System and method for sensing white paper
US6570653B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 4, 2001 |
| Grant date | May 27, 2003 |
| Priority date | — |
| Expiry date | Dec 4, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/6469
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Apparatus and methods are provided for sensing the presence of bright white paper on a conveyor of a paper sorting system. The conveyor is constantly illuminated with ultraviolet light. When bright white paper is present in the inspection zone of the conveyor, it will re-radiate fluorescent light energy as a result of the ultraviolet light. Periodically, the inspection zone of the conveyor is illuminated with a second light source in the visible light spectrum. Light is collected from the inspection zone of the conveyor, including reflected light from the secondary source and including emitted fluorescent light energy as a result of the ultraviolet light falling on bright white paper. Periodically a microprocessor associated with the sensor senses reflected light from the second source to determine whether any object if present on the conveyor. The microprocessor then senses the level of fluorescent light energy being emitted from any object on the conveyor. The system determines first whether any object is present on the conveyor, as a result of the reflected secondary light, and then determines whether that object is bright white paper depending upon the measured level of emitted…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.