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:
Jun. 07, 1994
Filed:
Aug. 12, 1993
Shori Mokuo, Kumamoto, JP;
Yoichi Deguchi, Tokyo, JP;
Mitsuo Nishi, Kumamoto, JP;
Shinji Tadakuma, Kumamoto, JP;
Tokyo Electron Limited, Tokyo, JP;
Tokyo Electron Kyushu Limited, Tosu, JP;
Abstract
A substrate detector device comprises a boat or chuck for holding substrates, a light emitting section having a plurality of light emitting elements, arranged side by side, for respectively applying light beams to the substrates, a light receiving section, facing the light emitting section and having a plurality of light receiving elements, for receiving light beams passed through the substrates, the light receiving elements arranged side by side so as not face the light emitting elements, a polarization filter provided on optical axes of the respective optical beams incident on the light receiving elements, a memory for storing, as reference data, an amount of light received by a receiving element which has been measured in advance when a light beam is applied to a substrate in a state where no other substrate is present on either side of the substrate, and controller for discriminating the presence, the number, and the state of arrangement of the substrates on the holding means based on the reference data and measured data based on the amount of light received by the light receiving elements after a light beam scattered by the substrate to be detected and a light beam wraparound substrates adjacent thereto are removed by the polarization filter.