US 8,913,329 B1Granted

Image lens assembly

AssigneeLargan Precision Co., Ltd.

InventorsDung-Yi Hsieh, Tsung-Han Tsai, Wei-Yu Chen

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Abstract

An image lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. The first lens element with positive refractive power has an object-side surface being convex in a paraxial. The second lens element with refractive power has an object-side surface being concave in a paraxial region. The third lens element with negative refractive power has an object-side surface being convex in a paraxial region and an image-side surface being concave in a paraxial region. The fourth lens element with positive refractive power has an object-side surface being concave in a paraxial region and an image-side surface being convex in a paraxial region. The fifth lens element with negative refractive power has an image-side surface being concave in a paraxial region.

Claims25

Dependent claims

An image lens assembly comprising, in order from an object side to an image side:

a first lens element with positive refractive power having an object-side surface being convex in a paraxial region thereof;
a second lens element with refractive power having an object-side surface being concave in a paraxial region thereof;
a third lens element with negative refractive power having an object-side surface being convex in a paraxial region thereof and an image-side surface being concave in a paraxial region thereof;
a fourth lens element with positive refractive power having an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof;
and
a fifth lens element with negative refractive power having an image-side surface being concave in a paraxial region thereof, wherein both of an object-side surface and the image-side surface of the fifth lens element are aspheric, and the image-side surface of the fifth lens element has at least one convex shape in an off-axis region;
wherein the image lens assembly has a total of five lens elements with refractive power, a focal length of the second lens element is f2, a focal length of the third lens element is f3, a central thickness of the second lens element is CT2, 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 the following relationships are satisfied:
−0.90<f3/|f2|<0;
0.65<T12/CT2<1.15;
and
0.75<T12/T23<7.5.

8 more elements

An image lens assembly comprising, in order from an object side to an image side:

a first lens element with positive refractive power having an object-side surface being convex in a paraxial region thereof;
a second lens element with refractive power having an object-side surface being concave in a paraxial region thereof;
a third lens element with negative refractive power having an image-side surface being concave in a paraxial region thereof;
a fourth lens element with positive refractive power having an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof;
and
a fifth lens element with negative refractive power having an image-side surface being concave in a paraxial region thereof, wherein both of an object-side surface and the image-side surface of the fifth lens element are aspheric, and the image-side surface of the fifth lens element has at least one convex shape in an off-axis region;
wherein the image lens assembly has a total of five lens elements with refractive power, a focal length of the second lens element is f2, a focal length of the third lens element is f3, a central thickness of the second lens element is CT2, 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, a curvature radius of the object-side surface of the first lens element is R1, a curvature radius of an image-side surface of the first lens element is R2, and the following relationships are satisfied:
−0.90<f3/|f2|<0;
0.65<T12/CT2<2.0;
0.75<T12/T23<2.4;
and
(R1−R2)/(R1+R2)<0.

9 more elements

An image lens assembly comprising, in order from an object side to an image side:

a first lens element with positive refractive power having an object-side surface being convex in a paraxial region thereof;
a second lens element with refractive power having an object-side surface being concave in a paraxial region thereof;
a third lens element with negative refractive power having an object-side surface being convex in a paraxial region thereof and an image-side surface being concave in a paraxial region thereof;
a fourth lens element with positive refractive power having an object-side surface being concave in a paraxial region thereof and an image-side surface to being convex in a paraxial region thereof;
and
a fifth lens element with negative refractive power having an image-side surface being concave in a paraxial region thereof, wherein both of an object-side surface and the image-side surface of the fifth lens element are aspheric, and the image-side surface of the fifth lens element has at least one convex shape in an off-axis region;
wherein the image lens assembly has a total of five lens elements with refractive power, a focal length of the second lens element is f2, a focal length of the third lens element is f3, a central thickness of the second lens element is CT2, 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 the following relationships are satisfied:
−0.90<f3/|f2|<0;
0.65<T12/CT2<2.0;
and
0.75<T12/T23<2.4.

8 more elements

Dependencies are inferred from the claim text.