An information processor having excellent operability and water-proof performance, having a small and thin structure, and capable of receiving a large capacity of information. Each of a number-of-pulses sensing unit (32) and a rotational direction sensing unit (33) reads an optical pattern formed on the under surface of a rotation bezel and generates a pulse signal. The number-of-pulse sensing unit (32) and the rotational direction sensing unit (33) are disposed in positions where a phase difference between the pulse signals is generated, so that the rotational direction of the rotation bezel can be detected from the phase difference. From the rotational direction thus sensed and the rotation angle of the rotation bezel sensed from the number of pulses of pulse signals generated by the number-of-pulses sensing unit (32), an information signal generating unit (81) generates an information signal.
