Patent ID: 6570840
Filing Date: 2003-05-27
Classification: G11B

Abstract:
A structure for storing selectively retrievable data, said structure comprising a data layer of substantially uniform composition for containing said data, said data layer having:a. a first level; and b. a first feature, said first feature elongated and three-dimensional, at least a portion of said first feature vertically displaced from said first level, said first feature having a principal axis substantially parallel to said first level, a transverse axis substantially normal to said principal axis and parallel to said first level, and a vertical axis substantially normal both to said principal axis and to said first level, said first feature characterized in that: (1) the outer shape of said first feature, defined by a transverse section thereof, displays no substantial slope discontinuity from the point at which said first feature begins its displacement from an index level defined upon said structure, at one transverse edge of said feature, until the point at which said displacement from said index level ends at the opposite transverse edge of said first feature; (2) the extent of said first feature along said vertical axis, in respect to said index level, is not more than approximately 0.25 micron, the extent of said first feature along said transverse axis is not more than approximately one micron and the extent of said first feature along said principal axis is at least twice as great as the extent of said first feature along said transverse axis; and (3) the ratio of the maximum displacement of said first feature from said index level in a first direction along said vertical axis to said displacement in the opposite vertical direction excludes a substantially zero value, a substantially infinite value, and values within the range extending from approximately 0.2 to approximately 5.0.