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:
May. 14, 2019
Filed:
Mar. 27, 2018
Brother Kogyo Kabushiki Kaisha, Nagoya-shi, Aichi-ken, JP;
BROTHER KOGYO KABUSHIKI KAISHA, Nagoya-Ahi, Aichi-Ken, JP;
Abstract
A brushless motor device configured to: determine a first upper limit of a current value which flows through a coil when a rotation speed of a rotor is accelerated from a first speed to a second speed, wherein, in a case where the current value of the first upper limit flows through the coil when the rotor is rotated at the second speed, a first time period, which is from a start of a non-energization time period of the coil until an induced voltage reaches a threshold value, is longer than a second time period, which is from the start of the non-energization time period until a counter-electromotive voltage becomes zero; and change switching of each switching element of an inverter circuit by using a second upper limit greater than the first upper limit and the first upper limit.