Imaging lens

Abstract

An imaging lens comprises, sequentially from the object side to the image side along the optical axis, a first to a fifth lens. The refractive powers of the first to fifth lenses are negative, positive, negative, positive, and positive, respectively. The imaging lens has a total of five lenses with refractive power. The imaging lens satisfies the condition R11 / DSP>0.423, where R11 is the radius of curvature of the object side of the first lens in the optical axis region, and DSP is the aperture diameter of the imaging lens; or the imaging lens satisfies the condition -1.893<(R11+R12) / (R11-R12)<-1.303, where R12 is the radius of curvature of the image side of the first lens in the optical axis region.

Claims

1. An imaging lens, comprising, in sequence along the optical axis from the object side to the image side: The first lens has a negative refractive power; The second lens has a positive refractive power; The third lens has a negative refractive power; The fourth lens has a positive refractive power; The imaging lens comprises five lenses with refractive power, wherein each of the first to fifth lenses has an object-side surface facing the object side and allowing imaging light to pass through, and an image-side surface facing the image side and allowing imaging light to pass through. The imaging lens satisfies the condition R11 / DSP > 0.423, where R11 is the radius of curvature of the object-side surface of the first lens in an optical axis region, and DSP is an aperture diameter of the imaging lens. Alternatively, the imaging lens satisfies the condition -1.893 < (R11+R12) / (R11-R12) < -1.303, where R12 is the radius of curvature of the image-side surface of the first lens in the optical axis region.

2. The imaging lens as described in claim 1 also satisfies the condition R11 / D11 > 0.293, where D11 is the effective light transmission diameter of the object-side surface of the first lens.

3. The imaging lens as described in claim 1 also satisfies the condition 0.819 < (R21+R22) / (R21-R22) < 1.325, where R21 is the radius of curvature of the object side of the second lens in the optical axis region, and R22 is the radius of curvature of the image side of the second lens in the optical axis region.

4. The imaging lens as described in claim 1 also satisfies the condition 1.174 < (R31+R42) / (R31-R42) < 2.486, where R31 is the radius of curvature of the object side of the third lens in the optical axis region, and R42 is the radius of curvature of the image side of the fourth lens in the optical axis region.

5. The imaging lens as described in claim 1 also satisfies the condition -48.781 < (R51+R52) / (R51-R52) < 29.085, where R51 is the radius of curvature of the object side of the fifth lens in the optical axis region, and R52 is the radius of curvature of the image side of the fifth lens in the optical axis region.

6. The imaging lens as described in claim 1 also satisfies the condition 0.409 < T1 / T2 < 1.011, where T1 is the thickness of the first lens on the optical axis and T2 is the thickness of the second lens on the optical axis.

7. The imaging lens as described in claim 1 also satisfies the condition -1.327 < F1 / F2 < -0.946, where F1 is the focal length of the first lens and F2 is the focal length of the second lens.

8. The imaging lens as described in claim 1 further satisfies the condition 0.369 < (T1+T12+T2) / TTL < 0.43, where T1 is the thickness of the first lens on the optical axis, T12 is the distance from the image side of the first lens to the object side of the second lens on the optical axis, and T2 is the thickness of the second lens on the optical axis.

9. The imaging lens as described in claim 1 also satisfies the condition -3.245 < (F1 / EFL) < -2.389, where F1 is the focal length of the first lens and EFL is the effective focal length of the imaging lens.

10. The imaging lens as described in claim 1 also satisfies the condition 1.893 < (A4 / A3) < 3.2, where A4 is the dispersion coefficient (Abbe number) of the fourth lens and A3 is the dispersion coefficient of the third lens.

Images