| 摘要 |
PURPOSE: To attain a high density recording of information by an optimum setting in accordance with the amount of recording information, the using purpose of a disk and a device using the disk, by stipulating plural kinds of line densities, the changing amount of line density on the same disk, and the recording area. CONSTITUTION: In the disk used exclusively for reproduction, the line density, the changing amount of line density and the width of recording area are changed in accordance with the kind of recording information. A laser beam used for an optical pickup of a disk player of this system is of the laser with a short wavelength of nearly 635nm. AV data such as mainly 1) computer data and 2) music, picture, etc., are applicable to the information to be recorded on the disk 1. A track pitch on the recording area 2 of the disk 1 for computer is nearly 0.8μm, and a pit of nearly 0.3μm width and nearly 0.48-1.8μm length is recorded on the track. In the case of the disk for AV data, the pit of nearly 0.3μm width and nearly 0.45μm length is recorded. The minimum length of the pit is nearly 0.45-0.49μm.
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