Light emitting device

Patent metadata

Field	Value
Publication number	US-9458984-B2
Application number	US-201414161537-A
Country	US
Kind code	B2
Filing date	Jan 22, 2014
Priority date	Jul 23, 2009
Publication date	Oct 4, 2016
Grant date	Oct 4, 2016

Abstract

A light emitting device includes: a frame having an opening; at least one light emitting diode (LED) disposed on the frame; a reflector disposed on the frame; and a reflective protrusion projecting from the reflector, wherein light emitted from at least one light emitting diode is reflected by the reflector through the opening, wherein the vertical axis of the reflective protrusion is perpendicular to a plane formed by extending the upper surface of the frame, wherein the upper surface of the frame contacts the reflector, and wherein a distance between two LEDs with one LED placed therebetween is greater than a distance between one LED and the reflector. Because a light source is disposed on the frame of the light emitting device, it is possible to easily exchange the light source of the light emitting diode by removing and attaching the frame without disassembling the entire lighting device.

First claim

What is claimed is:

1. A light emitting device comprising:
a circular frame including an opening and an upper surface;
a light emitting diode (LED) on the upper surface of the circular frame;
a reflector including a hemispheric reflection surface on the circular frame; and
a conical reflective protrusion projecting from an upper end of the reflector towards the opening,
wherein light emitted from the light emitting diode and directly incident on the conical reflective protrusion is reflected by the reflector,
wherein the light reflected by the reflector passes through the opening,
wherein a vertical axis of the conical reflective protrusion is perpendicular to a plane formed by extending the upper surface of the circular frame,
wherein the upper surface of the circular frame contacts the reflector, and
wherein, y>H−R×cot(θ),
wherein “y” is a height of the conical reflective protrusion, “H” is a height of the reflector, “R” is a radius of the circular frame, and “θ” is a half of an orientation angle of the LED,
wherein “y”, “H”, and “R” are all a same unit of measure and “θ” is in degrees,
wherein “θ” is an angle relative to the vertical axis, and
wherein a vertex of the conical reflective protrusion is closer to the opening than the upper end of the reflector.

2. The light emitting device of claim 1 , wherein the conical reflective protrusion contacts an inner surface of the reflector.

3. The light emitting device of claim 1 , wherein the conical reflective protrusion is formed on an inner surface of the reflector.

4. The light emitting device of claim 1 , wherein the vertex of the conical reflective protrusion is closer to the opening than a point where a vertical axis of the conical reflective protrusion meets light from the LED emitted to the conical reflective protrusion at a minimum angle with relation to the upper surface of the circular frame.

5. The light emitting device of claim 1 , wherein at least one of the conical reflective protrusion and the reflector has a patterned surface.

6. The light emitting device of claim 5 , wherein the patterned surface comprises a bumpy pattern to scatter reflected light.

7. The light emitting device of claim 5 , wherein the patterned surface is a rough surface to scatter reflected light.

8. The light emitting device of claim 1 , further comprising a heat radiator,
wherein the heat radiator is circular in shape, and
wherein the heat radiator surrounds an outer circumference of the circular frame such that a diameter associated with the heat radiator is greater than a diameter associated with the circular frame.

9. The light emitting device of claim 8 , wherein the circular frame is integrally formed with or connected to the heat radiator.

10. The light emitting device of claim 1 , wherein the circular frame is detachably connected to the reflector.

11. A light emitting device comprising:
a circular frame with an opening therethrough comprising an upper surface;
a heat radiator on an outer portion of the circular frame;
a light emitting diode (LED) on the upper surface of the circular frame;
a reflector including a hemispheric reflection surface on the circular frame; and
a conical reflective protrusion projecting from an upper end of the reflector towards the opening,
wherein light emitted from the light emitting diode and directly incident on the conical reflective protrusion is reflected by the reflector,
wherein the light reflected by the reflector passes through the opening,
wherein a vertical axis of the conical reflective protrusion is perpendicular to a plane formed by extending the upper surface of the circular frame,
wherein the upper surface of the circular frame contacts the reflector,
wherein the circular frame includes an upper surface on which the LED is directly disposed, a lower surface, an inner lateral surface defining the opening, and an outer lateral surface,
wherein the circular frame includes a projection extended from a lower part of the outer lateral surface, and
wherein a vertex of the conical reflective protrusion is closer to the opening than the upper end of the reflector.

12. The light emitting device of claim 11 , wherein the conical reflective protrusion is on an inner surface of the reflector.

13. The light emitting device of claim 11 , wherein the conical reflective protrusion contacts an inner surface of the reflector.

14. The light emitting device of claim 11 , wherein at least one of the conical reflective protrusion and the reflector has a patterned surface to scatter light.

15. The light emitting device of claim 11 , wherein the circular frame is detachably connected to the reflector.

16. The light emitting device of claim 11 , wherein the vertex of the conical reflective protrusion is closer to the opening than a point where the vertical axis of the conical reflective protrusion meets light from the LED emitted to the conical reflective protrusion at a minimum angle with relation to the upper surface of the circular frame.

17. The light emitting device of claim 14 , wherein the patterned surface comprises a bumpy pattern.

18. The light emitting device of claim 14 , wherein the patterned surface is a rough surface.

19. The light emitting device of claim 11 ,
wherein, y>H-R×cot(θ),
wherein “y” is a height of the conical reflective protrusion, “H” is a height of the reflector, “R” is a radius of the circular frame, and the “θ” is a half of an orientation angle of the LED,
wherein “y”, “H”, and “R” are all a same unit of measure and “θ” is in degrees, and
wherein “θ” is an angle relative to the vertical axis.

Assignees

• Lg Innotek Co Ltd

Inventors

• Jang Kee Youn

Classifications

• F21Y2103/33

  annular · CPC title

• F21Y2115/10

  Light-emitting diodes [LED] · CPC title

• F21V7/0025

  Combination of two or more reflectors for a single light source (array of reflectors for a cluster of light sources F21V7/0083) · CPC title

• F21S8/026

  intended to be recessed in a ceiling or like overhead structure, e.g. suspended ceiling · CPC title

• F21V19/001

  the light sources being semiconductors devices, e.g. LEDs · CPC title