System for optically identifying an object
US6301047A · kind A · utility
57Cited by
3References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 16, 1999 |
| Grant date | Oct 9, 2001 |
| Priority date | — |
| Expiry date | Nov 16, 2019 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB42D2033/26
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
The object to be identified is affixed with an identification medium comprising a reflective layer consisting of a reflective hologram or diffraction grating. The high polymer cholesteric liquid crystal provides an inexpensive identification medium, and the use of the second light receiving unit for providing a reference signal provides a high S/N output signal which is highly distinct and resistant to the contamination of the identification medium. Also, the elimination of the need for expensive optical elements such as beam splitters also contributes to the reduction of cost.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.