| 摘要 |
In the present invention there is disclosed an optical disk memory for binary information stored in series as a sequence of holes (21) and areas on a spiral trace in a smooth optical reference surface, where the length of the holes (21) and the areas, which are independent on each other represent stored binary values that can be read through the mediation of a tracking focused laser beam by making use of the interference principle. This memory can be identified by a way that prevents confusion and unauthorized copying in such a manner that a selected number from the total number of the areas are performed as depressions (23) that are shallow when compared with the depth of the holes (21). This identification sign of substantially any form can be either so small, that is easily visible only b making use of electron microscope or it can be so big, that it is visible in diffused light by eye. |
