In one embodiment, the display unit constitutes {TAIL ~ a part} of {HEAD ~ a portable electronic device} 
In one embodiment , the display unit constitutes { TAIL ~ a part } of { HEAD ~ a portable electronic device }
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD