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:
Aug. 14, 1984
Filed:
Sep. 16, 1982
Hitoshi Hirobe, Tokyo, JP;
Shigeo Enomoto, Tokyo, JP;
Tadashi Minakuchi, Tokyo, JP;
Shinji Urata, Tokyo, JP;
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
An automatic focusing device for moving a photographic lens to an optimum focusing position by detecting an object image contrast signal that changes with the varying position of the photographic lens. The device stops the photographic lens while it is being moved between an infinite distance photographing position to a least distance photographing position when the level of the detected contrast signal becomes less than a threshold level. The invention compares a first signal, which is set to correspond to a position at which the photographic lens is to be stopped, and a second signal, which is generated when the contrast signal level is less than the preset threshold level.