In this drive device, a control unit is provided with a detection determination unit. A high threshold value and a low threshold value, configured in an initial state as the threshold values for determining whether or not a detection signal is captured, are configured in the detection determination unit such that it is possible to switch between the two. If, prior to drive processing, the detection determination unit determines signal capture, then, on the basis of the detection result, the control unit performs low switching processing to switch from the high threshold value to the low threshold value until drive processing has been started; if, after said low switching processing, the detection determination unit determines signal capture, then drive stopping processing is performed for stopping the drive unit from driving.