Zoom lens and image pickup apparatus having the zoom lens
AssigneeCanon Kabushiki Kaisha
InventorNobuyuki Miyazawa
Life of this patent
Estimating the term…
Abstract
A zoom lens includes, in order from an object side to an image side, a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, a third lens unit having a negative refractive power, a fourth lens unit having a positive or negative refractive power, and a fifth lens unit having a positive refractive power. In the zoom lens, the first lens unit is stationary during zooming. At least the second lens unit, the third lens unit, and the fifth lens unit move along an optical axis during zooming. Furthermore, in the zoom lens, a focal length of the entire zoom lens at a wide-angle end (fw) and an amount of movement of the second lens unit during zooming from the wide-angle end to a telephoto end (m2z) are appropriately set.
Claims9
A zoom lens comprising, in order from an object side to an image side:
- a first lens unit having a negative refractive power;
- a second lens unit having a positive refractive power;
- a third lens unit having a negative refractive power;
- a fourth lens unit having a positive or negative refractive power;
- and
- a fifth lens unit having a positive refractive power,
- wherein the first lens unit is stationary during zooming,
- wherein at least the second lens unit, the third lens unit, and the fifth lens unit move along an optical axis during zooming, and
- wherein, when fw is a focal length of the entire zoom lens at a wide-angle end and m2z is an amount of movement of the second lens unit during zooming from the wide-angle end to a telephoto end, and
- wherein a sign of the amount of movement m2z is positive when the second lens unit is positioned closer to the image plane at the telephoto end than at the wide-angle end and the sign of the amount of movement m2z is negative when the second lens unit is positioned close to the object side at the telephoto end than at the wide-angle end,
- the following condition is satisfied:
- 0.2<fw/m2z<1.5.
An image pickup apparatus comprising:
- a zoom lens;
- and
- a photoelectrical conversion element located at an image plane of the zoom lens and configured to receive an image formed by the zoom lens,
- wherein the zoom lens comprises, in order from an object side to an image side:
- a first lens unit having a negative refractive power;
- a second lens unit having a positive refractive power;
- a third lens unit having a negative refractive power;
- a fourth lens unit having a positive or negative refractive power;
- and
- a fifth lens unit having a positive refractive power,
- wherein the first lens unit is stationary during zooming,
- wherein at least the second lens unit, the third lens unit, and the fifth lens unit move along an optical axis during zooming, and
- wherein, when fw is a focal length of the entire zoom lens at a wide-angle end and m2z is an amount of movement of the second lens unit during zooming from the wide-angle end to a telephoto end, and
- wherein a sign of the amount of movement m2z is positive when the second lens unit is positioned closer to the image plane at the telephoto end than at the wide-angle end and the sign of the amount of movement m2z is negative when the second lens unit is positioned close to the object side at the telephoto end than at the wide-angle end,
- the following condition is satisfied:
- 0.2<fw/m2z<1.5.
Dependencies are inferred from the claim text.