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:
May. 09, 1978
Filed:
Dec. 13, 1976
Naoyuki Uno, Urawa, JA;
Masahiro Kawasaki, Tokyo, JA;
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JA;
Abstract
A light meter circuit for an SLR camera implements full aperture viewfinding with a preselected exposure time by providing an integrating capacitor 25 for controlling the exposure time, a first switch 24 for enabling the charging of the capacitor, circuit means 26, 29 for controlling the charging of the capacitor, a variable resistor 30 for establishing the lens aperture value in an exposure time display mode, a fixed resistor 31 for establishing the aperture value in an exposure time control mode, and a second switch 32 for connecting one of the resistors to an input of the charging control circuit. When the shutter release button is depressed the second switch is transferred from the variable to the fixed resistor, and the first switch is subsequently opened to enable the charging of the capacitor.