| 摘要 |
<p>There is provided a rotational signal detecting apparatus comprising a housing (l0l), a rotor shaft (l06) attached to said housing so as to be freely rotatable, said rotor shaft rotating in synchronism with a crankshaft or a cam shaft of an engine, a photoelectric pickup comprising a rotating portion (l76) fixed to said rotor shaft so as to rotate with said rotor shaft as one body and a fixed portion (l7l, l72) integrally attached to said housing, said fixed portion having photoelectric conversion means (l72) for outputting a signal varying according to the quantity of incident light varied in synchronism with the rotation of said rotating portion, an electromagnetic pickup comprising a rotating portion (l9l) fixed to said rotor shaft so as to rotate with said rotor shaft as one body and a fixed portion integrally attached to said housing, said fixed portion having magnetic field detecting means (l92) for outputting a signal varying according to the magnetic field varied in synchronism with the rotation of said rotating portion, one of said photoelectric pickup and said electromagnetic pickup being used as the backup for the other. </p> |
