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:
Jul. 18, 2000
Filed:
May. 25, 1999
Yukitsugu Hata, Kanagawa, JP;
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Abstract
In a flash device, a three-terminal switch is provided for connecting or disconnecting between a secondary coil of an oscillating transformer and a base of an oscillating transistor, between the secondary coil of the oscillating transformer and a triggering capacitor, and between the triggering capacitor and a primary coil of a triggering transformer. When the three-terminal switch is turned on, a biasing current is supplied to the base of the oscillating transistor, so a current flows through a primary coil of the oscillating transformer, and a secondary current from the secondary coil of the oscillating transformer is supplied to the main capacitor through the three-terminal switch and a base-emitter circuit of the oscillating transistor, to charge the main capacitor. The secondary current is also supplied to the triggering capacitor through the three-terminal switch, to charge the triggering capacitor. When a triggering switch is turned on while the three-terminal switch is on, the triggering capacitor discharges current through the primary coil of the triggering transformer, generating a triggering voltage for a flash discharge tube. If the three-terminal switch is turned off, the biasing current and the secondary current are cut from the oscillating transistor, and the triggering capacitor cannot discharge.