Method of manufacturing an optical storage medium and optical storage medium

Abstract

A method of manufacturing an optical storage medium is provided, which comprises at least a transparent spacer layer (22) or transparent cover layer. This layer is provided by spincoating a liquid layer (22) between an inner radius ri and outer radius ro and substantial solidification by means of exposure to e.g. UV-radiation. The solidification of the liquid (22) is started at ri at a moment in time defined as t = ti. The solidification of the liquid (22) at ro takes place at a moment in time defined as t=to and to = ti + d and d > 1 s. The solidification of the liquid (22) between ri and ro takes place at a moment in time between ti and to. The advantage is that the radial thickness uniformity of the solidified liquid (22) is substantially improved and better than + / - 1 m. Further an optical storage medium is provided manufactured using the method wherein additionally a stamper, preferably transparent to radiation, is pressed into an unsolidified top portion of the liquid layer (22) and solidified using a special device. In this way information is provided into the spacer layer (22) without disturbing the thickness uniformity of the spacer layer (22).

Description

technical field [0001] The invention relates to a method of manufacturing an optical storage medium comprising a substrate and a plurality of layers deposited on the substrate, the layers comprising at least one of a transparent spacer layer and a transparent cover layer, the layer being formed by the following process : The liquid is applied to the rotating substrate, which is further rotated so as to spread the liquid substantially uniformly into the inner diameter r i and outer diameter r 0 and using radiation exposure to substantially solidify the liquid layer, and [0002] in r i Freezing of the liquid layer at takes place at defined as t = t i at the moment of r 0 Freezing of the liquid layer at takes place at defined as t = t 0 and t 0 = t i +δ and δ>1s, at r i and r 0 Freezing of the liquid layer between occurs at t i and t 0 moments in between. [0003] The invention also relates to an optical storage medium produced by said method. Background techniq...

AI Technical Summary

Problems solved by technology

The 4.7GB single-layer rewritable DVD format is similar to, for example, conventional compact discs (CDs) for ease of handling, however for video recording purposes it does not provide sufficient storage capacity

This causes problems in re-using the stamper, and the burrs at the edge of the DVD substrate can cause trouble in subsequent processing steps in the manufacture of optical storage media, such as when applying a transparent cover layer

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