Zoom lens system, imaging device and camera
AssigneePanasonic Corporation
InventorTakakazu Bito
Life of this patent
Estimating the term…
Abstract
A zoom lens system comprising: a positive first lens unit; a negative second lens unit; a positive third lens unit; a fourth lens unit; and an aperture diaphragm provided between the third lens unit and the fourth lens unit, wherein in zooming, the first to third lens units are moved along an optical axis to perform magnification change, the third lens unit includes two or more lens elements and one or more inter-lens-element air spaces, and the conditions: −7.0<f1/f2<−4.0 and fT/fW>9.0 (f1 and f2: composite focal lengths of the first and second lens units, fW and fT: focal lengths of the entire system at a wide-angle limit and a telephoto limit) are satisfied.
Claims12
A zoom lens system, in order from an object side to an image side, comprising:
- a first lens unit having positive optical power;
- a second lens unit having negative optical power;
- a third lens unit having positive optical power;
- a fourth lens unit having optical power;
- and
- an aperture diaphragm provided between the third lens unit and the fourth lens unit, wherein
- in zooming from a wide-angle limit to a telephoto limit at the time of image taking, the first lens unit, the second lens unit, and the third lens unit are moved along an optical axis to perform magnification change,
- the third lens unit includes two or more lens elements, and one or more inter-lens-element air spaces, and
- the following conditions (1) and (a) are satisfied:
- −7.0<f1/f2<−4.0 (1)
- fT/fW>9.0 (a)
- where,
- f1 is a composite focal length of the first lens unit,
- f2 is a composite focal length of the second lens unit,
- fW is a focal length of the entire system at a wide-angle limit, and
- fT is a focal length of the entire system at a telephoto limit.
Dependencies are inferred from the claim text.