LED tube lamp

• US 10,612,731 B2
• Filed: 05/03/2019
• Issued: 04/07/2020
• Est. Priority Date: 09/28/2014
• 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): Tran, Anh Q
• Application Number:
  US16/402,576
• Publication Number:
  US 20190264879A1
• Time in Patent Office: 340 Days
• Field of Search: None
• 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: F21V 15/015 Devices for covering joints between adjacent lighting devices; End coverings
• CPC Class Codes: F21V 23/003 the elements being electronics drivers or controllers for operating the light source, e.g. for a LED array
• CPC Class Codes: F21V 23/005 the substrate is supporting also the light source
• 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 25/02 coming into action when lighting device is disturbed, dismounted, or broken
• CPC Class Codes: F21V 29/70 characterised by passive heat-dissipating elements, e.g. heat-sinks
• CPC Class Codes: F21V 29/83 the elements having apertures, ducts or channels, e.g. heat radiation holes
• CPC Class Codes: F21V 3/061 the material being glass
• 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 45/34 Voltage stabilisation; Maintaining constant voltage
• 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: H05K 1/00 Printed circuits
• CPC Class Codes: Y02B 20/30 : Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

A driving method for driving an LED tube lamp is disclosed. The LED tube lamp includes a lamp tube, two end caps, an LED module, and a power supply module including an electric shock detection circuit. The driving method is capable of detecting whether a human touches the conductive part of the LED tube lamp when one end of the LED tube lamp has been inserted into a lamp socket.

Claims

1. A driving method for driving a light-emitting diode (LED) tube lamp having at least a first and second external connection terminal, comprising:

receiving an external driving signal from the first and second external connection terminals;

controlling a first current path to detect whether an external impedance is electrically connected to the LED tube lamp; and

while the external driving signal is being received and when an external impedance is not electrically connected to the LED tube lamp, the driving method further comprises;

transmitting current to drive an LED module of the LED tube lamp to emit light via a second current path, wherein the second current path is electrically connected to the LED module to form a power loop; and

cutting off the first current path.

2. The driving method according to claim 1, wherein the LED tube lamp comprises a rectifying circuit, a filtering circuit, and a driving circuit, which are electrically connected in sequence,

the first current path is formed between a ground terminal and an input side of one of the rectifying circuit, the filtering circuit, and the driving circuit, and

the second current path is formed by at least part of electronic elements of the rectifying circuit, the filtering circuit, and the driving circuit.

3. The driving method according to claim 2, wherein the input side has two input terminals, and the first current path is formed by:

at least one resistor, having a first end and a second end and electrically connected to either the input side or the ground terminal; and

a transistor, having a first terminal, a second terminal electrically connected to the first end of the resistor, and a control terminal for receiving the detection control signal,

wherein when the first terminal of the transistor is electrically connected to the ground terminal, the second end of the resistor is electrically connected to the input side, and

wherein when the first terminal of the transistor is electrically connected to the input side, the second end of the resistor is electrically connected to the ground terminal.

4. The driving method according to claim 2, wherein the first current path is formed between the ground terminal and an input terminal of the rectifying circuit.

5. The driving method according to claim 2, wherein the first current path is formed between the ground terminal and an input terminal of the filtering circuit.

6. The driving method according to claim 2, wherein the first current path is formed between the ground terminal and an input terminal of the driving circuit.

7. The driving method according to claim 1, wherein the step of controlling the first current path to detect whether the external impedance is electrically connected to the LED tube lamp comprises:

controlling a conduction state of the first current path during detecting whether the external impedance is electrically connected to the LED tube lamp, so as to cause a discontinuous current being generated on the power loop.

8. The driving method according to claim 7, wherein the step of controlling the conduction state of the first current path during detecting whether the external impedance is electrically connected to the LED tube lamp comprises:

generating a detection control signal having pulse waveform to cause the discontinuous current on the power loop.

9. The driving method according to claim 8, wherein a pulse period of the discontinuous current is between 10 μ

s and 1 ms.

10. The driving method according to claim 7, wherein the step of controlling the first current path to detect whether the external impedance is electrically connected to the LED tube lamp further comprises:

detecting a signal which reflects size of the current passing through the first current path; and

outputting a detection result indicating whether the external impedance is detected.

11. The driving method according to claim 10, wherein the LED tube lamp comprises a driving circuit configured to convert the external driving signal into a lamp driving signal for driving the LED module, and the step of controlling the first current path to detect whether the external impedance is electrically connected to the LED tube lamp further comprises:

disabling the generation of the lamp driving signal when the detection result indicates the external impedance is detected.

12. The driving method according to claim 1, wherein the number of electronic elements disposed on the second current path is less than a number of electronic elements disposed on the first current path.

13. A driving method for driving a light-emitting diode (LED) tube lamp having a lamp tube and two end caps respectively disposed on opposite sides of the lamp tube, wherein the LED tube lamp comprises a rectifying circuit having an input side electrically connected to external connection terminals disposed on the end caps, the driving method comprising:

receiving an external driving signal from at least two of the external connection terminals;

controlling a detection current path disposed between the input side of the rectifying circuit and a ground terminal to detect whether an external impedance is electrically connected to the LED tube lamp; and

transmitting current to drive an LED module of the LED tube lamp to emit light when the external driving signal is being received and the external impedance is not electrically connected.

14. The driving method according to claim 13, wherein the step of controlling the detection current path disposed between the input side of the rectifying circuit and a ground terminal to detect whether the external impedance is electrically connected to the LED tube lamp comprises:

controlling a conduction state of the detection current path during detecting whether the external impedance is electrically connected to the LED tube lamp, so as to cause a discontinuous current being generated in the LED tube lamp.

15. The driving method according to claim 13, wherein when the external impedance is not detected while the external driving signal is being received, the driving method further comprises:

cutting off the detection current path.

16. The driving method according to claim 13, wherein the step of controlling the detection current path disposed between the input side of the rectifying circuit and a ground terminal to detect whether the external impedance is electrically connected to the LED tube lamp comprises:

determining whether to conduct a current passing through the detection current path according to a detection control signal.

17. The driving method according to claim 16, wherein the step of controlling the detection current path disposed between the input side of the rectifying circuit and a ground terminal to detect whether the external impedance is electrically connected to the LED tube lamp further comprises:

generating the detection control signal having a pulse waveform to cause a discontinuous current in the LED tube lamp.

18. The driving method according to claim 17, wherein a pulse period of the discontinuous current is between 10 μ

s to 1 ms.

19. The driving method according to claim 16, wherein the step of controlling the detection current path disposed between the input side of the rectifying circuit and a ground terminal to detect whether the external impedance is electrically connected to the LED tube lamp further comprises:

detecting a signal which reflects a size of the current passing through the detection current path; and

outputting a detection result indicating whether the external impedance is detected.

20. The driving method according to claim 19, wherein when the detection result indicates the external impedance is not detected, the driving method further comprises:

rectifying the external driving signal by the rectifying circuit to generate a rectified signal;

filtering the rectified signal to generate a filtered signal;

generating a lighting control signal by a controller;

turning on or off a switch circuit in response to the lighting control signal; and

charging or discharging an energy storage circuit according to the on/off state of the switch circuit, so as to convert the filtered signal into a lamp driving signal for driving the LED module.

21. The driving method according to claim 19, wherein when the detection result indicates the external impedance is detected, the driving method further comprises:

disabling the controller from generating the lighting control signal.

22. The driving method according to claim 16, wherein the detection current path is formed by:

at least a first resistor, having a first end and a second end and electrically connected to an input terminal of the rectifying circuit; and

a transistor, having a first terminal electrically connected to the ground terminal, a second terminal electrically connected to the first end of the first resistor, and a control terminal for receiving the detection control signal.

23. A driving method for driving a light-emitting diode (LED) tube lamp having a lamp tube and two end caps respectively disposed on opposite sides of the lamp tube, comprising:

receiving an external driving signal from at least two external connection terminals disposed on the end caps;

detecting whether an external impedance is electrically connected to the LED tube lamp;

when the external impedance is not detected while the external driving signal is being received, the driving method comprises;

rectifying the external driving signal by a rectifying circuit to generate a rectified signal;

filtering the rectified signal by a filtering circuit to generate a filtered signal;

converting the filtered signal into a lamp driving signal by a driving circuit; and

providing the lamp driving signal to drive an LED module of the LED tube lamp, wherein a power loop is formed by a current path passing through the rectifying circuit, the filtering circuit, the driving circuit and the LED module; and

when the external impedance is detected while the external driving signal is being received, the driving method comprises;

disabling the driving circuit from converting the filtered signal, so as to limit a current from conducting on the power loop.

24. The driving method according to claim 23, wherein the step of converting the filtered signal into the lamp driving signal comprises:

generating a lighting control signal by a controller;

turning on or off a switch circuit connected to the controller in response to the lighting control signal; and

charging or discharging an energy storage circuit according to the on/off state of the switch circuit, so as to convert the filtered signal into the lamp driving signal.

25. The driving method according to claim 24, wherein the step of disabling the driving circuit from converting the filtered signal comprises:

disabling the controller from generating the lighting control signal.

26. The driving method according to claim 23, wherein the step of detecting whether the external impedance is electrically connected to the LED tube lamp comprises:

controlling a conduction state of a detection current path for detection, so as to cause a discontinuous current being generated on the power loop.

27. The driving method according to claim 26, wherein the step of detecting whether the external impedance is electrically connected to the LED tube lamp further comprises:

detecting a signal which reflects size of the current passing through the detection current path; and

outputting a detection result indicating whether the external impedance is detected.

28. The driving method according to claim 26, wherein when the external impedance is not detected, the driving method further comprises:

cutting off the detection current path.

29. The driving method according to claim 26, wherein the number of electronic elements disposed on the detection current path is less than a number of electronic elements disposed on the power loop.

30. The driving method according to claim 26, wherein the detection current path is formed between a ground terminal and an input side of one of the rectifying circuit, the filtering circuit, and the driving circuit.

31. The driving method according to claim 30, wherein the detection current path is formed between the ground terminal and an input terminal of the rectifying circuit.

32. The driving method according to claim 30, wherein the detection current path is formed between the ground terminal and an input terminal of the filtering circuit.

33. The driving method according to claim 30, wherein the detection current path is formed between the ground terminal and an input terminal of the driving circuit.

34. The driving method according to claim 26, wherein the step of controlling the conduction state of the detection current path for detection comprises:

determining whether to conduct a current passing through the detection current path according to a detection control signal.

35. The driving method according to claim 34, wherein the detection current path is formed by:

at least one resistor, having a first end and a second end and electrically connected to the input side or the ground terminal; and

a transistor, having a first terminal, a second terminal electrically connected to the first end of the resistor, and a control terminal for receiving the detection control signal,

wherein when the first terminal of the transistor is electrically connected to the ground terminal, the second end of the resistor is electrically connected to the input side, and

wherein when the first terminal of the transistor is electrically connected to the input side, the second end of the resistor is electrically connected to the ground terminal.

36. The driving method according to claim 34, wherein the step of controlling the conduction state of the detection current path for detection further comprises:

generating the detection control signal having pulse waveform, wherein a pulse period of the detection control signal is between 10 μ

s to 1 ms.