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:
Jan. 30, 2018
Filed:
Oct. 14, 2016
Schaft Inc., Tokyo, JP;
Junichi Urata, Tokyo, JP;
Masayuki Inaba, Chiba, JP;
Schaft Inc., Tokyo, JP;
Abstract
To suppress a decline in the control accuracy of an applied voltage associated with an increase in quantum noise, and to increase the control accuracy of a motor speed. When generating a driving voltage signal supplied to a motor from a driving command signal, a motor-driving voltage control device reduces the gradation level and performs noise-shaping modulation before performing PWM modulation. Reducing the gradation level allows the degree of gradation of the driving voltage signal to be within the resolution range of the PWM modulation, and thus PWM modulation can be performed even when the driving voltage signal has a high frequency. Noise-shaping modulation reduces the level of quantum noise near the low frequency range by causing the quantum noise due to digitization, included in the driving voltage signal, to be biased toward the high frequency range side. Of modulation signals with the reduced-gradation level, the components near the high frequency band are cut, while the components near the low frequency range are used to suppress quantum noise and control the driving voltage applied to the motor with a high accuracy.