| 摘要 |
PURPOSE:To permit higher speed processing of information and increasing of the density thereof by forming an annular recording region to an optical card of a wallet size and rotating the optical card. CONSTITUTION:The annular recording region 3 is provided around a bearing aperture 2 of the optical card 1 of the wallet size and pits which permits optical reading-out and writing are spirally disposed thereto. The short sides are formed as arc-shaped semi-annular recording regions 4. These regions 3, 4 are constituted of recording layers 5 and protective layers 1'. Since this optical card 1 is subjected to reading-out and writing by subjecting the card to the prescribed rotation, an optical head is moved not intermittently but continuously. The higher speed processing is thus possible. Since tracking tracks as commonly usable as clocking tracks, the higher density of the information is attained. |
