Includes the foreign material detection device and the foreign material detection device the process line

摘要

PROBLEM TO BE SOLVED: To obtain a foreign-matter detecting device by which a foreign-matter can be detected simply and at low cost by a method wherein the intensity of a first beam of light received by a first light-receiving optical system is detected in real time and the magnitude of a first detection signal is compared with a prescribed value. ;SOLUTION: A first projection optical system 142 emits a first beam of light in a first direction parallel to the main axis of an object 120 on a stage 110 which is conveyed in a conveyance axial direction. A first light-receiving optical system 144 receives the first beam of light which is passed on the main face of the object 120. The intensity of the first beam of light received by the first light-receiving optical system 144 is detected in real time by a detector. In addition, a first detection signal according to the intensity is output. The magnitude of the first detection signal is compared with a prescribed value by a judgment circuit. On the basis of a compared result, a foreign-matter detection signal which indicates whether a foreign-matter exists or not is output. Thereby, the foreign body, in various shapes, whose surface is not smooth or even the foreign-matter having a size of about 20 μm or higher can be classified and judged individually not as a foreign body group. In addition, the foreign body can be detected without lowering the sensitivity of a detection. In addition, the foreign-body detecting device can be inserted easily into a process line.;COPYRIGHT: (C)2000,JPO