LED bulb

• US 7,168,839 B2
• Filed: 09/20/2004
• Issued: 01/30/2007
• Est. Priority Date: 09/20/2004
• Status: Expired due to Fees

• Current Assignee: Varroc Lighting Systems S.R.O. (Varroc Engineering Limited)
• Original Assignee: Visteon Global Technologies Incorporated (Visteon Corporation)
• Inventors: Li, John, Erion, Jeffrey Allen, Chinniah, Jeyachandrabose, Eichelberger, Christopher L.
• Primary Examiner(s): Luebke; Renee
• Assistant Examiner(s): Bennett; Zahra I.
• Application Number:
  US10/945,321
• Publication Number:
  US 20060061990A1
• Time in Patent Office: 862 Days
• Field of Search: 362/545, 362/555, 362/326, 362/307, 362/309, 362/329, 362/511
• US Class Current: 362/555
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: F21K 9/61 using light guides
• 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]

Abstract

A LED bulb and light module utilizes a LED light source and directs light therefrom in a manner which improves efficiency and illumination. Ideally, the LED bulb is structured to create a virtual image whereby the efficiency of light directed out of the module is greatly improved, even with a single LED light source.

Claims

1. A LED bulb for directing light from a LED light source, the LED bulb comprising:

a light pipe receiving light from the LED light source and guiding the light downstream along a longitudinal axis defined by the light pipe;

the light pipe defining a conical reflector redirecting the light radially outwardly; and

a plurality of ribs on the outer surface of the light pipe, the ribs redirecting the light to define a virtual image of the LED light source.

2. The LED bulb of claim 1, wherein the conical reflector includes a series of alternating first and second surfaces, the first surfaces oriented generally parallel to the longitudinal axis, the second surfaces angled relative to the longitudinal axis.

3. The LED bulb of claim 2, wherein the ribs are axially aligned with the second surfaces of the conical reflector.

4. The LED bulb of claim 2, wherein the ribs are axially spaced apart from each other a distance corresponding to the axial distance spanned by each first surface.

5. The LED bulb of claim 1, wherein the ribs are axially aligned with the conical reflector.

6. The LED bulb of claim 1, wherein the ribs are tapered.

7. The LED bulb of claim 1, wherein the ribs have a triangular shape.

8. The LED bulb of claim 1, wherein each rib has an upstream face and a downstream face, the downstream face being angled relative to the longitudinal axis.

9. The LED bulb of claim 8, wherein the downstream face is angled in the range of 30 to 89 degrees.

10. The LED bulb of claim 8, wherein the upstream face is generally perpendicular to the longitudinal axis.

11. The LED bulb of claim 1, wherein at least one rib projects radially away from the light pipe a distance shorter than the other ribs project.

12. The LED bulb of claim 11, wherein the at least one rib is one of the upstream ribs.

13. The LED bulb of claim 1, wherein the light pipe is formed to define the conical reflector.

14. The LED bulb of claim 1, wherein the light pipe is molded from a clear optical grade material to define the ribs.

15. The LED bulb of claim 1, wherein the ribs redirect the light upstream to define the virtual image.

16. A light bulb of claim 1, wherein an upstream end of the light pipe includes a recess for receiving the LED light source.

17. The light bulb of claim 16, wherein the upstream end defines a lens adjacent the recess for focusing the light longitudinally downstream.

18. The light bulb of claim 16, wherein the upstream end is structured to collimate light from the LED light source and direct the light longitudinally downstream.

19. A light module for an automobile, the light module comprising:

a reflector defining a cavity and a reflective surface receiving light from in front of the reflector and directing the light outwardly away from the vehicle;

a LED light source;

a LED bulb having an entrance end receiving light from the LED light source and an exit end for directing the light to the reflector, the exit end positioned within the cavity; and

the exit end of the LED bulb structured to define a virtual image of the LED light source that is positioned in front of the reflector.

20. The light module of claim 19, wherein the entrance end of the LED bulb is positioned behind the reflector.

21. The light module of claim 19, wherein the LED bulb includes a light pipe having a conical reflector surface and a plurality of ribs on the outer surface of the light pipe, the light pipe receiving light from the LED source and guiding the light downstream along a longitudinal axis defined by the light pipe, the conical reflector surface redirecting the light radially outwardly, and the ribs redirecting the light to define a virtual image of the LED source.

22. The light module of claim 21, wherein the conical reflector surface includes a series of alternating first and second surfaces, the first surfaces oriented generally parallel to the longitudinal axis, the second surfaces angled relative to the longitudinal axis, and wherein the ribs are axially aligned with the second surfaces of the conical reflector surface.

23. The light module of claim 21, wherein each rib has an upstream side and a downstream side, the downstream side being angled relative to the longitudinal axis.