Led tube lamp with improved compatibility with an electrical ballast

Patent metadata

Field	Value
Publication number	US-2016323948-A1
Application number	US-201615205011-A
Country	US
Kind code	A1
Filing date	Jul 8, 2016
Priority date	Sep 28, 2014
Publication date	Nov 3, 2016
Grant date	—

Abstract

A light emitting diode (LED) tube lamp includes a lamp tube; a first external connection terminal coupled to the lamp tube and for receiving an external driving signal; a second external connection terminal coupled to the lamp tube and for receiving an external driving signal; a first rectifier coupled to the first external connection terminal and configured to rectify the external driving signal to produce a rectified signal; a second rectifier coupled to the second external connection terminal for rectifying the external driving signal; a filtering circuit coupled to the first rectifier and the second rectifier and configured to filter the rectified signal to produce a filtered signal; an LED lighting module coupled to the filtering circuit and configured to receive the filtered signal for emitting light; and a first bypass circuit coupled between the first rectifying circuit and the second external connection terminal. The first external connection terminal is an input terminal for the first rectifier and a first node is directly electrically connected to an output terminal for the first rectifier. In addition, the second external connection terminal is an input terminal for the second rectifier and a second node is directly electrically connected to an output terminal for the second rectifier. Further the first bypass circuit includes a first terminal connected to second external connection terminal and a second terminal connected to the first node, and the first bypass circuit is configured such that when the external driving signal is initially input between the first external connection terminal and the second external connection terminal, the first bypass circuit initially conducts current bypassing the LED lighting module to prevent the LED tube lamp from emitting light, until the bypass circuit enters an open-circuit state, allowing a current to flow through the LED lighting module and thereby allowing the LED tube lamp to emit light.

First claim

1 . A light emitting diode (LED) tube lamp, comprising:
a lamp tube; a first external connection terminal coupled to the lamp tube and for receiving an external driving signal; a second external connection terminal coupled to the lamp tube and for receiving an external driving signal; a first rectifying circuit coupled to the first external connection terminal and configured to rectify the external driving signal to produce a rectified signal; a second rectifying circuit coupled to the second external connection terminal for rectifying the external driving signal; a filtering circuit coupled to the first rectifying circuit and the second rectifying circuit, and configured to filter the rectified signal to produce a filtered signal; an LED lighting module coupled to the filtering circuit and configured to receive the filtered signal for emitting light; and a first ballast interface circuit coupled between the first rectifying circuit and the second external connection terminal, wherein the first ballast interface circuit is configured such that when the external driving signal is initially input between the first external connection terminal and the second external connection terminal, the first ballast interface circuit initially conducts current bypassing the LED lighting module to prevent the LED tube lamp from emitting light, until the ballast interface circuit enters an open-circuit state, allowing a current input at the first external connection terminal and second external connection terminal to flow through the LED lighting module and thereby allowing the LED tube lamp to emit light.

2 . The LED tube lamp of claim 1 , further comprising:
a third external connection terminal coupled to the second rectifying circuit; and a second ballast interface circuit coupled between the third external connection terminal and the first rectifying circuit.

3 . The LED tube lamp of claim 1 , further comprising:
a node at which a first terminal of the first ballast interface circuit, a first terminal of the second ballast interface circuit, a terminal of the first rectifying circuit, and a terminal of the filtering circuit connect to each other.

4 . The LED tube lamp of claim 1 , wherein:
the first ballast interface circuit is coupled between the first rectifying circuit and the second rectifying circuit.

5 . The LED tube lamp of claim 1 , wherein:
the first ballast interface circuit includes at least one electronic switch.

6 . The LED tube lamp of claim 5 , wherein:
the first ballast interface circuit is configured so that: when the external driving signal is initially input between the first external connection terminal and the second external connection terminal, the first ballast interface circuit initially conducts current by the at least one switch conducting.

7 . The LED tube lamp of claim 6 , further comprising:
an RC circuit included in the first ballast interface circuit, wherein: the RC circuit causes the electronic switch to be in an open state to cut off current after a period of time of the initial conduction of current by the at least one switch.

8 . The LED tube lamp of claim 5 , wherein the at least one electronic switch is coupled between the first rectifying circuit and the second external connection terminal.

9 . The LED tube lamp of claim 8 , wherein the at least one electronic switch includes a first switch connected between a first resistor, a first capacitor, and a first diode.

10 . The LED tube lamp of claim 9 , wherein the at least on electronic switch includes a second switch connected in parallel with the first switch.

11 . The LED tube lamp of claim 1 , wherein:
the second rectifying circuit includes: a rectifier coupled to a terminal adapter circuit.

12 . The LED tube lamp of claim 11 , wherein:
the rectifier is coupled between the second external connection terminal and the terminal adapter circuit; and the terminal adapter circuit is coupled between a first node of the rectifier and the first rectifying circuit.

13 . The LED tube lamp of claim 12 , wherein:
the first ballast interface circuit, terminal adapter circuit, and rectifier connect to each other at the first node.

14 . (canceled)

15 . The LED tube lamp of claim 11 , wherein:
the terminal adapter circuit is coupled between the second external connection terminal and the rectifier; and the rectifier is coupled between the terminal adapter circuit and the first rectifying circuit.

16 . The LED tube lamp of claim 15 , further comprising:
a third external connection terminal coupled to the terminal adapter circuit; wherein the terminal adapter circuit comprises a filament-simulating circuit including a resistor and a capacitor connected in parallel between the second external connection terminal and the third external connection terminal.

17 . The LED tube lamp of claim 15 , further comprising:
a third external connection terminal coupled to the terminal adapter circuit; wherein the terminal adapter circuit comprises a filament-simulating circuit including at least one negative temperature coefficient resistor.

18 . The LED tube lamp of claim 1 , further comprising:
a third external connection terminal [ 504 ] coupled to the second rectifying circuit; and a filament-simulating circuit coupled between the second external connection terminal and the third external connection terminal.

19 . The LED tube lamp of claim 18 , wherein:
the filament-simulating circuit includes a resistor and capacitor connected in parallel between the first node and one of the second external connection terminal or the third external connection terminal.

20 . The LED tube lamp of claim 18 , wherein:
the second rectifying circuit includes the filament-simulating circuit and a rectifier.

21 . (canceled)

22 . The LED tube lamp of claim 18 , wherein:
the filament-simulating circuit simulates the operation of filaments of a fluorescent tube lamp, so that a current flowing through the filament-simulating circuit when an external lamp driving circuit performs filament detection is below about 1 [A].

23 . (canceled)

24 . The LED tube lamp of claim 1 , wherein the LED lighting module includes:
a flexible circuit sheet on which a plurality of light emitting diodes (LEDs) are disposed, wherein the plurality of light emitting diodes are connected to emit light based on the filtered signal.

25 . The LED tube lamp of claim 24 , wherein the flexible circuit sheet extends along a length of the lamp tube and includes end portions at opposite ends of the lamp tube on which LEDs are not disposed and which bends away from the lamp tube.

26 . The LED tube lamp of claim 25 , wherein the end portions are an integral portion of the flexible circuit sheet.

27 . The LED tube lamp of claim 25 , wherein the flexible circuit sheet passes through a transition region in the lamp tube where the lamp tube narrows.

28 . A light emitting diode (LED) tube lamp, comprising:
a lamp tube; a first external connection terminal coupled to the lamp tube and for receiving an external driving signal; a second external connection terminal coupled to the lamp tube and for receiving an external driving signal; a first rectifier coupled to the first external connection terminal and configured to rectify the external driving signal to produce a rec

Assignees

• Jiaxing Super Lighting Electric Appliance Co Ltd

Inventors

• Xiong Aiming
• Ye Qifeng
• Jiang Tao

Classifications

• F21K9/272 Primary

  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 title

• F21Y2103/10

  comprising a linear array of point-like light-generating elements · CPC title

• F21V29/83

  the elements having apertures, ducts or channels, e.g. heat radiation holes · CPC title

• F21K9/278

  Arrangement or mounting of circuit elements integrated in the light source · CPC title

• F21V23/02

  the elements being transformers, impedances {or power supply units, e.g. a transformer with a rectifier} · CPC title