Imaging lens system
AssigneeLargan Precision Co., Ltd.
InventorsPo-Lun Hsu, Wei-Yu Chen, Chun-Che Hsueh
Life of this patent
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Abstract
This invention provides an imaging lens system, in order from an object side to an image side comprising: a first positive lens element having a convex object-side surface at a paraxial region and a convex image-side surface at the paraxial region; a plastic positive second lens element having a concave object-side surface at the paraxial region, a convex image-side surface at the paraxial region, and both of the object-side and image-side surfaces being aspheric; and a plastic negative third lens element having a concave object-side surface at the paraxial region, a concave at the paraxial region and convex at a peripheral region image-side surface, and both of the object-side and image-side surfaces being aspheric.
Claims18
An imaging lens system, in order from an object side to an image side comprising:
- a first lens element with positive refractive power having a convex object-side surface at a paraxial region and a convex image-side surface at a paraxial region;
- a plastic second lens element with positive refractive power having a concave object-side surface at a paraxial region, a convex image-side surface at a paraxial region, and both of the object-side and image-side surfaces thereof being aspheric;
- and
- a plastic third lens element with negative refractive power having a concave object-side surface at a paraxial region, a concave at a paraxial region and convex at a peripheral region image-side surface, and both of the object-side and image-side surfaces thereof being aspheric;
- wherein the lens elements of the imaging lens system with refractive power are only the first lens element, the second lens element, and the third lens element, a curvature radius of the object-side surface of the first lens element is R1, a curvature radius of the image-side surface of the first lens element is R2, a focal length of the first lens element is f1, a focal length of the second lens element is f2, and they satisfy the following relations:
- −0.5<(R1+R2)/(R1−R2)<1.0;
- and
- 1.65<f1/f2<5.0.
An imaging lens system, in order from an object side to an image side comprising:
- a first lens element with positive refractive power having a convex object-side surface at a paraxial region and a convex image-side surface at a paraxial region;
- a plastic second lens element with positive refractive power having a concave object-side surface at a paraxial region, a convex image-side surface at a paraxial region, and both of the object-side and image-side surfaces thereof being aspheric;
- and
- a plastic third lens element with negative refractive power having a concave at a paraxial region and convex at a peripheral region image-side surface, and both of an object-side surface and the image-side surface thereof being aspheric;
- wherein the lens elements of the imaging lens system with refractive power are only the first lens element, the second lens element, and the third lens element, the imaging lens system is used for optical wavelengths ranging from 780 nm to 950 nm, a curvature radius of the object-side surface of the first lens element is R1, a curvature radius of the image-side surface of the first lens element is R2, a focal length of the first lens element is f1, a focal length of the second lens element is f2, and they satisfy the following relation:
- −0.5<(R1+R2)/(R1−R2)<1.0;
- and
- 2.0<f1/f2<3.4.
Dependencies are inferred from the claim text.