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:
Nov. 22, 1988
Filed:
Dec. 29, 1987
Taro Ohmori, Yokohama, JP;
Hiroaki Kameyama, Yokohama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A wafer detecting device usable with a carrier has a plurality of wafer carrying portions disposed in stories for carrying wafers thereon. The device comprises a light emitting portion for emitting a light beams so that it passes through the carrier from one side thereof to the other side thereof and in a direction substantially parallel to a plane in which a wafer is carried on a wafer carrying portion of the carrier. A light receiving portion is disposed at the other side of the carrier for detecting presence/absence of the light passed through the carrier. The light emitting portion is arranged to emit the light over a dimensional range covering all the wafer carrying portions with respect to a direction in which the wafer carrying portions are disposed in stories, and the light receiving portion is fixed relative to the carrier and has a light receiving surface having an effective dimensional range greater than the dimensional range covering all the wafer carrying portions with respect to the direction in which the wafer carrying portions are disposed in stories.