Device for the optical detection of foreign matter

Abstract

Abstract In the inside of a diffusion disc 10, an optical transmitter (11) and a receiver (12) are directly arranged. When the diffusion disc (10) is clean, the radiation emitted by the transmitter (11) passes almost completely through the diffusion disc (10). Only a small proportion is reflected at the glass/air interface and impinges on the receiver. This small proportion can be used for continuously checking the operability of the transmitter (11) and of the receiver (12). If dirt particles (14) are located on the outside of the diffusion disc (10), light is reflected on these and the proportion of the radiation impinging on the receiver (12) increases. A cleaning system can be triggered. The device is of simple construction and is largely free of interfering influences. <IMAGE>

Inventors

• 👤 Helmut Domann
• 👤 Frieder Dipl.-Ing. Heintz
• 👤 Robert Dipl.-Phys. Hugel
• 👤 Peter Dr.-Ing. Knoll
• 👤 Winfried Dr.-Ing. König
• 👤 Gerhard Dipl.-Ing. Lindae
• 👤 Peter Perthus
• 👤 Georg Riedel
• 👤 Konrad Dipl.-Ing. Wolf
• 👤 Erich Dr.-Ing. Zabler

Bibliographic Details