Patent ID: 6011767
Filing Date: 2000-01-04
Classification: G03H,G11B

Abstract:
A method for manufacturing an optical data storage disc having a surface relief comprising, in one area, a series of indentations defining a digital recording replayable under reflected light and, in another area, a pattern which provides a hologram visible to a naked human eye under reflected light, said method comprising the steps of:producing a master by a process comprising the steps of forming on said master a digital recording and a recording for a hologram, said recordings being formed on said master in different areas in successive optical exposures, so that the same said master carries both the digital recording and the recording for the hologram;forming impression means from said master, said impression means having a surface relief which is an inverse of said surface relief to be provided on said optical data storage disc; and,replicating said optical data storage disc from said impression means, said optical data storage disc thereby having an area formed with indentations defining said digital recording and another area formed with said surface relief pattern which, upon replay under reflected incident light, will produce a hologram visible to a naked human eye.