pick up {HEAD ~ means} for sensing the object and generating an image signal of {TAIL ~ the object} including a synchronizing signal; and 
pick up { HEAD ~ means } for sensing the object and generating an image signal of { TAIL ~ the object } including a synchronizing signal ; and
OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH