The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 28, 2000
Filed:
Nov. 10, 1998
Byung-seol Ahn, Kyungki-do, KR;
Samsung Electronics Co., Ltd., Suwon, KR;
Abstract
An apparatus for sensing an insertion state of a wafer disposed in a slot of a wafer cassette, includes a stage supporting the wafer cassette that is movable relative to a light beam source and photo-detector positioned on either side of the wafer cassette. A position determining mechanism is connected to the photo-detector and a timer is connected to the position determining mechanism. The position determining mechanism receives, from the photo-detector, a position signal indicative of a wafer disposed in the light path. The timer generates a pulse signal that is received by the position determining mechanism after a predetermined time period has elapsed from a time when the position signal is received by the position determining mechanism. The position determining mechanism generates a decision signal, indicative of a wafer incorrectly loaded in a slot of the wafer cassette, when the position signal and pulse signal overlap.