a photoelectric conversion element that converts an optical signal into {TAIL ~ an electrical signal} and that accumulates {HEAD ~ signal electric charge}, 
a photoelectric conversion element that converts an optical signal into { TAIL ~ an electrical signal } and that accumulates { HEAD ~ signal electric charge } ,
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH