Patent ID: 7872439
Filing Date: 2011-01-18
Classification: H02P

Abstract:
1. A motor driving apparatus comprising: a rotor that is rotatable and includes a magnet magnetized to n poles in a multipolar manner in a circumferential direction; a first coil; a first yoke to which a magnetic pole teeth excited by the first coil is formed; a second coil; a second yoke to which a magnetic pole teeth excited by the second coil is formed; a magnetic pole detecting unit including first and second magnetically sensitive poles, wherein the first magnetically sensitive pole senses a magnetic field change occurring as the magnet rotates and outputs a first signal, the second magnetically sensitive pole senses a magnetic field change occurring as the magnet rotates and outputs a second signal, an angle between straight lines connecting each of the center of the first and second magnetically sensitive poles to the rotating center of the rotor has a phase difference of α° compared to the half angle between straight lines connecting each of the center of the adjacent magnetic poles of the magnet to the rotating center of the rotor, a correction unit configured to calculate a first corrected signal by using a first arithmetic equation, and to calculate a second corrected signal by using a second arithmetic equation; and a control unit configured to switch a direction of electricity flowing through the first coil according to the first corrected signal, and to switch a direction of electricity flowing through the second coil according to the second corrected signal, wherein the first arithmetic equation is defined as the second arithmetic equation is defined as and coefficients A and B are determined by α.