Identification medium, method for reading data therefrom, apparatus for identification, and method and apparatus for production thereof
US8915437B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 2011 |
| Grant date | Dec 23, 2014 |
| Priority date | — |
| Expiry date | Jun 29, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H2250/41
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A technique detects counterfeit products having appearances similar to authentic products with high accuracy. A cholesteric liquid crystal layer in which hologram is processed and circularly polarized light of primary rotating direction having specific central wavelength can be selectively reflected and a code forming layer in which code printed pattern that is an objective of reading is formed, are arranged in this order seen from a side from which reading is performed. The hologram image that inhibits reading of information of the code while an optical reading device reads it together with the code, and it is formed by the hologram processing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.