Birefringent marking

US7033653B2 · kind B2 · utility

Assignee

• Merck Patent GmbH · DE

Inventors

• Matthias Kuntz · Seeheim-Jugenheim, DE
• Robert Hammond-Smith · Fordingbridge, GB
• Rodney Riddle · Holzminden, DE
• John Patrick · Carthage, US
• Donald Gordon Graham · Algonac, US

Key dates

• Filing date: Mar 28, 2002
• Grant date: Apr 25, 2006
• Expiry date: May 27, 2022

Classification

• Technology area (CPC G): Physics
• CPC primary: G03H2250/38
• WIPO field: Other consumer goods
• WIPO sector: Other fields

Abstract

The invention relates to a birefringent marking comprising a liquid crystal material. The invention further relates to method of providing such a birefringent marking and to the use of the birefringent marking for decorative or security applications.