| 摘要 |
Provided is a lens barrel having, in order from an object side to an image side, a first to a third group lens, the lens barrel including: a fixed frame; a cam frame supported by the fixed frame so as to be rotationally movable in a optical axis direction between a forward and a backward movement ends; and a shutter frame which moves in the optical axis direction in a rotation restricted state, through the rotation of the cam frame, in which: a third group frame is fixed to the shutter frame so that the object side of the third group lens is arranged on an inner peripheral side of the shutter frame; and the second frame is configured so that the image side of the frame is stored on the inner peripheral side of the shutter frame when the cam frame is positioned at the backward movement end. |
| 主权项 |
1. A lens barrel, comprising:
a fixed frame of the lens barrel, the lens barrel at least having, in order from an object side to an image side, a first group lens having a positive refractive power, a second group lens having a negative refractive power, and a third group lens having a positive refractive power; a cam frame supported by the fixed frame so as to be rotationally movable in a photographing optical axis direction between a forward movement end and a backward movement end which are each defined in the photographing optical axis direction; a guide frame which moves in a rotation restricted state together with the cam frame, in the photographing optical axis direction; a shutter frame which holds a shutter and moves in the photographing optical axis direction in a rotation restricted state, through the rotation of the cam frame; a first group frame which holds the first group lens, fits in an inner periphery of the guide frame, and moves in the photographing optical axis direction in the rotation restricted state, through the rotation of the cam frame; a second group frame which holds the second group lens, moves in the photographing optical axis direction in a rotation restricted state, through the rotation of the cam frame, and, upon the cam frame being positioned at the backward movement end, fits in, at least in part thereof on the image side, an inner peripheral side of the shutter frame; a third group frame which holds the third group lens formed of five lenses including two negative lenses, and fixed as fitting, at least in part thereof on the object side, in the inner peripheral side of the shutter frame; an ND filter which is provided to the third group frame, on the image side of the third group lens; and an ND filter frame disposed on the image side of the third group frame, wherein, in the third group lens, at least part of a lens surface on the image side of the fifth lens cemented to and held by the fourth lens falls inside the ND filter frame when viewed from a direction orthogonal to the photographing optical axis. |
