Retrofit light emitting diode tube

• US 7,053,557 B2
• Filed: 09/25/2003
• Issued: 05/30/2006
• Est. Priority Date: 11/30/2001
• Status: Expired due to Term

• Current Assignee: Mule Lighting, Inc.
• Original Assignee: Mule Lighting, Inc.
• Inventors: Cross, Robert Hartwell, Cross, Jeffrey Parker, Cross, Robert Porter
• Primary Examiner(s): Lee, Wilson
• Assistant Examiner(s): VU, JIMMY T
• Application Number:
  US10/671,167
• Publication Number:
  US 20040062041A1
• Time in Patent Office: 978 Days
• Field of Search: 315/73, 315/74, 315/246, 315/291, 315/307, 315/185.R, 313/21, 313/39, 313/249, 313/558
• US Class Current: 315/74
• 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: F21Y 2103/10 comprising a linear array of point-like light-generating elements
• CPC Class Codes: F21Y 2107/60 on stacked substrates
• CPC Class Codes: F21Y 2107/90 on two opposite sides of supports or substrates
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H05B 45/305 Frequency-control circuits
• CPC Class Codes: H05B 45/3578 Emulating the electrical or functional characteristics of discharge lamps
• CPC Class Codes: H05B 45/382 with galvanic isolation between input and output
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

An LED light tube for replacement for fluorescent light tubes includes an elongated cylindrical transparent envelope, a base cap at each end of the envelope, and at least one LED device in electrical communication with the base cap. The LED light tube is adapted for use in troffer light fixtures.

Claims

1. An LED light tube for replacement of a fluorescent light tube, the LED light tube comprising:

an elongated, cylindrical transparent envelope;

a base cap at each end of the envelope, wherein the base cap comprises a first prong and a second prong extending from the base cap;

at least one serial string of LEDs in electrical communication with the base cap having circuitry means for connection with an AC source through a nondissipative voltage dropping element, wherein each one of the at least one serial string of LEDs are connected in parallel with the other and are enclosed in the envelope; and

a varistor positioned in parallel with the at least one serial string of LEDs.

2. The LED light tube of claim 1, wherein the at least one serial string of LEDs comprises a plurality of organic light emitting diodes.

3. The LED light tube of claim 1, wherein the at least one serial string of LEDs comprises spacedly stacked circuit boards, wherein each one of the circuit boards include a plurality of serially connected LEDs mounted thereon.

4. A troffer LED light tube fixture comprising:

a housing comprising a tube holder, wherein the tube holder comprises electrical sockets adapted to receive and electrically communicate an LED light tube;

an LED light tube disposed in the tube holder, wherein the LED light tube comprises an elongated, cylindrical transparent envelope, a base cap at each end of the envelope, wherein the base cap comprises a first prong and a second prong extending from the base cap, and at least one serial string of LEDs in electrical communication with the base cap having circuitry means for connection with an AC source through a nondissipative voltage dropping element, wherein each one of the at least one serial string of LEDs are connected in parallel with the other and are enclosed in the envelope; and

a varistor positioned in parallel with the at least one serial string of LEDs.

5. The troffer light fixture according to claim 4, wherein the housing further comprises a reflective material disposed on a surface of the housing for maximizing the light output.

6. The troffer light fixture according to claim 4, wherein the at least one serial string of LEDs comprises a plurality of organic light emitting diodes.

7. The troffer light fixture of claim 4, further comprising a ballast transformer and means for bypassing the ballast transformer.

8. The troffer light fixture of claim 4, wherein the means for bypassing the ballast transformer comprises a voltage reduction circuit and frequency reduction circuit.