A head unit and a sensor unit are freely Rotatably mounted in a printer main body. yREN, in which AE= and D=Eu, and RE=La, Y, delivers a blue to yellow-orange emission and is distinguished by a high efficiency. The reflector is positioned on the light incident surface and faces the light source. The system and method dynamically or by command adjust the frame format protocol to increase or reduce the number of RF frames representing bitstream data that are transmitted or received during a time period in which, respectively, no RF frames are received or transmitted.