Zoom lens system
AssigneesHONG FU JIN PRECISION INDUSTRY (ShenZhen) CO., LTD., Hon Hai Precision Industry Co., Ltd.
InventorsHai-Jo Huang, Fang-Ying Peng, Sheng-An Wang, Xiao-Na Liu
Life of this patent
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Abstract
A zoom lens system includes, in the order from the object side to the image side thereof, a first lens group of positive refraction power, a second lens group of negative refraction power, a third lens group of positive refraction power, a fourth lens of positive refraction power, and an imaging plane. The first lens group and the third lens group are immovably mounted. The second lens group and the fourth lens group are movably mounted. The zoom lens system satisfies the formulae: 5<f3/f4<8.2; and 2.1<|f2/fw|<3.2, wherein f2-f4 respectively represent the effective focal lengths of the second, third and fourth lens groups, fw represents the shortest effective focal length of the zoom lens system.
Claims18
A zoom lens system, in the order from the object side to the image side thereof, comprising:
- a first lens group of positive refraction power;
- a second lens group of negative refraction power;
- a third lens group of positive refraction power;
- a fourth lens group of positive refraction power;
- and
- an imaging plane;
- wherein the first lens group and the third lens group are immovably positioned, the second lens group and the fourth lens group are movably positioned, the zoom lens system satisfies the formulae:
- 5<f3/f4<8.2;
- and
- 2.1<|f2/fw|<3.2,
- Where f2-f4 respectively represent the effective focal lengths of the second, third and fourth lens groups, fw represents the shortest effective focal length of the zoom lens system.
Dependencies are inferred from the claim text.