Linear transmission member driving unit for endoscope

Abstract

In the endoscope configured so as to drive a tip end portion movable lens for making the observation distance variable by the linear transmission member and to rotate this linear transmission member by a motor, a shaft of the motor is connected to a shaft connecting member, and a sliding guide hole having a predetermined length is formed on a cylindrical member wall of this shaft connecting member. And, within this shaft connecting member, a distal member of the linear transmission member is movably disposed, and this distal member is provided with a pin engaging with the sliding guide hole. This apparatus advances and retreats the linear transmission member in the rotating shaft direction during the bending operation, and provides a constant load to a motor rotating shaft, making it possible to obtain a stable magnification changing operation even though there may be a change in posture of an endoscope insertion unit. In addition, an outside diameter of the linear transmission member is formed to be smaller than a soft portion within an angle portion to reduce a frictional resistance during rotation.

Dependencies are inferred from the claim text.