KR20180119015A - Light-emitting diode driving module, method of operating thereof, and lighting apparatus including the same - Google Patents

Abstract

According to an embodiment of the present invention, a light emitting diode driving module with improved operational reliability comprises: a light emitting diode driving circuit connected to light emitting diodes receiving a modulated rectified voltage for dimming and driving nodes and configured to drive the light emitting diodes by applying currents to the driving nodes according to a level of the rectified voltage; a driving current controller configured to receive a dimming signal indicating a degree of modulation of the rectified voltage and to control the currents of the driving nodes in accordance with the dimming signal; and a current blocking circuit blocking the currents of the driving nodes when a dimming level of the dimming signal decreases and becomes lower than a first threshold and unblocking the currents of the driving nodes when the dimming level becomes higher than a second threshold higher than the first threshold.

Description

TECHNICAL FIELD [0001] The present invention relates to a light emitting diode driving module, a method of operating the same, and a lighting device including the light emitting diode driving module.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic apparatus, and more particularly, to a light emitting diode driving module for driving light emitting diodes, a method of operating the same, and a lighting apparatus including the same.

In order to drive light-emitting diodes (LEDs) using a rectified voltage, an illumination device including light-emitting diodes can convert an AC voltage to a rectified voltage and emit light-emitting diodes according to the level of the rectified voltage have.

There has been developed a lighting device that supports a dimming function capable of providing various levels of light outputs according to a user's need as well as a lighting device that provides a predetermined light output. However, since the light emitting diodes are driven by using the rectified voltage, it is not easy to implement the dimming function, and it is difficult to secure the linearity of the amount of light according to the dimming control.

It should be understood that the above description is intended to assist the understanding of the background of the technical ideas of the present invention only and thus it can not be understood that it corresponds to the prior art known to those skilled in the art.

Embodiments of the present invention are intended to provide a light emitting diode drive module having improved operational reliability, a method of operating the same, and a lighting apparatus including the same.

A light emitting diode driving module according to an embodiment of the present invention includes light emitting diodes receiving modulated rectified voltage for dimming and driving nodes connected through driving nodes and applying currents to the driving nodes according to the level of the rectified voltage A light emitting diode driving circuit configured to drive the light emitting diodes; A driving current controller configured to receive a dimming signal indicative of the degree of modulation of the rectified voltage and to control the currents of the driving nodes in accordance with the dimming signal; And a driving circuit for interrupting the currents of the driving nodes when the dimming level of the dimming signal decreases and becomes lower than a first threshold value, and when the dimming level is higher than a second threshold value higher than the first threshold value, And a current interrupting circuit configured to unblock the currents of the transistors.

Wherein the current interruption circuit enables a blocking signal when the dimming level of the dimming signal is lowered to a level lower than the first threshold value and when the dimming level is higher than a second threshold value higher than the first threshold value, The signal can be disabled. The currents of the driving nodes may be cut off when the blocking signal is enabled.

Wherein the LED driving circuit controls the currents of the driving nodes according to a voltage of the current setting node and the driving current controller controls the voltage of the current setting node according to the dimming signal, can do. The light emitting diode driving module may further include a voltage sensing circuit configured to cut off the currents of the driving nodes when the voltage of the current setting node is higher than a first threshold voltage.

Wherein the voltage sensing circuit interrupts the current of the drive nodes when the voltage of the current setting node increases to be higher than the first threshold voltage and the voltage of the current setting node decreases to be lower than the second threshold voltage And to unblock the currents of the driving nodes. At this time, the second threshold voltage is lower than the first threshold voltage.

The light emitting diode driving module may further include a DC power source configured to generate a DC voltage using the rectified voltage. At this time, the DC voltage may be supplied to the outside through the output node. The light emitting diode driving module may further include a current sensing circuit configured to cut off the currents of the driving nodes when the current of the output node is higher than a first threshold current.

Wherein the current sensing circuit interrupts the currents of the drive nodes when the current of the output node increases to be higher than the first threshold current and when the current of the output node decreases and becomes lower than the second threshold current, And to unblock the currents of the driving nodes. At this time, the second threshold current is lower than the first threshold current.

The LED driving module may further include a dimming level sensor having a resistance-capacitor integration circuit. The dimming level sensor may integrate the rectified voltage to output the dimming signal.

The dimming level may be a voltage level of the dimming signal.

Wherein the light emitting diode driving module includes: a phase detector for outputting a dimming phase signal when the rectified voltage is equal to or higher than a predetermined level; And a pulse counter configured to receive the clock signal and count pulses of the clock signal that are toggled when the dimming phase signal is output. At this time, the dimming signal may indicate the number of counted pulses.

The dimming level may be a count of the counted pulses.

Another aspect of the present invention relates to a method of driving light emitting diodes. A method of driving light emitting diodes controlled through driving nodes using a modulated rectified voltage for dimming according to an embodiment of the present invention includes receiving a dimming signal indicative of the degree of modulation of the rectified voltage step; Controlling the currents of the driving nodes according to the dimming signal to drive the light emitting diodes; Blocking the currents of the driving nodes when the dimming level of the dimming signal decreases and becomes lower than a first threshold value; And unblocking the currents of the driving nodes when the dimming level of the dimming signal increases and becomes higher than a second threshold value higher than the first threshold value.

In the step of driving the light emitting diodes according to the dimming signal, the voltage of the current setting node is controlled based on the dimming signal, and the currents of the driving nodes may be adjusted according to the voltage of the current setting node.

The method may further include blocking the currents of the driving nodes when the voltage of the current setting node is higher than a first threshold voltage.

The currents of the drive nodes are cut off when the voltage of the current setting node is increased to be higher than the first threshold voltage and when the voltage of the current setting node is decreased to be lower than the second threshold voltage, The currents can be unblocked. At this time, the second threshold voltage is lower than the first threshold voltage.

The method further comprising generating the direct current voltage using the rectified voltage, wherein the direct current voltage is provided externally through the output node; And blocking the currents of the drive nodes when the current of the output node is higher than the first threshold current.

Wherein the currents of the drive nodes are cut off when the current of the output node is increased to be higher than the first threshold current and when the current of the output node is decreased to be lower than the second threshold current, It can be unblocked. At this time, the second threshold current is lower than the first threshold current.

Another aspect of the invention relates to a lighting device comprising light emitting diodes. An illumination device according to an embodiment of the present invention includes: light emitting diodes receiving modulated rectified voltage for dimming; And a light emitting diode driving module connected to the light emitting diodes through driving nodes. Wherein the light emitting diode driving module comprises: a light emitting diode driving circuit configured to apply currents to the driving nodes according to a level of the rectified voltage to drive the light emitting diodes; A driving current controller configured to receive a dimming signal indicative of the degree of modulation of the rectified voltage and to control the currents of the driving nodes in accordance with the dimming signal; And a driving circuit for interrupting the currents of the driving nodes when the dimming level of the dimming signal decreases and becomes lower than a first threshold value, and when the dimming level is higher than a second threshold value higher than the first threshold value, And a current interrupting circuit configured to unblock the currents of the transistors.

According to embodiments of the present invention, a light emitting diode drive module having improved operational reliability, a method of operating the same, and a lighting device including the same are provided.

1 is a block diagram showing a lighting apparatus according to an embodiment of the present invention.
Fig. 2 is a circuit diagram showing exemplary embodiments of the light emitting diode group of Fig. 1; Fig.
3 is a circuit diagram showing embodiments of the light emitting circuit, the light emitting diode driver, and the current setting circuit of FIG.
4 is a flowchart illustrating a method of driving light emitting diodes according to an embodiment of the present invention.
5 is a timing diagram illustrating a method of driving light emitting diodes according to an embodiment of the present invention.
6 is a block diagram illustrating a lighting apparatus according to another embodiment of the present invention.
Fig. 7 is a circuit diagram showing an embodiment of the dimming level sensor of Fig. 6; Fig.
8 is a block diagram illustrating a lighting apparatus according to another embodiment of the present invention.
9 is a timing chart showing the rectified voltage, the dimming phase signal, and the clock signal of FIG.
10 is a block diagram illustrating a lighting apparatus according to another embodiment of the present invention.
11 is a flowchart illustrating a method of driving light emitting diodes according to another embodiment of the present invention.
12 is a block diagram illustrating a lighting apparatus according to another embodiment of the present invention.
13 is a flowchart showing a method of driving light emitting diodes according to another embodiment of the present invention.
14 is a block diagram showing an application example of a lighting apparatus according to an embodiment of the present invention.

In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of various embodiments. It will be apparent, however, that the various embodiments may be practiced without these specific details, or with one or more equivalents. In other instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the various embodiments unnecessarily.

In the drawings, the sizes or relative sizes of layers, films, panels, regions, etc. may be exaggerated for clarity and illustration purposes. Also, like reference numerals designate like elements.

If an element or layer is described as being "connected" to another element or layer, this includes not only being directly connected, but also indirectly connecting it with another element or layer in between . However, if a part is described as "directly connected" to another part, it means that there are no other elements between that part and the other part. At least one selected from the group consisting of "X, Y and Z and at least one selected from the group consisting of X, Y and Z" is X, Y, Z, (E.g., XYZ, XYY, YZ, ZZ). Herein, "and / or" includes all combinations of one or more of the corresponding configurations.

The terms first, second, etc. may be used herein to describe various elements, structures, regions, layers, and / or sections, but such elements, Or sections are not limited to these terms. These terms are used to distinguish one element, configuration, region, layer, and / or section from another element, configuration, region, layer, and / or section. Thus, the first element, configuration, region, layer, and / or section in an embodiment may be referred to as a second element, configuration, region, layer, and / or section in another embodiment.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. Throughout the specification, when a component is referred to as "comprising ", it means that it can include other components as well, without departing from the other components unless specifically stated otherwise. Unless defined otherwise, terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

1 is a block diagram showing a lighting device 100 according to an embodiment of the present invention. Fig. 2 is a circuit diagram showing exemplary embodiments of the light emitting diode group of Fig. 1; Fig.

1, the lighting apparatus 100 includes a dimmer 115, a rectifier 120, a rectifier 120, a light emitter 130, a light emitter 130, and a rectifier 130. The rectifier 120 is connected to the AC power source 110 and receives the AC voltage Vac. A driving current setting circuit 150, a driving current controller 160, a current blocking circuit 170, and a direct current (DC) And may include a power source 180 (DC Power Source).

The dimmer 115 receives the AC voltage Vac from the AC power supply 110 and modulates the AC voltage Vac according to the user's control (or selection) for dimming the light emitting circuit 130, Voltage can be output.

As an embodiment, the dimmer 115 may include a triac dimmer that uses TRIAC to phase-cut the AC voltage Vac, a pulse width dimmer that modulates the pulse width of the AC voltage Vac, and the like Can be used.

When the dimmer 115 is a triac dimmer, the dimmer 115 can output the modulated AC voltage by cutting the phase of the AC voltage Vac under the control of the user. At this time, control for the TRIAC Trigger Current may be required. To this end, the light modulation apparatus 100 may further include a bleeder circuit (not shown) connected between the dimmer 115 and the rectifier 120. The bleeder circuit may include, for example, a bleeder capacitor and a bleeder resistor.

In FIG. 1, a dimmer 115 is shown as being provided as a component of the illumination device 100. However, the embodiments of the present invention are not limited thereto. The dimmer 115 may be disposed outside the illumination device 100 and may be electrically connected to the illumination device 100.

The rectifier 120 is configured to rectify the alternating voltage modulated by the dimmer 115 and output the rectified voltage Vrct through the first power supply node VPND and the second power supply node VNND. The rectified voltage Vrct is output to the light emitting circuit 130.

As an embodiment, the illumination device 100 may further include a surge protection circuit (not shown) configured to protect the internal structures of the illumination device 100 from overvoltage and / or overcurrent. The surge protection circuit may, for example, be connected between the first and second power supply nodes (VPND, VNND).

The light emitting circuit 130 is connected between the first and second power supply nodes VPND and VNND. The light emitting circuit 130 receives the rectified voltage Vrct through the first and second power supply nodes VPND and VNND and emits light using the rectified voltage Vrct.

The light emitting circuit 130 operates under the control of the light emitting diode driver 140. The light emitting circuit 130 may include a first light emitting diode group (LED1), a second light emitting diode group (LED2), and a capacitor (Cp). The first and second light emitting diode groups LED1 and LED2 and the capacitor Cp are connected to the light emitting diode driver 140 through the driving nodes D1 and D2. In Fig. 1, the light emitting circuit 130 is shown as including two light emitting diode groups (LED1, LED2) and a capacitor Cp, but the embodiments of the present invention are not limited thereto. The number of the light emitting diode groups included in the light emitting circuit 130 and the number of capacitors, the connection relationship between the light emitting diode groups and the capacitors, the number of the driving nodes connecting the light emitting diode groups and the capacitors to the light emitting diode driver 140 And can be variously changed.

Each of the first and second light emitting diode groups LED1 and LED2 may include at least one light emitting diode. The number of light emitting diodes included in each light emitting diode group, and the connection relationship of light emitting diodes may be variously changed. Exemplary embodiments of each light emitting diode group are shown in Figures 2A-2D. Referring to FIG. 2A, each light emitting diode group may include a plurality of light emitting diodes connected in series. Referring to FIG. 2B, each light emitting diode group may include a plurality of light emitting diodes connected in parallel. Referring to FIG. 2C, each light emitting diode group includes subgroups connected in parallel to each other, and each subgroup may include light emitting diodes connected in series. Referring to FIG. 2d, each LED group includes subgroups connected in series, and each subgroup may include a plurality of LEDs connected in parallel. According to these embodiments, the first light emitting diode group LED1 and the second light emitting diode group LED2 may have the same forward voltage or different forward voltages. The forward voltage is a threshold voltage capable of driving the light emitting diode group.

Referring again to FIG. 1, the first and second light emitting diode groups LED1 and LED2 may be connected in series between the first power supply node VPND and the second driving node D2. The capacitor Cp may be connected between the output end of the first light emitting diode group LED1 (or the input end of the LED2) and the first drive node D1. The capacitor Cp is charged and discharged according to the level of the rectified voltage Vrct and can provide current to at least one of the first and second light emitting diode groups LED1 and LED2 when discharging. The first and second light emitting diode groups LED1 and LED2 can emit light even when the level of the rectified voltage Vrct is lowered by the capacitor Cp.

As an embodiment, the light emitting circuit 130 may further include first to fifth diodes DID1 to DID5 for preventing backflow. The first diode DID1 is connected between the first power supply node VPND and the first light emitting diode group LED1 and blocks the current flowing from the first light emitting diode group LED1 to the first power supply node VPND . The second diode DID2 is connected between the output terminal of the first light emitting diode group LED1 or the input terminal of the LED 2 and the capacitor Cp and is connected from the capacitor Cp to the output terminal of the first light emitting diode group LED1 It blocks the current flowing. The third diode DID3 is connected to the input terminal of the capacitor Cp and the first light emitting diode group LED1 and blocks the current flowing from the input terminal of the first light emitting diode group LED1 to the capacitor Cp. The fourth and fifth diodes DID4 and DID5 are connected between the ground node (i.e., VNND) and the first driving node D1 and the branch node between the fourth and fifth diodes DID4 and DID5 And is connected to the capacitor Cp. The fourth diode DID4 blocks the current flowing from the corresponding branch node to the ground node, and the fifth diode DID5 blocks the current flowing from the first drive node D1 to the corresponding branch node.

The light emitting diode driver 140 is connected to the light emitting circuit 130 through the first and second driving nodes D1 and D2. The light emitting diode driver 140 is configured to drive the light emitting circuit 130 by applying first and second driving currents DI1 and DI2 to the first and second driving nodes D1 and D2, respectively. The higher the level of each driving current, the larger the amount of light emitted by the light emitting diode group through which the driving current flows.

The light emitting diode driver 140 adjusts the level of each of the first and second driving currents DI1 and DI2 according to the voltage of the current setting node DISND. The voltage of the current setting node DISND may be a DC voltage. When the voltage of the current setting node DISND increases, the light emitting diode driver 140 may increase the levels of the first and second driving currents DI1 and DI2. When the voltage of the current setting node DISND decreases, the light emitting diode driver 140 may decrease the levels of the first and second driving currents DI1 and DI2.

The driving current setting circuit 150 adjusts the voltage of the current setting node DISND in accordance with the driving current control signal DICS. The driving current control signal DICS may have a DC voltage.

It is understood that the relationship between the voltage level of the drive current control signal DICS and the voltage level of the current setting node DISND can be changed according to the internal components of the drive current setting circuit 150. [ For example, the driving current setting circuit 150 can reduce the voltage of the current setting node DISND as the voltage of the driving current control signal DICS decreases. As another example, the driving current setting circuit 150 may decrease the voltage of the current setting node DISND as the voltage of the driving current control signal DICS increases. Hereinafter, for convenience of explanation, it is assumed that the driving current setting circuit 150 is configured to decrease the voltage of the current setting node DISND as the voltage of the driving current control signal DICS decreases.

The driving current controller 170 receives the dimming signal DS. At this time, the dimming signal DS may have a dimming level determined according to the degree of modulation of the rectified voltage Vrct.

The dimming signal DS provided to the driving current controller 170 may be provided in various ways. In this embodiment, the dimming signal DS may be generated by the dimmer 115 and provided to the driving current controller 170 via the dimming node ADIMND shown in Fig.

As an embodiment, the dimming signal DS may be a DC voltage indicating the dimming level. For example, the dimming signal DS may be a DC voltage having a level between 0V and 3V. As another example, the dimming signal DS may be a pulse width modulated signal indicative of the dimming level. In such a case, the drive current controller 160 may comprise components such as an integrator circuit for converting the pulse width modulated signal to a voltage level.

The driving current controller 170 is configured to adjust the driving current control signal DICS according to the dimming level indicated by the dimming signal DS. As the dimming level increases, the voltage level of the driving current control signal DICS increases, and as the dimming level decreases, the voltage level of the driving current control signal DICS may decrease.

The current interruption circuit 170 receives the dimming signal DS. The current interruption circuit 170 is configured to monitor the dimming signal DS and output the blocking signal STS when the dimming level is relatively low. The blocking signal STS may be provided to the driving current setting circuit 150. [ When the blocking signal STS is enabled, the driving current setting circuit 150 may control the light emitting diode driver 140 to block the driving currents DI1 and DI2. When the blocking signal STS is disabled, the driving current setting circuit 150 may control the light emitting diode driver 140 to unblock the driving currents DI1 and DI2.

In another embodiment, the blocking signal STS may be provided to the light emitting diode driver 140. The light emitting diode driver 140 can cut off the driving currents DI1 and DI2 in response to the blocking signal STS. For example, components such as an operational amplifier included in the LED driver 140 may be deactivated in response to the blocking signal STS.

The driving currents DI1 and DI2 are cut off according to the dimming level so that it is possible to prevent the light emitting circuit 130 from exhibiting unintended luminescence characteristics due to the low dimming level. For example, flicker of the light emitting diode groups LED1 and LED2 can be prevented. Therefore, the operational reliability of the lighting apparatus 100 can be improved. This will be described in detail with reference to Fig.

The current interruption circuit 170 includes a hysteresis comparator 171. [ The hysteresis comparator 171 enables the blocking signal STS when the dimming level indicated by the dimming signal DS is lowered to be lower than the first threshold value and when the dimming level is higher than the second threshold value, STS) can be disabled. At this time, the second threshold value is higher than the first threshold value.

It is assumed that the current interruption circuit 170 generates the blocking signal STS depending on whether the dimming level is lower than one threshold value. Due to noise included in the dimming signal DS, intentional adjustment of the dimming signal DS, etc., the dimming level may vary in a range similar to the threshold value. Accordingly, the blocking signal STS can be repeatedly enabled and disabled. This means that the driving currents DI1 and DI2 are repeatedly blocked and unblocked so that the light emitting diodes of the light emitting circuit 130 flicker.

According to the embodiment of the present invention, the current interruption circuit 170 can generate the shutoff signal STS using the hysteresis method. Thus, flicker of the light emitting diode groups (LED1, LED2) can be effectively prevented even if the dimming level varies in a relatively low range. Therefore, the operational reliability of the lighting apparatus 100 can be improved.

The DC power source 180 is connected between the first power supply node VPND and the second power supply node VNND and is configured to generate the DC voltage VCC using the rectified voltage Vrct. As another example, the DC power source 180 may generate the DC voltage VCC using the AC voltage Vac or the output voltage of the dimmer 115. [ As an example, the DC power source 180 may be a band gap reference circuit. The direct current voltage VCC may be provided as an operating voltage of the light emitting diode driver 140, the driving current setting circuit 150, the driving current controller 160, and the current cutoff circuit 170.

FIG. 3 is a circuit diagram showing embodiments of the light emitting circuit 130, the light emitting diode driver 140, and the current setting circuit 150 of FIG.

3, the light emitting diode driver 140 is connected to the light emitting circuit 130 through the first and second driving nodes D1 and D2 and is connected to the driving current setting circuit And a resistance circuit 142 connected to the light emitting diode driving circuit 141 through the first and second source nodes S1 and S2.

The light emitting diode driving circuit 141 includes a first transistor TR1 and a first comparator OP1 for controlling the first driving node D1 and a second transistor TR2 for controlling the second light emitting node D2 And a second comparator OP2.

The first transistor TR1 is connected between the first driving node D1 and the first source node S1. The first comparator OP1 has an output terminal connected to the gate of the first transistor TR1, and an inverting terminal connected to the first source node S1. The second transistor TR2 is connected between the second driving node D2 and the second source node S2. The second comparator OP2 has an output terminal connected to the gate of the second transistor TR2 and an inverting terminal connected to the second source node S2. The non-inverting terminals of the first and second comparators OP1 and OP2 may be connected in common to the current setting node DISND. The first and second transistors TR1 and TR2 may be NMOS transistors.

When the voltage of the first source node S1 is lower than the voltage of the current setting node DISND, the first transistor TR1 can be turned on by the output of the first comparator OP1. The first transistor TR1 can be turned off by the output of the first comparator OP1 when the voltage of the first source node S1 becomes higher than the voltage of the current setting node DISND by the rectified voltage Vrct have. In this manner, the first transistor TR1 can be turned on and off repeatedly. Accordingly, the voltage of the current setting node DISND can be reflected to the voltage of the first source node S1. Similarly, the voltage of the current setting node DISND may be reflected to the voltage of the second source node S2.

The first source resistance Rs1 is connected between the first source node S1 and the ground node. Therefore, according to the voltage of the first source node S1 and the first source resistance Rs1, the level of the first drive current DI1 can be determined. The second source resistance Rs2 is connected between the second source node S2 and the first source node S1. Therefore, the level of the second driving current DI2 can be determined according to the sum of the voltage of the second source node S2 and the first and second source resistances Rs1 and Rs2. For example, the level of the second driving current DI2 may be lower than the level of the first driving current DI1.

In this way, the levels of the first and second driving currents DI1 and DI2 can be respectively controlled according to the voltage of the current setting node DISND. As the voltage of the current setting node DISND increases, the level of each of the first and second driving currents DI1 and DI2 may increase.

The driving current setting circuit 150 may include a voltage regulator 151 and a setting resistor Rset.

The setting resistor Rset is connected between the current setting node DISND and the ground node. The setting resistance Rset has a predetermined resistance value such that the voltage of the current setting node DISND falls within a desired voltage range. A set capacitor Cset connected in parallel to the set resistor Rset may be further provided to eliminate the voltage noise of the current setting node DISND.

The voltage regulator 151 applies a voltage to the current setting node DISND in accordance with the driving current control signal DICS. Voltage regulator 151 may include a variable current source that generates a varying current in accordance with the drive current control signal DICS.

The drive current setting circuit 150 receives the shutoff signal STS from the current shutoff circuit 170. The driving current setting circuit 150 can cut off the driving currents DI1 and DI2 when the blocking signal STS is received. It will be appreciated that drive currents DI1 and DI2 may be blocked using various schemes. For example, the drive current setting circuit 150 may block the drive currents DI1 and DI2 by applying a ground voltage to the current setting node DISND in response to the shutoff signal STS. Alternatively, the driving current setting circuit 150 may block the driving currents DI1 and DI2 by deactivating the first and second comparators OP1 and OP2 of the light emitting diode driver 140 in response to the blocking signal STS .

4 is a flowchart illustrating a method of driving light emitting diodes according to an embodiment of the present invention.

Referring to FIGS. 1 and 4, in step S110, a dimming signal DS is received. In step S120, it is determined whether or not the dimming level indicated by the dimming signal DS decreases and becomes lower than the first threshold value. If so, step S150 is performed. If not, step S130 is performed.

In step S130, it is determined whether or not the dimming level increases and becomes higher than the second threshold value, which is higher than the first threshold value. If so, step S140 is performed.

The driving currents DI1 and DI2 corresponding to the dimming signal DS are applied to the light emitting circuit 130 in step S140. The driving currents DI1 and DI2 are applied according to the rectified voltage Vrct so that the light emitting diode groups LED1 and LED2 can emit light. If the driving currents DI1 and DI2 are cut off before step S140, the driving currents DI1 and DI2 are unblocked in step S140. If the driving currents DI1 and DI2 flow before step S140, the driving currents DI1 and DI2 are continuously applied in step S140.

In step S150, the driving currents DI1 and DI2 applied to the light emitting circuit 130 are cut off.

According to the embodiment of the present invention, the driving currents DI1 and DI2 are blocked according to the dimming level, thereby preventing the light emitting circuit 130 from exhibiting unintended luminescence characteristics due to a low dimming level. Further, by comparing the dimming level with the first and second thresholds to block and unblock the driving currents DI1 and DI2, even if the dimming level varies in a range similar to the first and second thresholds, Flickering of the groups LED1 and LED2 can be effectively prevented.

5 is a timing diagram illustrating a method of driving light emitting diodes according to an embodiment of the present invention.

Referring to Figs. 1 and 5, a rectified voltage Vrct is received. The rectified voltage Vrct can be phase-cut by the user's choice. In Fig. 5, seven phases (PRD1 to PRD7) of the rectified voltage (Vrct) are illustratively shown. The phase of each of the plurality of periods PRD1 to PRD7 of the rectified voltage Vrct can be adjusted by the user's selection.

At the first time t1, the rectified voltage Vrct of the first period PRD1 increases to reach the first voltage Vf1. The dimming signal DS having a dimming level determined according to the degree of modulation of the rectified voltage Vrct is received. For example, the dimming level may correspond to the area indicated by each period of the rectified voltage Vrct. In Fig. 5, it is exemplified that the dimming signal DS is provided as a DC voltage. In this case, the dimming level may be the level of the DC voltage. Since the voltage level of the dimming signal DS is higher than the first threshold value Vth1, the blocking signal STS can be disabled. For example, the blocking signal STS may have a logic value of zero. Accordingly, the first and second driving currents DI1 and DI2 are applied according to the rectified voltage Vrct to drive the light emitting circuit 130. [

The manner in which the light emitting circuit 130 is driven in accordance with the level of the rectified voltage Vrct includes the components of the light emitting circuit 130, the connection relationship between the components, the light emitting circuit 130 and the light emitting diode driver 140, And the number of driving nodes between the driving nodes. Hereinafter, the manner in which the light emitting circuit 130 is driven based on the light emitting circuit 130 shown in FIG. 1 will be described.

The first voltage Vf1 may be the sum of the forward voltages of the first and second light emitting diode groups LED1 and LED2. At this time, the input current from the first power supply node VPND flows through the first and second LED groups LED1 and LED2 and the second driving node D2 to apply the second driving current DI2 have. Accordingly, the first and second light emitting diode groups LED1 and LED2 emit light.

At the second time t2, the rectified voltage Vrct of the first period PRD1 further increases to reach the second voltage Vf2. The second voltage Vf2 may be the sum of the forward voltage of the first light emitting diode group LED1 and the voltage across the capacitor Cp. That is, the voltage across the capacitor Cp may be higher than the forward voltage of the second light emitting diode group LED2. At a second time t2, the input current from the first power supply node VPND flows through the first light emitting diode group LED1, the capacitor Cp, and the first driving node D1 to generate the first driving current DI1) can be applied. Accordingly, the first light emitting diode group LED1 emits light and the capacitor Cp is charged.

3, the first and second driving currents DI1 and DI2 commonly flow through the resistor Rs1 to ground and the second driving current DI2 flows through the first driving current DI1 and the second driving current DI2. And further passes through the resistor Rs2 to reach the resistor Rs1. Thus, due to the flow of the first driving current DI1 at the second time t2, the second driving current DI2 can be blocked because it has to further pass the resistance Rs2. For example, when the first drive current DI1 starts to flow, the second drive current DI2 can be gradually shut off. As a result, the first driving current DI1 is applied between the second time t2 and the third time t3.

At the third time t3, the rectified voltage Vrct of the first period PRD1 becomes lower than the second voltage Vf2. That is, the level of the rectified voltage Vrct is lower than the sum of the forward voltage of the first light emitting diode group LED1 and the voltage across the capacitor Cp. Therefore, the first driving current DI1 flowing through the first light emitting diode group LED1, the capacitor Cp, and the first driving node D1 is cut off. On the other hand, the rectified voltage Vrct of the first period PRD1 at the third time t3 is higher than the first voltage Vf1. The second driving current DI2 flows from the first power supply node VPND through the first and second light emitting diode groups LED1 and LED2 and the second driving node D2.

At the fourth time t4, the rectified voltage Vrct of the first period PRD1 further decreases and becomes lower than the first voltage Vf1. That is, the level of the rectified voltage Vrct is lower than the sum of the forward voltages of the first and second light emitting diode groups LED1 and LED2. Accordingly, the second driving current DI2 flowing through the first and second light emitting diode groups LED1 and LED2 and the second driving node D2 is cut off.

On the other hand, the voltage across the charged capacitor Cp may be higher than the first voltage Vf1. Charges charged in the capacitor Cp flow through the first and second light emitting diode groups LED1 and LED2 and the second driving node D2 to apply the second driving current DI2. For example, while the level of the rectified voltage Vrct is lower than the voltage across the capacitor Cp, the second driving current DI2 can flow through the charges charged in the capacitor Cp.

At the fifth time t5, the rectified voltage Vrct of the second period PRD2 is higher than the second voltage Vf2. The input current of the first power supply node VPND may flow through the first light emitting diode group LED1, the capacitor Cp and the first driving node D1 to apply the first driving current DI1. On the other hand, the voltage level of the dimming signal DV corresponding to the second period PRD2 is lower than the first period PRD1. Therefore, the first driving current DI1 flowing in the second period PRD2 may be lower than the first driving current DI1 flowing in the first period PRD1.

At the sixth time t6, the rectified voltage Vrct of the second period PRD2 is lower than the second voltage Vf2 and higher than the first voltage Vf1. The first drive current DI1 is interrupted and the input current of the first power supply node VPND flows through the first and second light emitting diode groups LED1 and LED2 and the second drive node D2, The current DI2 can be applied. On the other hand, since the voltage of the dimming signal DV corresponding to the second period PRD2 is lower than the first period PRD1, the second driving current DI2 flowing in the second period PRD2 is lower than the first period PRD1 The second driving current DI2 may be lower than the second driving current DI2.

At the seventh time t7, the rectified voltage Vrct of the first period PRD1 further decreases and becomes lower than the first voltage Vf1. The second driving current DI1 flowing from the first power supply node VPND1 is cut off and the charges of the capacitor Cp are applied to the first and second light emitting diode groups LED1 and LED2 and the second driving node D2 The second driving current DI2 is applied.

The operations of the eighth time t8, the ninth time t9 and the tenth time t10 in the third period PRD3 are the fifth time t5 in the second period PRD2, t6), and seventh time (t7), respectively. The operation of the eleventh time t11, the twelfth time t12 and the thirteenth time t13 in the fourth period PRD4 is also the fifth time t5 and the sixth time t6 in the second period PRD2 t6), and seventh time (t7), respectively. In each period, the light emitting circuit 130 is driven by receiving the first and second driving currents DI1 and DI2 according to the level of the rectified voltage Vrct.

In the fifth period PRD5, the voltage level of the dimming signal DS decreases and becomes lower than the first threshold value Vth1. Thus, the blocking signal STS is enabled. For example, the shutdown signal TS may be transitioned to a logical value 1. In response to the blocking signal STS being enabled, the driving currents DI1 and DI2 applied to the light emitting circuit 130 are cut off.

It is assumed that the driving currents DI1 and DI2 are not blocked even though the voltage level of the dimming signal DS is lower than the first threshold value Vth1. The rectified voltage Vrct of the fifth period PRD5 has a voltage level higher than the first voltage Vf1 but does not have a voltage level higher than the second voltage Vf2. When the rectified voltage Vrct of the fifth period PRD5 begins to be supplied, the input current of the first power supply node VPND1 is supplied to the first and second light emitting diode groups LED1 and LED2 and the second driving node D2, It is possible to apply the second driving current DI2. Then, when the rectified voltage Vrct of the fifth period PRD5 becomes lower than the first voltage Vf1, the second driving current DI2 flowing from the first power supply node VPND1 is cut off, Charges can flow through the first and second light emitting diode groups LED1 and LED2 and the second driving node D2 to apply the second driving current DI2. In the fifth period PRD5, the input current of the first power supply node VPND1 does not flow through the first light emitting diode group LED1 and the capacitor Cp. Therefore, the capacitor Cp can not be charged. If cycles having a degree of modulation similar to the fifth period PRD5 following the fifth period PRD5 are repeatedly received, the capacitor Cp may be discharged. This means that the second driving current DI2 can not be applied from the charges of the capacitor Cp, so that the light emitting circuit 130 may unintentionally flicker at some time intervals of each period. That is, when the driving currents DI1 and DI2 are not blocked even though the voltage level of the dimming signal DS is lower than the first threshold value Vth1, the light emitting circuit 130 exhibits unintended luminescence characteristics .

According to the embodiment of the present invention, when the voltage level of the dimming signal DS decreases and becomes lower than the first threshold value Vth1, the blocking signal STS is applied to the driving currents DI1 and DI2 Is blocked. Therefore, it is possible to prevent the light emitting circuit 130 from exhibiting unintended luminescence characteristics.

In the sixth period PRD6, the voltage level of the dimming signal DS is lower than the second threshold value Vth2. At this time, the second threshold value Vth2 is higher than the first threshold value Vth1. Since the voltage level of the dimming signal DS is lower than the second threshold value Vth2, the blocking signal STS is continuously enabled. In the sixth period PRD6, the voltage level of the dimming signal DS may be higher than the first threshold Vth1, but lower than the second threshold Vth2.

It is assumed that the driving currents DI1 and DI2 are unblocked in response to the voltage level of the dimming signal DS being higher than the first threshold value Vth1. The driving currents DI1 and DI2 can be repeatedly blocked and unblocked when periods having dimming levels in a range similar to the first threshold value Vth1 are received subsequent to the sixth period PRD6. This means that the light emitting circuit 130 is inadvertently flickered.

According to the embodiment of the present invention, by unblocking the driving currents DI1 and DI2 using the second threshold value Vth2 higher than the first threshold value Vth1, the light emitting circuit 130 unintentionally flickers the flicker Can be prevented.

In the seventh period PRD7, the dimming level of the dimming signal DS increases and becomes higher than the second threshold value Vth2. Thus, the blocking signal STS can be disabled, for example, by a logic value of zero. This means that the driving currents DI1 and DI2 applied to the light emitting circuit 130 are unblocked. Accordingly, the light emitting circuit 130 can receive the first and second driving currents DI1 and DI2 and emit light according to the level of the rectified voltage Vrct. The operations of the fourteenth time (t14), the fifteenth time (t15), and the sixteenth time (t16) are the fifth time t5, the sixth time t6, and the seventh time t6 in the second period PRD2 (t7), respectively.

6 is a block diagram illustrating a lighting device 200 according to another embodiment of the present invention. 7 is a circuit diagram showing an embodiment of the dimming level sensor 210 of FIG.

Referring to FIG. 6, the lighting apparatus 200 may further include a dimming level sensor 210 configured to output a DC voltage having a level varying according to a rectified voltage Vrct, as a dimming signal DS. The dimming level sensor 210 may average the rectified voltage Vrct and output the dimming signal DS. For example, the dimming level detector 210 outputs a dimming signal DS of 3V when the dimming level selected by the user is 100% and a dimming signal DS of 2.7V when the dimming level selected by the user is 90% And when the dimming level selected by the user is 50%, the dimming signal DS of 1.5V can be outputted.

As an example, the dimming level sensor 210 may be an RC integrator circuit. Referring to FIG. 7, the dimming level sensor 210 may include first and second resistors R11 and R12, and a capacitor C1. The first resistor R11 is connected between the first power supply node VPND and the output node that outputs the dimming signal DS. The second resistor R12 and the capacitor C1 are connected between the output node that outputs the dimming signal DS and the ground (for example, VNND). According to this embodiment, the dimming level sensor 210 may function as an integrating circuit.

8 is a block diagram illustrating a lighting device 300 in accordance with another embodiment of the present invention.

Referring to FIG. 8, the lighting apparatus 300 may further include a dimming level sensor 310 configured to output a count value varying according to the rectified voltage Vrct as a dimming signal DS. At this time, the count value of the dimming signal DS may indicate the dimming level. The dimming level sensor 310 may include a phase detector 311 and a pulse counter 312. The phase detector 311 is configured to output a dimming phase signal DP when the rectified voltage Vrct is at a predetermined voltage level, for example, 0.3V or more. At this time, the light modulation phase signal DP may include information indicating a phase at which the modulated rectified voltage Vrct is provided. The pulse counter 312 receives the clock signal CLK. The pulse counter 312 is configured to count pulses of the clock signal CLK being toggled while the dimming phase signal DP is received and output the counted value as the dimming signal DS.

The current interruption circuit 320 may enable the blocking signal STS when the received count value decreases and becomes lower than the first threshold value. The current interruption circuit 320 may disable the shutoff signal STS when the received count value increases to be higher than a second threshold value higher than the first threshold value. The current interruption circuit 320 may include a hysteresis comparator 321 for providing such a hysteresis function.

In this embodiment, the drive current controller 360 may include a converter 361 configured to convert the count value to a DC voltage level. Based on the converted DC voltage level, the drive current controller 360 can generate the drive control signal DICS.

9 is a timing chart showing the rectified voltage Vrct, the dimming phase signal DP, and the clock signal CLK in Fig.

Referring to Fig. 9, a modulated rectified voltage Vrct is provided. The dimming phase signal DP can be enabled when the level of the rectified voltage Vrct is higher than the reference voltage Vrf. For example, the reference voltage Vrf may be 0.3V. The time at which the dimming phase signal DP is enabled may be related to the phase at which the modulated rectified voltage Vrct is provided.

The pulses of the clock signal CLK being toggled when the dimming phase signal DP is enabled are counted. In Fig. 9, while the dimming phase signal DP is enabled, seven pulses are counted. The counted value is compared with the first and second thresholds, and the blocking signal STS can be enabled or disabled according to the comparison result.

The rectified voltage Vrct may have a residual voltage (RV) corresponding to noise. When the reference voltage Vrf is set higher than the residual voltage RV, the residual voltage may not be reflected in the dimming level. Thus, according to the present embodiment, a lighting device 300 for detecting a dimming level of improved reliability is provided.

10 is a block diagram illustrating a lighting device 400 in accordance with another embodiment of the present invention.

Referring to FIG. 10, the lighting device 400 may further include a voltage sensing circuit 410. The drive current setting circuit 450 receives the first cutoff signal STS1 from the current cutoff circuit 170 and receives the second cutoff signal STS2 from the voltage sense circuit 410. [ The first blocking signal STS1 is described in the same manner as the blocking signal STS described with reference to Fig. The driving current setting circuit 450 may control the light emitting diode driver 140 to cut off the driving currents DI1 and DI2 in response to the first and second blocking signals STS1 and STS2. As an embodiment, the drive current setting circuit 450 may block the drive currents DI1 and DI2 when at least one of the first and second shutoff signals STS1 and STS2 is enabled.

The voltage sensing circuit 410 is configured to generate the second blocking signal STS2 according to the voltage of the current setting node DISND. As described with reference to FIG. 3, as the voltage of the current setting node DISND increases, the levels of the driving currents DI1 and DI2 may increase. When the voltage of the current setting node DISND becomes unintentionally high, an overcurrent may flow to the driving nodes D1 and D2.

According to an embodiment of the present invention, the voltage sensing circuit 410 may output the second blocking signal STS2 depending on whether the voltage of the current setting node DISND is higher than the threshold voltage. Accordingly, even if the voltage of the current setting node DISND unexpectedly rises, the overcurrent can be prevented from flowing to the driving nodes D1 and D2. Therefore, the light emitting circuit 130 and the light emitting diode driver 140 are protected from the overcurrent.

11 is a flowchart illustrating a method of driving light emitting diodes according to another embodiment of the present invention.

Referring to FIGS. 10 and 11, in step S210, the voltage of the current setting node DISND is sensed. In step S220, it is determined whether or not the voltage of the current setting node DISND is higher than the threshold voltage. If so, step S230 is performed. If not, step S240 is performed.

In step S230, the driving currents DI1 and DI2 applied to the light emitting circuit 130 are cut off. The second blocking signal STS2 may be enabled. The driving currents DI1 and DI2 corresponding to the dimming signal DS are applied to the light emitting circuit 130 in step S240. The second blocking signal STS2 may be disabled.

As another example, a hysteresis function may be provided for voltage sensing of the current setting node DISND. When the voltage of the current setting node DISND increases and becomes higher than the first threshold voltage, the second blocking signal STS2 is enabled so that the driving currents DI1 and DI2 can be cut off. When the voltage of the current setting node DISND decreases and becomes lower than the second threshold voltage lower than the first threshold voltage, the second blocking signal STS2 is disabled so that the driving currents DI1 and DI2 can be applied. In this case, it is possible to prevent the light emitting diode groups (LED1, LED2) from flickering when the voltage of the current setting node DISND changes in a range similar to the threshold voltage.

12 is a block diagram showing a lighting device 500 according to another embodiment of the present invention.

Referring to FIG. 12, the illumination device 500 may further include a current sensing circuit 510 connected to a DC power supply node VCCND for outputting a DC voltage. The lighting apparatus 500 may further include a capacitor C2 connected between the DC power supply node VCCND and ground so that noise of the DC voltage is removed.

The drive current setting circuit 550 receives the first cutoff signal STS1 from the current cutoff circuit 170 and receives the second cutoff signal STS3 from the current sense circuit 510. [ The first blocking signal STS1 is described in the same manner as the blocking signal STS described with reference to Fig. The driving current setting circuit 550 may cut off the driving currents DI1 and DI2 when at least one of the first and third blocking signals STS1 and STS3 is enabled.

The DC voltage may be supplied to an external device (not shown) via the DC power supply node VCCND as well as to the components inside the illumination device 500 via the DC power supply node VCCND. When an overcurrent is output to the external device through the DC power supply node (VCCND), normal operation of the lighting device 500 may not be ensured. In this case, operational reliability of the lighting apparatus 500 can not be guaranteed. According to an embodiment of the present invention, the current sensing circuit 510 is configured to generate a third blocking signal STS3, depending on whether the current of the DC power supply node VCCND is higher than the threshold current. Thus, the output of the overcurrent through the DC power supply node (VCCND) is prevented.

13 is a flowchart showing a method of driving light emitting diodes according to another embodiment of the present invention.

12 and 13, in step S310, the current of the DC power supply node VCCND is sensed. In step S320, it is determined whether or not the current of the DC power supply node VCCND is higher than the threshold current. If so, step S330 is performed. If not, step S340 is performed.

In step S330, the driving currents DI1 and DI2 applied to the light emitting circuit 130 are cut off. The third blocking signal STS3 may be enabled. The driving currents DI1 and DI2 corresponding to the dimming signal DS are applied to the light emitting circuit 130 in step S340. The third blocking signal STS3 may be disabled.

As another example, a hysteresis function may be provided for current sensing of the DC power supply node (VCCND). The third blocking signal STS3 is enabled when the current of the DC power supply node VCCND increases to become higher than the first threshold current so that the driving currents DI1 and DI2 can be cut off. When the current of the DC power supply node VCCND decreases and becomes lower than the second threshold voltage lower than the first threshold current, the third blocking signal STS3 may be disabled and the driving currents DI1 and DI2 may be applied. In this case, flickering of the light emitting diode groups (LED1, LED2) can be prevented when the voltage of the DC power supply node (VCCND) changes in a range similar to the threshold current.

FIG. 14 is a block diagram showing an application example 1000 of a lighting apparatus according to an embodiment of the present invention.

Referring to Fig. 14, the lighting apparatus 1000 is connected to the AC voltage 1100. Fig. The lighting apparatus 1000 includes a dimmer 1150, a rectifier 1200, a light emitting circuit 1300, a light emitting diode driving circuit 1410, a voltage regulator 1510, a driving current controller 1600, a current interrupting circuit 1700, A DC power source 1800, a voltage sensing circuit 1900, a current sensing circuit 2000, a capacitor C1, a set resistor Rset, a set capacitor Cset, and first and second source resistors Rs1, Rs2).

The lighting apparatus 1000 may further include a fuse 1160. The fuse 1160 can electrically disconnect the lighting apparatus 1000 from the AC power source 1100 when a high voltage unintendedly applied, for example, from the AC voltage 1100 is applied.

A current control circuit 1600, a current cutoff circuit 1700, a DC power source 1800, a voltage sensing circuit 1900, and a current sensing circuit 2000 And may be mounted on one semiconductor chip (CHP) as a light emitting diode driving module. The light emitting diode driving circuit 1410 and the voltage regulator 1510 may be configured similarly to the light emitting diode driving circuit 141 and the voltage regulator 151 described with reference to FIG. The drive current controller 1600, the current interruption circuit 1700 and the DC power source 1800 are connected to the drive current controller 160, the current interruption circuit 170, and the DC power source 180 described with reference to Fig. Respectively. At this time, the driving current controller 1600 and the current interruption circuit 1700 can receive the dimming signal DS (see FIG. 1) through the dimming node ADIMND. The voltage sensing circuit 1900 and the current sensing circuit 2000 may be configured similarly to the voltage sensing circuit 410 of FIG. 10 and the current sensing circuit 510 of FIG. 12, respectively. The current interrupting circuit 1700, the voltage sensing circuit 1900 and the current sensing circuit 2000 are connected to the first to third blocking signals STS1 and STS2 , STS3), respectively. The voltage regulator 1510 may block or unblock the driving currents according to the generated first to third blocking signals STS1, STS2, and STS3.

As an example, the semiconductor chip CHP may further include at least one of the dimming level detectors 210, 310 described with reference to FIGS. In this case, the driving current controller 1600 and the current cutoff circuit 1700 can receive the dimming signal DS through the corresponding dimming level sensor.

The semiconductor chip CHP may further include a bleeder circuit 2100. The bleeder circuit 2100 can control the triac arc current between the first and second bleeder nodes BLDR1 and BLDR2. The bleeder circuit 2100 may be connected to suitable nodes according to the location of the dimmer 1150 in the illumination device 1000 and the like, depending on the characteristics of the dimmer 1150, according to embodiments of the lighting device 1000. In an embodiment, the first and second bleeder nodes BLDR1 and BLDR2 may be connected to the first and second nodes ND1 and ND2, respectively. In another embodiment, the first and second bleeder nodes BLDR1 and BLDR2 may be connected to the third and fourth nodes ND3 and ND4, respectively.

The capacitor C2 is connected between the DC voltage node VCCND and ground as described with reference to FIG. 12 to eliminate the DC voltage noise. The lighting apparatus 100 may provide a DC voltage to an external device (not shown) through the DC voltage node VCCND. The set resistor Rset and the set capacitor Cset are connected to the voltage regulator 1510 through the current setting node DISND and are connected in parallel to the set resistor Rset and the set capacitor Cset . The first and second source resistors Rs1 and Rs2 are connected to the light emitting diode driving circuit 1410 through the first and second source nodes S1 and S2 respectively and are connected to the first And the second source resistors Rs1 and Rs2.

The capacitor C2, the setting resistor Rset, the setting capacitor Cset, and the first and second source resistors Rs1 and Rs2 may be disposed outside the semiconductor chip CHP. In this case, the impedances of the capacitor C2, the setting resistance Rset, the setting capacitor Cset, and the source resistances Rs1 and Rs2 can be suitably selected according to the user's request.

As described above, the present invention has been described with reference to particular embodiments, such as specific elements, and specific embodiments and drawings. However, it should be understood that the present invention is not limited to the above- And various modifications and changes may be made thereto by those skilled in the art to which the present invention pertains.

Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

100: Lighting device
130: Light emitting circuit
140: Light emitting diode driver
141: Light-emitting diode driving circuit
150: drive current setting circuit
151: voltage regulator
160: Driving current controller
170: current interruption circuit
171: Hysteresis comparator

Claims (17)

A light emitting diode driving circuit connected to driving nodes through light emitting diodes receiving modulated rectified voltage for dimming and driving the light emitting diodes by applying currents to the driving nodes according to a level of the rectifying voltage;
A driving current controller configured to receive a dimming signal indicative of the degree of modulation of the rectified voltage and to control the currents of the driving nodes in accordance with the dimming signal; And
When the dimming level of the dimming signal decreases and becomes lower than the first threshold value, the currents of the driving nodes are blocked, and when the dimming level is increased to be higher than a second threshold value higher than the first threshold value, And a current interruption circuit configured to unblock the currents. The method according to claim 1,
Wherein the current interruption circuit enables a blocking signal when the dimming level of the dimming signal is lowered to a level lower than the first threshold value and when the dimming level is higher than a second threshold value higher than the first threshold value, Disables the signal,
And wherein the currents of the drive nodes are blocked when the blocking signal is enabled. The method according to claim 1,
Wherein the light emitting diode driving circuit is connected to a current setting node and adjusts the currents of the driving nodes according to a voltage of the current setting node,
The driving current controller controls the voltage of the current setting node according to the dimming signal,
And a voltage sensing circuit configured to block the currents of the driving nodes when the voltage of the current setting node is higher than a first threshold voltage. The method of claim 3,
The voltage sensing circuit includes:
The current setting node is turned off when the voltage of the current setting node is increased and becomes higher than the first threshold voltage, and when the voltage of the current setting node is decreased and becomes lower than the second threshold voltage, And is configured to unblock the current,
Wherein the second threshold voltage is lower than the first threshold voltage. The method according to claim 1,
Further comprising a DC power source configured to generate a DC voltage using the rectified voltage,
The DC voltage is provided to the outside through an output node,
And to block the currents of the drive nodes when the current of the output node is higher than the first threshold current. 6. The method of claim 5,
The current sensing circuit comprising:
Blocking the currents of the drive nodes when the current of the output node is increased to be higher than the first threshold current and decreasing the currents of the drive nodes when the current of the output node is decreased and becomes lower than the second threshold current Unblocking < / RTI >
Wherein the second threshold current is lower than the first threshold current. The method according to claim 1,
Further comprising a dimming level sensor having a resistance-capacitor integration circuit,
And the dimming level sensor integrates the rectified voltage to output the dimming signal. 8. The method of claim 7,
Wherein the dimming level is a voltage level of the dimming signal. The method according to claim 1,
A phase detector for outputting a dimming phase signal when the rectified voltage is equal to or higher than a predetermined level; And
Further comprising a pulse counter configured to receive a clock signal and count pulses of the clock signal that are toggled when the dimming phase signal is output,
Wherein the dimming signal indicates the number of pulses counted. 10. The method of claim 9,
Wherein the dimming level is a number of the counted pulses. A method of driving light-emitting diodes operated with modulated rectified voltage for dimming and controlled through driving nodes, the method comprising:
Receiving a dimming signal indicative of the degree of modulation of the rectified voltage;
Controlling the currents of the driving nodes according to the dimming signal to drive the light emitting diodes;
Blocking the currents of the driving nodes when the dimming level of the dimming signal decreases and becomes lower than a first threshold value; And
And unblocking the currents of the driving nodes when the dimming level of the dimming signal increases and becomes higher than a second threshold value higher than the first threshold value. 12. The method of claim 11,
In the step of driving the light emitting diodes according to the dimming signal,
The voltage of the current setting node is controlled based on the dimming signal,
Wherein the currents of the drive nodes are adjusted according to the voltage of the current setting node. 13. The method of claim 12,
And blocking the currents of the drive nodes when the voltage of the current setting node is higher than a first threshold voltage. 14. The method of claim 13,
The currents of the drive nodes are cut off when the voltage of the current setting node is increased to be higher than the first threshold voltage and when the voltage of the current setting node is decreased to be lower than the second threshold voltage, The currents are unblocked,
Wherein the second threshold voltage is lower than the first threshold voltage. 12. The method of claim 11,
Generating a direct current voltage using the rectified voltage, wherein the direct current voltage is provided to the outside through an output node; And
And blocking the currents of the drive nodes when the current of the output node is higher than a first threshold current. 16. The method of claim 15,
Wherein the currents of the drive nodes are cut off when the current of the output node is increased to be higher than the first threshold current and when the current of the output node is decreased to be lower than the second threshold current, Unblocked,
Wherein the second threshold current is lower than the first threshold current. Light emitting diodes receiving modulated rectified voltage for dimming; And
And a light emitting diode driving module connected to the light emitting diodes through driving nodes,
The light emitting diode driving module includes:
A light emitting diode driving circuit configured to drive the light emitting diodes by applying currents to the driving nodes according to a level of the rectified voltage;
A driving current controller configured to receive a dimming signal indicative of the degree of modulation of the rectified voltage and to control the currents of the driving nodes in accordance with the dimming signal; And
When the dimming level of the dimming signal decreases and becomes lower than the first threshold value, the currents of the driving nodes are blocked, and when the dimming level is increased to be higher than a second threshold value higher than the first threshold value, And a current blocking circuit configured to unblock the currents.

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