Patent ID: 8159176
Filing Date: 2012-04-17
Classification: B41J,H02P

Abstract:
1. A motor driving device comprising: a switching element having one end connected to one end of a first coil of a stepping motor including the first coil and a second coil, and having the other end connected to a ground side, the switching element configured to control a current passed through the first coil, the other end of the first coil and one end of the second coil electromagnetically coupled and connected to a power source side; a rectifier element having one end connected to the other end of the second coil, and having the other end connected to the ground side, the rectifier element configured to be energized in a direction from the ground side toward the second coil; a coil current detection unit configured to detect a current passed through the first coil; a regeneration current detection unit configured to detect a current passed through the rectifier element; a control unit configured to turn on the switching element at predetermined intervals, and turn off the switching element when the current passed through the first coil reaches a predetermined set current based on a detection result of the coil current detection unit; and a negative current detection unit configured to detect whether or not a negative current greater in absolute value than a predetermined set value is passed through the rectifier element based on a detection result of the regeneration current detection unit during a period when the switching element is off after being on, the control unit keeping the switching element off when the negative current is not passed therethrough, based on a detection result of the negative current detection unit.