Image pick-up device for endoscopes

An imaging unit for endoscopes comprising:

• optical elements for forming an optical image;
• an imaging device for photoelectrically converting the optical image formed by the optical elements;
• a cylindrical hollow member for holding the imaging device, the cylindrical hollow member forming a camera assembly;
• a case for hermetically storing the optical elements and the camera assembly;
• a fixing member provided at a predetermined position in the case for fixing the optical elements;
• an inner ring provided with a helical cam groove, the inner ring being rotatably provided in the case;
• an outer ring movable by a user to rotate around the case;
• a magnet for magnetically coupling the inner ring and the outer ring via the case, the magnet driving the inner ring in accordance with the operation of the outer ring;
• a rectilinear groove formed in the case along an optical axis of the optical elements;
• a cam pin provided in the outer peripheral surface of the hollow member, which engages the helical cam groove and the rectilinear groove and moves along the rectilinear groove as the inner ring rotates;
• wherein the rectilinear groove restricts the movement of the cam pin in a rotating direction and guides the camera assembly in advancing and withdrawing directions with respect to the optical elements;
• and
• an elastic member interposed between the front end of the cylindrical hollow member for holding the imaging device and an inner side of a front end of the case for hermetically storing the optical elements and the camera assembly such that backlash of the cylindrical hollow member is minimized.