2927results about "Optical recording systems" patented technology

It is an object of the present invention to improve reliability of defect management. By providing a plurality of management data areas each including a defect management area typically in a lead-in zone of a disc inner-side region enclosed by a circumference having a predetermined radius on a disc-shaped recording medium, reliability of the defect management can be obtained. In addition, by placing a plurality of the defect management areas (information areas Info1 and Info2) at locations, which are separated from each other in the radial direction of the disc-shaped recording medium, sandwiching a recording / reproduction condition adjustment area OPC having a relatively large size, the reliability of the defect management areas can be further improved. Furthermore, by providing each of the defect management areas with a plurality of recording areas, which include a currently used recording area for recording defect management information and spare recording areas each usable as a substitute for the currently used recording area, the currently used recording area can be replaced with one of the spare recording areas in accordance with an update count of the currently used recording area or error status of this currently used recording area.

A recording medium that is a write-once recording medium with data rewritability, thereby increasing the usability of the write-once recording medium, is provided. In a write-once recording medium, a main data area has a normal record and playback sub-area (a user data section), a rewriting replacement sub-area (an OSA), and a replacement management sub-area (an ISA). In response to a request to write data to an address at which data has been recorded, the rewritten data is recorded in the rewriting replacement sub-area (the OSA), and replacement management information that associates the original address with the address in the rewriting replacement sub-area is recorded into the replacement management sub-area (the ISA). Thus, data rewriting is achieved. Accordingly, a write-once recording medium can be substantially used as a data rewritable recording medium.

A method and apparatus for recording on an optical recording medium, including the recording of management information, are described as a standard for the write-once Blu-ray disc. The management information is recorded in a management area of the disc, such as a temporary defect management area (TDMA), and includes record status information and update information. The record status information is a space bitmap (SBM) indicating whether a recording operation has been performed for a predetermined area of the disc, and the update information is SBM update information indicating whether the record status information is to be continuously managed. The SBM update information controls the state of an SBM-on / off function for each of a plurality of recording areas and may be in the form of either start position information and length information corresponding to the respective areas or an SBM update flag. The SBM update information is recorded in the TDMA and is stored in a memory of an optical disc recording / reproducing device for use during recording and reproducing operations. At the time of recording in the predetermined area, an SBM-on state enables a logical overwriting operation to be performed as necessary.

An information recording medium provided with: a data area for recording therein record data; and a temporary defect management area for temporarily recording therein defect management information which is a basis of defect management for a defect in the data area, the defect management information being divided into a plurality of divisional defect management information in which one divisional defect management information can be updated independently of another divisional defect management information and being recorded, if the defect management information exceeds a predetermined size.

A write-once optical disc, and a method and apparatus for recording management information on the write-once optical disc, are provided. The optical disc includes at least one recording layer, and at least one SRR entry. Each SRR entry corresponds to an SRR and includes at least one status field for indicating a recording status of the corresponding SRR. The status field includes a session start flag for indicating whether the corresponding SRR is a start of a session, the session being formed by a group of the SRRs. Each SRR entry further includes a start address field indicating where the corresponding SRR starts, and a last address field indicating the last recorded address of the corresponding SRR.

Information is recorded on an information recording medium such as a magneto-optical recording medium, having two recording tracks arranged alternately, typically in a double spiral manner. The two recording tracks have different recording characteristics and information is firstly recorded on the recording track less liable to cross write, typically on a land section, and subsequently on the recording track more liable to cross write, typically on a groove section.

Methods and systems for write compensation for optimizing the performance of a data storage or communication channel are disclosed. In one embodiment, a method comprises determining channel sensitivity to modifications in write signal parameters, detecting systematic errors in a read signal recovered from data written with a first set of write parameters, and adjusting the write signal parameters by an amount determined from the channel sensitivity such that the systematic errors are reduced when data are written with the adjusted write parameters.

In order to enhance the usability of a write-once recording medium, the recording medium is provided with an ordinary recording / reproduction area, an alternate area, a first alternate-address management information area and a second alternate-address management information area. In addition, written / unwritten state indication information is recorded in a predetermined area. The second alternate-address management information area is an area allowing alternate-address management information recorded therein to be renewed by adding alternate-address management information to the area. Alternate-address management information recorded in the second alternate-address management information area includes information recorded in a first information format and information recorded in a second information format. The first information format shows an alternate source address and an alternate destination address for each data unit. On the other hand, the second information format shows an alternate source address and an alternate destination address for a group of a plurality of physically continuous data units. The second information format is used as a format for effectively carrying out an alternate-address process on such a group of data units. All alternate-address management information is recorded in the first alternate-address management information area in the first information format.

Information indicative of disk-applicable recording speeds is incorporated in lead-out start time information within ATIP information that is recorded in pre-grooves located in a lead-in area of an optical disk. Once the optical disk is inserted in an optical disk recording device, the lead-out start time information is read out, so that recording is performed on the optical disk after a recording speed is automatically set to a highest settable speed value within a range specified by the read-out lead-out start time information. This arrangement can reliably prevent recording at speeds beyond predetermined limit values unique to the optical disk.

Provision is made to perform a write trial process in a stable manner at all times in a write trial area for the purpose of determining optimum recording power. Sub-areas of the write trial area are used successively from an inner circumference side of the medium to an outer circumference side of the medium with respect to the spiral direction that extends from the outer circumference side of the medium to the inner circumference side of the medium, and the sub-areas of the write trial area are used successively from the outer circumference side of the medium to the inner circumference side of the medium with respect to the spiral direction that extends from the inner circumference side of the medium to the outer circumference side of the medium With this provision, the write trial process is performed by accessing a sub-area portion of interest without accessing the sub-area portion having undergone the write trial, no matter which record layer is used. Servo control and address read can thus be stabilized. As a result, a seek operation toward the sub-area of interest is also stabilized, thereby achieving a stable write trial process.

The present invention allows the usability of a write-once recording medium to be enhanced. The write-once recording medium is provided with an ordinary recording / reproduction area, an alternate area, a first alternate-address management information area (DMA) and a second alternate-address management information area (TDMA). In addition, written / unwritten state indication information (a space bitmap) is also recorded. The second alternate-address management information area is an area allowing alternate-address management information recorded therein to be renewed by adding alternate-address management information thereto. In addition, the written / unwritten state indication information indicates whether or not data has been recorded in each data unit (cluster) on the recording medium. Thus, it is possible to correctly execute management of defects and properly implement renewal of data in the write-once recording medium.

A method of overwriting data in a write-once information storage medium and a data recording and / or reproducing apparatus therefor. In the data overwriting method, a command to overwrite new data in a first area of the write-once information storage medium where data has already been recorded is issued. Then, the first area is considered as a defective area, and the new data is recorded in a second area. Thereafter, updated defect management information, including information about the locations of the first and second areas, is recorded in the write-once information storage medium. Accordingly, overwriting can be performed in write-once information storage media, which is incapable of physical overwriting, by using a logical overwriting technique. Thus, data recorded in the write-once information storage medium may be changed or updated.

A high-density optical recording medium and method of recording data on the optical recording medium. The optical recording medium includes a plurality of data recording / reproducing surfaces having reflectances for light passing through a pit area, a land / groove area, and a land / groove area on which data are recorded, of a data recording / reproducing surface included between a light source for emitting light and a recording / reproducing surface selected from the plurality of data recording / reproducing surfaces, the reflectances satisfy the expressions r1≧r2≧r3 and {(r1−r3) / r3}≦0.2, where r1, r2 and r3 are the reflectances of the pit area, the land / groove area and the land groove area on which data are recorded, respectively.

For an optical disk for which a record strategy is not prepared in a memory and an optical disk which cannot obtain a good signal quality by using the record strategy prepared in the memory, test recording is performed by using all record strategies prepared in the memory or properly adopted record strategies by changing the record power. A record strategy providing a relatively high signal quality is selected to record data in the optical disk. The record strategies for such optical disks can be easily set.

An optical information recording medium includes a substrate 1 and two information layers (2, 4) formed on the substrate. The information layer is formed of a thin film showing a change that can be detected optically by irradiation of a light beam 7. A separating layer 3 that is transparent to a wavelength of the light beam 7 is formed between the information layers 2 and 4. Each information layer (2, 4) includes a sector area having sector address portions (9, 13) and data areas (8, 12) for recording information signals, the sector address portion and the data area being divided in the circumferential direction, and a management area (10, 14) for recording identification information about the amount of dislocation between the sector address portions 9 and 14 in the circumferential direction. Thus, the identification information about the amount of dislocation can be recorded, so that demodulation errors during reproduction can be reduced by switching amplification gain or slice level during reproduction according to the identification information. Also, stable data recording can be achieved by switching recording power according to a gate signal.

A method of evaluating the quality of a read signal from the viewpoint of the detection margin of a Viterbi decoder in the PRML method in which a target signal level varies depending on the read signal, and an optical disc apparatus implementing the method. A method of evaluating the quality of a signal pattern comprising a combination of minimum run lengths from the viewpoint of edge shift, and an optical disc apparatus implementing the method. From the target signal level that varies depending on the read signal, a target signal is generated based on a decoding result, and an error target signal is generated in which the decoding result is edge-shifted. The signal quality is evaluated by calculating a Euclidean distance between these signals and the read signal. A virtual state that is not included in the Viterbi decoder and that is less than the minimum run length is defined, and a target signal level for the virtual state is generated using a target signal level table inside the Viterbi decoder, based on the concept of convolution. In this way, the signal quality can be evaluated by the same method as mentioned above even in cases where the pattern of a combination of the minimum run lengths has edge-shifted.

A high-density optical disc such as BD-RE (Blu-ray Disc Rewritable) or BD-ROM, and a recording / reproducing method thereof are disclosed. Diverse additional information such as disc reflectivity information, disc layer information or disc type information is efficiently recorded in a particular information field included in a data unit recorded on the burst cutting area of a high-density optical disc or a particular 1-byte address field included in an address unit recorded on the high-density optical disc so that it can be read when the high-density optical disc is loaded in an optical disc apparatus or when a data recording or reproducing operation for the high-density optical disc is carried out. Accordingly, it is possible to achieve optimal optical power control and automatic gain control or identification of a current position, while enabling a normal data recording or reproducing operation corresponding to the type of the optical disc.

A method of recording and reproducing information in a phase-change optical recording medium by irradiation of an electromagnetic wave for recording, reproducing and / or rewriting information is proposed, wherein when information is recorded in the phase-change optical recording medium by modulating an input signal and conducting pulse width modulation recording, a recording pulse string for recording and rewriting is a continuous electromagnetic wave, and a recording pulse string for input signal, is an electromagnetic wave pulse string having a front-pulse portion fp, a multi-pulse portion mp with a total pulse duration period T and a duty ratio y, and an off-pulse portion op, wherein the duty ratio y is decreased as a recording linear velocity for the phase-change change optical recording medium is increased, whereby multi-speed recording or CAV (constant angular velocity) recording is carried out. An information recording and reproducing apparatus, using the above method, is also proposed.

An information recording apparatus is provided, which can control over the power of light beams emitted from a light source and various types of servo control with higher accuracy. A laser beam is emitted from a semiconductor laser to write information onto an optical disc. A detection signal indicative of the power of the laser beam output from a light-receiving device is sampled and held with a sample and hold circuit via an I-V converter at a timing delayed by the time corresponding to the delay time of the I-V converter. A tracking error generation circuit and a focus error generation circuit generate a tracking error signal and a focus error signal, respectively, on the basis of a detection signal having information about tracking error and focus error and output from a light-receiving device. Sample and hold circuits sample and hold the tracking error signal and the focus error signal at a timing delayed by the time corresponding to the delay time of each of the generation circuits, respectively. Power control, tracking servo, and focus servo are performed using each of the signals held by the sample and hold circuits, respectively.

A method is designed for recording contents information along a track of an optical disk of a writeable type. A volume detection step is carried out for detecting an actual volume of the contents information to be recorded into the optical disk. A capacity detection step is carried out for detecting a nominal capacity of the optical disk, which indicates a rated volume of information to be recorded at maximum. A density determination step is carried out for determining a recording density of the contents information based on the detected actual volume and the detected nominal capacity. A record step is carried out for recording the contents information into the optical disk at the determined recording density such that the actual volume of the contents information can fit into the nominal capacity of the optical disk.

A method of recording read / write compatibility information on an optical disc. Extended part version information, latest part version having recording capability, and latest part version having reproducing capability are stored in n.xy form on 6 bytes of a reserved zone of a physical format information zone of the optical disc. A recording / reproducing apparatus to record extended part version information on a reserved zone of a physical format information zone of a recording medium. The recording / reproducing apparatus has a base part version and a comparing unit to determine recording / reproducing compatibility with a recording medium having a detailed extended part version stored in a reserved zone of a physical format information zone.

An optical information storage medium includes information on recording layers having the same reproduction channel characteristics or different reproduction channel characteristics. Nominal recording speed information is recorded in a read-only zone, and maximum and minimum recordable speed information is recorded in a recordable zone of an area other than a user data area. The nominal recording speed information is reproduced using a differential signal channel or a sum channel, and the maximum and the minimum recordable speed information is reproduced using the sum channel. The optical information storage medium addresses a situation where the nominal recording speed is not satisfied due to errors occurring during the manufacture of the storage medium. Thus, the defective disc proportion can be reduced, and loss of user data due to application of inaccurate recording layer information can be prevented.

An optical disk device for estimating optimum recording power for high speed recording at an outer part of an optical disk, with high accuracy, even when an OPC for high speed recording at the outer part cannot be performed. The optical disk device includes a first optimum recording power calculation part for performing test recording at a first speed lower than the maximum recording speed of a test area by using recording parameters of a required recording speed to calculate first optimum recording power, and a second optimum recording power calculation part for performing test recording at a second speed to calculate second optimum recording power. The first speed is different from the second speed. The optical disk device further includes an estimation part for estimating optimum recording power for based on the first optimum recording power and the second optimum recording power.

The present invention provides a device and method for an optical disc such as a DVD which can keep proper edge position of a recording pulse to record data of high quality without depending on a fluctuation in a supply voltage and a fluctuation in a temperature. The optical disc device according to the present invention comprises a laser driver for driving a laser to record data on an optical disc, a recording pulse generator for generating a recording pulse signal by using a predetermined delay circuit, to control the switching of the laser power of the laser driver, a delay amount measuring section for measuring the delay amount of a delay circuit in the recording pulse generator, and a recording pulse position correction section for correcting the predetermined edge position of the recording pulse based on the result of the measurement.

A data processing apparatus manages the address of recording data indicative of the outermost location managed by the apparatus, and forces all unrecorded ranges inside of the outermost recording address managed upon additional write prohibition (finalization) to be recorded ranges, thereby accomplishing new finalization which does not limit recording modes without losing such features as “not requiring the finalization or a long time therefor,” and “protection from tampering.”