Patent ID: 8708892

Claim:
An endoscope comprising: an insertion portion which includes a first bending portion and a second bending portion provided on the proximal side of the first bending portion, an initial position being set for the second bending portion; an operation portion which is provided on the proximal side of the insertion portion, and which includes a first bending operation input portion configured to input a bending operation to bend the first bending portion; an input amount detector which is configured to detect, as a bending operation input amount, the bending operation input to the first bending operation input portion; a first bending drive mechanism which is configured to bend the first bending portion to a bending amount corresponding to the bending operation input amount; a bending amount calculator which is configured to calculate a bending amount of the first bending portion driven to bend by the first bending drive mechanism; a second bending drive mechanism which is configured to bend the second bending portion; a driving portion which is coupled to the second curving drive mechanism and which is configured to generate driving force to drive the second bending drive mechanism; a setting portion which is configured to set a first threshold and a second threshold, the first threshold being stored in advance and being compared with the bending amount of the first bending portion, the second threshold having an absolute value less than the absolute value of the first threshold and being compared with the first bending portion; a determination portion which is configured to determine whether the bending amount of the first bending portion calculated by the bending amount calculator is more than the first threshold, and which is configured to determine whether the bending amount of the first bending portion calculated by the bending amount calculator is less than the second threshold; and a controller which is configured to continuously output, to the driving portion, a bending drive signal that drives the second bending drive mechanism to bend the second bending portion in the same direction as the bending direction of the first bending portion when the determination portion determines that the bending amount of the first bending portion is more than the first threshold, and which is configured to output, to the driving portion, a bending drive signal that drives the second bending drive mechanism to return the second bending portion to the initial position when the determination portion determines that the bending amount of the first bending portion is less than the second threshold after the bending amount of the first bending portion has exceeded the absolute value of the first threshold.