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. 21, 1992
Filed:
Mar. 27, 1991
Kazuo Tanaka, Neyagawa, JP;
Shinji Hirata, Toyonaka, JP;
West Electric Co., Ltd., Osaka, JP;
Abstract
In an electronic flash unit, a voltage applying device is provided to apply a predetermined voltage to the gate of an insulated gate bipolar transistor (IGBT), connected in series with a flash tube, for controlling the light-emission operation of the flash tube. The voltage applying device produces the predetermined voltage in response to the start of the operation of a DC high voltage power source. Thus, the voltage applying device applies a driving voltage to the gate of the IGBT without responding to a light-emission command signal. The IGBT enters a conduction standby state in response to the start of the operation of the DC high voltage power source, and is placed in a fully `on` state when a trigger circuit is operated by the light-emission command signal. The driving voltage can be applied to the gate in a very simple arrangement which does not require to respond to the trigger signal.