US Patent 7231273 Substrate processing apparatus and method including obstacle detection

A camera is fixed to a camera fixture extending forward and upward from a rear end of an arm mechanism. The camera picks up the direction of extension of the arm mechanism when the substrate is carried in and out. If a normal still image in a hot plate unit previously recorded and a still image picked up by the camera coincide with each other, a substrate transport robot TR carries in and out the substrate.