Wide Field of View Five Element Lens System

Patent metadata

Field	Value
Publication number	US-2024241350-A1
Application number	US-202418412914-A
Country	US
Kind code	A1
Filing date	Jan 15, 2024
Priority date	Oct 26, 2017
Publication date	Jul 18, 2024
Grant date	—

Abstract

Lens systems are described that may be used in small form factor cameras. An imaging lens system may include a front aperture and five lens elements, and provides a low F-number (<=2.4), wide field of view (>=82 degrees), and short total track length (TTL). Lens system parameters and relationships may be selected at least in part to reduce, compensate, or correct for optical aberrations and lens artifacts and effects across the field of view.

First claim

1 .- 21 . (canceled)

22 . A lens system, comprising:
a plurality of optical elements arranged along an optical axis of the lens system, wherein the plurality of optical elements includes, in consecutive order along the optical axis from an object side to an image side of the lens system:
a front aperture stop;
a first refractive lens element L1;
a second refractive lens element L2;
a third refractive lens element L3;
a fourth refractive lens element L4; and
a fifth refractive lens element L5;
wherein F-number of the lens system is less than or equal to 2.4, and full field of view of the lens system is greater than or equal to 82 degrees; wherein respective Abbe numbers for L1, L3 and L5 are higher than respective Abbe numbers for L2 and L4; and wherein L2 satisfies the relationship:

❘
"\[LeftBracketingBar]"

fsys
/
f
⁢
2

❘
"\[RightBracketingBar]"

<
0.5

where fsys is effective focal length of the lens system, f2 is effective focal length of L2.

23 . The lens system as recited in claim 22 , wherein the lens system satisfies the relationship:

TTL
/
2
⁢
SD

<

0
.
8

⁢
5

,

where TTL is total track length of the lens system, and SD is semi-diagonal image height at an image plane of the lens system.

24 . The lens system as recited in claim 22 , wherein effective focal length f of the lens system is less than 3 mm.

25 . The lens system as recited in claim 22 , wherein total track length of the lens system is less than 4 mm.

26 . The lens system as recited in claim 22 , wherein L1 has positive refractive power, wherein an object side surface of L1 is convex in a paraxial region, and wherein L1 comprises a material with an Abbe number vd1, where 45<vd1<70.

27 . The lens system as recited in claim 22 , wherein L1 satisfies the relationships:

❘
"\[LeftBracketingBar]"

fsys
/
f
⁢
1

|>

0.5

,
and

08
<

❘
"\[LeftBracketingBar]"

R
⁢
1

+

R
⁢
2

❘
"\[RightBracketingBar]"

/

❘
"\[LeftBracketingBar]"

R
⁢
1

-

R
⁢
2

❘
"\[RightBracketingBar]"

<
1.5

,

where fsys is effective focal length of the lens system, f1 is effective focal length of L1, and R1 and R2 are radius of curvature of an object side surface and an image side surface of L1, respectively.

28 . The lens system as recited in claim 22 , wherein L2 has negative refractive power, wherein an object side surface of L2 is convex in a paraxial region, and wherein L2 comprises a material with an Abbe number vd2, where 15<vd2<30.

29 . The lens system as recited in claim 22 , wherein L3 has positive refractive power, wherein an object side surface of L3 is concave in a paraxial region, and wherein an image side surface of L3 is convex in a paraxial region.

30 . The lens system as recited in claim 22 , wherein L3 satisfies the relationships:

❘
"\[LeftBracketingBar]"

fsys
/
f
⁢
3

❘
"\[RightBracketingBar]"

>
0.5

;

❘
"\[LeftBracketingBar]"

R
⁢
5

+

R
⁢
6

❘
"\[RightBracketingBar]"

/

Assignees

• Apple Inc

Inventors

• Yao Yuhong

Classifications

• G02B9/60

  having five components only · CPC title

• G02B7/09

  adapted for automatic focusing or varying magnification · CPC title

• G02B5/208

  for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation · CPC title

• H04N23/55

  Optical parts specially adapted for electronic image sensors; Mounting thereof · CPC title

• G02B13/04

  Reversed telephoto objectives · CPC title