Image lens assembly
AssigneeLargan Precision Co., Ltd.
InventorsTsung-Han Tsai, Ming-Ta Chou
Life of this patent
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Abstract
This present disclosure provides an image lens assembly in order from an object side to an image side comprising five lens elements with refractive power: a first lens element with negative refractive power having a concave image-side surface; a second lens element with positive refractive power having a convex image-side surface; a third lens element with positive refractive power having a concave object-side surface and a convex image-side surface; a fourth lens element with negative refractive power; and a fifth lens element with positive refractive power. By such arrangement, sufficient field of view is provided, and the aberration of the lens assembly is corrected for obtaining higher image resolution.
Claims25
An image lens assembly comprising five lens elements with refractive power, in order from an object side to an image side:
- a first lens element with negative refractive power having a concave image-side surface;
- a second lens element with positive refractive power having a convex image-side surface;
- a third lens element with positive refractive power having a concave object-side surface and a convex image-side surface;
- a fourth lens element with negative refractive power;
- and
- a fifth lens element with positive refractive power;
- wherein a radius of the curvature of the image-side surface of the third lens element is R6, a radius of the curvature of the object-side surface of the fourth lens element is R7, an axial distance between the second lens element and the third lens element is T23, a central thickness of the second lens element is CT2, a focal length of the image lens assembly is f, 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:
- |R6/R7|<0.85;
- 0<T23/CT2<1.0;
- and
- 0.7<|f/f1|+f/f2<2.4.
An image lens assembly comprising, in order from an object side to an image side:
- a front lens group having positive refractive power comprising two lens elements with refractive power, in order from the object side to the image side:
- a first lens element with negative refractive power having a concave image-side surface;
- and
- a second lens element with positive refractive power having a convex image-side surface;
- a stop;
- a rear lens group having positive refractive power comprising, in order from the object side to the image side:
- a third lens element with positive refractive power having a concave object-side surface and a convex image-side surface;
- a fourth lens element with negative refractive power;
- and
- a fifth lens element with positive refractive power,
- wherein a radius of the curvature of the image-side surface of the third lens element is R6, a radius of the curvature of the object-side surface of the fourth lens element is R7, an axial distance between the second lens element and the third lens element is T23, a central thickness of the second lens element is CT2, a focal length of the image lens assembly is f, 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:
- |R6/R7|<0.85;
- 0<T23/CT2<1.0;
- and
- 0.7<|f/f1|+f/f2<2.4.
An image lens assembly comprising five lens elements with refractive power, in order from an object side to an image side:
- a first lens element with negative refractive power having a concave image-side surface;
- a second lens element with positive refractive power having a concave object-side surface and a convex image-side surface;
- a third lens element with positive refractive power having a convex image-side surface;
- a fourth lens element with negative refractive power, at least one of the object-side and the image-side surfaces thereof being aspheric, and the fourth lens element is made of plastic;
- and
- a fifth lens element with positive refractive power, at least one of the object-side and the image-side surfaces thereof being aspheric, and the fifth lens element is made of plastic;
- wherein a radius of the curvature of the image-side surface of the third lens element is R6, a radius of the curvature of the object-side surface of the third lens element is R5, a radius of the curvature of the object-side surface of the fourth lens element is R7, an axial distance between the second lens element and the third lens element is T23, a central thickness of the second lens element is CT2, a focal length of the image lens assembly is f, 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:
- |R6/R5|<0.6;
- |R6/R7|<0.85;
- 0<T23/CT2<1.0;
- and
- 0.7<|f/f1|+f/f2<2.4.
Dependencies are inferred from the claim text.