LENS BARREL AND LENS SYSTEM

PROBLEM TO BE SOLVED: To provide a lens barrel where a recessing notch for a dowel in a cam barrel is made small both in an optical axis direction and in a circumferential direction of the center of an optical axis to extend a cam formation free area in the cam barrel, consequently, a compact lens system is constituted, and to provide a lens system including the same. SOLUTION: The lens system has: a subject side group lens; a rear side group lens; a first fixed barrel; a rectilinear barrel arranged to slide in the optical axis direction inside the first fixed barrel and supporting the rear side group lens; a cam barrel arranged to freely slide in the optical axis direction and freely turn with the optical axis as center on the outside of the fixed barrel, and having at least two cams; a second fixed barrel provided more outside than the cam barrel; a rectilinear dowel provided at the subject side edge part of the rectilinear barrel; and a subject side group lens barrel supported to freely slide on the inner periphery of the second fixed barrel, having a rectilinear groove in which the rectilinear dowel is engaged, and supporting the subject side group lens. COPYRIGHT: (C)2007,JPO&INPIT