Optical Image Capturing System

• US 20180024319A1
• Filed: 12/12/2016
• Published: 01/25/2018
• Est. Priority Date: 07/21/2016
• Status: Active Grant

• Current Assignee: Ability Opto-Electronics Technology Co., Ltd.
• Original Assignee: Ability Opto-Electronics Technology Co., Ltd.
• Inventors: LAI, CHIEN-HSUN, LIAO, KUO-YU, LIU, YAO-WEI, CHANG, YEONG-MING
• Granted Patent: US 9,958,643 B2
• Time in Patent Office: Days
• CPC Class Codes: G02B 13/004 having four lenses
• CPC Class Codes: G02B 13/06 Panoramic objectives; So-called "sky lenses" including panoramic objectives having reflecting surfaces
• CPC Class Codes: G02B 13/146 with corrections for use in multiple wavelength bands, such as infrared and visible light, e.g. FLIR systems
• CPC Class Codes: G02B 27/0025 for optical correction, e.g. distorsion, aberration
• CPC Class Codes: G02B 5/005 Diaphragms for cameras G03B9/02
• CPC Class Codes: G02B 5/208 for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation
• CPC Class Codes: G02B 9/34 having four components only

Abstract

A four-piece optical lens for capturing image and a five-piece optical module for capturing image are provided. In the order from an object side to an image side, the optical lens along the optical axis includes a first lens with positive refractive power; a second lens with refractive power; a third lens with refractive power; and a fourth lens with refractive power; and at least one of the image-side surface and object-side surface of each of the four lens elements are aspheric. The optical lens can increase aperture value and improve the imagining quality for use in compact cameras.

Claims

1. An optical image capturing system, from an object side to an image side, comprising:

a first lens element with refractive power;

a second lens element with refractive power;

a third lens element with refractive power;

a fourth lens element with refractive power;

a first image plane, which is an image plane specifically for visible light and perpendicular to an optical axis;

a through-focus modulation transfer rate (value of MTF) at a first spatial frequency having a maximum value at central field of view of the first image plane; and

a second image plane, which is an image plane specifically for infrared light and perpendicular to the optical axis;

the through-focus modulation transfer rate (value of MTF) at the first spatial frequency having a maximum value at central of field of view of the second image plane;

wherein the optical image capturing system comprises four lens elements with refractive powers, at least one of the four lens elements has positive refractive power;

focal lengths of the four lens elements are respectively f1, f2, f3 and f4;

a focal length of the optical image capturing system is f, and an entrance pupil diameter of the optical image capturing system is HEP;

a distance on the optical axis from an object-side surface of the first lens element to the first image plane is HOS, a distance on the optical axis from the object-side surface of the first lens element to an image-side surface of the fourth lens element is InTL, a maximum effective diameter of the image-side surface of the fourth lens element is denoted by PhiA4, half of a maximum viewable angle of the optical image capturing system is denoted by HAF;

the optical image capturing system has a maximum image height HOI on the first image plane perpendicular to the optical axis;

a distance on the optical axis between the first image plane and the second image plane is denoted by FS;

conditions as follows are satisfied;

1≦

f/HEP≦

10, 0 deg<

HAF≦

150 deg, 0<

PhiA4/InTL≦

5, and |FS|≦

30 μ

m.

2. The optical image capturing system of claim 1, wherein a wavelength of the infrared light ranges from 700 nm to 1300 nm, and the first spatial frequency is denoted by SP1, which satisfies the following condition:

SP1≦

440 cycles/mm.

3. The optical image capturing system of claim 1, wherein an outline curve starting from an axial point on any surface of any one of the four lens elements, tracing along an outline of the surface, and ending at a coordinate point on the surface that has a vertical height of ½

entrance pupil diameter from the optical axis, has a length denoted by ARE, the following condition is satisfied;

0.9≦

2(ARE/HEP)≦

2.0.

4. The optical image capturing system of claim 1, wherein an image-side surface of the second lens element and an image-side surface of the third lens element on the optical axis are convex surfaces.

5. The optical image capturing system of claim 1, wherein half of a vertical maximum viewable angle of the optical image capturing system is denoted by VHAF, and the following conditions are satisfied:

VHAF≧

10 deg, 0<

PhiA4/HEP≦

4.0, and 0<

PhiA4/2HOI≦

2.0.

6. The optical image capturing system of claim 1, wherein the optical image capturing system satisfies the following condition:

HOS/HOI≧

1.2.

7. The optical image capturing system of claim 1, wherein an outline curve starting from an axial point on an object-side surface of the fourth lens element, tracing along an outline of the object-side surface, and ending at a coordinate point on the surface that has a vertical height of ½

entrance pupil diameter from the optical axis, has a length denoted by ARE41;

an outline curve starting from an axial point on the image-side surface of the fourth lens element, tracing along an outline of the image-side surface, and ending at a coordinate point on the surface that has a vertical height of ½

entrance pupil diameter from the optical axis, has a length denoted by ARE42;

a central thickness of the fourth lens element on the optical axis is TP4, which satisfies conditions as follows;

0.05≦

ARE41/TP4≦

25 and 0.05≦

ARE42/TP4≦

25.

8. The optical image capturing system of claim 1, wherein the first lens element has negative refractive power;

TV distortion for image formation in the optical image capturing system is TDT;

transverse aberration of a longest operation wavelength of a positive direction tangential fan of the optical image capturing system passing through an edge of an entrance pupil and incident at a position of 0.7 HOI on the first image plane is denoted by PLTA, and transverse aberration of a shortest operation wavelength of the positive direction tangential fan of the optical image capturing system passing through the edge of the entrance pupil and incident at the position of 0.7 HOI on the first image plane is denoted by PSTA;

transverse aberration of the longest operation wavelength of a negative direction tangential fan of the optical image capturing system passing through the edge of the entrance pupil and incident at the position of 0.7 HOI on the first image plane is denoted by NLTA, and transverse aberration of the shortest operation wavelength of a negative direction tangential fan of the optical image capturing system passing through the edge of the entrance pupil and incident at the position of 0.7 HOI on the first image plane is denoted by NSTA;

transverse aberration of the longest operation wavelength of a sagittal fan of the optical image capturing system passing through the edge of the entrance pupil and incident at the position of 0.7 HOI on the first image plane is denoted by SLTA, transverse aberration of the shortest operation wavelength of the sagittal fan of the optical image capturing system passing through the edge of the entrance pupil and incident at the position of 0.7 HOI on the first image plane is denoted by SSTA;

conditions as follows are satisfied;

PLTA≦

100 μ

m, PSTA≦

100 μ

m, NLTA≦

100 μ

m, NSTA≦

100 μ

m, SLTA≦

100 μ

m, SSTA≦

100 μ

m, and |TDT|<

100%.

9. The optical image capturing system of claim 1, further comprising an aperture stop;

wherein a distance from the aperture stop to the first image plane on the optical axis is InS, which satisfies condition as follows;

0.2≦

InS/HOS≦

1.1.

10. An optical image capturing system, from an object side to an image side, comprising:

a first lens element with positive refractive power;

a second lens element with refractive power, an image-side surface thereof on the optical axis being a convex surface;

a third lens element with refractive power, an image-side surface thereof on the optical axis being a convex surface;

a fourth lens element with refractive power;

a first image plane, which is an image plane specifically for visible light and perpendicular to an optical axis;

a through-focus modulation transfer rate (value of MTF) at a first spatial frequency having a maximum value at central field of view of the first image plane, and the first spatial frequency being 220 cycles/mm;

a second image plane, which is an image plane specifically for infrared light and perpendicular to the optical axis;

the through-focus modulation transfer rate (value of MTF) at the first spatial frequency having a maximum value at central of field of view of the second image plane, and the first spatial frequency being 220 cycles/mm; and

a first lens positioning element comprising a lens base,

wherein the lens base is hollow and opaque, and the lens base is disposed with a barrel portion and a base portion that are interconnected;

the barrel portion is configured to accommodate the first to fourth lens elements, and the base portion is between the fourth lens element and the first image plane;

an outer perimeter of the base portion is longer than an outer perimeter of the barrel portion;

a shortest side length of the base portion, which is measured on a plane perpendicular to the optical axis, has a maximum value denoted by PhiD, the optical image capturing system comprises four lens elements with refractive powers;

at least one of the second to fourth lens elements has positive refractive power;

focal lengths of the four lens elements are respectively f1, f2, f3 and f4;

a focal length of the optical image capturing system is f;

an entrance pupil diameter of the optical image capturing system is HEP;

a distance on an optical axis from an object-side surface of the first lens element to the first image plane is HOS, a distance on the optical axis from the object-side surface of the first lens element to an image-side surface of the fourth lens element is InTL, half of a maximum viewable angle of the optical image capturing system is denoted by HAF;

the optical image capturing system has a maximum image height HOI on the first image plane perpendicular to the optical axis;

a maximum effective diameter of the image-side surface of the fourth lens element is denoted by PhiA4;

an outline curve starting from an axial point on any surface of any one of the four lens elements, tracing along an outline of the surface, and ending at a coordinate point on the surface that has a vertical height of ½

entrance pupil diameter from the optical axis, has a length denoted by ARE;

a distance on the optical axis between the first image plane and the second image plane is denoted by FS;

conditions as follows are satisfied;

1≦

f/HEP≦

10, 0 deg<

HAF≦

150 deg, |FS|≦

30 μ

m, 0 mm<

PhiD≦

10 mm, and 0.9≦

2(ARE/HEP)≦

2.0.

11. The optical image capturing system of claim 10, wherein a maximum effective half diameter of any surface of any one of the four lens elements is denoted by EHD;

an outline curve starting from the axial point on any surface of any one of those lens elements, tracing along an outline of the surface, and ending at a point which defines the maximum effective half diameter, has a length denoted by ARS;

conditions as follows are satisfied;

0.9≦

ARS/EHD≦

2.0.

12. The optical image capturing system of claim 10, wherein half of a vertical maximum viewable angle of the optical image capturing system is denoted by VHAF, and the following conditions are satisfied:

VHAF≧

20 deg and 0<

PhiA4/InTL≦

5.

13. The optical image capturing system of claim 10, wherein the optical image capturing system satisfies the following condition:

HOS/HOI≧

1.4.

14. The optical image capturing system of claim 10, wherein the third lens element has positive refractive power.

15. The optical image capturing system of claim 10, wherein the fourth lens element has negative refractive power;

the image-side surface of the second lens element and the image-side surface of the third lens element on the optical axis are convex surfaces.

16. The optical image capturing system of claim 10, wherein a distance on the optical axis between the third lens element and the fourth lens element is IN34, which satisfies condition as follows:

0<

IN34/f≦

5.

17. The optical image capturing system of claim 10, wherein a distance on the optical axis between the first lens element and the second lens element is IN12, which satisfies condition as follows:

0<

IN12/f≦

60.

18. The optical image capturing system of claim 10, wherein a distance on the optical axis between the third lens element and the fourth lens element is IN34, central thicknesses of the third lens element and the fourth lens element on the optical axis are respectively TP3 and TP4, which satisfy condition as follows:

1≦

(TP4+IN34)/TP3≦

10.

19. The optical image capturing system of claim 10, satisfying the following conditions:

0<

PhiA4/2HOI≦

2.0 and 0 mm<

PhiA4≦

5 mm.

20. An optical image capturing system, from an object side to an image side, comprising:

a first lens element with positive refractive power;

a second lens element with refractive power, an image-side surface thereof on the optical axis being a convex surface;

a third lens element with refractive power, an image-side surface thereof on the optical axis being a convex surface;

a fourth lens element with refractive power;

a first average image plane, which is an image plane specifically for visible light and perpendicular to an optical axis;

the first average image plane being installed at the average position of the defocusing positions, where through-focus modulation transfer rates (values of MTF) of the visible light at central field of view, 0.3 field of view, and 0.7 field of view are at their respective maximum at a first spatial frequency;

the first spatial frequency being 220 cycles/mm;

a second average image plane, which is an image plane specifically for infrared light and perpendicular to the optical axis;

the second average image plane being installed at the average position of the defocusing positions, where through-focus modulation transfer rates of the infrared light (values of MTF) at central field of view, 0.3 field of view, and 0.7 field of view are at their respective maximum at the first spatial frequency;

the first spatial frequency being 220 cycles/mm; and

a first lens positioning element comprising a lens base; and

a second lens positioning element accommodated in the lens base,

wherein the lens base is hollow and opaque, and the lens base is disposed with a barrel portion and a base portion that are interconnected;

the barrel portion is configured to accommodate the first to fourth lens elements, and the base portion is between the fourth lens element and the first average image plane;

an outer perimeter of the base portion is longer than an outer perimeter of the barrel portion;

a shortest side length of the base portion, which is measured on a plane perpendicular to the optical axis, has a maximum value denoted by PhiD;

the second lens positioning element comprises a positioning portion and a connecting portion;

the positioning portion is hollow and comes into direct contact with any lens elements to accommodate those lens elements, such that those lens elements are aligned along the optical axis;

the connecting portion is disposed at an outer side of the positioning portion and comes into direct contact with an inner perimeter of the barrel portion;

a maximum outer diameter of the connecting portion, which is measured on a plane perpendicular to the optical axis, is denoted by PhiC;

the optical image capturing system comprises four lens elements with refractive power;

at least one of the third to fourth lens elements has positive refractive power;

focal lengths of the first lens element to the fourth lens elements are respectively f1, f2, f3 and f4;

a focal length of the optical image capturing system is f;

an entrance pupil diameter of the optical image capturing system is HEP;

a distance on the optical axis from an object-side surface of the first lens element to the first average image plane is HOS;

a distance on the optical axis from the object-side surface of the first lens element to an image-side surface of the fourth lens element is InTL, half of a maximum viewable angle of the optical image capturing system is denoted by HAP;

the optical image capturing system has a maximum image height HOI on the first average image plane perpendicular to the optical axis;

a maximum effective diameter of the image-side surface of the fourth lens element is denoted by PhiA4;

an outline curve starting from an axial point on any surface of any one of the four lens elements, tracing along an outline of the surface, and ending at a coordinate point on the surface that has a vertical height of ½

entrance pupil diameter from the optical axis, has a length denoted by ARE;

a distance on the optical axis between the first average image plane and the second average image plane is denoted by AFS;

half of a vertical maximum viewable angle of the optical image capturing system is denoted by VHAF, conditions as follows are satisfied;

1≦

f/HEP10, 0 deg<

HAF≦

150 deg, |AFS|≦

30 μ

m, VHAF≧

20 deg, PhiC<

PhiD, 0 mm<

PhiD≦

5 mm, and 0.9≦

2(ARE/HEP)≦

2.0.

21. The optical image capturing system of claim 20, wherein a maximum effective half diameter of any surface of any one of the four lens elements is denoted by EHD;

an outline curve starting from the axial point on any surface of any one of those lens elements, tracing along an outline of the surface, and ending at a point which defines the maximum effective half diameter, has a length denoted by ARS;

conditions as follows are satisfied;

0.9≦

ARS/EHD≦

2.0.

22. The optical image capturing system of claim 20, wherein the optical image capturing system satisfies the following condition:

HOS/HOI≧

1.6.

23. The optical image capturing system of claim 20, wherein a linear magnification of an image formed by the optical image capturing system on the second average image plane is LM, which satisfies the following condition:

LM≧

0.0003.

24. The optical image capturing system of claim 20, further comprising an aperture stop and an image sensing device;

wherein the image sensing device is disposed on the first average image plane and comprises at least 100 thousand pixels, a distance on the optical axis from the aperture stop to the first average image plane is InS;

condition as follows is satisfied;

0.2≦

InS/HOS≦

1.1.

25. The optical image capturing system of claim 20, further comprising an aperture stop, an image sensing device, and a driving module, wherein the image sensing device is disposed on the first average image plane and comprises at least 100 thousand pixels, a distance from the aperture stop to the first average image plane is InS, and the driving module couples with the four lens elements and enables movements of those lens elements;

conditions as follows are satisfied;

0.2≦

InS/HOS≦

1.1.