Light tube and power supply circuit

• US 9,006,993 B1
• Filed: 06/09/2014
• Issued: 04/14/2015
• Est. Priority Date: 02/11/2000
• Status: Expired due to Fees

• 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): A, Minh D
• Application Number:
  US14/299,915
• Time in Patent Office: 309 Days
• Field of Search: 315/224, 315/246, 315/291, 315/185.R
• US Class Current: 315/291
• 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 having a first end and a second end, a first end cap and a second end cap disposed at the first end and the second end, respectively, each configured to fit with a socket for the fluorescent light tube, a plurality of light emitting diodes disposed inside and extending between the first and second ends of the bulb portion, wherein the plurality of light emitting diodes is arranged to provide light through at least a portion of the bulb portion and power supply circuitry configured to receive power from a power source and configured to regulate the intensity of light emitted from the plurality of light emitting diodes by pulse-width modulating the received power.

Claims

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

a bulb portion having a first end and a second end;

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

a plurality of light emitting diodes disposed inside and extending between the first and second ends of the bulb portion, wherein the plurality of light emitting diodes is arranged to provide light through at least a portion of the bulb portion; and

power supply circuitry configured to receive power from a power source and configured to regulate the intensity of light emitted from the plurality of light emitting diodes by pulse-width modulating the received power.

2. The replacement light tube of claim 1, wherein the power supply circuitry is configured to regulate the intensity of light emitted from the plurality of light emitting diodes to compensate for voltage fluctuations from the power source.

3. The replacement light tube of claim 1, wherein the power supply circuitry is configured to regulate the intensity of light emitted from the plurality of light emitting diodes to compensate for ambient temperature changes.

4. The replacement light tube of claim 1, wherein at least a portion of the power supply circuitry is packaged inside the bulb portion.

5. The replacement light tube of claim 1, wherein the power supply circuitry includes a pulse width modulator configured to receive the power from the power source and configured to regulate the intensity of light emitted from the plurality of light emitting diodes by pulse-width modulating the received power and a current limiter having an inductive element electrically coupled between the pulse width modulator and at least some of the plurality of light emitting diodes, the current limiter configured to receive power from the pulse width modulator and to transmit power to the at least some of the plurality of light emitting diodes.

6. The replacement light tube of claim 5, wherein the current limiter and the pulse width modulator are packaged outside of the bulb portion.

7. The replacement light tube of claim 1, wherein the power supply circuitry is configured to switch power to the plurality of light emitting diodes on and off at a frequency and to cause the light emitted from the plurality of light emitting diodes to appear, when viewed by a human eye, to shine continuously.

8. The replacement light tube of claim 1, further comprising:

a rigid support structure having a planar portion having a first surface extending within the bulb portion between the first end and the second end and having spaced-apart sidewalls extending away from the first surface and extending within the bulb portion between the first end and the second end, at least a portion of the sidewalls in contact with an interior surface of the bulb portion.

9. The replacement light tube of claim 8, wherein the plurality of light emitting diodes are supported by a second surface of the planar portion opposite to the first surface and between the first end and the second end.

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

a housing having a first end and a second end;

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

a plurality of light emitting diodes disposed inside and extending between the first and second ends of the housing, wherein the plurality of light emitting diodes is arranged to provide light through at least a portion of the housing; and

a pulse width modulator configured to receive power from a power source and configured to regulate the intensity of light emitted from the plurality of light emitting diodes by cyclically switching the received power on and off according to a varying duty cycle.

11. The replacement light tube of claim 10, wherein the pulse width modulator is configured to regulate the intensity of light emitted from the plurality of light emitting diodes to compensate for voltage fluctuations from the power source.

12. The replacement light tube of claim 10, wherein the pulse width modulator is configured to regulate the intensity of light emitted from the plurality of light emitting diodes to compensate for ambient temperature changes.

13. The replacement light tube of claim 10, further comprising:

a current limiter having an inductive element electrically coupled between the pulse width modulator and at least some of the plurality of light emitting diodes, the current limiter configured to receive power from the pulse width modulator and to transmit power to the at least some of the plurality of light emitting diodes.

14. The replacement light tube of claim 13, wherein the current limiter and the pulse width modulator are packaged outside of the housing.

15. The replacement light tube of claim 10, further comprising:

a rigid support structure having a planar portion having a first surface extending within the housing between the first end and the second end and having spaced-apart sidewalls extending away from the first surface and extending within the housing between the first end and the second end, at least a portion of the sidewalls in contact with an interior surface of the housing.

16. The replacement light tube of claim 15, wherein the plurality of light emitting diodes are supported by a second surface of the planar portion opposite to the first surface and between the first end and the second end.

17. A method for operating a replacement light tube for replacing a fluorescent light tube, the replacement light tube including:

a bulb portion having a first end and a second end;

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

a plurality of light emitting diodes disposed inside and extending between the first and second ends of the bulb portion; and

power supply circuitry having a pulse-width modulator, the method comprising;

receiving power from a power source; and

regulating the intensity of light emitted from the plurality of light emitting diodes, wherein regulating the intensity comprises;

cyclically switching, using the pulse-width modulator, the received power on and off according to a varying duty cycle.

18. The method for operating the replacement light tube of claim 17, wherein regulating the intensity comprises:

regulating the intensity of light emitted from the plurality of light emitting diodes by cyclically switching, using the pulse-width modulator, the received power on and off according to a varying duty cycle to compensate for voltage fluctuations from the power source.

19. The method for operating the replacement light tube of claim 17, wherein regulating the intensity comprises:

regulating the intensity of light emitted from the plurality of light emitting diodes by cyclically switching, using the pulse-width modulator, the received power on and off according to a varying duty cycle to compensate for ambient temperature changes.

20. The method for operating the replacement light tube of claim 17, wherein regulating the intensity comprises:

regulating the intensity of light emitted from the plurality of light emitting diodes by cyclically switching, using the pulse-width modulator, the received power on and off according to a varying duty cycle, to compensate for at least one white light intensity-effecting factor.

21. The method for operating the replacement light tube of claim 17, wherein the power supply circuitry includes a pulse width modulator and a current limiter having an inductive element electrically coupled between the pulse width modulator and at least some of the plurality of light emitting diodes, the method further comprising:

limiting current to the plurality of light emitting diodes using the inductive element.

22. The method for operating the replacement light tube of claim 17, further comprising:

switching power to the plurality of light emitting diodes on and off at a frequency; and

causing the light emitted from the plurality of light emitting diodes to appear, when viewed by a human eye, to shine continuously.

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

a housing having a first end and a second end;

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

a plurality of light emitting diodes disposed inside and extending between the first and second ends of the housing, wherein the plurality of light emitting diodes is arranged to provide light through at least a portion of the housing; and

a pulse width modulator configured to regulate the intensity of light emitted from the plurality of light emitting diodes by cyclically switching the received power on and off according to a varying duty cycle and configured to compensate for at least one white light intensity-effecting factor by using the cyclically-switched power.

24. The replacement light tube of claim 23, wherein the at least one light intensity-effecting factor is voltage fluctuations from the power source.

25. The replacement light tube of claim 23, wherein the at least one light intensity-effecting factor is ambient temperature changes.

26. The replacement light tube of claim 23, further comprising:

a current limiter having an inductive element electrically coupled between the pulse width modulator and at least some of the plurality of light emitting diodes, the current limiter configured to receive power from the pulse width modulator and to transmit power to the at least some of the plurality of light emitting diodes.

27. The replacement light tube of claim 26, wherein the current limiter and the pulse width modulator are packaged outside of the housing.

28. The replacement light tube of claim 23, further comprising:

a rigid support structure having a planar portion having a first surface extending within the housing between the first end and the second end and having spaced-apart sidewalls extending away from the first surface and extending within the housing between the first end and the second end, at least a portion of the sidewalls in contact with an interior surface of the housing.

29. The replacement light tube of claim 28, wherein the plurality of light emitting diodes are supported by a second surface of the planar portion opposite to the first surface and between the first end and the second end.

30. The replacement light tube of claim 28, wherein the planar portion is integral with the sidewalls.