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. 09, 1986
Filed:
Jul. 25, 1985
Masaaki Yoshida, Tokyo, JP;
Hiroyuki Kataoka, Tokyo, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
In a flash device arranged to determine the aperture value of a photo-taking lens according to the measured level of a reflection light obtained by preliminary flashing and to control main flashing according to a light control level corresponding to the aperture value, when a light diffusing panel is arranged in front of a main flashing part for a wider flash illuminating angle, another light diffusing panel which gives an equal light reducing effect is also arranged for a preliminary flashing part. The light quantity of preliminary flashing is thus reduced in proportion to the degree of reduction in the light quantity of main flashing, so that the aperture value set by preliminary flashing and the light controllable range of main flashing for photographing can be made to be always in agreement with each other.