Optical lens assembly
AssigneeLargan Precision Co., Ltd.
InventorsChih Wen Hsu, Hsin Hsuan Huang
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Abstract
This invention provides an optical lens assembly comprising, in order from an object side to an image side: a first lens element with positive refractive power; a second lens element with positive refractive power; a third lens element with negative refractive power having a concave object-side surface and a convex image-side surface, at least one of the object-side and image-side surfaces thereof being aspheric; and a fourth lens element with positive refractive power having an aspheric object-side surface and an aspheric image-side surface; wherein the number of lens elements with refractive power is four.
Claims23
An optical lens assembly comprising, in order from an object side to an image side:
- a first lens element with positive refractive power;
- a second lens element with positive refractive power;
- a third lens element with negative refractive power having a concave object-side surface and a convex image-side surface, at least one of the object-side and image-side surfaces thereof being aspheric;
- and
- a fourth lens element with positive refractive power having an aspheric object-side surface and an aspheric image-side surface;
- wherein the number of lens elements with refractive power is four;
- and wherein a thickness of the first lens element on an optical axis is CT1, a thickness of the second lens element on the optical axis is CT2, a radius of curvature of the object-side surface of the fourth lens element is R7, a radius of curvature of the image-side surface of the fourth lens element is R8, a thickness of the fourth lens element on the optical axis is CT4, a focal length of the optical lens assembly is f, and they satisfy the relations:
- 0.0<CT1/CT2<0.6;
- |R7/R8|<1.0;
- and 0.25<CT4/f<0.85.
An optical lens assembly comprising, in order from an object side to an image side:
- a first lens element with positive refractive power;
- a second lens element with positive refractive power having a convex image-side surface;
- a third lens element with negative refractive power having a concave object-side surface and a convex image-side surface, at least one of the object-side and image-side surfaces thereof being aspheric;
- and
- a fourth lens element with positive refractive power having an aspheric convex object-side surface and an aspheric image-side surface;
- wherein the optical lens assembly further comprises an aperture stop;
- and wherein a thickness of the first lens element on an optical axis is CT1, a thickness of the second lens element on the optical axis is CT2, a thickness of the fourth lens element on the optical axis is CT4, a focal length of the optical lens assembly is f, a distance on the optical axis between the aperture stop and the image-side surface of the fourth lens element is Sd, a distance on the optical axis between an object-side surface of the first lens element and the image-side surface of the fourth lens element is Td, and they satisfy the relations:
- 0.0<CT1/CT2<0.6;
- 0.25<CT4/f<0.85;
- and 0.75<Sd/Td<0.94.
Dependencies are inferred from the claim text.