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:
Apr. 04, 1978
Filed:
Feb. 17, 1977
Shinji Hirata, Osaka, JA;
West Electric Company, Ltd., Osaka, JA;
Abstract
An automatic electronic flash device including: a flash discharge tube, a first switching element connected in series with the flash discharge tube, a main discharge capacitor adapted to supply its charged energy to the flash discharge tube for firing thereof so that an object to be photographed is illuminated, a light receiving circuit which receives light reflected from the object for turning on a second switching element when the amount of the received light reaches a predetermined value, a commutation capacitor which is made to discharge in response to the second switching element being turned on and supplies a reverse current through the first switching element whereby the first switching element is turned off so as automatically to stop illuminating, a trigger circuit for supplying a high voltage pulse to the trigger electrode of the flash discharge tube, and a high voltage supply circuit which generates a high voltage in synchronism with the operation of the trigger circuit so that the generated voltage is superposed on the charging voltage of the main discharge capacitor for being applied across the main electrodes of the flash discharge tube.