Abstract: An optical recording medium for accurately deriving the address information or the disc rotation control information despite narrow track pitch and for recording signals to a high density, and a method and apparatus for recording and/or reproducing such optical recording medium. The optical recording medium has a wobbled groove and pits formed at a pre-set interval in an area between turns of the wobbled groove. The recording/reproducing method includes controlling rotation of the optical recording medium by a wobbled signal from the groove and detecting the position on the optical recording medium of a recording signal by pit signals detected from the pits. The recording/reproducing apparatus includes a detection device for detecting the wobbled signal from the groove and a detection device for detecting pit signals from the pits.

Abstract: An optical recording medium for accurately deriving the address information or the disc rotation control information despite narrow track pitch and for recording signals to a high density, and a method and apparatus for recording and/or reproducing such optical recording medium. The optical recording medium has a wobbled groove and pits formed at a pre-set interval in an area between turns of the wobbled groove. The recording/reproducing method includes controlling rotation of the optical recording medium by a wobbled signal from the groove and detecting the position on the optical recording medium of a recording signal by pit signals detected from the pits. The recording/reproducing apparatus includes a detection device for detecting the wobbled signal from the groove and a detection device for detecting pit signals from the pits.

Abstract: During recording operations, decay processing is performed with regard to reflected light information signals (I1 and I2) during periods wherein the laser output is recording power which is comparatively high level, i.e., wherein data pits are being formed on the disk, and during recording operations, decay processing is not performed with regard to reflected light information signals during periods wherein the laser output is reproducing power which is comparatively low level, i.e., wherein the pits are not being formed on the disk. Accordingly, address information can be extracted in a stable manner while recording.

Abstract: An optical recording medium for accurately deriving the address information or the disc rotation control information despite narrow track pitch and for recording signals to a high density, and a method and apparatus for recording and/or reproducing such optical recording medium. The optical recording medium has a wobbled groove and pits formed at a pre-set interval in an area between turns of the wobbled groove. The recording/reproducing method includes controlling rotation of the optical recording medium by a wobbled signal from the groove and detecting the position on the optical recording medium of a recording signal by pit signals detected from the pits. The recording/reproducing apparatus includes a detection device for detecting the wobbled signal from the groove and a detection device for detecting pit signals from the pits.

Abstract: An optical recording medium for accurately deriving the address information or the disc rotation control information despite narrow track pitch and for recording signals to a high density, and a method and apparatus for recording and/or reproducing such optical recording medium. The optical recording medium has a wobbled groove and pits formed at a pre-set interval in an area between turns of the wobbled groove. The recording/reproducing method includes controlling rotation of the optical recording medium by a wobbled signal from the groove and detecting the position on the optical recording medium of a recording signal by pit signals detected from the pits. The recording/reproducing apparatus includes a detection device for detecting the wobbled signal from the groove and a detection device for detecting pit signals from the pits.

Abstract: This invention is applicable to an apparatus using an optical pickup to reproduce information recorded on an optical recording medium. By enabling the automatic setting of reproducing conditions applicable to a mounted optical recording medium so that a plurality of types of optical recording media can be compatibly mounted, the present invention enables recorded information to be reliably reproduced even if the recording medium has a low recording density.

Abstract: An optical recording medium for accurately deriving the address information or the disc rotation control information despite narrow track pitch and for recording signals to a high density, and a method and apparatus for recording and/or reproducing such optical recording medium. The optical recording medium has a wobbled groove and pits formed at a pre-set interval in an area between turns of the wobbled groove. The recording/reproducing method includes controlling rotation of the optical recording medium by a wobbled signal from the groove and detecting the position on the optical recording medium of a recording signal by pit signals detected from the pits. The recording/reproducing apparatus includes a detection device for detecting the wobbled signal from the groove and a detection device for detecting pit signals from the pits.

Abstract: An optical recording medium for accurately deriving the address information or the disc rotation control information despite narrow track pitch and for recording signals to a high density, and a method and apparatus for recording and/or reproducing such optical recording medium. The optical recording medium has a wobbled groove and pits formed at a pre-set interval in an area between turns of the wobbled groove. The recording/reproducing method includes controlling rotation of the optical recording medium by a wobbled signal from the groove and detecting the position on the optical recording medium of a recording signal by pit signals detected from the pits. The recording/reproducing apparatus includes a detection device for detecting the wobbled signal from the groove and a detection device for detecting pit signals from the pits.

Abstract: An optical recording medium for accurately deriving the address information or the disc rotation control information despite narrow track pitch and for recording signals to a high density, and a method and apparatus for recording and/or reproducing such optical recording medium. The optical recording medium has a wobbled groove and pits formed at a pre-set interval in an area between turns of the wobbled groove. The recording/reproducing method includes controlling rotation of the optical recording medium by a wobbled signal from the groove and detecting the position on the optical recording medium of a recording signal by pit signals detected from the pits. The recording/reproducing apparatus includes a detection device for detecting the wobbled signal from the groove and a detection device for detecting pit signals from the pits.

Abstract: This invention is applicable to an apparatus using an optical pickup to reproduce information recorded on an optical recording medium. By enabling the automatic setting of reproducing conditions applicable to a mounted optical recording medium so that a plurality of types of optical recording media can be compatibly mounted, the present invention enables recorded information to be reliably reproduced even if the recording medium has a low recording density.

Abstract: An optical recording medium for accurately deriving the address information or the disc rotation control information despite narrow track pitch and for recording signals to a high density, and a method and apparatus for recording and/or reproducing such optical recording medium. The optical recording medium has a wobbled groove and pits formed at a pre-set interval in an area between turns of the wobbled groove. The recording/reproducing method includes controlling rotation of the optical recording medium by a wobbled signal from the groove and detecting the position on the optical recording medium of a recording signal by pit signals detected from the pits. The recording/reproducing apparatus includes a detection device for detecting the wobbled signal from the groove and a detection device for detecting pit signals from the pits.

Abstract: This invention is applicable to an apparatus using an optical pickup to reproduce information recorded on an optical recording medium. By enabling the automatic setting of reproducing conditions applicable to a mounted optical recording medium so that a plurality of types of optical recording media can be compatibly mounted, the present invention enables recorded information to be reliably reproduced even if the recording medium has a low recording density.

Abstract: An optical disc apparatus for recording/reproducing desired information, e.g. a "write once, read many times" optical disc system, is described. It is desired to securely detect speed information and address data recorded in a pregroove, even when the position of incidence of the light beam with respect to the light receiving element has been changed. Output signals of light receiving surfaces of an optical pickup adjacent to each other in the received radial direction of an optical disc have their relative signal levels corrected so that the signal levels of RF components mixed into these output signals are equalized to each other. A difference signal thereof is then generated to recover the speed information and address data.

Abstract: Outputs of first and second photodetectors are supplied to first and second normalizing circuits and are also added by an adding circuit. An output of the adding circuit is supplied to the normalizing circuits. By the output supplied from the adding circuit to the normalizing circuits, the outputs supplied from the photodetectors to the normalizing circuits are normalized. A subtraction is performed between the outputs of the normalizing circuits by a subtracting circuit.

Abstract: The present invention is directed to a writable optical disk recording apparatus in which an output power of a laser beam is controlled even during a recording period. During a calibration mode, a reproduced (reflected) signal from a matrix circuit (12) is supplied to level hold circuits (37), (38). The level hold circuits (37), (38) are controlled at predetermined timings relative to recording EFM (eight-to-fourteen modulated) signals of bit lengths (3T) and (11T) under the control of a microcomputer (CPU) (31). Signals from the level hold circuits (37), (38) are supplied to a calculating circuit (39) which calculates, for example, a difference or ratio between the two signals. A calculated value is stored in a memory (40). The value stored in the memory (40) and a value newly calculated by the calculating circuit (39) during EFM data recording are compared with each other by a subtracting circuit (41).

Abstract: A servo apparatus of an optical disc, comprises an amplitude detector for detecting an amplitude of a servo detection signal which was extracted by an optical pickup when servo focusing is operating. A gain control signal generator generates a gain control signal for providing a predetermined relation between the amplitude detected by the amplitude detector and a reference value. A controller holds the gain control signal generated by the gain control signal generator and controls the amplitude of the servo detection signal by the gain control signal upon a recording or reproducing operation by the optical pickup.

Abstract: This invention is directed to a method comprising the steps of detecting the intensity of a return laser beam from an optical recording medium of a recording laser beam for forming pits onto the optical recording medium at the time of a recording mode to record information thereon, and controlling a power of the recording laser beam on the basis of a ratio between a detected output of the intensity of a return laser beam within a predetermined time required until pits are actually formed on the optical recording medium and a detected output of the intensity of a return laser beam within a time period during which pits are actually formed, whereby even if the relationship between the recording laser power and pits formed varies due to characteristic unevenness, skew (inclination), or temperature of the medium, etc., this method permits formation of pits in a fixed reasonable dimension to carry out an optimum information recording.

Abstract: An optical recording apparatus for recording desired information signals by an optical head on an optical disc, on which information signals may be optically recorded, is disclosed. The apparatus includes a peak-holding circuit for holding a peak value of reproduced RF signals from the optical head, a bottom-holding circuit for holding a minimum value of the reproduced RF signals, and a decision circuit for deciding if the optical recording disc is an unrecorded disc by comparing the peak value from the peak-holding circuit with the minimum value from the bottom-holding circuit.

Abstract: An optical disc recording apparatus for recording information signals on an optical disc having an optical recording medium with a larger than normal thermal time constant, such as an organic dyestuff base material, by irradiating the disc with a recording light modulated by signals produced by eight/fourteen modulation of information signals, is disclosed. The apparatus includes a recording pulse forming unit for forming recording pulses from the eight/fourteen modulated signals, which recording pulses are of pulse widths shorter than the eight/fourteen modulated signals by a pulse width corresponding to the elongation from the regular length of a pit formed on the recording medium on the basis of the eight/fourteen modulated signals, and an optical head supplied with the recording pulses formed by the pulse forming unit for producing the light which has been pulse width modulated by the recording pulses.