a phase difference detector configured to receive {HEAD ~ the object light} {TAIL ~ whose light path} has been changed by the mirror unit using a range finding sensor and generate a phase difference detection signal 
a phase difference detector configured to receive { HEAD ~ the object light } { TAIL ~ whose light path } has been changed by the mirror unit using a range finding sensor and generate a phase difference detection signal
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH