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.
Patent No.:
Date of Patent:
Nov. 23, 2004
Filed:
Nov. 26, 2001
Kenneth John Drinkwater, Surrey, GB;
Brian William Holmes, Middlesex, GB;
De la Rue International Limited, Basingstoke, GB;
Abstract
A security device includes a holographic optically variable effect generating structure having at least two discrete section. The sections that generate in response to white light illumination an optically variable image having at least two defined graphical elements located at or near an image plane either on or adjacent to the plane of the device. In response to coherent illumination, the sections generate at least two discrete covert images, in the form of indicia, whose image planes are located at a distance away from the real place of the device. The covert images are reconstructed at different angles to a normal to a substrate supporting the device such that the covert images are spatially separated on their image plane, the covert images being non-visible under white light illumnination.