Patent ID: 7724613
Filing Date: 2010-05-25
Classification: G11B,G11C

Abstract:
1. A method to store information in a holographic data storage medium, comprising the steps of: supplying a holographic data storage medium comprising an outer radius R O and an inner radius R I ; providing information; defining an Active storage portion for said holographic data storage medium; establishing a threshold access interval; determining if said information was last accessed within said threshold access interval; operative if said information was last accessed within said threshold access interval, storing said information as one or more holograms encoded in said Active storage portion of said holographic data storage medium; defining a Fossil storage portion for said holographic data storage medium; calculating an Active-Fossil boundary radius R AF using the equation: R AF =[(R O 2 −R I 2 )/2] 1/2 wherein the portion of said holographic data storage medium having a radius greater than said Active-Fossil boundary radius R AF is defined as said Active storage portion; operative if said information was not last accessed within said threshold access interval, storing said information as one or more holograms encoded in said Fossil storage portion of said holographic data storage medium.