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. 18, 1986
Filed:
Jul. 03, 1985
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An automatic focusing device having a light projecting device, a light receiving device arranged to detect a reflection light quantity reflected by an object to be photographed as a result of light projection by the light projecting device and a distance measuring device arranged to measure a distance to the object by the reflection light quantity received by the light receiving device is capable of adequately performing a focusing operation even in cases where the reflection light quantity is at a level too low for the distance measuring device to give any result of distance measurement. This advantage is attained by the following arrangement: (i) the automatic focusing device is provided with a current control device which is arranged to increase the power of a light flux to be emitted from the light projecting device; (ii) a lens driving operation is brought to a stop in the event of an object of a low reflection factor; (iii) the light quantity accumulating time of the light receiving means can be lengthened; or (iv) a comparison level can be lowered.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile