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. 09, 1998
Filed:
Apr. 07, 1997
Shigeyuki Uchiyama, Setagaya, JP;
Nikon Corporation, Tokyo, JP;
Abstract
The invention eliminates field mask eclipse related to a focal detection apparatus that uses a phase variation detection method, and provides an adjustment device and method for the focal detection apparatus. The focal detection apparatus includes a field mask; a separator optical system that divides and forms a set of light images of a beam of light transmitted through the field mask; an image sensor that photoelectrically converts light images from the separator optical system; a light-receiving area memory device; a masking device that masks the photoelectric output of the image sensor according to the light-receiving areas written into the light-receiving area memory device; and a focal computation device that computes a defocusing amount from the photoelectric output masked by the masking device. The adjustment device and method writes into the light-receiving area memory device the light-receiving areas not incurring optical eclipse when uniform illumination is projected onto the image sensor via the field mask and the separator optical system.