Patent ID: 7298977

Claim:
An optical transmitter comprising: a high-pass filter for passing the high-frequency components of an optical transmission input signal having a pulse waveform, a binary circuit for binarizing the output signal of said high-pass filter so as to be returned to a pulse waveform, a light-emitting device for optical transmission, and a light-emitting device driving circuit for driving said light-emitting device depending on the output signal of said binary circuit, wherein: when said optical transmission input signal has a pulse width shorter than a predetermined time period determined by a time constant of said high-pass filter and a binarization threshold value of said binary circuit, said binary circuit provides an output signal having a pulse width which is unchanged from said pulse width of said optical transmission input signal, and when said optical transmission input signal has a pulse width longer than said predetermined time width, said binary circuit provides an output signal having a pulse width of said predetermined time period.