OPTICAL DATA STORAGE DISC

摘要

An optical data storage disc comprising a first component disc (10) formed over one side with a pattern of indentations defining digital data, the indented side of the first component disc being provided with a reflective coating (11), and a second component disc (12) bonded to the indented side of the said component disc. The second component disc carries a surface relief pattern which defines a holographic or other optically variable image.