US 8,797,658 B2Granted

Capturing lens system

AssigneeLargan Precision Co., Ltd.

InventorsTsung-Han Tsai, Wei-Yu Chen

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Abstract

This invention provides a capturing lens system in order from an object side to an image side comprising: a first lens element with positive refractive power; a plastic second lens element with negative refractive power having a concave object-side surface and a convex image-side surface, both the object-side and image-side surfaces thereof being aspheric; and a plastic third lens element with positive refractive power having a convex object-side surface and a concave image-side surface, both the object-side and image-side surfaces thereof being aspheric, and at least one inflection point is formed on at least one of the object-side and image-side surfaces thereof. Additionally, the central thickness of the second lens element is controlled favorably for the efficient spatial arrangement of the lens assembly and the simpler individual lens production while assuring suitable thickness of the second lens element, thereby assuring high image quality and improving yield rate of the product.

Claims20

Dependent claims

A capturing lens system comprising, in order from an object side to an image side:

a first lens element with positive refractive power;
a plastic second lens element with negative refractive power having a concave object-side surface and a convex image-side surface, both the object-side and image-side surfaces thereof being aspheric;
and
a plastic third lens element with positive refractive power having a convex object-side surface and a concave image-side surface, both the object-side and image-side surfaces thereof being aspheric, and at least one inflection point is formed on at least one of the object-side and image-side surfaces thereof;
wherein there are three lens elements with refractive power in the capturing lens system, which are the first lens element, the second lens element and the third lens element;
and the second lens element has the greatest central thickness among the three lens elements;
a central thickness of the first lens element is CT1, a central thickness of the second lens element is CT2, a central thickness of the third lens element is CT3, an axial distance between the first lens element and the second lens element is T12, an axial distance between the second lens element and the third lens element is T23, and they satisfy the following relations:
0.2<CT1/CT2<1.0;
0.2<CT3/CT2<1.0;
and
0.3<T12/T23<1.8.

8 more elements

A capturing lens system comprising, in order from an object side to an image side:

a first lens element with positive refractive power;
a plastic second lens element with negative refractive power having a concave object-side surface and a convex image-side surface, both the object-side and image-side surfaces thereof being aspheric;
and
a plastic third lens element with positive refractive power having a convex object-side surface and a concave image-side surface, both the object-side and image-side surfaces thereof being aspheric, and at least one inflection point is formed on at least one of the object-side and image-side surfaces thereof;
wherein there are three lens elements with refractive power in the capturing lens system, which are the first lens element, the second lens element and the third lens element;
and the second lens element has the greatest central thickness among the three lens elements;
a central thickness of the first lens element is CT1, a central thickness of the second lens element is CT2, a central thickness of the third lens element is CT3, an axial distance between the first lens element and the second lens element is T12, an axial distance between the second lens element and the third lens element is T23, an Abbe number of the second lens element is V2, and they satisfy the following relations:
0.2<CT1/CT2<1.0;
0.2<CT3/CT2<1.0;
0.2<T12/T23<1.8;
and
10<V2<27.

9 more elements

Dependencies are inferred from the claim text.