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. 23, 1977
Filed:
Jul. 28, 1975
Toshihiro Kondo, Chofu, Tokyo, JA;
Toshihiro Kondo, Chofu, JA;
Fuji Photo Film Co., Ltd., BOTH OF, JA;
Abstract
A density-variable optical filter is mounted on a camera so that the density of the filter may be freely selected by manual operation independently of the aperture size of a diaphragm and the shutter speed. In a preferred embodiment, a rotatable ring for controlling the density of the density-variable filter graduated with a scale of one unit system is mounted to the lens barrel of the taking lens of the camera and an exposure meter which has a needle swingable in the field of view of a view finder graduated with a scale of the same unit system as that of the rotatable ring for controlling the filter density is provided to indicate the scene brightness. In another embodiment, a diaphragm control ring, a shutter speed setting dial and a film sensitivity setting dial are connected with the exposure meter to input the exposure information regarding the aperture size, shutter speed and film sensitivity into the exposure meter so that the needle of the exposure meter may indicate the desirable density of the filter to result normal exposure.