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. 05, 1978
Filed:
Feb. 25, 1977
Kenji Kanemaru, Musashino, JP;
Fuji Photo Optical Co., Ltd., Omiya, JP;
Abstract
A photoreceptor is connected to an operational amplifier to convert the scene brightness to a voltage. The output of the operational amplifier is connected to a light emitting indicator to indicate exposure information. The output of the operational amplifier is also connected to an indicator brightness control circuit which changes the luminance of the light emitting indicator according to the scene brightness so that the luminance of the indicator is increased when the scene brightness is high and vice versa. The control circuit includes a digital signal generator which outputs digital level signals and a selecting circuit which selects the digital signals and controls the luminance of the indicator according to the selected signals. In order to prevent flickering of the indicator, a hysteresis is provided in the selecting circuit.