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:
Mar. 01, 1977
Filed:
Jun. 30, 1975
Tsukumo Nobusawa, Tokyo, JA;
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JA;
Abstract
Focusing apparatus for use in optical systems, such as photographing cameras, is disclosed. The focusing apparatus of the invention comprises an electronic system for developing, through either a single or two separate channels, pulse trains, the number of pulses contained in the pulse trains being related to the brightness of the image forming light received by the optical system as focused on photoconductive elements. The electronic system further includes a comparing subsystem for comparing the number of pulses included in the two pulse trains and, in accordance therewith, generating an information output signal related to the focus state of the optical system. Alternatively, the output signal may control a drive system adapted to move the imaging lens portion of the optical system toward focus.