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:
Jun. 28, 2011
Filed:
Mar. 16, 2009
Yuuichi Ueda, Osaka, JP;
Yuuichi Ueda, Osaka, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A charge pump provides high boosting efficiency with low power loss even with a heavy load. Plural charge transfer switches are connected in series forming two lines of charge transfer circuits operated by out-of-phase clock signals. Capacitors are connected to each of nodes in the charge transfer circuits. The charge transfer circuits include a first control unit, a second control unit, and a voltage comparison output unit. The second control unit includes a switch unit configured to selectively feed a signal from a previous-stage node or a later-stage node to the gate of a charge transfer switch in the second control unit, depending on the phase of the clock signal.