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:
Sep. 22, 1981
Filed:
May. 17, 1977
Michihiro Mese, Hachioji, JP;
Seiji Kashioka, Hachioji, JP;
Masakazu Ejiri, Tokorozawa, JP;
Takafumi Miyatake, Hachioji, JP;
Isamu Yamazaki, Tachikawa, JP;
Toshimitsu Hamada, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An apparatus for detecting the position of an object. The apparatus has an optical device for magnifying or enlarging a plurality of portions on the object, a photoelectric converter adapted for converting the enlarged portion image into electric signals, a plurality of thresholding circuits adapted for changing analogue signals from the respective photoelectric converter into binary signals with a threshold value determined by a signal level given by a first signal holding circuit, a circuit for calculating the threshold value from the analogue signals, a circuit for detecting the approximate position of a specific pattern in the enlarged portion images through a coarse sampling of the binary signals. A circuit for detecting the exact position of the specific pattern through measuring the area of a specific brightness in a plurality of regions in the enlarged portion images, by a fine sampling of the binary signals, and a controller for controlling the operations of respective circuits.