Sucked material detector, sucked material detecting method using the same detector, shift detecting method using the same detector, and cleaning method using the same detector

摘要

PCT No. PCT/JP97/01810 Sec. 371 Date Nov. 24, 1998 Sec. 102(e) Date Nov. 24, 1998 PCT Filed May 28, 1997 PCT Pub. No. WO97/46071 PCT Pub. Date Apr. 12, 1997The present apparatus includes an attracting transport arm for attracting an attraction object via a nozzle hole by vacuum and transporting the attraction object in a horizontal or vertical direction. An upwardly directed light emitting sensor is disposed on the rear side of a portion of a stage at which the attraction object is to be placed. At the location at which the attraction object is to be placed, a through-hole which is intended to prevent interception upward rays of light of the light emitting element is perforated. Meanwhile, a downwardly directed light receiving element for receiving rays of light from the light emitting element is disposed in the interior of the nozzle hole of the attracting transport arm.