Patent ID: 7609017

Claim:
An open/close body drive device, which is capable of motor-driving an open/close body attached to a motor vehicle so as to open and close said open/close body, comprising: a DC brushless motor acting as a drive source; a motor drive unit switching drive voltage applied to stator coils on the basis of a rotational position and rotation number of a rotor, which have been detected by a plurality of magnetic pole sensors for detecting positions of magnetic pole positions of a rotor magnet; and a control unit for controlling said motor drive unit so as to open and close said open/close body on the basis of detection signals of the magnetic pole sensors, wherein said control unit determines that the sensor has failed and temporarily stops drive of said DC brushless motor when said control unit detects an abnormal logic as a detection pattern of the magnetic pole sensors, and said motor drive unit generates a phase switching signal to prolong one of electric connection patterns for performing sensorless drive when restarting said DC brushless motor.