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