Light-emission error preventing circuit for optical transmitter

A light-emission error preventing circuit for an optical transmitter having a light-emitting element for optically outputting a data signal at fixed intervals a pre-bias signal generates, the light-emission error preventing circuit for the optical transmitter comprising:

• a light-emission error detecting circuit for pre-bias for monitoring the pre-bias signal, and for outputting an abnormality detection alarm signal when no modulation occurs for a prescribed period of time;
• and
• a forcedly-stopping unit for halting, when receiving the abnormality detection alarm signal from the light-emission error detecting circuit for pre-bias, the optical output of the optical transmitter,
• wherein the light-emission error detecting circuit for pre-bias comprises a one-shot multivibrator IC (Integrated Circuit) for outputting a fixed length signal when detecting a rising edge of the pre-bias signal, and for outputting the abnormality detection alarm signal when the signal the one-shot multivibrator IC outputs is interrupted.