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:
Mar. 30, 2004
Filed:
Jun. 09, 2003
Applicant:
Inventors:
Wen-Hwa Lin, Taipei, TW;
Chien-Kuo Hsu, Taipei, TW;
Assignee:
Premier Image Technology Corporation, Taipei, TW;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B 1/505 ; H05B 4/126 ;
U.S. Cl.
CPC ...
G03B 1/505 ; H05B 4/126 ;
Abstract
A capacitor charging device for a flash, finishes charging the flash capacitor in a gradual manner. It has a flash capacitor, a voltage transforming circuit, a voltage mode pulse width modulation (PWM) control circuit and a charging control circuit. The charging control circuit has a time control capacitor to make the pulse width of the pulse voltage output from the voltage mode PWM control circuit increase gradually. The voltage transforming circuit is driven to provide a gradually increasing induced current to the flash capacitor to reduce the damage of the external circuit, flash capacitor and rechargeable battery.