Patent ID: 8333692

Claim:
An endoscope comprising: an insertion portion including a bending portion; a base portion connected to the insertion portion; an operation wire extending from the bending portion toward the base portion; a drive source unit which is provided in the base portion and which is configured to drive the operation wire; and a drive force transmission unit which is connected to the operation wire and the drive source unit and which is configured to transmit drive force driven by the drive source unit to the operation wire, wherein the drive source unit includes: a first plane which is disposed inside the base portion and which is parallel to a central axis of the insertion portion; a second plane which is provided in parallel to the first plane and which is provided at a position farther from the central axis of the insertion portion than the first plane; a drive source which is provided to project from the first plane toward the second plane in a state supported by the first plane and which is configured to generate drive force in the second plane; a first gear as a sun gear which is connected to permit the transmission of the drive force of the drive source and which is rotatably held on the second plane; a second gear as an epicyclic gear which is geared with the first gear and which is configured to revolve around an outer periphery of the first gear; a third gear including internal teeth geared with the second gear, which is configured to hold the second gear revolvably around the first gear; a fourth gear which is rotated on the first plane in accordance with the revolving of the second gear and which is configured to axially drive the operation wire and configured to transmit the drive force from the drive source to the drive force transmission unit, wherein said fourth and said first gears having a common rotation axis; and a rotational position detection mechanism which is provided to project from the first plane toward the second plane in a state supported by the second plane and which is connected to the fourth gear to detect a rotational position of the fourth gear.