Patent ID: 7098954

Claim:
An interchangeable lens assembly video camera system comprising a camera and an interchangeable lens assembly, wherein said camera comprises extracting means for extracting a predetermined image signal component varying depending on a focus state from an image sensing signal corresponding to one or a plurality of focus detection areas defined on an image sensing plane of said camera, an operation member for manipulating a zooming operation, and transmitting means for transmitting the predetermined image signal component and a state of said operation member to said lens assembly; said lens assembly comprises receiving means for receiving the predetermined image signal component and the state of said operation member from said camera, a zoom lens for performing a zooming operation; a focus lens for maintaining an in-focus state during the zooming operation, memory means for storing data representing a positional relationship between said zoom lens and said focus lens, zoom lens driving means for driving said zoom lens in accordance with the state of said operation member, control means for judging an in-focus state on the basis of the predetermined image signal component and determining a driving direction and a driving velocity of said focus lens while compensating for a movement of a focal plane caused by the zooming operation of said zoom lens on the basis of the data, and focus lens driving means for driving said focus lens in accordance with the driving direction and the driving velocity; and said lens assembly controls operations of said focus lens and said zoom lens.