Patent ID: 11940667
Assignee: LARGAN PRECISION CO., LTD.
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. An optical photographing lens assembly comprising five lens elements, the five lens elements being, 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;
wherein each of the five lens elements has an object-side surface facing towards the object side and an image-side surface facing towards the image side;
wherein the first lens element has positive refractive power, the object-side surface of the first lens element is convex in a paraxial region thereof, and the image-side surface of the first lens element is concave in a paraxial region thereof; the second lens element has negative refractive power, the object-side surface of the second lens element is convex in a paraxial region thereof, and the image-side surface of the second lens element is concave in a paraxial region thereof; the third lens element has positive refractive power, the object-side surface of the third lens element is convex in a paraxial region thereof, and the image-side surface of the third lens element is concave in a paraxial region thereof; the object-side surface of the fourth lens element is concave in a paraxial region thereof;
wherein the optical photographing lens assembly further comprises an aperture stop; a focal length of the fourth lens element and a focal length of the fifth lens element have different signs; a focal length of the optical photographing lens assembly is f, an axial distance between the object-side surface of the first lens element and an image surface is TL, an axial distance between the aperture stop and the image-side surface of the fifth lens element is SD, an axial distance between the object-side surface of the first lens element and the image-side surface of the fifth lens element is TD, 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, and the following conditions are satisfied:

0.95<f/TL<1.35;

0.60<SD/TD<1.2; and

(R1+R2)/(R1−R2)<−1.0.