US Patent 7796347 Lens barrel

A lens barrel has a first lens group, a second lens group, a third lens group, a first support frame for supporting the first lens group, a second support frame for supporting the second lens group, a first driving unit, a shutter unit, and an aperture unit. The first lens group has an overall negative refractive power, and includes a prism. The second support frame is driven along a second optical axis by the first driving unit. The shutter unit has a shutter mechanism, a shutter drive motor configured to drive the shutter mechanism, a neutral density filter, and a filter drive motor configured to drive the neutral density filter. The shutter drive motor and the filter drive motor are disposed flanking the second optical axis when viewed in a direction along the second optical axis.