LED UNIT

• US 20110110098A1
• Filed: 01/15/2010
• Published: 05/12/2011
• Est. Priority Date: 11/09/2009
• Status: Active Grant

• Current Assignee: Foxconn Technology Co., Ltd., Fuzhun Precision Industry Company Limited (Foxconn Technology Co., Ltd.)
• Original Assignee: Foxconn Technology Co., Ltd., Fuzhun Precision Industry Company Limited (Foxconn Technology Co., Ltd.)
• Inventors: FU, REN-TAO, CHEN, CHIN-CHUNG
• Granted Patent: US 8,231,248 B2
• Time in Patent Office: Days
• US Class Current: 362/308
• CPC Class Codes: F21K 9/69 Details of refractors forming part of the light source
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21V 7/0091 using total internal reflection
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

An LED unit includes an LED and a lens receiving the LED. The lens includes a first light-incident face confronting the LED to refract the light emitted from the LED with a small angle into the lens, a second light-incident face surrounding the LED to refract the light emitted from the LED with a large angle into the lens, a light-reflecting face to reflect the light from the second light-incident face towards a top of the LED, a first light-emergent face to refract the light from the first light-incident face out of the lens, and a second light-emergent face to refract the light from the light-reflecting face out of the lens.

Claims

1. An LED (light emitting diode) unit, comprising:

an LED; and

a lens mounted on the LED, the lens comprising a light-incident face adjacent to the LED, a light-emergent face remote from the LED, and a light-reflecting face between the light-incident face and the light-emergent face, wherein light emitted from the LED with a small angle is refracted by the light-incident face and the light-emergent face out of the LED unit, light emitted from the LED with a large angle is sequentially refracted by the light-incident face, reflected by the light-reflecting face and refracted by the light-emergent face out of the LED unit; and

wherein the light-reflecting face comprises a first light-reflecting face and a second light-reflecting face having a curvature different from that of the first light-reflecting face.

2. The LED unit as claimed in claim 1, wherein the first light-reflecting face is conical and gradually expands upwardly along a bottom-to-top direction of the lens.

3. The LED unit as claimed in claim 1, wherein the curvature of the first light-reflecting face ranges between 0.02 mm⁻

1 and 0.06 mm<sup>−

1</sup>.

4. The LED unit as claimed in claim 1, wherein the curvature of the second light-reflecting face is 0.

5. The LED unit as claimed in claim 1, wherein the first light-reflecting face and the second light-reflecting face are discontinuous from each other.

6. The LED unit as claimed in claim 5, wherein a flange is protruded outwardly between the first light-reflecting face and the second light-reflecting face, the flange being located adjacent to a top of the lens.

7. The LED unit as claimed in claim 1, wherein the light-emergent face comprises a first light-emergent face and a second light-emergent face surrounding the first light-emergent face, the second light-emergent face directly connecting the second light-reflecting face.

8. The LED unit as claimed in claim 7, wherein the first light-emergent face comprises a flat top face and a curved circumferential face surrounding the flat top face.

9. The LED unit as claimed in claim 7, wherein the second light-emergent face is concaved downwardly to have a conical shape.

10. The LED unit as claimed in claim 7, wherein the second light-emergent face has a curvature ranging between 0 and 0.12 mm⁻

1, and the first light-emergent face has a curvature ranging between 0 and 0.09 mm<sup>−

1</sup>.

11. The LED unit as claimed in claim 1, wherein the light-incident face comprises a first light-incident face facing the LED, and a second light-incident face surrounding the LED.

12. The LED unit as claimed in claim 11, wherein the first light-incident face is flat.

13. The LED unit as claimed in claim 11, wherein the second light-incident face is protruded towards the LED.

14. The LED unit as claimed in claim 13, wherein the second light-incident face has a curvature ranging between 0.05 mm⁻

1 and 0.08 mm<sup>−

1</sup>.

15. The LED unit as claimed in claim 1, wherein the lens has a window defined in a bottom thereof and a cavity defined in an interior thereof, the window communicating with the cavity, the window and the cavity together receiving the LED therein, the first and second light-incident faces being formed by the lens defining the cavity, the cavity having a shape of a truncated cone.