Abstract: An endoscope includes: an operation lever portion provided in an operation portion, the operation lever portion including an operation shaft and being capable of adjusting a bending angle of a bending portion in linkage with a tilting action; a sliding body disposed so as to be freely movable back and forth in an axial direction of the operation shaft; a flexible exterior cover watertightly fixed to the operation portion so as to cover an outer periphery of the sliding body and the operation shaft, the flexible exterior cover being deformable by fluctuation of an internal pressure of the operation portion; and a return member configured to return the sliding body to a side of the operation portion when the internal pressure of the operation portion is depressurized.

Abstract: In an endoscope bending tube provided in a bending portion of an endoscope in which a first bending tube region and a second bending tube region are arranged, a slit width of a plurality of bending slits arranged in the bending tube region is set to be smaller than a slit width of a plurality of bending slits arranged in the bending tube region, a width of the bending slits on the distal end side between the neighboring bending slits is set to be smaller than a width of the slits on the proximal end side, and an interval between the neighboring bending slits of a slit row in the bending region located on the distal end side is set to be smaller than an interval between the neighboring bending slits of the slit row in the bending region located on the proximal end side.

Abstract: An endoscope insertion portion includes: a first bending portion disposed on a distal end side; a second bending portion connected to a proximal end of the first bending portion and provided with flexural rigidity higher than flexural rigidity of the first bending portion; a tubular member, a first tubular part of which on a distal end side disposed inside the first bending portion has a bending tendency in a predetermined direction and shape-memorized, and which is provided with a second tubular part on a proximal end side disposed inside the second bending portion; a first wire configured to move the first tubular part and independently bend only the first bending portion; and second wires configured to move the second tubular part and independently bend only the second bending portion.

Abstract: An endoscope bending portion includes a tubular member provided with a treatment instrument channel and a string guide configured to hold wires, an interval of a plurality of first slots formed in a first tubular region on a distal end side is made to be smaller than an interval of a plurality of second slots formed in a second region at an intermediate portion, and a third interval of a plurality of third slots formed in a third tubular region is also made to be smaller than the interval of the plurality of second slots, and a dimensional ratio between a width and the interval of the first slots, a dimensional ratio between a width and the interval of the second slots and a dimensional ratio between a width and the interval of the third slots are equalized.