Optical imaging system

• US 10,386,612 B2
• Filed: 02/02/2018
• Issued: 08/20/2019
• Est. Priority Date: 10/19/2015
• Status: Active Grant

• Current Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Lee, Tae Youn
• Primary Examiner(s): Choi, William
• Application Number:
  US15/887,253
• Publication Number:
  US 20180157009A1
• Time in Patent Office: 564 Days
• Field of Search: 359713, 359752, 359756, 359761, 359762
• CPC Class Codes: G02B 13/0045 having five or more lenses
• CPC Class Codes: G02B 9/62 having six components only

Abstract

There is provided an optical imaging system including a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens. The first lens includes a negative refractive power and a concave object-side surface. The second lens includes a concave object-side surface. The fourth lens includes a negative refractive power. The sixth lens includes an inflection point formed on an image-side surface thereof. The first to sixth lenses are sequentially disposed from an object side toward an imaging plane.

Claims

1. An optical imaging system, comprising:

a first lens comprising a concave object-side surface;

a second lens comprising a convex image-side surface;

a third lens comprising a convex object-side surface and a convex image-side surface;

a fourth lens comprising a convex object-side surface;

a fifth lens; and

a sixth lens comprising an inflection point formed on an image-side surface thereof,

wherein the first to sixth lenses are sequentially disposed from an object side toward an imaging plane.

2. The optical imaging system of claim 1, wherein 0.7<

|f/f6|<

1.8, in which f is an overall focal length of the optical imaging system, and f6 is a focal length of the sixth lens.

3. The optical imaging system of claim 1, wherein 1.5<

f/EPD<

2.1, in which f is an overall focal length of the optical imaging system, and EPD is an entrance pupil diameter of the optical imaging system.

4. The optical imaging system of claim 1, wherein 0.4<

(t1+t2)/t3<

1.3, in which t1 is a thickness at an optical axis center of the first lens, t2 is a thickness at an optical axis center of the second lens, and t3 is a thickness at an optical axis center of the third lens.

5. The optical imaging system of claim 1, wherein 0<

|n1−

n2|<

0.25, in which n1 is a refractive index of the first lens, and n2 is a refractive index of the second lens.

6. An optical imaging system, comprising:

a first lens comprising a concave image-side surface;

a second lens comprising a convex image-side surface;

a third lens comprising a convex object-side surface and a convex image-side surface;

a fourth lens comprising a convex object-side surface;

a fifth lens; and

a sixth lens comprising a concave image-side surface,

wherein the first, the fourth, and the sixth lenses have a same refractive power, different than a refractive power of the third and fifth lenses.

7. The optical imaging system of claim 6, wherein the first, the fourth, and the sixth lenses comprise a negative refractive power.

8. The optical imaging system of claim 6, wherein the second, the third, and the fifth lenses comprise a positive refractive power.

9. The optical imaging system of claim 6, wherein the fourth lens comprises a concave image-side surface and the fifth lens comprises a concave object-side surface and a convex image-side surface.

10. The optical imaging system of claim 6, wherein −

35.0<

{(1/f)*(Y/tan θ

)−

1}*100<

−

5.0, in which f is an overall focal length of the optical imaging system, Y is ½

of a diagonal length of an imaging plane, and θ

is equal to half a field of view of the optical imaging system.

11. The optical imaging system of claim 6, wherein TL/2Y<

0.95, in which TL is a distance from an object-side surface of the first lens to an imaging plane, and 2Y is a diagonal length of the imaging plane.

12. The optical imaging system of claim 6, wherein R1/f<

−

0.5, in which f is an overall focal length of the optical imaging system, and R1 is a radius of curvature of an object-side surface of the first lens.

13. The optical imaging system of claim 6, wherein −

5.5<

(R1+R2)/(R1−

R2)<

0.5, in which R1 is a radius of curvature of an object-side surface of the first lens, and R2 is a radius of curvature of the image-side surface of the first lens.

14. The optical imaging system of claim 6, wherein −

1.5<

f/f1<

−

0.05, in which f is an overall focal length of the optical imaging system, and f1 is a focal length of the first lens.

15. The optical imaging system of claim 6, wherein 0.5<

f/f3<

2.0, in which f is an overall focal length of the optical imaging system, and f3 is a focal length of the third lens.