LENS SYSTEM, IMAGING DEVICE, AND IMAGING SYSTEM

A lens system (IL) that forms an image on an imaging element (12), includes: a first lens element (L1), a second lens element (L2), and a third lens element (L3) arranged in order from an object side to an image surface side along an optical axis; and a diaphragm (A). At least one of the first and second lens elements has a free-curved surface that is asymmetric with respect to the optical axis. The first lens element has a shape of a surface facing the object side, convex toward the object side. The second lens element has a shape of a surface facing the image surface side, convex toward the object side. The third lens element has a shape of a surface facing the object side, convex toward the image surface side. The lens system has one or more free-curved surfaces closer to the image surface side than the diaphragm.