ALEXANDRIA, Va., July 9 -- United States Patent no. 12,355,375, issued on July 8, was assigned to ORIENTAL MOTOR Co. LTD. (Tokyo).
"Stepping motor drive device" was invented by Kei Kozakai (Tsukuba, Japan) and Makoto Morimoto (Tsukuba, Japan).
According to the abstract* released by the U.S. Patent & Trademark Office: "A stepping motor driver which drives a stepping motor according to a position angle command includes: a current detector that detects a phase current; an inverter that applies a current to a winding; and a control unit that controls the inverter. The control unit includes: a phase current coordinate transformer that transforms the phase current to generate a dp-axis detection current and a qp-axis detection current; a torque...