Image pickup unit and endoscope

An image pickup unit including an objective lens including a plurality of optical system members via which an object image is formed, the image pickup unit comprising:

• a moving lens including one or more lenses, the moving lens forming a part of the objective lens;
• a fixed lens holding barrel that holds the optical system members other than the moving lens in the objective lens;
• a cylindrical fixed barrel fixed to the fixed lens holding barrel with an optical axis of the objective lens as a center axis;
• a moving lens holding barrel that holds the moving lens and is disposed so as to be slidable along the optical axis inside the fixed barrel;
• and
• a voice coil motor section that generates a drive force for moving the moving lens holding barrel relative to the fixed barrel along the optical axis;
• a position detection magnet fixed to the moving lens holding barrel;
• and
• a magnetism detecting section whose position relative to the fixed barrel is fixed, the magnetism detecting section detecting magnetism of the position detection magnet,
• wherein the voice coil motor section is disposed so that a center axis of action of a generated thrust force passes through a gravity center of a driven member to be driven by the voice coil motor section;
• wherein the objective lens is configured so that an image magnification thereof is changed as a result of the moving lens holding barrel being moved in the optical axis direction and as the moving lens holding barrel becomes closer to one end of a movable range, the magnification becomes lower;
• wherein the voice coil motor section includes a coil wound on a periphery of the moving lens holding barrel around the optical axis, and a permanent magnet fixed to the fixed barrel;
• and
• wherein the position detection magnet is disposed so as to bias the moving lens holding barrel toward the one end of the movable range via a magnetic force between the position detection magnet and the permanent magnet.