Dust detecting device

Abstract

Abstract PURPOSE:To monitor remotely and continuously a cleaning degree in a clean room by placing only a lens system for causing a light scattering, at a measuring point in the clean room, and connecting a projector and a photodetector placed at the outside of the clean room by an optical fiber. CONSTITUTION:A light from a laser tube 13 passes through a lens 14 and goes into an end face 111 of an optical fiber 11, and it is collected and irradiated to a measuring point 5 in a measuring block. A scattered light generated in the measuring point 5 is transferred through the second optical fiber 12, and goes into a detecting electronic tube 9 through a condensing lens 15. A terminal of the optical fiber functions as an aperture, therefore, an aperture plate is not required. Also, when the end face of the optical fiber is formed in a shape of a convex lens, and a good image is formed in the measuring point 5 by adjusting distance to the measuring point 5, condensing lenses 4, 7, 14 and 15 become unnecessary.

Inventors

• 👤 Hideo Izumi
• 👤 泉　秀雄

Bibliographic Details