Patent ID: 7636171
Filing Date: 2009-12-22
Classification: G11B

Abstract:
1. A method for monitoring the degradation of a data storage medium having a data recording material within said medium, comprising: providing a plurality of monitor elements arranged within said medium, each of said monitor elements having an optical property sensitive to at least one of the presence of a contaminant within said medium adjacent to said monitor element and a deformation of said medium adjacent to said monitor element; performing a first measurement of the optical property of at least one of said plurality of monitor elements to generate a map of an initial state of said medium; performing at least one second measurement at a subsequent point in time of the optical property of said at least one of said plurality of monitor elements to generate a map of an intermediate state of said medium; and after each at least one second measurement, determining whether said medium has degraded as a result of either having been contaminated or deformed by comparing said map of said initial state to said map of said intermediate state to detect any changes in said optical property of said at least one of said plurality of monitor elements, wherein said medium is determined to have degraded if said optical property of said at least one of said plurality of monitor elements has changed.