successively adding β α1 and β α2, for controlling {TAIL ~ operation} of {HEAD ~ said zoom operation processing circuit} 
successively adding β α1 and β α2 , for controlling { TAIL ~ operation } of { HEAD ~ said zoom operation processing circuit }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD