ZOOM LENS AND IMAGE PICKUP APPARATUS INCLUDING THE SAME

• US 20150015968A1
• Filed: 06/30/2014
• Published: 01/15/2015
• Est. Priority Date: 07/10/2013
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Eguchi, Yosuke
• Granted Patent: US 9,207,439 B2
• Time in Patent Office: Days
• US Class Current: 359/683
• CPC Class Codes: G02B 15/145121 arranged +-+-+
• CPC Class Codes: G02B 15/173 arranged +-+

Abstract

A zoom lens, including, in order from object side, a positive first unit, a negative second unit, a positive third unit, a negative fourth unit, and a positive fifth unit. The first unit includes, in order from object side, a negative first sub unit which does not move for focusing, a positive second sub unit which moves during focusing, and a positive third sub unit which does not move for focusing and includes a negative lens. 1.6<L2tm/L2t<1000.0; L2w/L3w<1.0; and −0.5<f2/f3<−0.05 are satisfied, where L2t represents an second-third unit interval at a telephoto end, L2tm represents second-third unit interval at a zoom position at which an interval between the third and fourth units is minimum, L2w represents second-third unit interval at a wide-angle end, L3w represents third-fourth unit interval at the wide-angle end, and f2 and f3 represent focal lengths of the second and third units, respectively.

Claims

1. A zoom lens comprising, in order from an object side to an image side:

a first lens unit having a positive refractive power which does not move for zooming;

a second lens unit having a negative refractive power which moves during zooming;

a third lens unit having a positive refractive power which moves during zooming;

a fourth lens unit having a negative refractive power which moves during zooming; and

a fifth lens unit having a positive refractive power which does not move for zooming,

wherein;

the first lens unit comprises, in order from the object side to the image side, a first sub lens unit having a negative refractive power which does not move for focusing, a second sub lens unit having a positive refractive power which moves during focusing, and a third sub lens unit having a positive refractive power which does not move for focusing;

the third sub lens unit comprises a negative lens; and

the following conditions are satisfied;

1.6<

L2tm/L2t<

1000.0;

L2w/L3w<

1.0; and

−

0.5<

f2/f3<

−

0.05,

where L2t represents an interval between the second lens unit and the third lens unit at a telephoto end, L2tm represents an interval between the second lens unit and the third lens unit at a zoom position at which an interval between the third lens unit and the fourth lens unit is minimum, L2w represents an interval between the second lens unit and the third lens unit at a wide-angle end, L3w represents an interval between the third lens unit and the fourth lens unit at the wide-angle end, f2 represents a focal length of the second lens unit, and f3 represents a focal length of the third lens unit.

2. The zoom lens according to claim 1, wherein the following condition is satisfied:

L2w/L2tm<

1.6.

3. The zoom lens according to claim 1, wherein the following conditions are satisfied:

−

20.0<

f4/fw<

−

2.0; and

−

3.0<

f2/fw<

−

0.7,

where f4 represents a focal length of the fourth lens unit and fw represents a focal length of the zoom lens at the wide-angle end.

4. The zoom lens according to claim 1, wherein the third lens unit comprises at least one negative lens and one positive lens.

5. An image pickup apparatus comprising:

a zoom lens comprising, in order from an object side to an image side;

a first lens unit having a positive refractive power which does not move for zooming;

a second lens unit having a negative refractive power which moves during zooming;

a third lens unit having a positive refractive power which moves during zooming;

a fourth lens unit having a negative refractive power which moves during zooming; and

a fifth lens unit having a positive refractive power which does not move for zooming,

wherein;

the first lens unit comprises, in order from the object side to the image side, a first sub lens unit having a negative refractive power which does not move for focusing, a second sub lens unit having a positive refractive power which moves during focusing, and a third sub lens unit having a positive refractive power which does not move for focusing;

the third sub lens unit comprises a negative lens; and

the following conditions are satisfied;

1.6<

L2tm/L2t<

1000.0;

L2w/L3w<

1.0; and

−

0.5<

f2/f3<

−

0.05,

where L2t represents an interval between the second lens unit and the third lens unit at a telephoto end, L2tm represents an interval between the second lens unit and the third lens unit at a zoom position at which an interval between the third lens unit and the fourth lens unit is minimum, L2w represents an interval between the second lens unit and the third lens unit at a wide-angle end, L3w represents an interval between the third lens unit and the fourth lens unit at the wide-angle end, f2 represents a focal length of the second lens unit, and f3 represents a focal length of the third lens unit; and

a solid state image pickup element for receiving an image formed by the zoom lens.