Patent ID: 7611457

Claim:
An endoscope comprising: an inserted portion, which is to be inserted into a tubular organ, including a bendable portion that is adapted to bend arbitrarily by a remote operation and a distal unit with a window for observation to capture an image of inside the tubular organ, wherein a plurality of grooves are formed in parallel with an axis of the distal unit on an outer peripheral surface of the distal unit and extend entirely across the axis along the outer peripheral surface of the distal unit, and are spaced from each other, each of the plurality of grooves having a depth, wherein the distal unit is configured to hook a crease of an organ and to advance the inserted portion, wherein an outer diameter of the distal unit is configured to be greater than an outer diameter of the bendable portion, wherein a step having a height is formed at a boundary of the bendable portion and the distal unit, and wherein the depth of each of the plurality of grooves is equal to the height of the step.