Patent ID: 7433595

Claim:
An optical signal transmission apparatus that carries out bi-directional light transmission, the apparatus comprising: a light sending module that sends an optical main-signal having at least one data width, and receives an optical sub-signal including a control signal; a light receiving module that receives the optical main-signal and sends the optical sub-signal; and an optical cable that connects the light sending module with the light receiving module, wherein the light sending module comprises a control component which controls the output of the optical main-signal such that, the output of the optical main-signal is stopped when the optical sub-signal, which includes data indicating a reception status of the optical main-signal, is not being received by the light sending module, and the output of the optical main-signal is stopped when the reception status of the optical main-signal is indicating non-receiving by the light receiving module, and when the optical main-signal is being stopped by the control component, and the optical sub-signal changes from not being received to being received, a reset operation is repeated a prescribed number of times for each prescribed time interval until the reception status of the optical main-signal changes to indicating receiving, wherein during the reset operation, the control component releases stopping of the output of the optical main-signal, and if the reception status of the optical main-signal remains indicating non-receiving for a predetermined period of time, the control component re-stops the output of the optical main-signal.