LENS FRAME GUIDING DEVICE FOR ZOOM LENS BARREL

摘要

PROBLEM TO BE SOLVED: To obtain a lens frame guiding device by which an eccentric error is hardly caused between plural lens groups in a zoom lens barrel in which plural lens groups advance/retreat in an optical axis direction by the rotation of a cam ring having a cam groove.;SOLUTION: This lens frame guiding device for a zoom lens barrel has plural lens frames having plural pairs of projections projecting in a radial direction and follower pins in the radial direction provided on the projections separated in a peripheral direction; a straight advance guiding ring which is positioned on the outside of the plural lens frames and whose rotation is regulated; plural straight advance guiding piercing grooves in a direction parallel with an optical axis which are formed on the guiding ring by the same number as the number of the pairs of the projections and the follower pins of the plural lens frames and in which the respective projections of the plural lens frames are fit to freely slide in common; the cam ring fit to freely rotate on the outer periphery of the guiding ring; and blind cam grooves which are formed in a different cam locus for the lens frame by the same number as the number of the pairs of the projections and the follower pins of the plural lens frames on the inner peripheral surface of the cam ring and in which the follower pins are engaged, and the focal distance is changed by moving the plural lens frames in the optical axis direction by the rotation of the cam ring.;COPYRIGHT: (C)2001,JPO