| 摘要 |
An imaging lens includes: a first lens group; an aperture stop; and a second lens group having a positive power, in this order from an object side. The first lens group includes a first lens having a negative power and a second lens having a positive power. The imaging lens satisfies Conditional Formulae (1), (2), and (3):;−0.50<f/f1<0.20 (1);0.08<d12/f<0.35 (2);2.5<TL/Y<4.0 (3)wherein f is the focal length of the entire system, f1 is the focal length of the first lens group, d12 is a distance along an optical axis from the image side lens surface of the first lens to the object side lens surface of the second lens, TL is the distance along the optical axis from the most object side lens surface within the first lens group to an imaging surface Sim, and Y is a maximum image height, when focused on an object at infinity. |
| 主权项 |
1. An imaging lens, substantially consisting of:
a first lens group having a negative or a positive refractive power; an aperture stop; and a second lens group having a positive refractive power, provided in this order from an object side; the first lens group being constituted by an 11 lens group having a negative refractive power and a 12 lens group having a positive refractive power, which are constituted by 3 or fewer lenses as a whole, provided in this order from the object side; the 11 lens group being constituted by a single first lens, and the 12 lens group being constituted by a single lens provided at a spatial interval from the first lens or by a cemented lens, which is a positive lens component, provided at a spatial interval from the first lens; the second lens group substantially consisting of a 21 lens group having a positive refractive power and a 22 lens group having a negative refractive power, provided in which order from the object side; the 21 lens group having at least one positive lens and at least one negative lens; the 22 lens group substantially consisting of a total of three lenses including at least one positive lens and at least one negative lens; and the imaging lens satisfying Conditional Formulae (1), (2), and (3) below:
−0.50<f/f1<0.20 (1)0.08<d12/f<0.35 (2)2.5<TL/Y<4.0 (3) wherein f is the focal length of the entire lens system, f1 is the focal length of the first lens group, d12 is a distance along an optical axis from the lens surface toward an image side of the first lens within the first lens group to the lens surface most toward the object side of the positive lens component, TL is the distance along the optical axis from the lens surface most toward the object side within the first lens group to the imaging surface, and Y is a maximum image height, when focused on an object at infinity. |
