An endoscope includes an insertion portion. First and second electronic instruments are located in the insertion portion and are supplied with drive power from different systems. A plurality of power limiting portions limit the drive power supplied to the first and second electronic instruments, respectively, via mutually different systems. First and second wirings, at least a portion of which are located inside the insertion portion, connect respective power limiting portions with the respective ones of the first and second electronic instruments. A ground conductor extends from one end of the insertion portion to the other end of the insertion portion and is connected between a first connection connecting the first electronic instrument and the first wiring and a second connection connecting the second electronic instrument and the second wiring.
1. An endoscope comprising:
an insertion portion;
a first electronic instrument that is provided inside the insertion portion;
a second electronic instrument that is provided inside the insertion portion and is supplied with drive power from a separate system from that used for the first electronic instrument;
a plurality of power limiting portions that limit to a predetermined value or less the drive power that supply to the first electronic instrument and the second electronic instrument respectively via mutually different systems;
a first wiring of which at least a portion is placed inside the insertion portion, the first wiring electrically connecting one of the power limiting portions with the first electronic instrument and supplying drive power to the first electronic instrument;
a second wiring of which at least a portion is placed inside the insertion portion, the second wiring electrically connecting another of the power limiting portions with the second electronic instrument and supplying drive power to the second electronic instrument; and
a system separating component which is a ground that is interposed in an electrical separation state between a first connection connecting the first electronic instrument and the first wiring and a second connection connecting the second electronic instrument and the second wiring, the ground being a conductor that continuously extends from one end of the insertion portion to the other end of the insertion portion, and the ground being used in common with both the first electronic instrument and the second electronic instrument.
2. The endoscope according to claim 1 , wherein
the system separating component has a distal end rigid portion that is made from metal and is provided at a distal end side of the insertion portion, the distal end rigid portion supporting the first electronic instrument and the second electronic instrument.
3. The endoscope according to claim 1 , further comprising a main unit to which one end of the insertion portion is attached,
wherein the system separating component has a heat discharge wire that is made from a continuous metal wire, a distal end of the heat discharge wire being fixed to the distal end rigid component and a proximal end of the heat discharge wire being placed inside the main unit.
4. The endoscope according to claim 1 ,
wherein the system separating component has a shield that is formed by a conductive body and covers the entire circumference of at least one of the first wiring or the second wiring.
5. The endoscope according to claim 4 , further comprising a distal end rigid portion that is made from metal and is provided at a distal end side of the insertion portion, the distal end rigid portion supporting the first electronic instrument and the second electronic instrument,
wherein the shield is connected to the distal end rigid portion.
6. The endoscope according to claim 1 , further comprising a power supply for the first electronic instrument and the second electronic instrument, the power supply being electrically connected to the power limiting portion, and
the system separating component is connected to a negative terminal of the power supply.
7. The endoscope according to claim 6 further comprising a main unit to which one end of the insertion portion is attached,
wherein the power supply is a rechargeable battery provided inside the main unit,
the system separating component is connected to a negative terminal of the rechargeable battery.
8. The endoscope according to claim 1 , wherein the system separating component is earthed.
9. The endoscope according to claim 1 ,
wherein the system separating component electrically separates the first connection from the second connection so as to conform to an intrinsically safe explosion-proof structure.
10. The endoscope according to claim 1 ,
wherein the system separating component is interposed between the first connection and the second connection in a non-contact state.