Optical photographing system, image capturing apparatus and electronic device

Patent metadata

Field	Value
Publication number	US-11619804-B2
Application number	US-202016846632-A
Country	US
Kind code	B2
Filing date	Apr 13, 2020
Priority date	Oct 5, 2016
Publication date	Apr 4, 2023
Grant date	Apr 4, 2023

Abstract

An optical photographing system includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element. The first lens element has an image-side surface being convex in a paraxial region thereof. The third lens element has positive refractive power. The fourth lens element has an object-side surface being concave in a paraxial region thereof. The fifth lens element with positive refractive power has two surfaces being both aspheric. The sixth lens element has an image-side surface being concave in a paraxial region thereof, wherein the surfaces of the sixth lens element are both aspheric, and the image-side surface of the sixth lens element includes at least one convex shape in an off-axial region thereof.

First claim

What is claimed is:

1. An optical photographing system comprising, in order from an object side to an image side:
a first lens element having an object-side surface being concave in a paraxial region thereof;
a second lens element having an image-side surface being concave in a paraxial region thereof;
a third lens element having positive refractive power;
a fourth lens element having an object-side surface being concave in a paraxial region thereof;
a fifth lens element with positive refractive power having an object-side surface and an image-side surface being both aspheric; and
a sixth lens element having an image-side surface being concave in a paraxial region thereof, wherein an object-side surface and the image-side surface of the sixth lens element are both aspheric, and the image-side surface of the sixth lens element comprises at least one convex shape in an off-axial region thereof;
wherein the optical photographing system has a total of six lens elements, a focal length of the second lens element is f2, a focal length of the third lens element is f3, a curvature radius of the object-side surface of the fourth lens element is R7, a curvature radius of an image-side surface of the fourth lens element is R8, a central thickness of the second lens element is CT2, a central thickness of the third lens element is CT3, and the following conditions are satisfied:
| f 3/ f 2|<1.0;
−1.45<( R 7− R 8)/( R 7+ R 8)<0; and

1.90<CT3/CT2≤3.37.

2. The optical photographing system of claim 1 , wherein the object-side surface of the first lens element comprises a convex shape in an off-axial region thereof.

3. The optical photographing system of claim 1 , wherein the fourth lens element has negative refractive power, and the sixth lens element has negative refractive power.

4. The optical photographing system of claim 1 , wherein an axial distance between the third lens element and the fourth lens element is T34, an axial distance between the fourth lens element and the fifth lens element is T45, and the following condition is satisfied:
0< T 45/ T 34<2.0.

5. The optical photographing system of claim 1 , wherein a central thickness of the first lens element is CT1, the central thickness of the second lens element is CT2, the central thickness of the third lens element is CT3, a central thickness of the fourth lens element is CT4, a central thickness of the fifth lens element is CT5, and the following condition is satisfied:
(CT1+CT2+CT4)/(CT3+CT5)<0.80.

6. The optical photographing system of claim 1 , further comprising:
an aperture stop, wherein an axial distance between the object-side surface of the first lens element and an image surface is TL, an axial distance between the aperture stop and the image-side surface of the sixth lens element is SD, an axial distance between the object-side surface of the first lens element and the image-side surface of the sixth lens element is TD, and the following conditions are satisfied:
3.0 mm< TL< 7.0 mm; and
0.70< SD/TD< 0.93.

7. The optical photographing system of claim 1 , wherein a curvature radius of an object-side surface of the second lens element is R3, a curvature radius of the image-side surface of the second lens element is R4, and the following condition is satisfied:
−0.20<( R 3− R 4)/( R 3+ R 4)<0.20.

8. The optical photographing system of claim 1 , wherein a displacement in parallel with an optical axis from an axial vertex on the object-side surface of the first lens element to a maximum effective radius position on the object-side surface of the first lens element is SAG11, a maximum effective radius of the object-side surface of the first lens element is Y11, and the following condition is satisfied:
| SAG 11/ Y 11|<0.20.

9. The optical photographing system of claim 1 , wherein the curvature radius of the object-side surface of the fourth lens element is R7, a maximum image height of the optical photographing system is ImgH, and the following condition is satisfied:
−1.0< R 7/Img H <0.

Assignees

• Largan Precision Co Ltd

Inventors

• Hsueh Chun-Che
• Tseng Yu-Tai
• Huang Hsin-Hsuan

Classifications

• G02B13/0045 Primary

  having five or more lenses · CPC title

• G02B27/0025

  for optical correction, e.g. distorsion, aberration · CPC title

• G02B9/62

  having six components only · CPC title

• G02B13/04

  Reversed telephoto objectives · CPC title