| 摘要 |
PURPOSE:To facilitate discrimination of a track and to improve the discrimina tion accuracy by constituting a unit information area recorded on a track of a grid, and differentiating the shape or condition of the grid from the adjacent grid. CONSTITUTION:Recording pits 11, 12, 13, etc. on tracks 21, 22, etc. recorded with information are constituted respectively of a grid 12. In this case, the angle between the arrangements of the grids in the recording pits 11 and 12 is regulated to 90 deg.. The arrangement is alternately changed in the tracks 21, 22, 23, etc. Namely, the condition of the grid of the recording pit is different from the adjacent track. The direction of the light diffracted by the grid is determined by the direction of the arrangement of the iron. Accordingly, the track can be discriminated by detecting the distribution of the light reflected from the recording pit. By such a structure, the track can be discriminated with high accuracy, and high-density recording is made possible. |
