| 摘要 |
A vari-focal lens system comprising, in the order from the object side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power and a fourth lens unit; adapted to perform variation of focal length by moving the second lens unit and the third lens unit along the optical axis; and adapted to perform focusing by moving the second lens unit toward the object side.
|
