Zoom Lens System, Imaging Device and Camera
AssigneePanasonic Corporation
InventorsSatoshi Kuzuhara, Yoshio Matsumura
Life of this patent
Estimating the term…
Abstract
A zoom lens system, in order from an object side to an image side, comprising: a first lens unit having negative optical power; a second lens unit having positive optical power; a third lens unit having negative optical power; and a fourth lens unit having positive optical power, wherein the third lens unit is composed of two or less lens elements, the fourth lens unit is composed of two or less lens elements, the first lens unit has at least one air space between lens elements constituting the first lens unit, and the condition: Dair/fW>0.75 (Dair: an air space located on the most object side in the first lens unit, fW: a focal length of the entire system at a wide-angle limit) is satisfied; an imaging device; and a camera are provided.
Claims20
A zoom lens system having a plurality of lens units, each lens unit being composed of at least one lens element, the zoom lens system, in order from an object side to an image side, comprising:
- a first lens unit having negative optical power;
- a second lens unit having positive optical power;
- a third lens unit having negative optical power;
- and
- a fourth lens unit having positive optical power, wherein
- the third lens unit is composed of two or less lens elements,
- the fourth lens unit is composed of two or less lens elements,
- the first lens unit has at least one air space between lens elements constituting the first lens unit, and
- the following condition (1) is satisfied:
- Dair/fW>0.75 (1)
- where,
- Dair is an air space located on the most object side in the first lens unit, and
- fW is a focal length of the entire system at a wide-angle limit.
A zoom lens system having a plurality of lens units, each lens unit being composed of at least one lens element, the zoom lens system, in order from an object side to an image side, comprising:
- a first lens unit having negative optical power;
- a second lens unit having positive optical power;
- and
- at least one subsequent lens unit, wherein
- in zooming from a wide-angle limit to a telephoto limit at the time of image taking, at least three lens units among the lens units individually move along an optical axis so that magnification change is achieved,
- a lens unit located on the most image side among the lens units belonging to the subsequent lens units is composed of two or less lens elements,
- the first lens unit is composed of three or less lens elements including a lens element having positive optical power and a lens element having negative optical power, and has at least one air space between lens elements constituting the first lens unit, and
- the following conditions (1), (2), and (3) are satisfied:
- Dair/fW>0.75 (1)
- Dair×tan(ωW/2)/fG1<−0.23 (2)
- Dback/fW<1.50 (3)
- where,
- Dair is an air space located on the most object side in the first lens unit,
- fW is a focal length of the entire system at a wide-angle limit,
- ωW is a half value of a maximum view angle)(°) at a wide-angle limit,
- fG1 is a focal length of the first lens unit, and
- Dback is a distance from an image side surface of a lens element located on the most image side in the entire system to an image surface.
Dependencies are inferred from the claim text.