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 bar code formation method for an optical disk, which produces bar codes of position information for piracy protection as a kind of ID and executes laser trimming to a reflection film of a PCA region of an optical disk. An optical disk is produced according to this method. As shown in the Figure, a reflection film of a PCA region (998) is partially removed in the PCA region (998) of a pre-pit signal region of this optical disk to which data are recorded by CLV so that bar codes (923) and (938) are written in superposition. In this optical disk, therefore, bar code data can be reproduced by the same optical pickup.
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 disc which has a rewritable first recording region and a read-only second recording region. The first recording region has first tracks which are composed of group tracks and land tracks which are alternately provided on a disc substrate spirally or concentrically. Each first track is divided into a plurality of first sectors. Each first sector has a first header region where identification data by which the first sector is identified are recorded and a first data region in which user data are recorded with recording marks where the optical characteristics of the recording surface are changed. The second recording region has second tracks which are composed of a physical pit row which are provided on the disc substrate spirally or concentrically. Each second track is divided into a plurality of second sectors. Each second sector has a second header region where identification data by which the second sector is identified are recorded and a second data region in which read-only data are recorded by means of the pit row. The first header region includes a first physical pit row. Each pit of the first pit row has a width in a radial direction of the disc which is substantially equal to the width of the group track and, further, the pits are staggered along the center line of the group track radially with pitches of approximately a quarter of the pitch of the group track. The second header region includes a second physical pit row. Each pit of the second pit row has a width in a radial direction of the disc which is smaller than the width of the group track and, further, the pits are arranged generally along the center line of the second track to be tracked.