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:
Mar. 23, 2021
Filed:
Jul. 24, 2019
Seiko Epson Corporation, Tokyo, JP;
Reiko Nagahama, Shiojiri, JP;
Takashi Kawaguchi, Shiojiri, JP;
Abstract
Provided is a motor drive circuit capable of driving a stepper motor even if the load on the stepper motor varies. A motor drive circuit has a first drive circuit that outputs a first drive signal to the driver; a second drive circuit that outputs a second drive signal to the driver; a controller that controls the first drive circuit and second drive circuit. The first drive circuit is configured to output a first drive signal based on the current value of current flow of a coil of a stepper motor. The second drive circuit is configured to output multiple types of second drive signals that differ by the supply time of drive current supplied to the coil. Based on a result of driving by the first drive circuit, the controller selects the type of second drive signal the second drive circuit outputs.