| 摘要 |
An endoscope includes an insertion portion which has a bendable portion; an operation portion; a first bending operation knob which is arranged on a surface of the operation portion and includes plural depressions and plural first protrusions, to bend the bendable portion in a first direction when rotated; and a second bending operation knob which is arranged over the first bending operation knob and includes plural depressions and plural second protrusions, to bend the bendable portion in a second direction when rotated. A length of the plural second protrusions from a center of rotation to a tip portion is longer than a length of one of the plural first protrusions from the center of rotation to a tip portion, and each of the plural second protrusions has a depression on a surface facing the first bending operation knob in a proximity to a projection of a circular orbit of rotation of each tip portion of the plural first protrusions. |
