Patent ID: 8279273

Claim:
An endoscope apparatus configured for use in a potentially explosive environment, the endoscope comprising: an explosion-proof unit that has an image pickup device that outputs photographed video images as video image signals; and an A/D converter that converts the video image signals into digitalized image signals; a control unit that controls the explosion-proof unit; and an energy limiting circuit that is provided at the control unit and that limits electrical energy of digital signals to satisfy intrinsic safety when sending and receiving of the digital signals, wherein the explosion-proof unit is connected to the control unit via the energy limiting circuit with a signal line, and the energy limiting circuit is configured to limit a current value, which is transmitted through the signal line by the digital signals, to be the current value that satisfies the intrinsic safety, and limits a cutoff frequency to be transmission clock frequency that determines a transmission speed of the digital signals to an extent sufficient to eliminate the digital signals as a factor in causing explosion in said potentially explosive environment.