Patent ID: 8206287

Claim:
An endoscope having an insertion portion to be inserted into a body cavity, the endoscope comprising: a bending portion provided at a distal end side of the insertion portion and configured to be actively bendable in accordance with a bending operation of an operator, the bending portion including inside thereof a plurality of annular bending pieces rotatably connected to each other by a first set of pivots, the bending portion including a first region in which opposed peripheral portions of adjacent bending pieces are in contact with each other at a first curvature radius at which the bending portion is maximally bent; a first flexible tube portion connected to a proximal end side of the bending portion, and configured not to be actively bendable in accordance with the bending operation of the operator, but to be passively bent by a provided predetermined force quantity, the first flexible tube portion including inside thereof a plurality of annular curvature regulation pieces rotatably connected to each other by a second set of pivots, the first flexible tube portion including a second region which is regulated with opposed peripheral portions of adjacent curvature regulation pieces being into contact with each other, is disposed at a distal end side, and is maximally bent at a second curvature radius smaller than the first curvature radius, and a third region which is connected at a more proximal end side than the second region and is maximally bent at a third curvature radius larger than the second curvature radius; and a second flexible tube portion composed of a spiral tube connected to a proximal end side of the first flexible tube portion, a braid covering an outer circumference of the first flexible tube portion and the second flexible tube, and an outer cover resin coveting the braid, the outer cover resin having a first outer cover resin portion coveting the second region and having a first flexibility and a second cover resin portion covering the third region and having a second flexibility that is different from the first flexibility, wherein the first outer cover resin and the second outer cover resin are configured to increase a flexural rigidity of the first flexible tube portion from the distal end side to the proximal end side.