A plurality of analog signals are detected in a sensor in accordance with a displacement of a scale on which a pattern with a predetermined cycle is formed. The plurality of analog signals are subjected to signal processing in a signal processing portion, and then output from a sensor head. Setup switching is performed by a setup switching portion provided in the sensor head in such a manner that an output signal at this moment complies with a signal input specification of a positional information output device. Further, the sensor, the signal processing portion and the setup switching portion form an integrated circuit.