Information reading method
US5220166A · kind A · utility
20Cited by
3References
13Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 9, 1991 |
| Grant date | Jun 15, 1993 |
| Priority date | — |
| Expiry date | Sep 9, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/12
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An information reading method includes the steps of irradiating a phosphor activated by neodymium and ytterbium ions with exciting light of a wavelength between 500 nm and 780 nm that can excite the neodymium ions, and reading the information by receiving the light emitted from the phosphor with a photodetector designed to detect light with wavelengths between 840 m and 1100 nm. Consequently, the information recorded using the phosphor activated by neodymium and ytterbium ions can be read with a high performance without using a filter for cutting the exciting light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.