Producing glass pattern for disc-shaped optical memory involves separate image and data application processes in which only image or data are applied to separate spiral image or data tracks

摘要

The method involves applying binary information to a spiral data track (12) on a layer of photoresist as pits (16) separated by lands using a focused laser or electron beam, Separate image and data application processes are performed in which only image or data are applied to separate spiral image or data tracks respectively. The method involves applying binary information to a spiral data track (12) on a layer of photoresist as pits (16) separated by lands using a focused laser or electron beam, whereby the lengths of the pits and lands represent the data. Data are read using a focused beam following the track and using the interference principle. Visually readable information forming an image is applied to the smooth optical reference surface with depth less than the data pits so as to not affect binary information read-out. Separate image and data application processes are performed in which only image or data are applied to separate spiral image or data tracks respectively.