US Patent No. 9,860,959

LED TUBE LAMP COMPATIBLE WITH DIFFERENT SOURCES OF EXTERNAL DRIVING SIGNAL


Patent No. 9,860,959
Issue Date January 02, 2018
Title Led Tube Lamp Compatible With Different Sources Of External Driving Signal
Inventorship Aiming Xiong, Jiaxing (CN)
Xintong Liu, Jiaxing (CN)
Xiaojia Wu, Jiaxing (CN)
Hechen Hu, Jiaxing (CN)
Assignee Jiaxing Super Lighting Electric Appliance Co., Ltd., Xiuzhou Area, Jiaxing...

Claim of US Patent No. 9,860,959

1. An LED tube lamp, comprising:
a lamp tube having a first pin and a second pin at a first end of the lamp tube and a third pin and a fourth pin at a second
end of the lamp tube, for receiving an external driving signal;

a light strip disposed in the lamp tube, comprising an LED module for emitting light;
a driving circuit configured to drive the LED module;
a rectifying circuit for rectifying the external driving signal to produce a rectified signal, the rectifying circuit comprising
a first rectifying circuit and a second rectifying circuit, and the first rectifying circuit and the second rectifying circuit
each comprising four diodes, wherein a common cathode of two diodes of the first rectifying circuit is coupled to a common
cathode of two diodes of the second rectifying circuit, and a common anode of the other two diodes of the first rectifying
circuit is coupled to a common anode of the other two diodes of the second rectifying circuit;

a filtering circuit coupled to the rectifying circuit and the driving circuit, for filtering the rectified signal in order
to drive the LED module;

a first capacitor coupled between the first pin and the second pin;
a second capacitor coupled between the third pin and the fourth pin;
a first current-limiting element for receiving the external driving signal input at one or more of the pins from a lamp driving
circuit, the first current-limiting element coupled between the second pin and the third pin, and coupled to the first rectifying
circuit; and

a second current-limiting element coupled between the first pin and the fourth pin; and a ballast detection circuit coupled
to or in the first rectifying circuit, or coupled to or in the second rectifying circuit,

wherein the ballast detection circuit comprises a detection circuit and a mode switching circuit; the detection circuit is
configured to generate a control signal according to the frequency of the external driving signal, to control the mode switching
circuit on whether to perform a first driving mode or a second driving mode; when the mode switching circuit determines on
performing the first driving mode, the driving circuit receives a filtered signal from the filtering circuit to drive the
LED module; and when the mode switching circuit determines on performing the second driving mode, the received external driving
signal or the filtered signal in the LED tube lamp is transmitted to reach the LED module by bypassing at least some components
of the driving circuit.