Patent ID: 7583300

Claim:
An image pickup apparatus which includes a zoom lens and an image pickup element and has a first image pickup mode and a second image pickup mode which can be arbitrarily selected upon image pickup by said image pickup apparatus, said image pickup element having an image pickup plane which is used, when the first image pickup mode is selected, over a range as great as possible as an effective screen region but is used, when the second image pickup mode is selected, over a smaller range than that when the first image pickup mode is selected as an effective screen region, comprising: said zoom lens includes an additional lens set having a positive refractive index and provided at a position nearest to the image side for movement (a) to a position on an optical axis of said zoom lens and (b) to a position outside a light path, wherein said additional lens set is moved, in response to changeover from the first image pickup mode to the second image pickup mode, to the position on the optical axis to reduce a focal length range of said zoom lens but is moved, in response to changeover from the second image pickup mode to the first image pickup mode, to the position outside the light path to increase the focal length range thereby to moderate a variation of an angle of view which is caused by a difference in range of the effective screen region of said image pickup element when the first image pickup mode is selected and when the second image pickup mode is selected, position detecting device detecting the movement of said additional lens; and control device receiving the detected movement of said additional lens set from said position detecting device and setting components of said image pickup apparatus to respective conditions suitable for the first image pickup mode or the second image pickup mode based upon the detected movement, wherein the first image pickup mode is a still picture image pickup mode for picking up an image of a still picture, that the second image pickup mode is a moving picture image pickup mode for picking up an image of a moving picture, and that, where the diagonal dimension of the effective screen region of said image pickup element is 1 in the moving picture image pickup mode but 1+α in the still picture image pickup mode, the relationship between the focal lengths of said zoom lens in the moving and still picture image pickup modes and the diagonal dimension of the effective screen region of said image pickup element satisfies a condition of 0.4 α<fw 1/ fw 2−1<1.1α where fw 1 is the focal length at the wide angle end of said zoom lens in the still picture image pickup mode, and fw 2 is the focal length at the wide angle of said zoom lens in the moving picture image pickup mode.