Invisible, machine-detectable security marking, production of the security marking, and security system comprising this security marking

• Main Authors: SCHWALB GEORG, KUEPFER JUERGEN, LEIGEBER HORST, MUELLER-REES CHRISTOPH
• Format: Patent
• Language: English
• Published: 22.07.2008
• Subjects: AUXILIARY PROCESSES IN PHOTOGRAPHY; BOOK COVERS; BOOKBINDING; CALCULATING; CHECKING-DEVICES; CINEMATOGRAPHY; COLOUR PRINTING; COMPUTING; COUNTING; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDEDFOR; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; ELECTROGRAPHY; ELECTROPHOTOGRAPHY; FILES; FREQUENCY-CHANGING; HANDLING OF COINS OR OF PAPER CURRENCY OR SIMILAR VALUABLEPAPERS, e.g. TESTING, SORTING BY DENOMINATIONS, COUNTING,DISPENSING, CHANGING OR DEPOSITING; HANDLING RECORD CARRIERS; HOLOGRAPHY; LINING MACHINES; LOOSE LEAVES; MAGNETOGRAPHY; MOVABLE-STRIP WRITING OR READING APPARATUS; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICAL LOGIC ELEMENTS; OPTICS; PERFORMING OPERATIONS; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR,STEREO-PHOTOGRAPHIC PROCESSES; PHOTOGRAPHY; PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHYSICS; PRESENTATION OF DATA; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITYFEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOTOTHERWISE PROVIDED FOR; PRINTING; PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; RECOGNITION OF DATA; RECORD CARRIERS; SPECIAL PRINTED MATTER; STAMPS; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; TRANSPORTING; TYPEWRITERS

The invention relates to a security marking whose level of proof against forgery is greater than that of known security markings, comprising liquid-crystalline material with chiral phase, wherein the security marking is imperceptible to the eye and the properties of the liquid-crystalline material with chiral phase can be detected with the aid of detection systems.