Lens barrel and imaging device

A lens barrel for forming an optical image of a subject on an imaging element, comprising:

• a first lens unit including a first lens element and a first lens support frame supporting the first lens element;
• a second lens unit including a second lens element arranged to vary the focal length by moving relative to the first lens element in the optical axis direction, and a second lens support frame supporting the second lens element;
• a focus lens unit including a focus lens arranged to vary the focal state of the optical image by moving relative to the first lens element or the second lens element in the optical axis direction, and a focus lens support frame supporting the focus lens;
• a zoom mechanism arranged to relatively move the first lens unit and the second lens unit in the optical axis direction, including a zoom control arranged to be operated by the user, with which the operating force inputted to the zoom control is mechanically transmitted to the first lens unit and/or the second lens unit;
• and
• a focus actuator being fixed to the second lens unit and configured to electrically drive the focus lens unit relative to the second lens unit in the optical axis direction,
• the second lens unit or the focus lens unit disposed nearest to the image plane in the optical system including the first lens element, the second lens element, and the focus lens.