| 摘要 |
An imaging lens system includes, arranged in succession from an object side to an image side, an aperture stop S, a first lens L1 having a positive refractive power, a second lens L2 having a negative refractive power, a third lens L3 having a positive refractive power, a fourth lens L4 having a positive refractive power, and a fifth lens L5 having a negative refractive power. 0.70≦f1/f≦0.85; −1.15≦(R1+R2)/(R1−R2)≦−1.00; −0.55≦(R3+R4)/(R3−R4)≦−0.20; 0.09≦d8/f≦0.15; f/f1 is respectively a focal length of the lens system LA or lens L1; R1/R2 is respectively a curvature radius of the object/image side of the lens L1; R3/R4 is a curvature radius of the object/image side of the lens L2; d8 is an axial distance between the image side of the lens L4 to the object side of the lens L5. |
| 主权项 |
1. An imaging lens system LA comprising, arranged in succession from an object side to an image side:
a first lens L1 having a positive refractive power, a second lens L2 having a negative refractive power, a third lens L3 having a positive refractive power, a fourth lens L4 having a positive refractive power, and a fifth lens L5 having a negative refractive power, wherein the following conditions (1)˜(4) are satisfied:
0.70≦f1/f≦0.85 (1)−1.15≦(R1+R2)/(R1−R2)≦−1.00 (2)−0.55≦(R3+R4)/(R3−R4)≦−0.20 (3)0.09≦d8/f≦0.15 (4) where, f is a focal length of the imaging lens system LA; f1 is a focal length of the first lens L1; R1 is a curvature radius of the object side of the first lens L1; R2 is a curvature radius of the image side of the first lens L1. R3 is a curvature radius of the object side of the second lens L2; R4 is a curvature radius of the image side of the second lens L2; d8 is an axial distance between the image side of the fourth lens L4 to the object side of fifth lens L5. |
