| 摘要 |
<p>Data are reproduced by reciprocally driving an optical card (200) in a direction parallel with tracks (T). A guide portion (G) without data pit is formed on both sides of each of the tracks to prevent read errors from occuring during the acceleration and deceleration of reciprocal movement. Track identification data (I) and end-of-track data (E) are recorded adjacent to the guide portion, and user data (U) are recorded therebetween. The user data are divided into groups which are recorded on the optical card in a dispersed manner. On the optical card are provided a directory pointer region (212), a directory region (213) and a data region (214). When the directory is changed accompanying a change in the data region, a new directory is written on the directory region, and a directory pointer that always indicates the position of the latest directory is written onto the directory pointer region.</p> |
