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:
Oct. 06, 1981
Filed:
Jun. 04, 1979
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A focus detecting device for a lens system having a subsystem for dividing the image of an object into two optically equal images and for shifting the two images of the object in the opposite directions or shifting only one of the two images of the object. Two photoelectric conversion element groups are adapted to convert the variations in relative position of the two images of the object into electrical signals. An optical system projects the images of the object onto the two photoelectric conversion element groups, in which the following outputs are obtained from the outputs of photoelectric conversion elements forming the two photoelectric conversion element groups by using a calculating circuit: ##EQU1## where: n is the number of photoelectric conversion elements forming each photoelectric conversion element group, m is the number in order of a photoelectric conversion element and, i.sub.1 through i.sub.n and i'.sub.1 through i'.sub.n are the outputs of photoelectric conversion elements which are proportional to the quantities of light applied thereto, respectively.