VARIABLE FOCAL DISTANCE LENS SYSTEM AND IMAGING DEVICE

A first lens unit and a third lens unit are constituted by a lens which is rotationally symmetrical with respect to an optical axis and are disposed on the same optical axis, a first freeform-curved surface lens and a second freeform-curved surface lens have the same shape and are disposed to be rotated at 180 degrees with respect to the optical axis, the first freeform-curved surface lens and the second freeform-curved surface lens are movable in a Y-axis direction when the optical axes of the first lens unit and the third lens unit are set to be a Z-axis, an axis perpendicular to the Z-axis on an image surface is set to be a Y-axis, and an axis perpendicular to the Y-axis and the Z-axis on the image surface is set to be an X-axis, a refractive power of the second lens unit is variable due to the first freeform-curved surface lens and the second freeform-curved surface lens moving in opposite directions, and the first freeform-curved surface lens and the second freeform-curved surface lens are moved in the Y-axis direction in association with movement of some of lens groups constituting the first lens unit and the third lens unit when positional states of the lenses are changed from a wide angle end state in which a focal distance is shortest to a telephoto end state in which a focal distance is longest.