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:
Oct. 07, 2003
Filed:
Sep. 24, 2001
Applicant:
Inventor:
Takashi Birumachi, Chiba, JP;
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02M 3/24 ;
U.S. Cl.
CPC ...
H02M 3/24 ;
Abstract
A switching power supply unit is capable of performing zero-voltage switching in the entire load region to reduce switching loss and noise and improve the voltage transmission efficiency. The switching power supply unit has a main switching device, and an auxiliary switching device for controlling resonance so as to prevent power loss accompanying a switching action of the main switching device. A control circuit varies the OFF period, during which the main switching device and the auxiliary switching device are OFF simultaneously, according to power consumption by a load on an apparatus in which the switching power supply unit is installed.