| 摘要 |
PURPOSE:To prevent writing by reading-out light at the time of turning over and stop of an optical card as the card moves by providing a transparent base material having track grooves on the surface, an optical recording layer on the grooved surface and an opaque card base material in contact with the optical recording layer and providing an unrecordable part to part of the optical recording layer. CONSTITUTION:An optical recording material is provided on the card base material. This optical recording material consists of the transparent base material 21 having the track grooves and the optical recording layer 22 provided on the track groove surface. The optical recording material is so provided that the optical recording layer 22 contacts the opaque card base material 24 and the unrecordable part is provided to part of the optical recording layer 22. The writing by the reading-out light upon stopping of the optical card which arises when the movement of the optical card is turned over during tracking of the card is thereby entirely prevented and the generation of the tracking error is prevented in spite of repeated reading-out. |
