controlling the reading and {HEAD ~ writing} of {TAIL ~ signals} to and from said memory, respectively, in said zoom operation processing circuit 
controlling the reading and { HEAD ~ writing } of { TAIL ~ signals } to and from said memory , respectively , in said zoom operation processing circuit
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH