Light emitting diode and lens for the same

• US 9,200,778 B2
• Filed: 10/21/2013
• Issued: 12/01/2015
• Est. Priority Date: 10/18/2004
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Yoon, Ju-Young, Lee, Jong-Seo, Song, Chun-Ho, Park, Se-Ki, Lee, Sang-Gil, Kang, Seock-Hwan, Kim, Gi-Cherl
• Primary Examiner(s): BANNAN, JULIE A
• Application Number:
  US14/058,898
• Publication Number:
  US 20140043831A1
• Time in Patent Office: 771 Days
• US Class Current: 1/1
• CPC Class Codes: F21V 5/008 Combination of two or more successive refractors along an optical axis
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 19/0014 at least one surface having optical power
• CPC Class Codes: G02B 19/0061 the light source comprising a LED semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission H01L33/00
• CPC Class Codes: G02B 3/04 with continuous faces that are rotationally symmetrical but deviate from a true sphere , e.g. so called "aspheric" lenses
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

A lens has a refractive index of n, and includes a base, a first curved circumferential surface extending from the base, a curved center-edge surface extending from the first curved circumferential surface, and a curved centermost surface extending from the curved center-edge surface. The base includes a groove for receiving a light emitting chip. A distance from a center of the base to a point of the curved center-edge surface is shorter than the radius of curvature for the point of the curved center-edge surface. The curved centermost surface has a concave shape with respect to the base. The lens satisfies A1+A2<90+sin⁻¹(1/n), where A1 an obtuse angle between a main axis and a tangent line of the curved centermost surface, and A2 is an acute angle between a straight line linking the center of the base to the point of the curved centermost surface and the main axis.

Claims

1. A lens for a light emitting diode formed from a material having a refractive index of n, the lens comprising

a base;

a first curved circumferential surface extending from the base;

a curved center-edge surface extending from the first curved circumferential surface,

a curved centermost surface extending from the curved center-edge surface, and

an uneven pattern disposed at the curved centermost surface,

wherein a distance from a center of the base to a point of the curved center-edge surface is shorter than a radius of curvature for the point of the curved center-edge surface,

wherein the curved centermost surface has a concave shape when viewed from the center of the base,

wherein the uneven pattern is a minute pattern and is disposed at the entire curved centermost surface, and the uneven pattern is further disposed at the entire curved center-edge surface and the partial curved circumferential surface.

2. The lens of claim 1, wherein A1+A2<

90+sin<sup>−

1</sup>(1/n), wherein A1 is an obtuse angle formed between a main axis of the lens and a tangent line of a point on the curved centermost surface, and A2 is an acute angle formed between a straight line linking the center of the base to the point on the curved centermost surface and the main axis of the lens.

3. The lens of claim 2, wherein a main axis of the lens is intersected with a tangent line of a boundary point of the curved center-edge surface and the curved centermost surface at an angle of 90 degrees.

4. The lens of claim 3, wherein a boundary region of the curved center-edge surface and the first curved circumferential surface is positioned within about 20 degrees to about 50 degrees with respect to a center axis of the base.

5. The lens of claim 4, wherein the curved centermost surface forms a cone-shaped groove.

6. A lens for a light emitting diode formed from a material having a refractive index of n, the lens comprising

a base;

a first curved circumferential surface extending from the base;

a curved center-edge surface extending from the first curved circumferential surface,

a curved centermost surface extending from the curved center-edge surface;

an uneven pattern disposed at the curved centermost surface; and

a hollow portion formed from the base of the lens,

wherein a distance from a center of the base to a point of the curved center-edge surface is shorter than a radius of curvature for the point of the curved center-edge surface, and

wherein the curved centermost surface has a concave shape when viewed from the center of the base,

wherein the hollow portion forms an inner surface of the lens and is comprised of a second curved circumferential surface and a curved central surface extending from the second curved circumferential surface, and

wherein a distance from the center of the base to a point of the curved central surface is longer than a radius of curvature for the point of the curved central surface.

7. The lens of claim 6, wherein the uneven pattern is a minute pattern and is disposed at the boundary of the curved centermost surface and the curved center-edge surface.

8. The lens of claim 7, wherein the uneven pattern is further disposed at the boundary of the curved center-edge surface and the first curved circumferential surface.

9. The lens of claim 8, wherein A1+A2<

90+sin<sup>−

1</sup>(1/n), wherein A1 is an obtuse angle formed between a main axis of the lens and a tangent line of a point on the curved centermost surface, and A2 is an acute angle formed between a straight line linking the center of the base to the point on the curved centermost surface and the main axis of the lens.

10. The lens of claim 9, wherein a main axis of the lens is intersected with a tangent line of a boundary point of the curved center-edge surface and the curved centermost surface at an angle of 90 degrees.

11. The lens of claim 10, wherein a boundary region of the curved center-edge surface and the first curved circumferential surface is positioned within about 20 degrees to about 50 degrees with respect to a center axis of the base.

12. The lens of claim 11, wherein the curved centermost surface forms a cone-shaped groove.