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:
Dec. 02, 1986
Filed:
Oct. 12, 1984
Hiroaki Nakamura, Hachioji, JP;
Olympus Optical Company, Ltd., Tokyo, JP;
Abstract
An electronic flash of series controlled type is provided. It comprises a series connection of a flash discharge tube and a main thyristor, which series connection is further connected in series with a thyristor which forms a reverse charging path for a commutating capacitor. The series combination of the flash discharge tube, the main thyristor and the last mentioned thyristor is connected in parallel with a main capacitor. A diode is connected in series with the commutating capacitor so that their series combination is in parallel with the reverse charging thyristor. The reverse charging thyristor is rendered conductive as the main thyristor is rendered conductive so as to establish a reverse charging path for the commutating capacitor therethrough when a commutating operation is to be performed. This prevents a reverse charging current to the commutating capacitor from passing through the flash discharge tube, thus enabling an accurate control over the amount of exposure produced by flashlight.