ZOOM LENS APPARATUS AND METHOD OF CONTROLLING SAME

摘要

Provided are a zoom lens apparatus as well as a method of controlling the apparatus for alleviating astigmatism. A lens is moved along the direction of the optical axis of the zoom lens apparatus in accordance with zoom magnification. The angle of rotation of a ring that rotates about the optical axis of the zoom lens apparatus is read from a table stored in advance. The ring is rotated through the read angle of rotation. A lens holding frame holding the lens has a surface is contact with the ring, and the surface has protrusions and cavities so that when the ring is rotated, the lens holding frame is tilted and so is the lens. The tilt angle is decided in such a manner that astigmatism is reduced in accordance with zoom magnification. Astigmatism is reduced even though the lens is moved in accordance with zoom magnification.

主权项

1. A zoom lens apparatus that includes multiple lens groups each constituted by two or more lenses, comprising:
a lens tilting mechanism for tilting at least one lens of the two or more lenses constituting the lens group; a lens-group driving mechanism for moving at least one lens group, among the multiple lens groups included in the zoom lens apparatus, along the direction of an optical axis of the zoom lens apparatus in accordance with zoom magnification; and a control mechanism for causing said lens tilting mechanism to tilt the at least one lens at a tilt angle that corresponds to the zoom magnification.