| 摘要 |
PURPOSE:To attain access of an object track in a 1st time card scanning to reduce the access time even if coarse access is attended by providing n-kind of proximity track discrimination mark in consecutive n-track less than all track numbers so as to be different from each track. CONSTITUTION:When an optical card 11 is stopped and a beam spot for applying recording and reproduction is located at a position S1, and when the address is known, at first a difference between an object address and a present address is calculated so as to discriminate whether or not the absolute value is smaller than a setting value. If the difference is small, track jump is repeated by the difference and when the difference is larger, the entire optical head is moved to apply coarse access. Then a pattern for discriminating a proximity track recorded to an identification part 12B is read while moving the optical card 11 in the track direction thereby moving the beam spot from a point S3 to a point S4. then an ID part 48 is read to confirm an object address. |
