EURion constellation

The EURion constellation (also known as Omron rings[1] or doughnuts[2]) is a pattern of symbols incorporated into a number of secure documents such as banknotes, cheques, and ownership title certificate designs worldwide since about 1996.

[4] The EURion constellation first described by Kuhn consists of a pattern of five small yellow, green or orange circles, which is repeated across areas of the banknote at different orientations.

[2] A 1995 patent application[5] suggests that the pattern and detection algorithm were designed at Omron, a Japanese electronics company.

The term Omron anti-photocopying feature appeared in an August 2005 press release by the Reserve Bank of India.

[8] The members of Central Bank Counterfeit Deterrence Group (CBCDG) are the European Central Bank and the central banks of Australia, Austria, Belgium, Bulgaria, Canada, Cyprus, Czechia, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Japan, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, South Africa, Spain, Sweden, Switzerland, Turkey, the United Kingdom, and the United States.