Opening/closing body drive device and control method thereof

An opening/closing body drive device comprising:

• a motor which opens or closes an opening/closing body;
• a drive unit which rotates the motor;
• and
• a control unit which controls the drive unit, wherein
• the drive unit includes
• a first integrated circuit having first and second switching elements which are connected to each other in series with respect to a positive electrode side and a negative electrode side of a power source and a connection point of which is connected to one terminal of the motor, and
• a second integrated circuit having third and fourth switching elements which are connected to each other in series with respect to the positive electrode side and the negative electrode side and a connection point of which is connected to the other terminal of the motor,
• first to fourth freewheeling diodes are incorporated in or attached in parallel to the first to fourth switching elements,
• the control unit turn-on drives the first and fourth switching elements when driving the motor to be rotated forward and turn-on drives the second and third switching elements when driving the motor to be rotated reversely,
• the control unit turn-on drives only the second switching element of the first to fourth switching elements when braking the motor during the forward rotation of the motor and turn-on drives only the fourth switching element of the first to fourth switching elements when braking the motor during the reverse rotation of the motor, or the control unit turn-on drives only the third switching element of the first to fourth switching elements when braking the motor during the forward rotation of the motor and turn-on drives only the first switching element of the first to fourth switching elements when braking the motor during the reverse rotation of the motor,
• the first integrated circuit has a first protection function of, when an overcurrent of the first switching element is detected during the turn-on driving of the first switching element, switching the turn-on driving of the first switching element to the turn-on driving of the second switching element, and when an overcurrent of the second switching element is detected during the turn-on driving of the second switching element, switching the turn-on driving of the second switching element to the turn-on driving of the first switching element, and
• the second integrated circuit has a second protection function of, when an overcurrent of the third switching element is detected during the turn-on driving of the third switching element, switching the turn-on driving of the third switching element to the turn-on driving of the fourth switching element, and when an overcurrent of the fourth switching element is detected during the turn-on driving of the fourth switching element, switching the turn-on driving of the fourth switching element to the turn-on driving of the third switching element.