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. 15, 2000
Filed:
Jul. 20, 1999
Shinichi Kojima, Kanagawa, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A power-supply switching portion compares an input voltage and an output voltage, after a boost converter circuit is started. Before a step-up operation is started, that is, in a condition in which the input voltage is higher than the output voltage, the power-supply switching portion provides, via a first MOSFET, the input voltage to a power-supply line. The power-supply line supplies operation power for the boost converter circuit. After the step-up operation is started, that is, in a condition in which the output voltage is equal to or higher than the input voltage, the power-supply switching portion provides, via a second MOSFET, the output voltage, instead of the input voltage, to the power-supply line.