Fluorescent tube replacement having longitudinally oriented LEDs

• US 7,946,729 B2
• Filed: 07/31/2008
• Issued: 05/24/2011
• Est. Priority Date: 07/31/2008
• Status: Active Grant

• Current Assignee: Ilumisys Incorporated (Altair Engineering Incorporated)
• Original Assignee: Altair Engineering Incorporated
• Inventors: Simon, David L, Ivey, John
• Primary Examiner(s): O Shea; Sandra L
• Assistant Examiner(s): Dunwiddie; Meghan K
• Application Number:
  US12/183,363
• Publication Number:
  US 20100027259A1
• Time in Patent Office: 1,027 Days
• Field of Search: 362/227, 362/235, 362/254, 362/260, 362/296.01, 362/317, 362/326, 362/341
• US Class Current: 362/254
• CPC Class Codes: F21K 9/27 Retrofit light sources for lighting devices with two fittings for each light source, e.g. for substitution of fluorescent tubes
• CPC Class Codes: F21K 9/60 Optical arrangements integrated in the light source, e.g. for improving the colour rendering index or the light extraction
• CPC Class Codes: F21V 7/043 with cylindrical surface
• CPC Class Codes: F21V 7/24 characterised by the material
• CPC Class Codes: F21V 7/28 characterised by coatings
• CPC Class Codes: F21Y 2103/10 comprising a linear array of point-like light-generating elements
• CPC Class Codes: F21Y 2103/33 annular
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

An LED-based light for replacing a conventional fluorescent tube in a fixture is provided. The LED-based light includes an elongate light transmitting rod defining a bore and at least one LED positioned at one or both ends of the rod and oriented to produce light longitudinally into a portion of the rod radially outward of the bore. At least one connector is physically coupled to an end of the rod and electrically coupled to the at least one LED. The at least one connector is adapted for physical and electrical connection to the fixture. In operation, the directional light produced by the at least one LED is dispersed by way of reflection, refraction, and/or diffusion while traveling longitudinally through the rod to reduce the appearance of bright spots.

Claims

1. An LED-based light for replacing a conventional fluorescent tube in a fixture, the LED-based light comprising:

an elongate light transmitting rod having a first end and an opposing, second end and defining a bore extending at least partially between the first end and the second end, the bore having an outer surface spaced apart from an outer surface of the rod such that a material of the rod fills a portion of the rod between the outer surface of the bore and the outer surface of the rod;

at least one LED positioned at one or both of the first and second ends of the rod and oriented to produce light longitudinally into the portion of the rod radially outward of the outer surface of the bore; and

a connector physically coupled to the first end or the second end of the rod, the connector adapted for physical connection to the fixture.

2. The LED-based light of claim 1, wherein the rod includes an uneven light refracting texture.

3. The LED-based light of claim 2, wherein the texture varies over a length of the bore.

4. The LED-based light of claim 2, wherein the texture is less dense adjacent the at least one LED and more dense further away from the at least one LED.

5. The LED-based light of claim 2, wherein the light refracting texture is shaped in the form of one of an alphanumeric character and a picture.

6. The LED-based light of claim 1, wherein the bore encloses a reflector.

7. The LED-based light of claim 1, wherein the bore encloses a light diffusing material.

8. The LED-based light of claim 7, wherein the light diffusing material includes silicone.

15. The LED-based light of claim 1, wherein the at least one LED is positioned at the one or both of the first and second ends of the rod radially outside an inner edge of the LED-based light defined by the outer surface of the bore and within an outer edge of the LED-based light defined by the outer surface of the rod.

9. An LED-based light for replacing a conventional fluorescent tube in a fixture, the LED-based light comprising:

an elongate light transmitting rod having a first end and an opposing, second end and defining a bore extending at least partially between the first end and the second end, the bore having an outer surface spaced apart from an outer surface of the rod such that a material of the rod fills a portion of the rod between the outer surface of the bore and the outer surface of the rod;

multiple LEDs positioned at one or both of the first and second ends of the rod and oriented to produce light longitudinally into the portion of the rod radially outward of the outer surface of the bore; and

a pair of bi-pin end caps coupled to the opposing ends of the rod, at least one of the bi-pin end caps in electrical communication with the multiple LEDs.

10. The LED-based light of claim 9, wherein the rod includes an uneven light refracting texture.

11. The LED-based light of claim 10, wherein the texture varies over a length of the bore.

12. The LED-based light of claim 10, wherein the texture is less dense adjacent the LEDs and more dense further away from the LEDs.

13. The LED-based light of claim 10, wherein the light refracting texture is shaped in the form of one of an alphanumeric character and a picture.

14. The LED-based light of claim 9, wherein the bore encloses one of a reflector and a light diffusing material.

16. The LED-based light of claim 9, wherein the multiple LEDs are positioned between an outer edge of the LED-based light defined by the outer surface of the rod and an inner edge of the LED-based light defined by the outer surface of the bore and between a respective one of the pair of bi-pin end caps coupled to the opposing ends of the rod and one of the first and second ends of the rod.

17. A method of forming an LED-based light for replacing a conventional fluorescent tube in a fixture, the method comprising:

providing an elongate light transmitting rod defining a bore, the bore having an outer surface spaced apart from an outer surface of the rod such that a material of the rod fills a portion of the rod between the outer surface of the bore and the outer surface of the rod;

positioning at least one LED to produce light longitudinally into the portion of the rod radially outward of the outer surface of the bore; and

attaching a pair of bi-pin end caps to opposing ends of the rod, with each of the pair of end caps in physical communication with an opposing mount of the fixture.

18. The method of claim 17, further comprising forming an uneven light reflecting texture on the rod.

19. The method of claim 17, further comprising placing a reflector in the bore.

20. The method of claim 17, further filling the bore with silicone.