| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To precisely detect an object OB to be detected even if it is thin. <P>SOLUTION: Laser light emitted from a laser light source 10 is made incident on a mirror 14, through a convex lens 12 while the beam diameter is made small, and is reflected. The laser light reflected by the mirror 14 passes through a light aperture 3a to be sent to a detection passage A. The laser light sent to the detection passage A converges on a center position of the detection passage A and then is made incident on a mirror 16, through a light aperture 3b of a left casing 2b while the beam diameter is made large. The laser light made incident on the mirror 16 is reflected and focused on a photodetection surface of a photodetector 20, through a convex lens 18. The photodetector 20 receives the laser light and outputs a photodetection signal corresponding to the intensity of the received light. Therefore, when the object OB to be detected passes the convergence position of the laser light, the photodetection signal has large variation. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
