Fluorescent detecting apparatus and method
US5608225A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Mar 8, 1995 |
| Grant date | Mar 4, 1997 |
| Priority date | — |
| Expiry date | Mar 8, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K19/14
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A fluorescent light emitted from a marking containing at least one fluorescent substance is detected by illuminating the marking with an exciting light having an intensity that varies at a predetermined cycle, converting a change in intensity of light reflected from a position where the exciting light is irradiated into a varying electric signal and selectively extracting from the converted electric signal, only an electric signal component having a frequency matching with but a phase displaced from, that of a signal component corresponding to light reflected from the marking. A fluorescent detecting apparatus for this purpose includes a light source for irradiating at an irradiating station a marking formed on a medium with rays of light having an intensity that varies cyclically, the marking having at least one fluorescent substance. The apparatus further includes a photo-electric detector for detecting incident rays of light reflected from the irradiating station and converting the rays of light into an electric signal, and a phase detector for extracting from the electric signal respective signal components corresponding to the rays of light reflected from the marking and the m…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.