Optical imaging system

Patent metadata

Field	Value
Publication number	US-10365458-B2
Application number	US-201715593391-A
Country	US
Kind code	B2
Filing date	May 12, 2017
Priority date	Dec 28, 2016
Publication date	Jul 30, 2019
Grant date	Jul 30, 2019

Abstract

An optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens, sequentially disposed from an object side to an imaging plane. The optical imaging system satisfies the expression BFL/f<0.15, where BFL represents a distance from an image-side surface of the eighth lens to an imaging plane of an image sensor and f represents an overall focal length of the optical imaging system.

First claim

What is claimed is:

1. An optical imaging system comprising:
a first lens comprising a positive refractive power, a second lens comprising a negative refractive power, a third lens comprising a refractive power, a fourth lens comprising a positive refractive power, a fifth lens comprising a negative refractive power, a sixth lens comprising a refractive power, a seventh lens comprising a refractive power, and an eighth lens comprising a refractive power, sequentially disposed from an object side to an imaging plane,
wherein BFL/f<0.15, where BFL represents a distance from an image-side surface of the eighth lens to an imaging plane of an image sensor and f represents an overall focal length of an optical system including the first to eighth lenses.

2. The optical imaging system of claim 1 , wherein 0.7<TTL/f<1.0, where TTL represents a distance from an object-side surface of the first lens to the imaging plane of the image sensor.

3. The optical imaging system of claim 1 , wherein f/ImgH<2.9, where ImgH represents a half of a diagonal length of the imaging plane of the image sensor.

4. The optical imaging system of claim 1 , wherein −30<f 6 /f<30, where f 6 represents a focal length of the sixth lens.

5. The optical imaging system of claim 1 , wherein TTL/ImgH>1.0, where TTL represents a distance from an object-side surface of the first lens to the imaging plane of the image sensor and ImgH represents a half of a diagonal length of the imaging plane of the image sensor.

6. The optical imaging system of claim 1 , further comprising a stop disposed between the third lens and the fourth lens or between the fourth lens and the fifth lens.

7. The optical imaging system of claim 1 , wherein object-side surfaces and image-side surfaces of the first to eighth lenses are aspherical.

8. The optical imaging system of claim 1 , wherein the first lens comprises a convex object-side surface along an optical axis.

9. The optical imaging system of claim 1 , wherein the second lens comprises a convex object-side surface along an optical axis and a concave image-side surface along the optical axis.

10. The optical imaging system of claim 1 , wherein the third lens comprises a convex object-side surface along an optical axis and a concave image-side surface along the optical axis.

11. The optical imaging system of claim 1 , wherein the fourth lens comprises a convex object-side surface along an optical axis and a concave image-side surface along the optical axis.

12. The optical imaging system of claim 1 , wherein the fifth lens comprises a concave image-side surface along an optical axis.

13. The optical imaging system of claim 1 , wherein the sixth lens comprises a concave object-side surface along an optical axis.

14. The optical imaging system of claim 1 , wherein the seventh lens comprises a negative refractive power, a concave object-side surface along an optical axis, and a concave image-side surface along the optical axis.

15. The optical imaging system of claim 1 , wherein the eighth lens comprises a positive refractive power and a convex object-side surface along an optical axis.

16. The optical imaging system of claim 1 , wherein
the first lens, second lens, the third lens, the fourth lens, and the eighth lens each comprise a convex object-side surface,
the second lens, the third lens, the fourth lens, the fifth lens, and the seventh lens each comprise a concave image-side surface, and
the sixth lens and the seventh lens each comprise a concave object-side surface.

17. An optical imaging system comprising:
a first lens comprising a positive refractive power, a second lens comprising a negative refractive power, a third lens comprising a refractive power, a fourth lens comprising a positive refractive power, a fifth lens comprising a negative refractive power, a sixth lens comprising a refractive power, a seventh lens comprising a refractive power, and an eighth lens comprising a refractive power, sequentially disposed from an object side to an imaging plane, and
wherein 0.7<TTL/f<1.0, where TTL represents a distance from an object-side surface of the first lens to an imaging plane of an image sensor and f represents an overall focal length of the optical imaging system.

18. The optical imaging system of claim 17 , wherein
the first lens, second lens, the third lens, the fourth lens, and the eighth lens each comprise a convex object-side surface,
the second lens, the third lens, the fourth lens, the fifth lens, and the seventh lens each comprise a concave image-side surface, and
the sixth lens and the seventh lens each comprise a concave object-side surface.

19. An optical imaging system comprising:
a first lens having a positive refractive power;
a second lens comprising a negative refractive power, a third lens comprising a refractive power, a fourth lens comprising a positive refractive power, a fifth lens comprising a negative refractive power, a sixth lens comprising a refractive power, and a seventh lens comprising a refractive power;
an eighth lens having a refractive power and a convex object-side surface along an optical axis,
wherein the first to eighth lenses are sequentially disposed from an object side to an imaging plane,
wherein an F-number of the optical imaging system is 2.4 or less,
wherein a field of view (FOV) of the optical imaging system is 40° or less, and
wherein 0.7<TTL/f<1.0, where TTL represents a distance from an object-side surface of the first lens to an imaging plane of an image sensor and f represents an overall focal length of the optical imaging system.

20. The optical imaging system of claim 19 , wherein
the first lens, second lens, the third lens, and the fourth lens each comprise a convex object-side surface,
the second lens, the third lens, the fourth lens, the fifth lens, and the seventh lens each comprise a concave image-side surface, and
the sixth lens and the seventh lens each comprise a concave object-side surface.

Assignees

• Samsung Electro Mech

Inventors

• Jung Jin Hwa
• Jo Yong Joo

Classifications

• G02B13/0045 Primary

  having five or more lenses · 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

• G02B27/0012

  Optical design, e.g. procedures, algorithms, optimisation routines · CPC title

• G02B13/0015 Primary

  characterised by the lens design · CPC title

• G02B7/021

  for more than one lens · CPC title