Optical lens system
AssigneeLargan Precision Co., Ltd.
InventorsChun-Shan Chen, Hsin-Hsuan Huang
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Abstract
An optical lens system comprises, in order from an object side to an image side: the first lens element with negative refractive power having a convex object-side surface and a concave image-side surface; the second lens element with positive refractive power; the third lens element with positive refractive power having the object-side surface and the image-side surface being aspheric; the fourth lens element with negative refractive power having a concave image-side surface and at least one aspheric surface. There are four lens elements with refractive power. Such arrangements can enable a larger field of view, reduce the volume of the system, and further obtain higher resolution for the optical lens system of the present invention.
Claims21
An optical lens system comprising, in order from an object side to an image side:
- a first lens element with negative refractive power having a convex object-side surface and a concave image-side surface;
- a second lens element with positive refractive power;
- a third lens element with positive refractive power, both object-side and image-side surfaces of the third lens element being aspheric;
- a fourth lens element with negative refractive power having a concave image-side surface, both object-side and image-side surfaces of the fourth lens element being aspheric;
- wherein there are four lens elements with refractive power, a distance on an optical axis between the first lens element and the second lens element is T12, a focal length of the optical lens system is f, a center thickness of the first lens element is CT1;
- wherein the optical lens system is further provided with an aperture stop, a distance from the aperture stop to an image plane along the optical axis is SL, a distance from the object-side surface of the first lens element to the image plane along the optical axis is TTL, and they satisfy the relations:
- 0.1<T12/f<0.3;
- 0.30<CT1/f<0.75;
- 0.52<SL/TTL<0.82.
An optical lens system comprising, in order from an object side to an image side:
- a first lens element with negative refractive power having a convex object-side surface and a concave image-side surface;
- a second lens element with positive refractive power;
- a third lens element with positive refractive power;
- a fourth lens element with negative refractive power having a concave image-side surface, at least one inflection point formed on the fourth lens element;
- wherein there are four lens elements with refractive power, a focal length of the first lens element is f1, a focal length of the fourth lens element is f4, a center thickness of the first lens element is CT1 a center thickness of the second lens element is CT2;
- wherein the optical lens system is further provided with an aperture stop, a distance from the aperture stop to an image plane along an optical axis is SL, a distance from the object-side surface of the first lens element to the image plane along the optical axis is TTL, and they satisfy the relations:
- 0.2<f4/f1<0.6;
- 0.2<CT2/CT1<0.5;
- 0.52<SL/TTL<0.82.
An optical lens system comprising, in order from an object side to an image side:
- a first lens element with negative refractive power having a convex object-side surface and a concave image-side surface;
- a second lens element with positive refractive power;
- a plastic third lens element with positive refractive power having a convex object-side surface and a convex image-side surface, both object-side and image-side surfaces of the third lens element being aspheric;
- a plastic fourth lens element with negative refractive power having a concave image-side surface, an object-side and the image-side surfaces of the fourth lens element being aspheric, at least one inflection point formed on the fourth lens element;
- wherein there are four lens elements with refractive power, a distance on an optical axis between the first lens element and the second lens element is T12, a focal length of the optical lens system is f, a focal length of the second lens element is f2, a focal length of the third lens element is f3;
- wherein the optical lens system is further provided with an aperture stop, a distance from the aperture stop to an image plane on the optical axis is SL, a distance from the object-side surface of the first lens element to the image plane along the optical axis is TTL, and they satisfy the relations:
- 0.07<T12/f<0.50;
- 0.2<f3/f2<0.7;
- 0.52<SL/TTL<0.82.
Dependencies are inferred from the claim text.