| 摘要 |
<p>Apparatus (10) and methods are provided for sensing the presence of bright white paper on a conveyor (100) of a paper sorting system. The conveyor (100) is constantly illuminated with ultraviolet light (12). When bright white paper is present in the inspection zone (19), it will re-radiate fluorescent light energy. Periodically, the inspection zone (19) is illuminated with a second light source (20) in the visible light spectrum. Light is collected from the inspection zone (19), including reflected light from the secondary source (20) and including emitted fluorescent light energy. Periodically a microprocessor (140) senses reflected light to determine whether any object is present on the conveyor (100). The microprocessor (140) then senses the level of fluorescent light energy being emitted from any object on the conveyor (100). The system determines first whether any object is present on the conveyor (100), and then determines whether that object is bright white paper depending upon the measured level of emitted fluorescent light energy.</p> |
