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:
Apr. 28, 2020
Filed:
Jul. 22, 2016
DE LA Rue International Limited, Basingstoke, Hampshire, GB;
Brian William Holmes, Fleet, GB;
DE LA RUE INTERNATIONAL LIMITED, Basingstoke, GB;
Abstract
A diffractive security device is disclosed, including first and second diffractive structures defined in a carrier layer. The first diffractive structure is a diffractive zone plate structure of a continuously curved surface configured such that when the device is illuminated by on-axis light, a first diffraction pattern generated by the first diffractive structure can be viewed from at least a first side of the device at substantially all viewing angles, the first diffraction pattern exhibiting a reference point or reference line relative to which other features of the first diffraction pattern appear to move when the viewing angle is changed. The second diffractive structure is an off-axis diffractive structure configured such that when the device is illuminated by on-axis light a second diffraction pattern generated by the second diffractive structure can be viewed from at least the first side of the device at at least some off-axis viewing angles.