Patent ID: 8379135

Claim:
A zoom lens containing a plurality of lens groups including a focus lens group, comprising: a focus cam operable to convert a first rotation amount provided by a focus operation into a movement of the focus lens group, and further converting, in addition to the first rotation amount, a second rotation amount provided by a zoom operation into a movement of the focus lens group; a zoom cam operable to convert the second rotation amount provided by the zoom operation into a movement of a predetermined lens group; a focus driving unit operable to rotate the focus cam by the first rotation amount; a zoom driving unit operable to rotate the zoom cam by the second rotation amount; and a focus cam follower engaged with the focus cam and operable to move in the focus cam, wherein the zoom driving unit rotates the focus cam follower in the focus cam according to a rotation amount of the zoom driving unit so that the focus lens group is moved, the focus cam is configured so that a moving amount of the focus lens group corresponding to a unit rotation amount of the focus driving unit varies according to a rotational position of the zoom driving unit, and a lift amount of the focus cam is defined by a cam curve so that a rotation amount of the focus driving unit from a far end position to an infinite position when the rotational position of the zoom driving unit is at a wide-angle end becomes larger than the rotation amount when the rotational position of the zoom driving unit is at a telephoto end.