FIVE-PIECE OPTICAL LENS SYSTEM

• US 20140247509A1
• Filed: 03/03/2013
• Published: 09/04/2014
• Est. Priority Date: 03/03/2013
• Status: Active Grant

• Current Assignee: Newmax Technology Co., Ltd
• Original Assignee: Newmax Technology Co., Ltd
• Inventors: TSAI, Fei-Hsin
• Granted Patent: US 9,007,702 B2
• Time in Patent Office: Days
• US Class Current: 359/714
• CPC Class Codes: G02B 13/0045 having five or more lenses

Abstract

A five-piece optical lens system comprises, in order from the object side to the image side: a first lens element with a negative refractive power having a convex object-side surface; a second lens element with a negative refractive power having a concave image-side surface; a third lens element with a positive refractive power having a convex object-side surface; a stop; a fourth lens element with a positive refractive power having a convex image-side surface; a fifth lens element with a negative refractive power having a concave object-side surface, each of the second, third, fourth and fifth lens elements has at least one aspheric surface. Thereby, such a system has a wide field of view and can improve the yield rate when being applied to biomedicine, car recorder, camera or other electronic products.

Claims

1. A five-piece optical lens system comprising, in order from an object side to an image side:

a first lens element with a negative refractive power having a convex object-side surface;

a second lens element with a negative refractive power having a concave image-side surface, at least one of an object-side and the image-side surfaces of the second lens element being aspheric;

a third lens element with a positive refractive power having a convex object-side surface, at least one of the object-side and an image-side surfaces of the third lens element being aspheric;

a stop;

a fourth lens element with a positive refractive power having a convex image-side surface, at least one of an object-side and the image-side surfaces of the fourth lens element being aspheric; and

a fifth lens element with a negative refractive power having a concave object-side surface, at least one of the object-side and an image-side surfaces of the fifth lens element being aspheric.

2. The five-piece optical lens system as claimed in claim 1, wherein a focal length of the first lens element is f1, a focal length of the second lens element is f2, and they satisfy the relation:

2.5<

|f1|/|f2|<

6.

3. The five-piece optical lens system as claimed in claim 1, wherein a focal length of the second lens element is f2, a focal length of the third lens element is f3, and they satisfy the relation:

0.3<

|f2|/|f3|<

.

4. The five-piece optical lens system as claimed in claim 1, wherein a focal length of the third lens element is f3, a focal length of the fourth lens element is f4, and they satisfy the relation:

1.0<

|f3|/|f4|<

3.0.

5. The five-piece optical lens system as claimed in claim 1, wherein a focal length of the fourth lens element is f4, a focal length of the fifth lens element is f5, and they satisfy the relation:

|f4|/|f5|<

0.7.

6. The five-piece optical lens system as claimed in claim 1, wherein a focal length of the first lens element, the second lens element and the third lens element combined is f123, a focal length of the five-piece optical lens system is f, and they satisfy the relation:

0.5<

|f1|/|f23|<

2.3.

7. The five-piece optical lens system as claimed in claim 1, wherein a focal length of the first lens element is f1, a focal length of the second lens element and the third lens element combined is f23, and they satisfy the relation:

0.5<

|f1|/51 f23|<

2.3.

8. The five-piece optical lens system as claimed in claim 1, wherein a focal length of the five-piece optical lens system is f, a distance from the object-side surface of the first lens element to an image plane along an optical axis is TL, and they satisfy the relation:

|f/TL|<

0.4.

9. The five-piece optical lens system as claimed in claim 1, wherein the first, second, third, fourth and fifth lens elements are made of plastic, the image-side surface of the first lens element is concave, the object-side surface and the image-side surface of the first lens element are aspheric, the object-side surface of the second lens element is convex, the object-side surface and the image-side surface of the second lens element are aspheric, the image-side surface of the third lens element is concave, the object-side surface and the image-side surface of the third lens element are aspheric, the object-side surface of the fourth lens element is convex, the object-side surface and the image-side surface of the fourth lens element are aspheric, the image-side surface of the fifth lens element is convex, the object-side surface and the image-side surface of the fifth lens element are aspheric.

10. The five-piece optical lens system as claimed in claim 1, wherein the first lens element is made of glass, the second, third, fourth and fifth lens elements are made of plastic, the image-side surface of the first lens element is concave, the object-side surface and the image-side surface of the first lens element are aspheric, the object-side surface of the second lens element is concave, the object-side surface and the image-side surface of the second lens element are aspheric, the image-side surface of the third lens element is concave, the object-side surface and the image-side surface of the third lens element are aspheric, the object-side surface of the fourth lens element is convex, the object-side surface and the image-side surface of the fourth lens element are aspheric, the image-side surface of the fifth lens element is convex, the object-side surface and the image-side surface of the fifth lens element are aspheric.