Patent ID: 6165391
Filing Date: 2000-12-26
Classification: B29C,B29D,B29L,B30B,G03H,G11B,Y10S

Abstract:
A method of providing a micro-relief pattern on an optical data storage disc formed with a peripheral ridge extending at least around part of the periphery of said disc comprising the steps of providing an embossing member adapted to form a required micro-relief pattern on the optical data storage disc, providing a support member which is thicker at its periphery than at the center, supporting said disc on said support member, applying a force to bring said embossing member and said disc into contact with each other, the application of said force being such that a relatively small initial force is first applied to the disc for a brief period of time before subsequently increasing the force to a much greater force-value to the extent where the micro-relief pattern from the embossing member is transferred to the disc, such that the force is applied in a manner to at least initially increase the pressure to which the disc is subjected in the region of said peripheral ridge compared with the remainder of the disc.