Light tube and power supply circuit

• US 9,416,923 B1
• Filed: 09/25/2015
• Issued: 08/16/2016
• Est. Priority Date: 02/11/2000
• Status: Expired due to Term

• Current Assignee: Ilumisys Incorporated (Altair Engineering Incorporated)
• Original Assignee: Ilumisys Incorporated (Altair Engineering Incorporated)
• Inventors: Timmermans, Jos, Raymond, Jean C., Ivey, John
• Primary Examiner(s): Ton, Anabel
• Application Number:
  US14/865,325
• Time in Patent Office: 326 Days
• US Class Current: 1/1
• CPC Class Codes: B60Q 3/80 Circuits; Control arrangements for dashboards B60Q3/16; for mass transit vehicles B60Q3/47
• CPC Class Codes: F21K 9/272 Details of end parts, i.e. the parts that connect the light source to a fitting; Arrangement of components within end parts F21K9/278 takes precedence
• CPC Class Codes: F21K 9/275 Details of bases or housings, i.e. the parts between the light-generating element and the end caps; Arrangement of components within bases or housings F21K9/278 takes precedence
• CPC Class Codes: F21K 9/278 Arrangement or mounting of circuit elements integrated in the light source
• 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: F21K 9/66 Details of globes or covers forming part of the light source
• CPC Class Codes: F21K 9/90 Methods of manufacture
• CPC Class Codes: F21S 4/28 rigid, e.g. LED bars
• CPC Class Codes: F21V 15/015 Devices for covering joints between adjacent lighting devices; End coverings
• CPC Class Codes: F21V 19/003 Fastening of light source holders, e.g. of circuit boards or substrates holding light sources
• CPC Class Codes: F21V 19/008 of straight tubular light sources, e.g. straight fluorescent tubes, soffit lamps
• CPC Class Codes: F21V 23/00 Arrangement of electric circuit elements in or on lighting devices characterised by cooling arrangements F21V29/508
• CPC Class Codes: F21V 23/009 the casing being inside the housing of the lighting device
• CPC Class Codes: F21V 23/02 the elements being transformers, impedances or power supply units, e.g. a transformer with a rectifier
• CPC Class Codes: F21V 23/023 Power supplies in a casing F21V23/003 takes precedence
• CPC Class Codes: F21V 23/06 the elements being coupling devices , e.g. connectors
• CPC Class Codes: F21V 3/02 characterised by the shape
• CPC Class Codes: F21Y 2103/10 comprising a linear array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 25/13 the devices being of a type provided for in group H01L33/00
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 : Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H05B 45/10 : Controlling the intensity of the light
• CPC Class Codes: H05B 45/14 : using electrical feedback from LEDs or from LED modules
• CPC Class Codes: H05B 45/325 : Pulse-width modulation [PWM]
• CPC Class Codes: H05B 45/3578 : Emulating the electrical or functional characteristics of discharge lamps
• CPC Class Codes: H05B 45/3725 : Switched mode power supply [SMPS]
• CPC Class Codes: H05B 47/10 : Controlling the light source
• CPC Class Codes: Y02B 20/30 : Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

A replacement light tube for replacing a fluorescent light tube includes a bulb portion extending between a first end and a second end, the bulb portion comprising a support structure, a plurality of white light emitting diodes (LEDs) and an elongate light-transmissive cover. The support structure has a first surface extending between the first end and the second end. The plurality of LEDs are supported by the first surface and arranged between the first end and the second end. The elongate light-transmissive cover extends between the first end and the second end and over the first surface of the support structure. A first end cap and a second end cap are disposed on the first end and the second end, respectively, each configured to fit with a socket for a fluorescent light tube. A power supply circuit is configured to provide power to the plurality of LEDs. The plurality of LEDs are arranged to emit light through the elongate light-transmissive cover and at least a portion of the power supply circuit is packaged inside at least one of the end caps.

Claims

1. A replacement light tube for replacing a fluorescent light tube, comprising:

a bulb portion extending between a first end and a second end, the bulb portion comprising a support structure, a plurality of white light emitting diodes (LEDs) and an elongate light-transmissive cover, wherein;

the support structure has a first surface extending between the first end and the second end;

the plurality of LEDs are supported by the first surface and arranged between the first end and the second end; and

the elongate light-transmissive cover extends between the first end and the second end and over the first surface of the support structure;

a first end cap and a second end cap disposed on the first end and the second end, respectively, each configured to fit with a socket for a fluorescent light tube; and

a power supply circuit configured to provide power to the plurality of LEDs,

wherein the plurality of LEDs are arranged to emit light through the elongate light-transmissive cover and at least a portion of the power supply circuit is packaged inside at least one of the end caps.

2. The replacement light tube of claim 1, wherein the power supply circuit comprises a rectifier configured to receive alternating current (AC) input to provide direct current (DC) output.

3. The replacement light tube of claim 2, wherein the power supply circuit is configured to receive AC power from a ballast and converts the AC power to DC power.

4. The replacement light tube of claim 3, wherein the ballast is a conventional magnetic or electronic fluorescent ballast.

5. The replacement light tube of claim 3, wherein the rectifier is packaged inside one of the end caps.

6. The replacement light tube of claim 1, wherein the power supply circuit comprises an inductor.

7. The replacement light tube of claim 6, wherein the power supply circuit comprises a current-limiting circuit comprising the inductor.

8. The replacement light tube of claim 1, wherein the power supply circuit comprises a resistor.

9. The replacement light tube of claim 8, wherein the power supply circuit comprises a current-limiting circuit comprising the resistor.

10. The replacement light tube of claim 8, wherein the power supply circuit comprises a pulse width modulator and a current limiter, the current limiter receiving power from the pulse width modulator and transmitting power to at least some of the plurality of LEDs.

11. The replacement light tube of claim 1, wherein the support structure defines a channel, the first surface forming the base of the channel.

12. The replacement light tube of claim 1, wherein the support structure includes spaced-apart sidewalls on either side of the plurality of white light emitting diodes.

13. The replacement light tube of claim 12, wherein at least a portion of the sidewalls is in contact with an interior surface of the elongate light-transmissive cover.

14. The replacement light tube of claim 12, wherein the sidewalls each have a substantially uniform cross-section along a length of the elongate tubular housing.

15. The replacement light tube of claim 12, wherein the support structure has a substantially uniform cross-section along a length of the elongate tubular housing.

16. The replacement light tube of claim 12, wherein the support structure is a printed circuit board.

17. The replacement light tube of claim 1, wherein the LEDs are arranged to emit light through only one side of the bulb portion.

18. The replacement light tube of claim 1, wherein the first end cap and the second end cap comprise a respective pair of electrical bi-pin connectors.

19. The replacement light tube of claim 1, wherein LEDs are white LEDs.

20. A replacement light tube for replacing a fluorescent light tube, comprising:

a bulb portion extending between a first end and a second end, the bulb portion comprising a support structure, a plurality of white light emitting diodes (LEDs) and an elongate light-transmissive cover, wherein;

the support structure has a first surface extending between the first end and the second end;

the plurality of LEDs are supported by the first surface and arranged between the first end and the second end, the LEDs being disposed along a base of a channel defined by the support structure; and

the elongate light-transmissive cover extends between the first end and the second end and over the first surface of the support structure;

a first end cap and a second end cap disposed on the first end and the second end, respectively, each configured to fit with a socket for a fluorescent light tube; and

a power supply circuit configured to provide power to the plurality of LEDs, the power supply circuit comprising a rectifier configured to receive alternating current (AC) input from a ballast and to provide direct current (DC) output,

wherein the plurality of LEDs are arranged to emit light through the elongate light-transmissive cover and at least a portion of the power supply circuit is packaged inside at least one of the end caps.