Zoom lens having vibration prevention function

Patent metadata

Field	Value
Publication number	US-9313384-B2
Application number	US-201314075123-A
Country	US
Kind code	B2
Filing date	Nov 8, 2013
Priority date	Dec 7, 2012
Publication date	Apr 12, 2016
Grant date	Apr 12, 2016

Abstract

A zoom lens includes, sequentially from an object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power. When zoom is changed from a wide angle end to a telephoto end, an interval between the first lens group and the second lens group increases, and an interval between the second lens group and third lens group decreases. The second lens group comprises, sequentially from the object side, a second A lens group having a negative refractive power and a second B lens group having a negative refractive power, and the second B group is displaced in a direction perpendicular to an optical axis to perform a vibration prevention function.

First claim

What is claimed is:

1. A zoom lens comprising, sequentially from an object side:
a first lens group having a positive refractive power;
a second lens group having a negative refractive power; and
a third lens group having a positive refractive power,
wherein when zoom is changed from a wide angle end to a telephoto end, an interval between the first lens group and the second lens group increases, and an interval between the second lens group and the third lens group decreases, and
the second lens group comprises, sequentially from the object side, a second A lens group having a negative refractive power and a second B lens group having a negative refractive power, and the second B lens group is displaced in a direction perpendicular to an optical axis to perform a vibration prevention function,
wherein the zoom lens satisfies the following conditions:
2.0< f 1/ fw< 8.0, and
3.0< f 2 b/f 2<10.0,

wherein, f1 denotes a focal length of the first lens group, f2 denotes a focal length of the second lens group, f2b denotes a focal length of the second B lens group, and fw denotes a focal length of the zoom lens at the wide angle end,
wherein the second A lens group and the second B lens group move integrally when zoom is changed.

2. The zoom lens of claim 1 , wherein:
the second A lens group comprises, sequentially from the object side, a first negative lens, a second negative lens, and a positive lens; and
the zoom lens satisfies the following condition:
1.5< f 2 a/f 2<5.0,

wherein, f2a denotes a focal length of the second A lens group.

3. The zoom lens of claim 2 , wherein the zoom lens further satisfies the following condition:
2.0< f 2 a/f 2<3.5.

4. The zoom lens of claim 1 , wherein a lens surface of the second A lens group, which is closest to the object side, is convex toward the object side.

5. The zoom lens of claim 1 , wherein:
the second A lens group comprises, sequentially from the object side, a negative meniscus lens having a convex surface facing the object side, and a cemented lens including a negative biconcave lens and a positive biconvex lens; and
the second B lens group is configured as a cemented lens including a biconcave lens and a biconvex lens.

6. The zoom lens of claim 5 , wherein the second lens group further comprises:
a second C lens group that is disposed on an image side of the second B lens group; and
the second C lens group is configured as a meniscus lens having a convex surface facing the image side.

7. The zoom lens of claim 1 , wherein the first lens group comprises, sequentially from the object side:
a cemented lens including a meniscus lens, which has a convex surface facing the object side, and a biconvex lens; and
a meniscus lens having a convex surface facing the object side.

8. The zoom lens of claim 1 , wherein the third lens group is configured as a cemented lens including a biconvex lens and a biconcave lens.

9. The zoom lens of claim 1 , further comprising a fourth lens group having a positive refractive power and is disposed on an image side of the third lens group.

10. The zoom lens of claim 9 , wherein when zoom is changed from the wide angle end to the telephoto end, an interval between the third lens group and the fourth lens group decreases.

11. An electronic device comprising:
the zoom lens of claim 1 ; and
an imaging element that receives an optical image formed by the zoom lens and converts the optical image into an electrical image signal.

12. A camera comprising:
a housing;
the zoom lens of claim 1 that is configured as an interchangeable lens and is detachably coupled to the housing; and
an imaging element disposed in the housing, receives an optical image formed by the zoom lens, and converts the optical image into an electrical image signal.

13. A zoom lens comprising, sequentially from an object side:
a first lens group having a positive refractive power;
a second lens group having a negative refractive power; and
a third lens group having a positive refractive power,
wherein when zoom is changed from a wide angle end to a telephoto end, an interval between the first lens group and the second lens group increases, and an interval between the second lens group and the third lens group decreases, and
the second lens group comprises, sequentially from the object side, a second A lens group having a negative refractive power and a second B lens group having a negative refractive power, and the second B lens group is displaced in a direction perpendicular to an optical axis to perform a vibration prevention function,
wherein the zoom lens satisfies the following conditions:
2.0< f 1/ fw< 8.0,
3.0< f 2 b/f 2<10.0,
0.03<| f 2|/ ft< 0.25, and
0.1< f 3/ ft< 1.0,

wherein, f1 denotes a focal length of the first lens group, f2 denotes a focal length of the second lens group, f2b denotes a focal length of the second B lens group, fw denotes a focal length of the zoom lens at the wide angle end, f3 denotes the focal length of the third lens group, and ft denotes a focal length of the zoom lens at the telephoto end.

14. The zoom lens of claim 13 , wherein the zoom lens further satisfies the following conditions:
0.05<| f 2|/ ft< 0.20, and
0.2< f 3/ ft< 0.8.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Misaka Makoto

Classifications

• G02B15/173

  arranged +-+ · CPC title

• G02B15/14

  by axial movement of one or more lenses or groups of lenses relative to the image plane for continuously varying the equivalent focal length of the objective · CPC title

• H04N5/2254 Primary

  Electricity · mapped topic

• G02B27/646 Primary

  compensating for small deviations, e.g. due to vibration or shake (movement of one or more optical elements for control of motion blur in cameras, projectors or printers G03B2205/0007; image stabilisation in cameras peculiar to the presence or use of an electronic image sensor H04N23/68) · CPC title

• G02B15/144113

  arranged +-++ · CPC title