LED tube lamp

Patent metadata

Field	Value
Publication number	US-9841174-B2
Application number	US-201715426785-A
Country	US
Kind code	B2
Filing date	Feb 7, 2017
Priority date	Apr 29, 2015
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

An LED tube lamp is provided herein, which implements the safety function for protecting the user from electric shock since it conducts only when both ends thereof have been correctly installed into a lamp socket. The LED tube lamp includes a lamp tube; two end caps, each having an external connection terminal, and each coupled to a respective end of the lamp tube, wherein the external connection terminals are configured to receive an external driving signal; an LED module, configured to emit light based on the external driving signal; and an installation detection module, coupled on a power loop of the LED tube lamp and configured to detect a sampling signal on the power loop and compare the sampling signal with a predefined signal, wherein when a signal level of the sampling signal is smaller than the predefined signal, the installation detection module limits a current on the power loop less than 5 MIU.

First claim

What is claimed is:

1. A light-emitting diode (LED) tube lamp, comprising:
a lamp tube;
two end caps, each having an external connection terminal, and each coupled to a respective end of the lamp tube, wherein the external connection terminals are configured to receive an external driving signal;
a rectifying circuit, coupled to the external connection terminals, for rectifying the external driving signal to produce a rectified signal;
a filtering circuit, coupled to the rectifying circuit, for filtering the rectified signal to produce a filtered signal;
a driving circuit, coupled to the filtering circuit, for converting the filtered signal into a driving signal;
an LED module, coupled to the driving circuit, for emitting light based on the driving signal; and
an installation detection module, configured to detect an installation state between the LED tube lamp and a lamp socket, wherein the installation detection module comprises:
a first circuit, configured to generate a pulse signal, wherein the first circuit comprises a discharge path;
a second circuit, coupled to the first circuit and configured to receive and output the pulse signal; and
a third circuit, coupled to a power loop of the LED tube lamp and the second circuit and configured to determine whether to conduct the power loop according to the pulse signal,

wherein the pulse signal is fed back to the discharge path of the first circuit, and the discharge path is conducted when the pulse signal is pulled to a high level voltage, and
wherein the pulse signal is pulled to a low level voltage after the discharge path has been conducted for a predetermined time period.

2. The LED tube lamp according to claim 1 , wherein the predetermined time period is a pulse-on period of the pulse signal.

3. The LED tube lamp according to claim 1 , wherein the discharge path is cut off when the pulse signal is pulled to the low level voltage.

4. The LED tube lamp according to claim 1 , wherein the third circuit comprises:
a first resistor, having one end connected to a driving signal;
a first capacitor, having one end connected to the other end of the first resistor, and the other end of the first capacitor being grounded;
a Schmitt trigger, having an input end connected to the one end of the first capacitor, and an output end connected to the second circuit;
a second resistor, having one end connected to the one end of the first capacitor;
a transistor, having a base, a collector connected to the other end of the second resistor, and an emitter being grounded; and
a third resistor, having one end connected to the base of the transistor, and the other end connected to the second circuit and the third circuit,
wherein the discharge path is formed by the transistor.

5. The LED tube lamp according to claim 1 , wherein the installation detection module further comprises:
a fourth circuit, configured to detect a sampling signal on the power loop so as to determine the installation state between the LED tube lamp and the lamp socket.

6. The LED tube lamp according to claim 5 , wherein the fourth circuit further compares the sampling signal with a predefined signal, the fourth circuit outputs a high level signal when a signal level of the sampling signal is greater than or equal to the predefined signal and outputs a low level signal when the signal level of the sampling signal is smaller than the predefined signal.

7. The LED tube lamp according to claim 6 , wherein the third circuit is conducted in response to the high level signal so as to cause the power loop to remain conductive.

8. The LED tube lamp according to claim 6 , wherein the third circuit is cut off in response to the low level signal so as to cause the power loop to remain open.

9. The LED tube lamp according to claim 6 , wherein the third circuit is cut off in response to the low level signal so as to reduce a current on the power loop less than 5 MIU (Measurement Indication Units).

10. A ballast by-pass light-emitting diode (LED) tube lamp, comprising:
a lamp tube;
two end caps, each having an external connection terminal, and each coupled to a respective end of the lamp tube, wherein the external connection terminals are configured to receive an external driving signal;
an LED module, configured to emit light based on the external driving signal; and
an installation detection module, coupled on a power loop of the LED tube lamp and configured to detect a transient current on the power loop and compare the transient current with a predefined signal,
wherein when a signal level of the transient current is smaller than the predefined signal, the installation detection module limits a current on the power loop less than 5 MIU by controlling a conduction state of the power loop.

11. The LED tube lamp according to claim 10 , wherein the installation detection module comprises:
a detection determining circuit, configured to detect the transient current, compare the transient current with the predefined signal, and output a high level signal or a low level signal according to a comparison result.

12. The LED tube lamp according to claim 11 , wherein the installation detection module further comprises:
a detection pulse generating module, configured to generate a pulse signal, wherein the detection determining circuit detects the transient current on the power loop during a pulse-on period of the pulse signal.

13. The LED tube lamp according to claim 12 , wherein the detection pulse generating module comprises a discharge path, the pulse signal is fed back to the discharge path and the discharge path is conducted when the pulse signal is pulled to a high level voltage, and wherein the pulse signal is pulled to a low level voltage after the discharge path has been conducted for a predetermined time period.

14. The LED tube lamp according to claim 13 , wherein the predetermined time period is the same as the pulse-on period of the pulse signal.

15. The LED tube lamp according to claim 13 , wherein the discharge path is cut off when the pulse signal is pulled to the low level voltage.

16. The LED tube lamp according to claim 12 , wherein the installation detection module further comprises:
a switch circuit, coupled to the detection determining circuit and the detection pulse generating module and configured to maintain a conductive state during the pulse-on period of the pulse signal or when receiving the low level signal from the detection determining circuit.

17. The LED tube lamp according to claim 16 , wherein the installation detection module further comprises:
a detection result latching circuit, coupled to the detection determining circuit, the detection pulse generating module, and the switch circuit, wherein at least one of the pulse signal, the high level signal, and the low level signal is provided to the switch circuit through the detection result latching circuit.

18. A detection method for a light-emitting device (LED) tube lamp for preventing a user from electric shock when the LED tube lamp is being installed on a lamp socket, the detection method comprising:
generating a pulse signal by a detection pulse generating module;
receiving the pulse signal by a switch circuit coupled on a power loop of the LED tube lamp, wherein the switch circuit is conducted during a pulse-on period of the pulse signal to cause the power loop to be conductive;
detecting a sampling signal on the power loop;
comparing the sampling signal with a predefined signal; and
limiting a current on the power loop less than 5 MIU when a s

Assignees

• Jiaxing Super Lighting Electric Appliance Co Ltd
• Jiaxing Super Lighting Electric Appliance Co Ltd

Inventors

• Liu Xintong
• Xiong Aiming
• Jiang Tao

Classifications

• F21V3/02

  characterised by the shape · CPC title

• F21K9/272

  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 title

• F21V29/10

  Arrangement of heat-generating components to reduce thermal damage, e.g. by distancing heat-generating components from other components to be protected · CPC title

• F21V25/02 Primary

  coming into action when lighting device is disturbed, dismounted, or broken · CPC title

• F21K9/278

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