Endoscope system

Abstract

An endoscope includes: a first lens located at a distal-most position, a part of the first lens being exposed outside; a movable lens barrel configured to be able to move, and configured to hold a movable lens disposed on a proximal end side with respect to the first lens; an actuator unit including a coil that drives the movable lens barrel and generates heat by receiving a supply of electric power; and a control section that outputs first electric power to the coil when holding the movable lens barrel at a predetermined position, and outputs second electric power larger than the first electric power to the coil when conducting heat generated from the coil to the first lens at the predetermined position.

What is claimed is: 
     
         1 . An endoscope system comprising:
 a first lens located at a distal-most position, a part of the first lens being exposed outside;   a movable lens barrel configured to be able to move, and configured to hold a movable lens disposed on a proximal end side with respect to the first lens;   an actuator unit including a coil that drives the movable lens barrel and generates heat by receiving a supply of electric power; and   a control section that outputs first electric power to the coil when holding the movable lens barrel at a predetermined position, and outputs second electric power larger than the first electric power to the coil when conducting heat generated from the coil to the first lens at the predetermined position.   
     
     
         2 . The endoscope system according to  claim 1 , wherein the movable lens barrel is provided so as to be able to advance and retreat in an optical axis direction of the first lens, and the coil is formed by a conductive wire being wound directly or indirectly on an outer circumference of the objective lens barrel, and configured to drive the movable lens barrel with a magnetic force generated by receiving the supply of electric power. 
     
     
         3 . The endoscope system according to  claim 1 , wherein
 a first holding position and a second holding position are set as the predetermined position; and   the endoscope system further includes:   a first position restricting portion that positions the movable lens barrel at the first holding position; and   a second position restricting portion that positions the movable lens barrel at the second holding position.   
     
     
         4 . The endoscope system according to  claim 3 , further comprising,
 a temperature detection section that is provided in the vicinity of an objective lens barrel and configured to directly or indirectly detect a temperature of the first lens,   wherein the control section, when determining that a detected temperature of the first lens detected by the temperature detection section is lower than a predefined temperature, supplies the second electric power to the coil such that the detected temperature becomes equal to or higher than a predetermined temperature.