The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Mar. 11, 2003

Filed:

Oct. 17, 2000
Applicant:
Inventors:

Nabil M. Lawandy, North Kingstown, RI (US);

Charles M. Zepp, Hardwick, MA (US);

Andrei Smuk, Providence, RI (US);

Marianne Krieg-Kowald, Barrington, RI (US);

Assignee:

SpectraDisc Corporation, Providence, RI (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B 3/70 ;
U.S. Cl.
CPC ...
G11B 3/70 ;
Abstract

Methods and apparatus are provided for making an optically readable media unreadable and tamper-resistant. A method has steps of (a) providing the media with a readout surface layer that is non-flat (i.e., textured in some way, such as by embossing, scratching, depositing a non-planar layer or regions, such as droplets) and that inhibits optical readout of the media; (b) applying a coating layer to the non-flat surface layer to smooth the non-flat surface and to enable optical readout of the media; and, after an initiation of a readout period, (c) removing the coating layer so as to expose the non-flat readout surface layer, thereby inhibiting optical readout of the media. Preferably, the coating layer is substantially index matched to the readout surface layer. The step of removing includes at least one of evaporating or subliming a component material of the coating layer A method is also disclosed for discouraging tampering with a readout-limiting mechanism by (a) providing the media with at least one layer that embodies the readout-limiting mechanism; (b) providing a textured surface that forms part of a layer that underlies the at least one layer, where the textured surface inhibits optical readout of the media; and (c) applying a coating layer over the textured surface to smooth the textured surface and to enable optical readout of the media, wherein removal of the coating layer exposes the textured surface thereby inhibiting optical readout of the media.


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