| 摘要 |
<p>[Problem] To provide a wide-angle compact imaging lens. [Solution] An imaging lens having positioned in order from the object side, a first lens group (G1), an aperture (St), and a second lens group (G2) having a positive refractive index, wherein in the first lens group (G1), a negative first lens (L1) is positioned on the side closest to the object, and in the second lens group (G2), a positive lens (L8) is positioned on the side closest to the imaging surface, and a negative lens (L7) having an aspherical lens surface at least on the object side and a recess formed on the object side is positioned closer to the object side than said lens (L8). The following conditional expressions are satisfied 0.03 < (∣︀Sagsp1∣︀-∣︀Sagas1∣︀)/Re1 < 0.35...(1) 1.75 < NdAB... (2), where Sagsp1 is the amount of sag in the reference spherical surface at the effective radial edge part of the object-side lens surface of the lens (L7), Sagas1 is the amount of sag in the aspherical surface, Re1 is the effective radius of the object-side lens surface, and NdAB is the average refractive index of the lens (L8) and lens (L8).</p> |
