Light-emitting diode driving module, method of operating thereof, and lighting apparatus including the same

• US 10,383,184 B2
• Filed: 10/29/2018
• Issued: 08/13/2019
• Est. Priority Date: 04/07/2017
• Status: Active Grant

• Current Assignee: Seoul Semiconductor Co., Ltd.
• Original Assignee: Seoul Semiconductor Co., Ltd.
• Inventors: Jin, SungHo, Lee, HyungJin, Han, SangWook
• Primary Examiner(s): Tan, Vibol
• Application Number:
  US16/172,867
• Publication Number:
  US 20190069357A1
• Time in Patent Office: 288 Days
• CPC Class Codes: H05B 41/3924 by phase control, e.g. using a triac H05B41/3922 takes precedence
• CPC Class Codes: H05B 41/3927 by pulse width modulation H05B41/3922 takes precedence
• CPC Class Codes: H05B 45/18 using temperature feedback
• CPC Class Codes: H05B 45/31 Phase-control circuits
• CPC Class Codes: H05B 45/325 Pulse-width modulation [PWM]
• CPC Class Codes: H05B 45/3575 by means of dummy loads or bleeder circuits, e.g. for dimmers
• CPC Class Codes: H05B 45/44 with an active control inside an LED matrix
• CPC Class Codes: H05B 45/46 having LEDs disposed in parallel lines
• CPC Class Codes: H05B 45/56 involving measures to prevent abnormal temperature of the LEDs
• CPC Class Codes: H05B 45/59 for reducing or suppressing flicker or glow effects
• CPC Class Codes: H05B 47/25 Circuit arrangements for protecting against overcurrent

Abstract

A light-emitting diode driving module includes an LED driving circuit to activate light-emitting diodes driven by a modified rectified voltage, and to adjust driving currents conducted to driving nodes to the light emitting diodes; a driving current controller to receive a dimming signal indicative of a degree of modulation of the rectified voltage, and to control currents conducted to the driving nodes depending on the dimming signal; and a current blocking circuit to block the currents of the driving nodes when a dimming level of the dimming signal decreases lower than a first threshold value, and unblock the currents of the driving nodes when the dimming level increases above a second threshold value higher than the first threshold value.

Claims

1. A light-emitting diode driving module comprising:

an LED driving circuit to activate light-emitting diodes driven by a modified rectified voltage, and to adjust driving currents conducted to driving nodes to the light emitting diodes;

a driving current controller to receive a dimming signal indicative of a degree of modulation of the rectified voltage, and to control currents conducted to the driving nodes depending on the dimming signal; and

a current blocking circuit to block the currents of the driving nodes when a dimming level of the dimming signal decreases lower than a first threshold value, and unblock the currents of the driving nodes when the dimming level increases above a second threshold value higher than the first threshold value.

2. The light-emitting diode driving module according to claim 1,

wherein the current blocking circuit enables a blocking signal when the dimming level of the dimming signal decreases lower than the first threshold value, and disables the blocking signal when the dimming level increases above the second threshold value, and

wherein the current conducted to the driving nodes is blocked when the blocking signal is enabled.

3. The light-emitting diode driving module according to claim 1,

wherein the LED driving circuit is connected to a driving current setting node to adjust the current conducted to the driving nodes depending on a voltage of the driving current setting node,

wherein the driving current controller is configured to control the voltage of the driving current setting node depending on the dimming signal, and

wherein the light-emitting diode driving module further comprises a voltage detection circuit configured to block the currents of the driving nodes when the voltage of the driving current setting node is higher than a first threshold voltage.

4. The light-emitting diode driving module according to claim 3,

wherein the voltage detection circuit is configured to block the currents of the driving nodes when the voltage of the driving current setting node increases higher than the first threshold voltage, and unblock the currents of the driving nodes when the voltage of the driving current setting node decreases below a second threshold voltage lower than the first threshold voltage.

5. The light-emitting diode driving module according to claim 1, further comprising:

a DC power source to generate a DC voltage based on the rectified voltage, the DC voltage being connected to an output node to supply DC voltage outside the light-emitting diode driving module; and

a current detection circuit to block the current conducted to the driving nodes when a current of the output node is higher than a first threshold current.

6. The light-emitting diode driving module according to claim 5,

wherein the current detection circuit is configured to block the current conducted to the driving nodes when the current of the output node increases higher than the first threshold current, and unblock the current conducted to the driving nodes when the current of the output node decreases lower than a second threshold current lower than the first threshold current.

7. The light-emitting diode driving module according to claim 1, further comprising:

a detector having a resistor-capacitor integrator circuit to sense a dimming level,

wherein the detector outputs the dimming signal by integrating the rectified voltage.

8. The light-emitting diode driving module according to claim 7, wherein the dimming level comprises a voltage level of the dimming signal.

9. The light-emitting diode driving module according to claim 1, further comprising:

a phase detector to output a dimming phase signal when the rectified voltage is equal to or higher than a predetermined level; and

a pulse counter to receive a clock signal and count pulses of the clock signal which toggles when the dimming phase signal is outputted,

wherein the dimming signal is indicative of a number of counted pulses.

10. The light-emitting diode driving module according to claim 9, wherein the dimming level comprises the count of the counted pulses.

11. A method for driving dimmable, light-emitting diodes activated by a modulated rectified voltage and controlled through driving nodes, the method comprising the steps of:

receiving a dimming signal indicative of a degree of modulation of the rectified voltage;

driving the light-emitting diodes by controlling current conducted to the driving nodes depending on the dimming signal;

blocking the current conducted to the driving nodes when a dimming level of the dimming signal decreases lower than a first threshold value; and

unblocking the current conducted to the driving nodes when the dimming level of the dimming signal increases above a second threshold value higher than the first threshold value.

12. The method according to claim 11, wherein the step of the driving of the light-emitting diodes by controlling currents depending on the dimming signal comprises controlling a voltage of a driving current setting node based on the dimming signal, and adjusting the current conducted to the driving nodes depending on the voltage of the driving current setting node.

13. The method according to claim 12, further comprising the step of:

blocking the current conducted to the driving nodes when the voltage of the driving current setting node is higher than a first threshold voltage.

14. The method according to claim 13, further comprising the step of:

unblocking the current conducted to the driving nodes when the voltage of the driving current setting node decreases below a second threshold voltage lower than the first threshold voltage.

15. The method according to claim 11, further comprising the step of:

generating a DC voltage by using the rectified voltage and supplying the DC voltage to an output node; and

blocking the current conducted to the driving nodes when a current of the output node is higher than a first threshold current.

16. The method according to claim 15, further comprising the steps of:

blocking the current conducted to the driving nodes when the current of the output node increases higher than the first threshold current, and unblocking the current conducted to the driving nodes when the current of the output node decreases below a second threshold current lower than the first threshold current.

17. A dimmable, lighting apparatus comprising:

light-emitting diodes configured to receive a modulated rectified voltage; and

a light-emitting diode driving module connected to the light-emitting diodes through driving nodes, the light-emitting diode driving module comprising;

an LED driving circuit to drive the light-emitting diodes by applying current to the driving nodes depending on a level of the rectified voltage;

a driving current controller to receive a dimming signal indicative of a degree of modulation of the rectified voltage, and to control the current conducted to the driving nodes depending on the dimming signal; and

a current blocking circuit to block the current conducted to the driving nodes when a dimming level of the dimming signal decreases lower than a first threshold value, and to unblock the current conducted to the driving nodes when the dimming level increases above a second threshold value higher than the first threshold value.