a cooling unit to perform a cooling process to lower a temperature of a light source when an instruction for turning off {HEAD ~ the power} of {TAIL ~ the communication apparatus} is received 
of
a cooling unit to perform a cooling process to lower a temperature of a light source when an instruction for turning off { HEAD ~ the power } of { TAIL ~ the communication apparatus } is received
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH