Abstract: According to one embodiment, an optical disk apparatus comprises an optical pickup which irradiates an optical disk with a light beam and receives reflected light from the disk, and a driving module which drives the pickup. The driving module includes an error detector which detects a tracking servo error with respect to a recording track on the disk from an output signal of the pickup and a tracking control module which performs tracking control over the pickup based on a servo error signal from the error detector. The control module is configured to temporarily set a tracking servo to an OFF state upon switching from a reproduction state to a recording state, measure an offset of the servo error signal, perform offset correction for the offset with respect to the servo error signal, and restore the tracking servo to an ON state after the offset correction.

Abstract: According to one embodiment, a reproduction unit of a recording medium in which in a field where a pattern signal repeated by a fixed frequency is recorded, reproduction data is recorded so that an integral multiple of a minimum unit of a pattern thereof is a one-byte unit, the reproduction unit includes a detection section for defecting a minimum unit pattern from the pattern signal, a synchronization code determination section for determining a synchronization code following the pattern signal and predicting head timing of data following the synchronization code, a pattern forming section for forming an integral number of phase pattern signals from the minimum unit pattern detected by the detection section, and timing coincidence determination section for determining whether each of the integral number of phase pattern signals coincides with the head timing of the data predicted by the synchronization code determination section.

Abstract: An optical disc apparatus includes a first lens shift amount detection unit which detects a first lens shift amount for a objective lens, on the basis of a push-pull signal which is generated in a state in which a main body of the optical disc apparatus is horizontally disposed, a memory unit which stores the first lens shift amount which is detected by the first lens shift amount detection unit, a second lens shift amount detection unit which detects a second lens shift amount for the objective lens on the basis of the push-pull signal at a time of recording/reproduction on/from an optical disc, and an addition unit which constantly adds to a tracking actuator of the objective lens a lens shift corresponding to a difference between the first lens shift amount stored in the memory unit and the second lens shift amount.

Abstract: By a controller, land and groove areas of an optical disc are tracked, two focus error signals are detected in PID portions in the respective land and groove areas, a difference of focus offset is calculated on the basis of the detection, and the two focus error signals are corrected so as to set the difference to zero.

Abstract: As an example of this invention, user data which is broken up into sectors and is scrambled for each sector using a randomly generated scramble pattern, and scramble pattern data for specifying the scramble pattern used in scrambling are recorded on a recording medium.

Abstract: A DVD-RAM recorder includes a disk drive which records information on an optical disk or plays back information, a temporary recording unit temporarily holds the information recorded on the optical disk by the disk drive or information played back from the optical disk, and an MPU which switches between information recording and information playback by the disk drive every predetermined time and, when a response corresponding to a result of instruction of information playback or information recording is not returned in a predetermined time, imposes a predetermined limitation on information playback. When one of the playback system and recording system executes an unstable processing operation during time-shift playback, priority is given to the recording operation. Accordingly, at least the probability of any loss in data in recording can be reduced.

Abstract: A front motor and I/V conversion circuit detect the emission power of a laser diode. A first differential circuit outputs a signal indicating a difference between a read power designating voltage and a low emission power detection signal sampled by a sample-and-hold circuit. A lowpass filter determines a loop band for laser power control, and has a wide band characteristic for a laser control band. A second differential circuit outputs a signal indicating a difference between a write power designating voltage and a high emission power detection signal sampled by a sample-and-hold circuit. An adder adds the output signal of the first differential circuit provided via the lowpass filter, to the output signal of the second differential circuit provided via a lowpass filter and switch. The resultant summed signal drives the laser diode via a laser driver.

Abstract: A detecting device includes an optical pickup which receives a first reference potential supplied thereto through a transmission line, sets the potential to a second reference potential affected by a noise component in the transmission line, generates detection signals from photodetector on the basis of the second reference potential, and outputs the detection signal and the second reference potential through the transmission line, and differential amplifiers which receive the detection signal and the second reference potential from the optical pickup through the transmission line to output potential difference between the detection signal and the second reference potential. The detecting device can remove the noise from a cable.

Abstract: An optical pickup includes a laser output section to emit a laser beam onto a recording medium, a photodetector to receive the light reflected by the recording medium, an amplifier to output a signal corresponding to the strength of the reflected light output from the photodetector, and a control circuit which can receive a signal which changes for data recording and playback, and suppresses the amplifier gain during recording.

Abstract: As an example of this invention, user data which is broken up into sectors and is scrambled for each sector using a randomly generated scramble pattern, and scramble pattern data for specifying the scramble pattern used in scrambling are recorded on a recording medium.

Abstract: The present invention provides an information storage medium that is manufactured to have a high yield. When information is to be reproduced by an information reproducing apparatus, there is little or no undesirable influence, such as oscillation or unstableness, from the reproducing apparatus onto the information storage medium. Thus, the information reproducing apparatus is capable of performing stable information reproductions. The information storage medium comprises a pre-groove having a groove-like, continuous projections-and-recess shape and a pre-pit having an intermittent projection-and-recess shape. The level difference of the depth or the height of the projections and recesses of the pre-pit is substantially equal to that of the pre-groove. Each of the pre-pit and pre-groove has a recording surface wobbling along a predetermined curved line.

Abstract: In this invention, in an optical disk on which data is to be recorded in units of one ECC block constructed by 16 sectors, dummy data is recorded at the manufacturing time or at the initial time such as the application starting time, then the dummy data is reproduced to determine a sector with primary defect, the physical address data of the sector which is determined to have the primary defect is recorded in the form of a primary defect list on the optical disk, and at the time of data recording, data recording is effected in units of one ECC block while skipping over the sector with the primary defect. Further, in the optical disk on which data is to be recorded in units of one ECC block, data is recorded at the time of data recording other than the initial time, then the data is reproduced to determine an ECC block having a sector with secondary defect, and data of the ECC block which is determined to have the sector with secondary defect is recorded in an ECC block which is separately prepared.

Abstract: An apparatus and method for detecting and replacing a defective sector on an optical disk. Recording data and error correction data are recorded on an optical disk at a manufacturing time or an initial time. The recorded data and the error correction data are reproduced in units of one sector. A defective sector is determined when address data in an address field cannot be reproduced or when a number of errors in at least one sector exceeds a specified value. Address data of the defective sector is recorded in a defect list on the optical disk. Recording data and error correction data are successively recorded on the optical disk in a plurality of successive block areas. Defective sectors are skipped and recording data and error correction data are recorded in a unit of one block beginning in a next sector area.

Abstract: In this invention, in an optical disk on which data is to be recorded in units of one ECC block constructed by 16 sectors, dummy data is recorded at the manufacturing time or at the initial time such as the application starting time, then the dummy data is reproduced to determine a sector with primary defect, the address of the sector which is determined to have the primary defect is recorded on the optical disk, and at the time of data recording, data recording is effected in units of one ECC block while skipping over the sector with the primary defect. The determining condition for the primary defect is a case where address data of the address field cannot be reproduced, or where the number of rows in which the number of error bytes is four or more is five or more.

Abstract: In this invention, in an optical disk on which data is to be recorded in units of one ECC block constructed by 16 sectors, data is recorded at the time other than the initial time, then the data is reproduced to determine an ECC block having a sector with secondary defect, and data for the ECC block which is determined to have the sector with secondary defect is recorded into an ECC block which is separately prepared.

Abstract: An apparatus and method for detecting and replacing a defective sector on an optical disk. Recording data and error correction data are recorded on an optical disk at a manufacturing time or an initial time. The recorded data and the error correction data are reproduced in units of one sector. A defective sector is determined when address data in an address field cannot be reproduced or when a number of errors in at least one sector exceeds a specified value. Address data of the defective sector is recorded in a defect list on the optical disk. Recording data and error correction data are successively recorded on the optical disk in a plurality of successive block areas. Defective sectors are skipped and recording data and error correction data are recorded in a unit of one block beginning in a next sector area.

Abstract: A data processing apparatus comprising a motor for revolving a disc-shaped recording medium by a given rate of revolution signal, a mechanism for storing data in and reproducing data from a specific region of the recording medium in response to a data storing/reproducing frequency signal, a circuit for selecting a constant mode or variable mode for the rate of revolution signal and supplying it to the motor, and a circuit for selecting a constant mode or variable mode for the frequency signal and supplying it to the storing/reproducing mechanism.

Abstract: An apparatus and method for detecting and replacing a defective sector on an optical disk. Recording data and error correction data are recorded on an optical disk at a manufacturing time or an initial time. The recorded data and the error correction data are reproduced in units of one sector. A defective sector is determined when address data in an address field cannot be reproduced or when a number of errors in at least one sector exceeds a specified value. Address data of the defective sector is recorded in a defect list on the optical disk. Recording data and error correction data are successively recorded on the optical disk in a plurality of successive block areas. Defective sectors are skipped and recording data and error correction data are recorded in a unit of one block beginning in a next sector area.

Abstract: An information storage medium, which is manufactured with high yield and is little influenced by a reproducing apparatus, and an information reproducing apparatus capable of performing stable information reproduction. The information storage medium has a pre-groove with a groove-like, continuous projection-and-recess shape and a pre-pit with an intermittent projection-and-recess shape. A level difference (depth or height) of the projection and recess of the pre-pit is substantially equal to that of the pre-groove. Each of the pre-pit and pregroove has a recording surface wobbling along a predetermined curved line. A reproduction signal from the information storage medium having the recording surface can be obtained by at least one pair of a preamplifier and a digitizing circuit.

Abstract: An apparatus and method for detecting and replacing a defective sector on an optical disc. Recording data and error correction data is recorded on an optical disk at a manufacturing time or an initial time. The recorded data and the error correction data are reproduced in units of one sector. A defective sector is determined when address data in an address field cannot be reproduced or when a number errors in at least one sector exceeds a specified value. Address data of the defective sector is recorded in a defect list on the optical disk. Recording data and error correction data are successively recorded on the optical disk in a plurality of successive block areas. Defective sectors are skipped and recording data and error correction data are recorded in a unit of one block beginning in a next sector area.