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. 01, 1981
Filed:
Sep. 06, 1979
Jean M Orban, Santa Monica, CA (US);
Vivitar Corporation, Santa Monica, CA (US);
Abstract
A device for activating an electronic slave flash unit for photographic use includes a circuit wherein there is a delay circuit responsive to a light sensing signal after a predetermined time delay to activate a flash unit. The time delay of the delay circuit is adjustable as required, and the delayed operation of the flash of the slave flash unit eliminates incorrect impulse signals being transmitted to light sensors of other slave flash units which would otherwise prematurely extinguish their flash and give a resultant incorrect lighting effect. The power for the circuit is obtained from a capacitor which is energized by a flash unit. The energy in the capacitor is used to power the delay circuit, and a Zener diode and unijunction transistor and variable resistance permit accurate variable time delays.