摘要:
There is provided an optical disc having preformed thereon a spiral wobbled track as a grove and/or land along with data is to be recorded. The track is wobbled for a series of predetermined signal units each composed of an FSK information bit part based on a waveform resulted from FSK modulation of information bit, and a singe-frequency part based on a waveform of a single frequency. The FSK modulation uses two different frequencies of which the one is the same as the single frequency and the other is different from the single frequency. These different frequencies are in such a relation that each of them has an even number of wobbles and an odd number of wobbles alternately in a predetermined cycle.
摘要:
In step S1, the address generator generates, address information composed of a sync signal which is recorded on an optical disc, address data and an error correction code for the address data, pre-encodes and supplies it to a modulator. At the same time, a carrier signal generator generates a carrier signal which is to carry the address information, and supplies it to the modulator. In step S2, the modulator makes MSK modulation of the carrier signal supplied from the carrier signal generator on the basis of the pre-encoded address information supplied from the address generator, and supplies a resultant MSK modulation signal to a wobbling unit. In step S3, the wobbling unit forms, on the optical disc, a spiral groove wobbled adaptively to the MSK modulation signal supplied from the modulator. In this optical disc, a given address can be accessed quickly and accurately.
摘要:
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. 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 and 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) are compared with each other by a subtracting circuit (41). A compared output is selected by a switch (34) and then supplied through a subtracting circuit (35) to a laser driver (3).
摘要:
An optical recording apparatus for recording desired information signals by an optical head on an optical disc (1), on which information signals may be optically recorded, is disclosed. The apparatus includes a peak-holding circuit (40) for holding a peak value of reproduced RF signals from the optical head, a bottom-holding circuit (41) for holding a bottom value of the reproduced RF signals, and a decision circuit (43, 50) for deciding if the optical recording disc (1) is an unrecorded disc on the basis of the peak value from the peak-holding circuit (40) and the bottom value from the bottom-holding circuit (41).
摘要:
An optical recording apparatus for recording desired information signals by an optical head on an optical disc (1), on which information signals may be optically recorded, is disclosed. The apparatus includes a peak-holding circuit (40) for holding a peak value of reproduced RF signals from the optical head, a bottom-holding circuit (41) for holding a bottom value of the reproduced RF signals, and a decision circuit (43, 50) for deciding if the optical recording disc (1) is an unrecorded disc on the basis of the peak value from the peak-holding circuit (40) and the bottom value from the bottom-holding circuit (41).
摘要:
There is provided an optical disc having preformed thereon a spiral wobbled track as a grove and/or land along with data is to be recorded. The track is wobbled for a series of predetermined signal units each composed of an FSK information bit part based on a waveform resulted from FSK modulation of information bit and a singe-frequency part based on a wavefonn of a single frequency. The FSK modulation uses two different frequencies of which the one is the same as the single frequency and the other is different from the single frequency. These different frequencies are in such a relation that each of then has an even number of wobbles and an odd number of wobbles alternately in a predetermined cycle.
摘要:
In step S1, the address generator generates address information composed of a sync signal which is recorded on an optical disc, address data and an error correction code for the address data, pre-encodes and supplies it to a modulator. At the same time, a carrier signal generator generates a carrier signal which is to carry the address information, and supplies it to the modulator. In step S2, the modulator makes MSK modulation of the carrier signal supplied from the carrier signal generator on the basis of the pre-encoded address information supplied from the address generator, and supplies a resultant MSK modulation signal to a wobbling unit. In step S3, the wobbling unit forms, on the optical disc, a spiral groove wobbled adaptively to the MSK modulation signal supplied from the modulator. In this optical disc, a given address can be accessed quickly and accurately.
摘要:
In step S1, the address generator generates, address information composed of a sync signal which is recorded on an optical disc, address data and an error correction code for the address data, pre-encodes and supplies it to a modulator. At the same time, a carrier signal generator generates a carrier signal which is to carry the address information, and supplies it to the modulator. In step S2, the modulator makes MSK modulation of the carrier signal supplied from the carrier signal generator on the basis of the pre-encoded address information supplied from the address generator, and supplies a resultant MSK modulation signal to a wobbling unit. In step S3, the wobbling unit forms, on the optical disc, a spiral groove wobbled adaptively to the MSK modulation signal supplied from the modulator. In this optical disc, a given address can be accessed quickly and accurately.