PHOTOGRAPHING LENS ASSEMBLY

• US 20140320981A1
• Filed: 05/07/2013
• Published: 10/30/2014
• Est. Priority Date: 04/25/2013
• Status: Active Grant

• Current Assignee: Largan Precision Co Limited (Largan Precision)
• Original Assignee: Largan Precision Co Limited (Largan Precision)
• Inventors: HSIEH, Dung-Yi, TSAI, Tsung-Han, HUANG, Hsin-Hsuan
• Granted Patent: US 9,019,626 B2
• Time in Patent Office: Days
• US Class Current: 359/713
• CPC Class Codes: G02B 13/0045 having five or more lenses
• CPC Class Codes: G02B 13/04 Reversed telephoto objectives
• CPC Class Codes: G02B 9/62 having six components only

Abstract

A photographing lens assembly 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 with positive refractive power has a convex object-side surface at a paraxial region. The second through the sixth lens elements have refractive power. The fourth lens element has a concave object-side surface at a paraxial region and a convex image-side surface at a paraxial region. The fifth lens element has an aspheric object-side surface and an aspheric image-side surface. The sixth lens element has a concave image-side surface at a paraxial region, wherein the image-side surface thereof has a convex shape at an off-axis region, and both surfaces thereof are aspheric. The photographing lens assembly has a total of six lens elements with refractive power.

Claims

1. A photographing lens assembly comprising, in order from an object side to an image side thereof:

a first lens element with positive refractive power having a convex object-side surface at a paraxial region thereof;

a second lens element having refractive power;

a third lens element having refractive power;

a fourth lens element with refractive power having a concave object-side surface at a paraxial region thereof and a convex image-side surface at a paraxial region thereof;

a fifth lens element having refractive power, wherein both of an object-side surface and an image-side surface of the fifth lens element are aspheric; and

a sixth lens element with refractive power having a concave image-side surface at a paraxial region thereof, wherein the image-side surface of the sixth lens element has a convex shape at an off-axis region thereof, and both of an object-side surface and the image-side surface of the sixth lens element are aspheric;

wherein the photographing lens assembly has a total of six lens elements with refractive power, a focal length of the photographing lens assembly is f, a curvature radius of the object-side surface of the fifth lens element is R9, a curvature radius of the image-side surface of the fifth lens element is R10, and the following relationship is satisfied;

|f/R9|+|f/R10|<

1.1.

2. The photographing lens assembly of claim 1, wherein the sixth lens element has negative refractive power.

3. The photographing lens assembly of claim 2, wherein the second lens element has negative refractive power.

4. The photographing lens assembly of claim 3, wherein a central thickness of the second lens element is CT2, a central thickness of the third lens element is CT3, and the following relationships are satisfied:

CT2<

0.3 mm; and

CT3<

0.3 mm.

5. The photographing lens assembly of claim 3, wherein the focal length of the photographing lens assembly is f, a curvature radius of an object-side surface of the third lens element is R5, a curvature radius of an image-side surface of the third lens element is R6, and the following relationship is satisfied:

|f/R5|+|f/R6|<

1.3.

6. The photographing lens assembly of claim 3, further comprising:

a stop located between an object and the first lens element, wherein an axial distance between the 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 relationship is satisfied;

0.85<

SD/TD<

1.05.

7. The photographing lens assembly of claim 3, wherein an Abbe number of the second lens element is V2, an Abbe number of the fifth lens element is V5, an Abbe number of the sixth lens element is V6, and the following relationship is satisfied:

V2+V5−

V6<

0.

8. The photographing lens assembly of claim 1, wherein a vertical distance between a non-axial critical point on the image-side surface of the sixth lens element and an optical axis is Yc62, 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 relationship is satisfied:

0.20<

Yc62/TD<

0.70.

9. The photographing lens assembly of claim 8, wherein a curvature radius of the object-side surface of the first lens element is R1, a curvature radius of an image-side surface of the first lens element is R2, and the following relationship is satisfied:

−

0.2<

R1/R2<

0.5.

10. The photographing lens assembly of claim 8, wherein the axial distance between the object-side surface of the first lens element and the image-side surface of the sixth lens element is TD, a vertical distance between a maximum effective diameter position on the image-side surface of the sixth lens element and the optical axis is SD62, and the following relationship is satisfied:

1.0<

TD/SD62<

1.6.

11. The photographing lens assembly of claim 8, wherein the focal length of the photographing lens assembly is f, a focal length of the fifth lens element is f5, and the following relationship is satisfied:

−

0.7<

f/f5<

0.2.

12. The photographing lens assembly of claim 8, wherein the object-side surface of the sixth lens element is convex at a paraxial region thereof.

13. The photographing lens assembly of claim 8, wherein the fourth lens element has positive refractive power.

14. The photographing lens assembly of claim 8, wherein the focal length of the photographing lens assembly is f, a curvature radius of an object-side surface of the second lens element is R3, a curvature radius of an image-side surface of the second lens element is R4, and the following relationship is satisfied:

|f/R3|+|f/R4|<

2.0.

15. A photographing lens assembly comprising, in order from an object side to an image side thereof:

a first lens element with positive refractive power having a convex object-side surface at a paraxial region thereof;

a second lens element having refractive power;

a third lens element having refractive power;

a fourth lens element with refractive power having a concave object-side surface at a paraxial region thereof and a convex image-side surface at a paraxial region thereof;

a fifth lens element having negative refractive power, wherein both of an object-side surface and an image-side surface of the fifth lens element are aspheric; and

a sixth lens element with negative refractive power having a concave image-side surface at a paraxial region thereof, wherein the image-side surface of the sixth lens element has a convex shape at an off-axis region thereof, and both of an object-side surface and the image-side surface of the sixth lens element are aspheric;

wherein the photographing lens assembly has a total of six lens elements with refractive power, a focal length of the photographing lens assembly is f, a curvature radius of the object-side surface of the fifth lens element is R9, a curvature radius of the image-side surface of the fifth lens element is R10, an axial distance between the first lens element and the second lens element is T12, an axial distance between the second lens element and the third lens element is T23, and the following relationships are satisfied;

|f/R9|+|f/R10|<

1.5; and

0≦

T12/T23<

0.40

16. The photographing lens assembly of claim 15, wherein the object-side surface of the sixth lens element is convex at a paraxial region thereof.

17. The photographing lens assembly of claim 15, wherein 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, a vertical distance between a maximum effective diameter position on the image-side surface of the sixth lens element and the optical axis is SD62, and the following relationship is satisfied:

1.0<

TD/SD62<

1.6.

18. The photographing lens assembly of claim 15, wherein the focal length of the photographing lens assembly is f, a curvature radius of an is object-side surface of the third lens element is R5, a curvature radius of an image-side surface of the third lens element is R6, and the following relationship is satisfied:

|f/R5|+|f/R6|<

1.0.

19. The photographing lens assembly of claim 15, wherein a vertical distance between a non-axial critical point on the image-side surface of the sixth lens element and an optical axis is Yc62, 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 relationship is satisfied:

0.20<

Yc62/TD<

0.70.

20. The photographing lens assembly of claim 15, further comprising:

a stop located between an object and the first lens element, wherein an axial distance between the 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 relationship is satisfied;

0.85<

SD/TD<

1.05.

21. The photographing lens assembly of claim 20, wherein the axial distance between the first lens element and the second lens element is T12, the axial distance between the second lens element and the third lens element is T23, and the following relationship is satisfied:

0≦

T12/T23<

0.2.

22. The photographing lens assembly of claim 20, wherein the second lens element has negative refractive power and the second lens element has a concave image-side surface at a paraxial region thereof.

23. The photographing lens assembly of claim 20, wherein an Abbe number of the second lens element is V2, an Abbe number of the fifth lens element is V5, an Abbe number of the sixth lens element is V6, and the following relationship is satisfied:

V2+V5−

V6<

0.

24. The photographing lens assembly of claim 20, wherein the fourth lens element has positive refractive power, the focal length of the photographing lens assembly is f, a focal length of the fifth lens element is f5, and the following relationship is satisfied:

−

0.7<

f/f5<

0.2.