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:
Aug. 31, 2004
Filed:
Dec. 24, 2002
Shoji Ichimasa, Kanagawa, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A strobe charging device includes a light-emitting tube; a main capacitor for accumulating energy and for supplying the energy to the light-emitting tube; a transformer circuit which includes primary and secondary coils in order to accumulate the energy of a power supply in the main capacitor; a control circuit for controlling a current flowing from the power supply to the primary coil; a current detection circuit for detecting a current flowing through the secondary coil; a time measuring circuit for measuring the time from when the control circuit stops a current flowing through the primary coil until the current detection circuit detects that the current flowing through the secondary coil reaches a predetermined level or until the current flowing through the secondary coil stops; a voltage detecting circuit for detecting the voltage of the main capacitor; and a determination circuit for determining the operation state of the device based on the measurement result generated by the time measuring circuit and on a voltage detected by the voltage detecting circuit.