OPTICAL UNIT AND IMAGE PICKUP APPARATUS

• US 20130242413A1
• Filed: 11/16/2011
• Published: 09/19/2013
• Est. Priority Date: 11/25/2010
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Baba, Tomohiko
• Granted Patent: US 8,922,917 B2
• Time in Patent Office: Days
• US Class Current: 359/753
• CPC Class Codes: G02B 13/04 Reversed telephoto objectives
• CPC Class Codes: G02B 13/18 with lenses having one or more non-spherical faces, e.g. for reducing geometrical aberration G02B13/002 takes precedence
• CPC Class Codes: G02B 9/12 having three components only

Abstract

An optical unit that is configured of a three-group wide-angle lens, that is capable of suppressing optical distortion to a small amount, that has favorable optical characteristics, and that is tolerant of reflow, and an image pickup apparatus are provided. An optical unit 100 includes: a first lens group 110 including a first lens element 111; a second lens group 120 including a second lens element 121, a first transparent member 122, and a third lens element 123 that are arranged in order from object plane toward image plane; and a third lens group 130 including a fourth lens element 131, a second transparent member 132, and a fifth lens element 33 that are arranged in order from the object plane toward the image plane, the first lens group 110, the second lens group 120, and the third lens group 130 being arranged in order from the object plane toward the image plane.

Claims

1. An optical unit comprising:

a first lens group including a first lens element;

a second lens group including a second lens element, a first transparent member, and a third lens element that are arranged in recited order from object plane toward image plane; and

a third lens group including a fourth lens element, a second transparent member, and a fifth lens element that are arranged in recited order from the object plane toward the image plane,

the first, second, and third lens groups being arranged in recited order from the object plane toward the image plane.

2. The optical unit according to claim 1, wherein a focal length fL1 of the first lens group and a focal length fL2 of the second lens group satisfy following conditional expressions,

−

10≦

fL1/f≦

−

2

0.8≦

fL2/f≦

5

where f is a focal length of whole of the optical unit.

3. The optical unit according to claim 1, wherein

the fourth lens element in the third lens group has a plano-concave shape having a concave shape on an object plane side thereof, and

the fifth lens element in the third lens group has a plano-convex shape having a convex shape on an image plane side thereof.

4. The optical unit according to claim 1, wherein an Abbe number ν

dE4 of the fourth lens element and an Abbe number ν

dE5 of the fifth lens element satisfy following conditional expressions.

24≦

ν

dE4≦

45

42≦

ν

dE5≦

66

5. The optical unit according to claim 1, wherein a number of lenses that are formed with a wafer shape are diced into pieces to form the second lens group and the third lens group.

6. The optical unit according to claim 1, wherein an angle of view satisfies following conditional expression expressed in units of degree,

65≦

2ω

≦

140

where ω

is a horizontal half angle of view.

7. An image pickup apparatus with an image pickup device and an optical unit forming an image of a subject in the image pickup device, the optical unit comprising:

a first lens group including a first lens element;

a second lens group including a second lens element, a first transparent member, and a third lens element that are arranged in recited order from object plane toward image plane; and

a third lens group including a fourth lens element, a second transparent member, and a fifth lens element that are arranged in recited order from the object plane toward the image plane,

the first, second, and third lens groups being arranged in recited order from the object plane toward the image plane.