| 摘要 |
An imaging lens consists essentially of, in order from the object side, a positive first lens group, a negative second lens group, a stop, and a positive third lens group. Focusing is effected by moving only the second lens group along the optical axis direction. Each of the first lens group and the third lens group includes at least three positive lenses and at least two negative lenses. The imaging lens satisfies the condition expression (1) below:;0.53<−f2/f<0.9 (1),;where f2 is a focal length of the second lens group, and f is a focal length of the entire system when the imaging lens is focused on an object at infinity. |
| 主权项 |
1. An imaging lens consisting of, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a stop, and a third lens group having a positive refractive power,
wherein focusing is effected by moving only the second lens group along the optical axis direction, the first lens group comprises at least three positive lenses and at least two negative lenses, the second lens group comprises a negative lens, the third lens group comprises at least three positive lenses and at least two negative lenses, and the condition expression (1) below is satisfied:
0.53<−f2/f<0.9 (1),where f2 is a focal length of the second lens group, and f is a focal length of the entire system when the imaging lens is focused on an object at infinity. |
