OPTICAL TRANSMITTER APPARATUS

摘要

It is an object to prevent a light−emitting diode from keeping emitting a light when the input terminal is fixed to a high−level state due to a software or the like and to avoid various problems,such as battery exhaustion,destruction of the light−emitting diode and the like,from occurring in a PDA,a mobile telephone or the like.The object is accomplished by providing,in the state preceding a light−emitting element driver circuit(23)that drives a light−emitting diode(8)used for optical transmission,a highpass filter(21)that permits passage of the high frequency components of an optical transmission input signal composed of a pulse waveform,and a binarizer circuit(22)that binarizes and returns an output signal from the highpass filter(21)to the pulse waveform.