LED tube lamp having mode switching circuit and auxiliary power module

• US 9,820,341 B2
• Filed: 06/23/2016
• Issued: 11/14/2017
• Est. Priority Date: 03/10/2015
• Status: Active Grant

• Current Assignee: Jiaxing Super Lighting Electric Appliance Co., Ltd.
• Original Assignee: Jiaxing Super Lighting Electric Appliance Co., Ltd.
• Inventors: Xiong, Aiming, Liu, Xintong
• Primary Examiner(s): Richardson, Jany
• Application Number:
  US15/190,626
• Publication Number:
  US 20160309550A1
• Time in Patent Office: 509 Days
• Field of Search: None
• CPC Class Codes: F21K 9/278 Arrangement or mounting of circuit elements integrated in the light source
• CPC Class Codes: F21V 15/015 Devices for covering joints between adjacent lighting devices; End coverings
• CPC Class Codes: F21V 23/006 the substrate being distinct from the light source holder
• 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: H05B 45/305 Frequency-control circuits
• CPC Class Codes: H05B 45/345 Current stabilisation; Maintaining constant current
• CPC Class Codes: H05B 45/375 using buck topology
• CPC Class Codes: H05B 45/38 using boost topology
• CPC Class Codes: H05B 45/50 responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits
• CPC Class Codes: H05B 45/59 for reducing or suppressing flicker or glow effects
• 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 tube lamp includes a lamp tube receiving an external driving signal; a rectifying circuit rectifying the external driving signal to produce a rectified signal; a filtering circuit filtering the rectified signal to produce a filtered signal; an LED lighting module comprising a driving circuit and an LED module, the driving circuit, in a first driving mode, receiving the filtered signal to produce a first driving signal for driving the LED module to emit light; and a mode switching circuit receiving the filtered signal as a second driving signal in a second driving mode for driving the LED module to emit light. Wherein, the first driving mode and the second driving mode are determined based on the external driving signal.

Claims

1. A light-emitting diode (LED) tube lamp, comprising:

a lamp tube, configured to receive an external driving signal;

a rectifying circuit, configured to rectify the external driving signal to produce a rectified signal;

a filtering circuit, configured to filter the rectified signal to produce a filtered signal;

an LED lighting module, comprising a driving circuit and an LED module, the driving circuit configured to receive the filtered signal in a first driving mode to produce a first driving signal for driving the LED module to emit light;

a mode switching circuit, configured to receive the filtered signal as a second driving signal in a second driving mode for driving the LED module to emit light, wherein the first driving mode and the second driving mode are determined according to the external driving signal; and

an auxiliary power module coupled to the filtering circuit, and configured such that when the first driving signal or the second driving signal is unable to drive the LED module to emit light, the auxiliary power module provides auxiliary power for the LED module to emit light.

2. The LED tube lamp according to claim 1, wherein the LED tube lamp is configured to enter the first driving mode when a frequency of the external driving signal is lower than a threshold amount, and the LED tube lamp is configured to enter the second driving mode when the frequency of the external driving signal is higher than the threshold amount.

3. The LED tube lamp according to claim 2, wherein the threshold amount is a predefined mode switching frequency of 60 Hz or higher.

4. The LED tube lamp according to claim 2, wherein the threshold amount is a predefined mode switching frequency of 10 kHz or lower.

5. The LED tube lamp according to claim 1, wherein the external driving signal includes a voltage difference between a first voltage level and a second voltage level.

6. The LED tube lamp according to claim 1, wherein the mode switching circuit includes a mode switch including a single pole double throw switch and/or an electronic switch.

7. The LED tube lamp according to claim 1, wherein the mode switching circuit includes two mode switches, each of which includes a single pole double throw switch and/or an electronic switch.

8. The LED tube lamp according to claim 1, wherein the mode switching circuit is on a printed circuit board and is electrically connected to the LED module on a bendable circuit sheet in the LED tube lamp, wherein the bendable circuit sheet is disposed below the printed circuit board to be electrically connected to the printed circuit board by soldering.

9. The LED tube lamp according to claim 8, wherein:

the bendable circuit sheet includes a first surface and a second surface;

a plurality of first soldering pads are formed on the first surface of the bendable circuit sheet;

the printed circuit board includes a top surface and a bottom surface;

a plurality of second soldering pads are formed on the top surface of the printed circuit board;

a plurality of third soldering pads respectively corresponding to the plurality of second soldering pads are formed on the bottom surface of the printed circuit board; and

the plurality of first soldering pads on the first surface of the bendable circuit sheet are electrically connected to the plurality of third soldering pads on the bottom surface of the printed circuit board by soldering.

10. The LED tube lamp according to claim 9, wherein the printed circuit board further includes a plurality of through holes correspondingly passing through the plurality of second and third soldering pads on the top surface and the bottom surface of the printed circuit board, wherein at least one of the plurality of through holes is filled with a soldering material to electrically connect to the bendable circuit sheet with the second and third soldering pads during a soldering process.

11. The LED tube lamp according to claim 10, wherein the bendable circuit sheet further includes at least one notch disposed on an edge of an end of the bendable circuit sheet, the at least one notch aligned with the at least one of the plurality of through holes and soldered to the printed circuit board.

12. The LED tube lamp according to claim 1, wherein the auxiliary power module includes an auxiliary power positive terminal, an auxiliary power negative terminal, an energy storage unit, and a voltage detection circuit;

the auxiliary power positive and negative terminals are coupled to the LED module; and

the voltage detection circuit is configured to detect a level of signal at the auxiliary power positive and negative terminals in order to determine whether to release energy or power of the energy storage unit to the LED module through the auxiliary power positive and negative terminals.

13. A mode switching circuit configured to change a signal path in a light-emitting diode (LED) tube lamp, the mode switching circuit comprising:

at least one switch, configured to receive a filtered signal as a driving signal to drive an LED module in the LED tube lamp to emit light, and when a frequency of an external driving signal received by the LED tube lamp is higher than a predefined mode switching frequency, output the driving signal to the LED module, wherein

the LED tube lamp comprises an auxiliary power module coupled to the mode switching circuit and the LED module, and the auxiliary power module is configured such that when the driving signal is unable to drive the LED module to emit light, the auxiliary power module provides auxiliary power for the LED module to emit light.

14. The mode switching circuit according to claim 13, wherein the predefined mode switching frequency is 10 kHz or lower.

15. The mode switching circuit according to claim 13, wherein the predefined mode switching frequency is 60 Hz or higher.

16. The mode switching circuit according to claim 13, wherein the at least one switch is further configured to cause a driving circuit in the LED tube lamp to receive the filtered signal and to produce another driving signal to drive the LED module to emit light when the frequency of the external driving signal received by the LED tube lamp is lower than the predefined mode switching frequency.

17. The mode switching circuit according to claim 16, wherein the predefined mode switching frequency is higher than 60 Hz.

18. The mode switching circuit according to claim 16, wherein the predefined mode switching frequency is 10 KHz or lower.

19. The mode switching circuit according to claim 13, wherein the external driving signal includes a voltage difference between a first voltage level and a second voltage level.

20. The mode switching circuit according to claim 13, wherein the signal path includes a first path extending from the external driving signal received by the LED tube lamp and including a rectifying circuit, a filtering circuit, the mode switching circuit, and the LED module.

21. The mode switching circuit according to claim 20, wherein the signal path includes a second path extending from the external driving signal received by the LED tube lamp and including the rectifying circuit, the filtering circuit, the LED module, and a driving circuit configured to drive the LED module.

22. The mode switching circuit according to claim 13, wherein the at least one switch includes a mode switch including a single pole double throw switch and/or an electronic switch.

23. The mode switching circuit according to claim 13, wherein the at least one switch includes two mode switches, each of which includes a single pole double throw switch and/or an electronic switch.

24. The mode switching circuit according to claim 13, wherein the mode switching circuit is on a printed circuit board and is electrically connected to the LED module on a bendable circuit sheet in the LED tube lamp, wherein the bendable circuit sheet is disposed below the printed circuit board to be electrically connected to the printed circuit board by soldering.

25. The mode switching circuit according to claim 24, wherein:

the bendable circuit sheet includes a first surface and a second surface;

a plurality of first soldering pads are formed on the first surface of the bendable circuit sheet;

the printed circuit board includes a top surface and a bottom surface;

a plurality of second soldering pads are formed on the top surface of the printed circuit board;

a plurality of third soldering pads respectively corresponding to the plurality of second soldering pads are formed on the bottom surface of the printed circuit board; and

the plurality of first soldering pads on the first surface of the bendable circuit sheet are electrically connected to the plurality of third soldering pads on the bottom surface of the printed circuit board by soldering.

26. The mode switching circuit according to claim 25, wherein the printed circuit board further includes a plurality of through holes correspondingly passing through the plurality of second and third soldering pads on the top surface and the bottom surface of the printed circuit board, wherein at least one of the plurality of through holes is filled with a soldering material to electrically connect to the bendable circuit sheet during a soldering process.

27. The mode switching circuit according to claim 26, wherein the bendable circuit sheet further includes at least one notch disposed on an edge of an end of the bendable circuit sheet, the at least one notch aligned with the at least one of the plurality of through holes and soldered to the printed circuit board.

28. The LED tube lamp according to claim 13, wherein the auxiliary power module includes an auxiliary power positive terminal, an auxiliary power negative terminal, an energy storage unit, and a voltage detection circuit;

the auxiliary power positive and negative terminals are coupled to the LED module; and

the voltage detection circuit is configured to detect a level of signal at the auxiliary power positive and negative terminals in order to determine whether to release energy or power of the energy storage unit to the LED module through the auxiliary power positive and negative terminals.

29. A light-emitting diode (LED) tube lamp, comprising:

a lamp tube, configured to receive an external driving signal;

a filtering circuit, configured to filter the external driving signal to produce a filtered signal based on the external driving signal;

an LED lighting module, coupled to the filtering circuit, comprising a driving circuit and an LED module;

a mode switching circuit, coupled to at least one output terminal of the filtering circuit and at least one output terminal of the driving circuit, configured to receive the filtered signal and determine whether to perform a first driving mode or a second driving mode,

wherein the driving circuit is configured to, when the mode switching circuit is set to the first driving mode allowing the filtered signal to be input to the driving circuit, transform the filtered signal to output a first driving signal for driving the LED module to emit light, and

wherein the filtering circuit is configured to, when the mode switching circuit is set to the second driving mode allowing the filtered signal to bypass the driving circuit, output the filtered signal as a second driving signal for driving the LED module to emit light; and

an auxiliary power module coupled to the filtering circuit, and configured such that when the first driving signal or the second driving signal is unable to drive the LED module to emit light, the auxiliary power module provides auxiliary power for the LED module to emit light.

30. The LED tube lamp according to claim 29, wherein the driving circuit is configured to receive the filtered signal in the first driving mode to output the first driving signal when a frequency of the external driving signal received by the LED tube lamp is lower than a predefined mode switching frequency, and

wherein the mode switching circuit includes at least one switch configured to receive the filtered signal in the second driving mode and to output the second driving signal when a frequency of the external driving signal received by the LED tube lamp is higher than the predefined mode switching frequency.

31. The LED tube lamp according to claim 30, wherein the predefined mode switching frequency is 60 Hz or higher.

32. The LED tube lamp according to claim 30, wherein the predefined mode switching frequency is 10 kHz or lower.

33. The LED tube lamp according to claim 29, wherein the auxiliary power module includes an auxiliary power positive terminal, an auxiliary power negative terminal, an energy storage unit, and a voltage detection circuit;

the auxiliary power positive and negative terminals are coupled to the LED module; and

the voltage detection circuit is configured to detect a level of signal at the auxiliary power positive and negative terminals in order to determine whether to release energy or power of the energy storage unit to the LED module through the auxiliary power positive and negative terminals.