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:
Apr. 23, 2013
Filed:
Sep. 13, 2011
Haruyuki Suzuki, Kanagawa, JP;
Haruyuki Suzuki, Kanagawa, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A motor driving device driving coil terminals of a three-phase motor to flow three-phase currents includes: a pulse modulator generating three-phase modulation pulses, each of which has a duty ratio in accordance with a voltage level of a coil terminal; a shift amount selection unit selecting a first shift amount corresponding to at least one of two predetermined amounts according to a pulse width of the longest pulse among the three-phase modulation pulses; a first shift unit shifting the second-longest pulse among the three-phase modulation pulses backward by the first shift amount to delay timing; a second shift unit shifting the third-longest pulse among the three-phase modulation pulses backward by a predetermined second shift amount to delay timing; and an inverter driving each of the coil terminals by switching a driving power supply with the three-phase modulation pulses by reflecting shift results of the first and second shift units.