Optical security device

• Main Authors: Zbynêk Ryzi, Marek Skeren, Roman Nahálka
• Format: Patent
• Language: English
• Published: 14.12.2022
• Subjects: BOOK COVERS; BOOKBINDING; CINEMATOGRAPHY; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDEDFOR; ELECTROGRAPHY; FILES; HOLOGRAPHIC PROCESSES OR APPARATUS; HOLOGRAPHY; LOOSE LEAVES; MOVABLE-STRIP WRITING OR READING APPARATUS; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PERFORMING OPERATIONS; PHOTOGRAPHY; PHYSICS; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITYFEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOTOTHERWISE PROVIDED FOR; SPECIAL PRINTED MATTER; TRANSPORTING

An optical security device (1) comprising a recorded or encoded representation of an optically variable image (40), the image (40) being reconstructable and viewable for security, authentication or identification purposes, the device (1) comprising: an optical structure (30) in which there is recorded or encoded a representation of the optically variable image (40) in the form of a plurality of discrete portions (e.g. 50) of the complete image (40) to be reconstructed, wherein the respective said plurality of portions (e.g. 50) of the optically variable image (40) can, when reconstructed, only be viewed in their totality by viewing the said image (40) at or over a plurality of different viewing angles or angle ranges (70) relative to the optical structure (30) and/or at or over a plurality of different angles or range of angles of illumination of the optical structure (10), and wherein the size, in at least one dimension, direction, axis or plane, of the complete image (40), when reconstructed, is greater than the corresponding size, in the same, or the respective same, dimension, direction, axis or plane, of a part of the optical structure (30) having the said plurality of portions (e.g. 50) of the image (40) collectively recorded or encoded therein.