Protuberant optical recording medium
AssigneeMinnesota Mining and Manufacturing Company
InventorsKent N. Maffitt, William B. Robbins, Richard F. Willson
Life of this patent
Estimating the term…
Abstract
An optical recording medium containing a light-absorbing film of amorphous carbon less than 60 nm thick and which is sufficiently plastic to allow plastic information upon localized heating is provided for exposure to a focused laser beam, whereupon localized heating of the light-absorbing film enables information storage in the form of localized protuberances in the heated areas which can subsequently be optically detected and can be used as a master information record for replication purposes.
Claims18
A recording medium for use with a focused laser beam, said recording medium having a substrate and a light-absorbing layer adjacent thereto for absorbing light from the laser beam is localized regions to thereby provide information storage, wherein in the improvement said light-absorbing layer comprises amorphous carbon having a thickness of less than 60 nm and a plasticity sufficient to allow plastic deformation upon localized heating resulting from impingement by said laser beam to enable the formation of localized protuberances which can subsequently be optically detected.
A method for recording information in a thin film recording medium, comprising the steps of
- (a) providing a recording medium having a substrate and a light-absorbing layer adjacent thereto, said layer including amorphous carbon and having a thickness of less than 60 nm and a plasticity sufficient to allow plastic deformation upon localized heating,
- (b) exposing said medium to a focused laser beam of limited power and duration to cause absorption of light therefrom in localized regions, and
- (c) deforming said absorbing layer as a result of said light absorption to form optically detectable protuberances at said localized regions.
A process for replicating information records comprising the steps of
- (a) providing a recording medium having a substrate and a light-absorbing layer adjacent thereto for absorbing light, wherein said light-absorbing layer comprises amorphous carbon having a thickness of less than 60 nm and plasticity sufficient to allow plastic deformation upon localized heating to enable the formation of localized protuberances which can subsequently be optically detected,
- (b) exposing said medium to a focused laser beam of sufficient duration and power to form on a surface of said light-absorbing layer a plurality of optically detectable localized protuberances, which protuberances form a pattern representing information recorded therein, and
- (c) placing said surface containing said protuberances in surface contact with a polymeric material or precursor thereof to form replicas of said protuberant pattern on a surface of said polymeric material.
An information record for use with playback apparatus employing a playback light beam, said information record having a substrate and adjacent thereto a light-absorbing layer comprising amorphous carbon having a thickness of less than 60 nm, a plasticity sufficient to allow plastic deformation upon localized heating, and a plurality of optically detectable localized protuberances representing recorded information.
Dependencies are inferred from the claim text.