POWER SUPPLY APPARATUS FOR LIGHT SOURCE OF ENDOSCOPE AND ENDOSCOPIC SYSTEM HAVING POWER SUPPLY APPARATUS FOR LIGHT SOURCE OF ENDOSCOPE
A power supply apparatus for a light source of an endoscope includes a light source unit including an input portion that a control signal is input from an output control unit, the light source unit switching a brightness of the illumination light by the control signal and a control signal cable connected to the output control unit and the input portion, and including a current control signal line to transmit the control signal, and a GND line. The power supply apparatus for a light source of an endoscope further includes a common-mode rejecting portion provided in the input portion, connected to the control signal cable, and rejects noise superimposed on the control signal cable.
1 . A power supply apparatus for a light source of an endoscope, comprising:
a light source unit including a control signal input portion that an analogue control signal is input from an output control unit that outputs the control signal to control a light source portion that emits illumination light, the light source unit switching a brightness of the illumination light by the control signal;
a control signal cable connected to the output control unit and the control signal input portion, and including a current control signal line to transmit the control signal, and a GND line; and
a common-mode rejecting portion provided in the control signal input portion, and rejects noise superimposed on the control signal cable.
2 . The power supply apparatus for a light source of an endoscope, according to claim 1 , wherein
the common-mode rejecting portion includes a differential amplifier circuit.
3 . The power supply apparatus for a light source of an endoscope, according to claim 1 , wherein
the common-mode rejecting portion includes a common-mode choke coil.
4 . The power supply apparatus for a light source of an endoscope, according to claim 1 , wherein
the common-mode rejecting portion includes an instrumentation circuit.
5 . An endoscopic system comprising:
a light source portion emitting illumination light;
an output control unit outputting an analogue control signal to control the light source portion; and
the power supply apparatus for a light source of an endoscope according to claim 1 .