LED tube lamp for operating in different modes

• US 10,683,970 B2
• Filed: 08/21/2019
• Issued: 06/16/2020
• Est. Priority Date: 04/29/2015
• 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, Wu, Xiaojia
• Primary Examiner(s): Tran, Anh Q
• Application Number:
  US16/546,319
• Publication Number:
  US 20190376651A1
• Time in Patent Office: 300 Days
• Field of Search: None
• CPC Class Codes: B23K 1/0016 Brazing of electronic components
• CPC Class Codes: B23K 2101/42 Printed circuits
• CPC Class Codes: B23K 3/047 electric
• CPC Class Codes: C03C 21/002 to perform ion-exchange between alkali ions C03C21/005 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 17/101 permanently, e.g. welding, gluing or riveting
• CPC Class Codes: F21V 23/006 the substrate being distinct from the light source holder
• 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 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: F21V 3/10 characterised by coatings
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H05B 45/3578 Emulating the electrical or functional characteristics of discharge lamps
• CPC Class Codes: H05B 45/37 Converter circuits
• CPC Class Codes: H05B 45/3725 Switched mode power supply [SMPS]
• 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 comprises: an LED module for emitting light; a rectifying circuit for rectifying an external driving signal to produce a rectified signal; and a mode determination circuit for determining to perform a first mode or a second mode of lighting according to the rectified signal; wherein the mode determination circuit comprises two voltage dividers for producing a first fraction voltage and a second fraction voltage of the rectified signal, and a control circuit coupled to the two voltage dividers and configured for receiving the first fraction voltage and for receiving the second fraction voltage. When the first fraction voltage signal is in a first voltage range, the mode determination circuit determines to perform the first mode of lighting; and when the second fraction voltage is in a second voltage range, the mode determination circuit determines to perform the second mode of lighting.

Claims

1. A light emitting diode (LED) tube lamp configured to receive an external driving signal, comprising:

an LED module for emitting light, the LED module comprising an LED unit comprising an LED;

a rectifying circuit for rectifying the external driving signal to produce a rectified signal, wherein the rectifying circuit has a first output terminal and a second output terminal for outputting the rectified signal;

a mode determination circuit configured to detect a state of a property of the rectified signal, for selectively determining on performing a first mode or a second mode of lighting according to the state of the property of the rectified signal;

wherein the mode determination circuit is configured such that when the LED tube lamp performs the first mode of lighting, the mode determination circuit allows continual current to flow through the LED unit until the external driving signal is disconnected from the LED tube lamp; and

when the LED tube lamp performs the second mode of lighting, the mode determination circuit regulates the continuity of current to flow through the LED unit; and

a noise suppressing circuit comprising an inductor coupled between the LED unit and an output terminal of the mode determination circuit, wherein the inductor has a first end and a second end, the first end is connected to a cathode terminal of the LED unit, and the noise suppressing circuit further comprises;

a resistor connected in series with the inductor between the inductor and the output terminal of the mode determination circuit; and

a transistor having a first terminal, a second terminal, and a third terminal, the first terminal connected to a connection node between the inductor and the LED unit, the second terminal and the third terminal respectively connected to two ends of the resistor, wherein the transistor is configured to conduct current according to a voltage drop of the resistor;

wherein the transistor is configured such that a conducting state of the transistor diverts some current from flowing through the inductor.

2. The LED tube lamp according to claim 1, wherein the mode determination circuit comprises:

a voltage divider for producing a first fraction voltage of the rectified signal and a second fraction voltage of the rectified signal; and

a control circuit for determining whether the voltage level of the first fraction voltage is in a first voltage range, and whether the voltage level of the second fraction voltage is in a second voltage range;

wherein when the first fraction voltage signal is in the first voltage range, the mode determination circuit determines on performing the first mode of lighting; and

when the second fraction voltage is in the second voltage range, the mode determination circuit determines on performing the second mode of lighting.

3. The LED tube lamp according to claim 2, wherein the control circuit comprises a switching circuit;

when the LED tube lamp performs the first mode of lighting, the mode determination circuit allows continuous current to flow through the LED unit by continuously turning on the switching circuit; and

when the LED tube lamp performs the second mode of lighting, the mode determination circuit allows discontinuous current to flow through the LED unit by alternately turning on and off the switching circuit.

4. The LED tube lamp according to claim 3, wherein the switching circuit has two terminals respectively coupled to the LED unit and a reference voltage.

5. The LED tube lamp according to claim 2, further comprising a switching circuit;

when the LED tube lamp performs the first mode of lighting, the mode determination circuit allows continuous current to flow through the LED unit by continuously turning on the switching circuit; and

when the LED tube lamp performs the second mode of lighting, the mode determination circuit allows discontinuous current to flow through the LED unit by alternately turning on and off the switching circuit.

6. The LED tube lamp according to claim 5, wherein the switching circuit has two terminals respectively coupled to the LED unit and a reference voltage.

7. The LED tube lamp according to claim 2, wherein the rectifying circuit has a first output terminal and a second output terminal for outputting the rectified signal, and the voltage divider comprises:

a first voltage divider comprising a first resistor and a second resistor connected to each other between the first and second output terminals of the rectifying circuit, to produce the first fraction voltage; and

a second voltage divider comprising a third resistor and a fourth resistor connected to each other between the first and second output terminals of the rectifying circuit, to produce the second fraction voltage;

wherein the control circuit is coupled to a connection node between the first resistor and the second resistor, for receiving the first fraction voltage; and

the control circuit is coupled to a connection node between the third resistor and the fourth resistor, for receiving the second fraction voltage.

8. The LED tube lamp according to claim 1, further comprising a filtering circuit connected in parallel with the LED unit.

9. The LED tube lamp according to claim 1, wherein the property is the voltage level or the frequency level of the rectified signal.

10. The LED tube lamp according to claim 1, wherein the mode determination circuit is configured such that upon the external driving signal being initially input to the LED tube lamp, the mode determination circuit will not enter a conduction state until a period of delay passes, wherein the period of delay is between about 10 milliseconds and about 1 second.