| 摘要 |
<p>A method of reproducing data from an optical disk having a diameter less than 140mm, a thickness of 1,2mm and a recording area divided into a lead-in area, and a program area, and wherein said data is recorded as pits representing modulated, error-correction encoded user information in sectors in user tracks in said program area and representing modulated, error-correcting encoded control information in sectors in one of said lead-in area or said program area, with said control information including addresses of respective user tracks, the tracks having a track pitch in the range of 0.646µm to 1.05µm, said method comprising the steps of rotating said disk to obtain a constant linear velocity;
projecting a pickup light beam through a lens for optically reading the rotating disk, said pickup light beam having a spatial frequency I=»/2NA, where the spatial frequency I is less than the track pitch, » is the wavelength of the pickup light beam and NA is the numerical aperture of the lens;
demodulating the data read from said disk;
error correcting the demodulated data;
separating the error corrected data into control information and user information; and
using said control information to access and read selected user tracks in response to access instructions from a user.</p> |
