In accomplishing the object, according to {HEAD ~ one aspect} of the present invention, there is provided a focus position detecting method comprising {TAIL ~ steps} of: 
In accomplishing the object , according to { HEAD ~ one aspect } of the present invention , there is provided a focus position detecting method comprising { TAIL ~ steps } of :
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH