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:
Feb. 16, 1993
Filed:
Apr. 15, 1992
Konica Corporation, Tokyo, JP;
Abstract
An electronic flash device includes a flash discharge tube, an IGBT, connected to the flash discharge tube, for controlling light emission, a trigger means for driving the flash discharge tube, an AC voltage generating means having an oscillation transformer for generating an AC voltage from an input voltage, and a power supply section for generating a gate drive voltage for the IGBT from a counter electromotive voltage generated at a terminal of a winding of the oscillation transformer. The electronic flash device further includes an IGBT drive voltage generating means, a first resistor connected between the IGBT drive voltage generating means and a gate of the IGBT, a capacitor having a terminal connected to the IGBT drive voltage generating means and having a capacitance larger than an electrostatic capacitance across the gate and an emitter of the IGBT, a second resistor having a terminal connected to the other terminal of the capacitor and the other terminal connected to the gate of the IGBT and a resistance smaller than that of the first resistor, and a third resistor connected between a ground terminal and a connection terminal between the IGBT drive voltage generating means and the first resistor.