Rotational state detecting apparatus

摘要

A rotational state detecting apparatus for detecting a rotational state of a direct current motor using a detection pulse outputted corresponding to rotation of the direct current motor includes a period measuring apparatus for measuring a period of the detection pulse, a period judging apparatus for judging whether the detection pulse is a rotation pulse indicating a rotational frequency of the direct current motor or a divided pulse into which the rotation pulse is divided on the basis of a period difference between a most recent rotation pulse and the detection pulse and a correcting apparatus for correcting the period of the detection pulse to a combined period of a plurality of serial divided pulses and generating the rotation pulse having the combined period in a situation where the detection pulse is judged to be the divided pulse.