Abstract:
A recording method is provided, which comprises the steps of (a) generating a plurality of pulse sequences corresponding to a plurality of linear velocities, (b) while rotating a recording medium with a linear velocity selected from the plurality of linear velocities, forming at least one of a recording mark and a space by irradiating the recording medium with a pulse sequence selected from the plurality of pulse sequences, the pulse corresponding to the linear velocity. The step (a) comprises the steps of (a-1) measuring at least one first recording parameter corresponding to at least one linear velocity selected from the plurality of linear velocities, (a-2) determining a second recording parameter corresponding to the plurality of linear velocities based on the at least one first recording parameter measured, and (a-3) generating the plurality of pulse sequences corresponding to the plurality of linear velocities based on the second recording parameter measured.
Abstract:
The optical data recording method comprising the steps of: modulating data to be recorded, to generate a plurality of recording modulation codes; and emitting a pulse-like light beam to an optical disc, so that a plurality of recording marks and spaces which have lengths corresponding to the plurality of recording modulation codes are formed on the optical disc. In the optical data recording method, at least two of the plurality of recording marks comprises: a first pulse which is disposed at a front and forms a leading edge of the recording mark, a last pulse which is disposed at a backend and forms a trailing edge of the recording mark, and a multi-pulse train which is disposed between the first pulse and the last pulse and forms a center of the recording mark. The multi-pulse train has a pulse period longer than T which represents a reference period of the recording modulation code.
Abstract:
A recording method is provided, which comprises the steps of (a) generating a plurality of pulse sequences corresponding to a plurality of linear velocities, (b) while rotating a recording medium with a linear velocity selected from the plurality of linear velocities, forming at least one of a recording mark and a space by irradiating the recording medium with a pulse sequence selected from the plurality of pulse sequences, the pulse corresponding to the linear velocity. The step (a) comprises the steps of (a-1) measuring at least one first recording parameter corresponding to at least one linear velocity selected from the plurality of linear velocities, (a-2) determining a second recording parameter corresponding to the plurality of linear velocities based on the at least one first recording parameter measured, and (a-3) generating the plurality of pulse sequences corresponding to the plurality of linear velocities based on the second recording parameter measured.
Abstract:
A laser beam in an optical recording and reproducing apparatus is narrowed into a very fine spot beam and is applied to an optical disc so as to induce a thermal change therein, to record or reproduce a signal. A mark (17) provided on an optical disc or a disc jacket is detected in order to judge the recording polarity of the optical disc, and, according to the result of the detection, analog gate switches (23a), (23b) are switched to change the polarity of the recording or reproduction signal to be positive or negative as appropriate. By so doing, it is possible to effect stable recording and reproduction with the same recording and reproducing apparatus, even with optical discs which have different reproduction signal polarities depending on the characteristics of the recording materials employed, such as erasable optical discs and nonerasable optical discs.
Abstract:
An information recording method is provided, which comprises the steps of (a) determining a power level of a pulse sequence, (b) generating the pulse sequence based on the power level determined, and (c) irradiating an information recording medium with light corresponding to the pulse sequence generated to record information represented by at least either a recording mark or a space onto the information recording medium. The pulse sequence comprises a multi-pulse chain for forming the recording mark. The multi-pulse chain comprises a plurality of pulses having a peak power level. In the step (a), a bottom power level is determined between the peak power level and an erase power level which is lower than the peak power level while keeping an interpulse spacing constant.
Abstract:
An optical disk storing write-once information usable for protecting the copyright of the software by preventing the duplication, unauthorized use, etc., of the software. In the optical disk, a recording layer (213) is formed on a disk substrate (211) with a dielectric layer (212) inbetween. Then, an intermediate dielectric layer (214) and a reflecting layer (215) are successively laminated upon the recording layer (213), and an overcoat layer (216) is formed on the surface of the reflecting layer (215). A plurality of BCA (one of write-once identification information systems) sections (220a and 220b) are recorded in the circumferential direction of the disk on the recording layer (213). The sections (220a and 220b) are recorded by lowering the vertical magnetic anisotropy of the recording layer (213). At the time or reproduction, the write-once information is detected from differential signals.
Abstract:
Various kinds of procedures including the operating procedure of a network-based disk application system are simplified. An auxiliary information recording area is provided on the optical disk to store a different IDs, encryption keys and decryption keys on different disks at the factory. The number of procedures required on the user side can be reduced by using IDs to decrypt software, encryption keys to send cryptograms, and decryption keys to receive cryptograms.