetic resin. On the other hand, an optical base 19, which has a sub-shaft bearing 6b to pass a sub-shaft 8 through and which supports a light emitter 11, a beam splitter 12, a collimator lens 13 and a photodetector 17, is formed by metal die casting process. And a pickup frame 6 is formed by bonding the supporting base 18 and the optical base 19 together with an adhesive.

Abstract: A write once disc allowing management of a data area, a method of managing the data area of the write once disc, an apparatus recording data on the write once disc, an apparatus and method of reproducing data from a write once disc. The write once disc, 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 recording and reproducing method for recording and/or reproducing information from a record carrier that comprises a plurality of recording layers layered in its film thickness direction and a guide layer having a plurality of tracks carrying tracking servo information, wherein a record mark is formed on each recording layer of the record carrier. The method comprises: a focusing step of converging a servo light beam onto the guide layer as well as selectively converging a main light beam group onto one of the recording layers through a common objective lens, wherein the main light beam group comprises a plurality of main light beams neighboring each other; a tracking step of performing a positioning control of the objective lens so that the servo light beam is tracking on one of the tracks; and a recording and/or reproducing step of performing recording and/or reproducing information with the main light beam group while performing the focusing step and the tracking step.