CONVEYER

PROBLEM TO BE SOLVED: To detect a proper position of a movable part of receiving base, arm, etc., and prevent previously an accident during conveyance, by providing a reflecting part in the movable part, and a reflection type light detector applying irradiation of detection light in the reflecting part. SOLUTION: An excessive load acts in a receiving base 8 or the like, a slip or the like is generated in an articulated part of an arm, when a difference is generated between a position of the arm recognized by an encoder mounted in a motor of a device controller and the actual position, in a homing position recognized by the controller, a first/second arm 4, 6 is not placed in a completely folded condition. Accordingly, the center of a high reflectance part of an index plate 18 is displaced from an optical axis of a reflector type photosensor 17, reflecting luminous energy in the high reflectance part is decreased, the controller detects generation of position displacement. When the position displacement is detected, stopping of a conveyer or correction of displacement are performed.