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. 25, 1980
Filed:
Dec. 21, 1978
Seiji Yamada, Sakai, JP;
Norio Beppu, Sennan, JP;
Minolta Camera Kabushiki Kaisha, Osaka, JP;
Abstract
A lamp control circuit for energizing a data imprinting lamp in response to an actuation of a flash trigger switch in a camera, for a given period so that data images illuminated by the lamp are imprinted on a film with a suitable exposure. The control circuit includes a series connection of a SCR element and a capacitor, a trigger circuit for applying a single pulse to the control terminal of the SCR element, a capacitor discharge circuit for discharging with a given time constant the capacitor that has been charged through the SCR element, and a switching circuit for energizing the lamp while the terminal voltage of the capacitor is above a threshold level. The trigger circuit has a high input impedance to protect the control circuit from high voltage which otherwise may be applied thereto through a camera synchro terminal to which the input terminal of the trigger circuit is connectable.