Patent ID: 8611381

Claim:
A laser oscillator control device comprising: a controller having a transmitter section and a receiver section; a laser oscillator having a transmitter section and a receiver section and communicating with the controller via a communication line, the laser oscillator further comprising a drive circuit to control operation of the laser oscillator; wherein the laser oscillator control device outputs a control signal from the controller to the drive circuit of the laser oscillator, based on a status signal indicating operational state of the laser oscillator sent from the laser oscillator to the controller, wherein the controller has an alternating signal transmitter circuit generating an alternating signal that changes at a predetermined period, and sends the alternating signal to the laser oscillator, wherein the laser oscillator has a return signal transmitter circuit generating a return signal that changes periodically in correspondence to the alternating signal from the controller, and sends the return signal to the controller, the alternating signal and the return signal bypassing the drive circuit of the laser oscillator, and wherein the controller further has a monitoring circuit monitoring the return signal from the laser oscillator, and if it determines that there is an abnormality in the return signal, outputs a stop control signal for stopping laser beam irradiation by the laser oscillator.