Spectra Systems Corporation

Brown University

Timothy J Driscoll

Nabil M Lawandy

Charles M Zepp

Thermochromic compositions that include combinations of at least one color former and at least one Lewis acid in a polymer mixture are disclosed. The thermochromic compositions reversibly change appearance from substantially transparent to substantially non-transparent above a lower critical solution temperature.

Thermochromic compositions of color formers and lewis acids

A method and a system is disclosed for affixing invisible or unobtrusive markings to mail pieces (), and subsequently collecting information from the mail pieces for sorting purposes. The system includes the affixation of an optically contrasting layer () to a mail piece, the layer changing optically upon the application of a stimulus to present a contrasting background for imaging encoded information () applied over the layer and related to the mail piece.

Contrast enhancing marking system for application of unobtrusive identification and other markings

This invention teaches a method for authenticating a document. The method includes the steps of: (a) providing a document to be authenticated; (b) illuminating at least a portion of the document with laser light that exceeds a threshold fluence; (c) detecting a narrow band laser-like emission of at least one wavelength from the document in response to the step of illuminating; and (d) declaring the document to be authentic only if the laser-like emission is detected.

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Pawtucket, RI, United States of America

Timothy J Driscoll