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. 24, 1985
Filed:
Oct. 01, 1984
Saburo Numata, Saitama, JP;
Fuji Photo Optical Co., Ltd., Saitama, JP;
Abstract
An automatic focusing apparatus of the type having an infrared light source for illuminating a subject wherein a position sensor for sensing infrared light reflected from the subject passing through two different portions of the picture-taking lens is provided to generate signals which represent condition of the picture-taking lens, that is, whether an image of the subject is in the best focus, front focus or rear focus. The position sensor comprises two position-sensing devices. By detecting the difference between the outputs from these two position-sensing devices, the condition of the picture-taking lens can be determined. A single position-sensing device can be used if AC signals are generated by a mechanical chopper in the forward position therefrom.