Imaging optical lens

摘要

PROBLEM TO BE SOLVED: To provide an imaging optical lens. From the object side to the image side, a first lens having a positive refractive power, a second lens having a positive refractive power, a third lens having a positive refractive power, and a negative refractive power are applied in this order. The fourth lens is provided, the focal distance of the imaging optical lens is f, the focal distance of the second lens is f2, the axial thickness of the third lens is d5, and the object side of the fourth lens from the image side surface of the third lens. The axial distance to the surface of the lens is d6, the radius of curvature of the surface of the third lens on the object side is R5, the radius of curvature of the surface of the third lens on the image side is R6, and the radius of curvature of the surface of the second lens on the object side is R5. R3, when the radius of curvature of the image side surface of the second lens is R4, 3.00 ≦ f2 / f ≦ 5.00, 13.00 ≦ d5 / d6 ≦ 25.00, 3.00 ≦ (R5 + R6) ) / (R5-R6) ≤10.00, 5.00≤R3 / R4≤50.00. The imaging optical lens of the present invention has good optical performance and meets the design requirements for a large aperture and a wide angle. [Selection diagram] Fig. 1