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. 03, 1992
Filed:
Nov. 26, 1990
Keiji Moriyama, Yokohama, JP;
Nikon Corporation, Tokyo, JP;
Abstract
A focus detecting apparatus has a condenser lens provided near a primary image of an object formed through an objective lens, and a plurality of focus detecting optical systems, each detecting deviation between the relative positions of a pair of secondary images. Each focus detecting optical system has a pair of stop openings provided rearwardly of the condenser lens for dividing a marginal area of the exit pupil of the objective lens into a pair of divided pupil areas that are symmetrically disposed with respect to the optic axis of the objective lens. A pair of re-imaging lenses is disposed rearwardly of each pair of stop openings for forming a pair of secondary images. The directions of deviation of the pairs of secondary images differ from each other. The interval between the centers of the stop openings of each pair of stop openings is substantially the same for all the pairs of stop openings, but the radii of circles that circumscribe respective pairs of stop openings differ from each other.