KR20180054148A - Apparatus of driving a light emitting device and A ligjt emitting module including the same - Google Patents

Abstract

The present invention provides a light emitting diode driving device capable of preventing breakage and life-shortening due to surge voltage, and a light emitting module including the same. According to an embodiment of the present invention, the light emitting diode driving device which controls a light emitting part including a plurality of light emitting diode arrays connected in series comprises: a rectifying part including a first output terminal and a second output terminal outputting a rectifying signal according to a result of rectifying an alternating current signal; a sensing resistance connected between a first node and a second node; a switching control part including a plurality of switching parts connecting the corresponding one of the output terminals of the light emitting diode arrays and the first node based on a level of the rectifying signal; and a first diode connected between the second node and an output terminal or an input terminal of one among the light emitting diode arrays.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting diode (LED)

Embodiments relate to a light emitting element driving apparatus for driving a light emitting element and a light emitting module including the same.

Due to the development of semiconductor technology, the efficiency of light emitting diodes (LEDs) has been greatly improved. Accordingly, the LED has an advantage that it is economical as well as environmentally friendly because it has a longer life and less energy consumption than conventional lighting devices such as incandescent lamps and fluorescent lamps. Due to these advantages, LEDs are now attracting attention as a light source to replace backlights of flat panel display devices such as traffic lights and liquid crystal displays (LCDs).

When the LED is used as a lighting device, a plurality of LEDs can be connected in series or in parallel, and the lighting and lighting of a plurality of LEDs can be controlled by a light-emitting element controller. By using the AC power source, the light emitting element control apparatus can control the turning on and off of a plurality of LEDs.

Embodiments provide a light emitting device driving apparatus and a light emitting module including the same that can prevent breakage due to a surge voltage and shortening the service life.

An exemplary embodiment of the present invention relates to a light emitting device driving apparatus for controlling a light emitting unit including a plurality of light emitting device arrays connected in series, comprising: a rectifying unit including a first output terminal and a second output terminal for outputting a rectified signal according to a result of rectifying an AC signal; A sensing resistor connected between the first node and the second node; And a plurality of switching units connecting the corresponding one of the output terminals of the light emitting device arrays to the first node based on the level of the rectified signal. And a first diode connected between the second node and the output or input terminal of any one of the light emitting device arrays, wherein the first node is a connection node at one end of the sensing resistor and the plurality of switches, The second node is a connection node between the first output terminal of the rectifying section and the other end of the sensing resistor.

The first diode may be connected to an output terminal of the last light emitting device array among the light emitting device arrays.

The operating voltage of the first diode may be lower than the voltage between the second node and the corresponding one of the output terminals.

The resistance value of both ends of the first diode may be lower than the resistance value of the sensing resistor.

Wherein the first diode is a PN junction diode, the P-type terminal of the first diode is connected to the second node, and the N-type terminal of the first diode is connected to the output terminal or the input terminal of any one of the light- .

The light emitting device driving apparatus may further include a second diode connected to either the output terminal or the input terminal of the second node and any one of the light emitting device arrays.

Type terminal of the second diode is connected to the second node and the N-type terminal of the second diode is connected to the output terminal or the input terminal of any one of the light-emitting element arrays, the second diode being a PN junction diode, Can be connected.

Each of the plurality of switching units includes an amplifier including a first input terminal connected to the first node, a second input terminal to which a corresponding one of the reference voltages is input, and an output terminal; And a transistor having a gate to which the output terminal of the amplifier is connected and a source and a drain connected between the corresponding one of the light emitting element arrays and the first node.

The first output terminal of the rectifying unit may be connected to the ground.

The resistance value of both ends of the second diode may be smaller than the resistance value of the sensing resistor.

Each of the plurality of switching units may further include a third diode connected in parallel to a source and a drain of the transistor.

A light emitting module according to an embodiment includes a rectifier for outputting a rectified signal according to a result of rectifying an AC signal; A light emitting unit including a plurality of groups, each of the plurality of groups including at least one light emitting element array; A sensing resistor connected between the first node and the second node; A switching controller for sensing the level of the rectified signal and for connecting the corresponding one of the plurality of groups to the first node based on the detected level of the rectified signal; And a first diode connected between the second node and an output or input of any one of the plurality of groups, wherein the first node is a connection node of the plurality of switches and the sensing resistor, The second node is a connection node between the first output terminal of the rectifying section and the other end of the sensing resistor.

The light emitting unit may further include a capacitor connected in parallel to each of the plurality of groups.

The light emitting unit may further include a fourth diode connected between two adjacent groups.

The embodiment can prevent the switching control section caused by the surge voltage from being damaged or shortened in life.

Figure 1 shows a schematic block diagram of a light emitting module according to an embodiment.
Fig. 2 shows an embodiment of the switching control unit shown in Fig.
3 shows a schematic block diagram of a light emitting module according to another embodiment.
Figure 4 shows a schematic block diagram of a light emitting module according to yet another embodiment.
5 shows the influence of the surge voltage on the switching control section without the protection section.
6 is a view for explaining the role of the protection unit according to the embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. In the description of the embodiments, it is to be understood that each layer (film), region, pattern or structure may be referred to as being "on" or "under" a substrate, each layer It is to be understood that the terms " on "and " under" include both " directly "or" indirectly " do. In addition, the criteria for the top / bottom or bottom / bottom of each layer are described with reference to the drawings.

In the drawings, dimensions are exaggerated, omitted, or schematically illustrated for convenience and clarity of illustration. Also, the size of each component does not entirely reflect the actual size. The same reference numerals denote the same elements throughout the description of the drawings.

1 shows a schematic block diagram of a light emitting module 100 according to an embodiment.

Referring to FIG. 1, the light emitting module 100 includes a light emitting portion 101 for emitting light and a light emitting element driving portion 102 for driving and controlling the light emitting portion 101.

The light emitting unit 101 includes a plurality of light emitting device arrays (LED1 to LEDn, n> 1 natural number) connected in series.

For example, the light emitting unit 101 may include first through n-th light emitting device arrays (LED1 through LEDn, n> 1) sequentially connected in series. 1, the case of n = 4 is shown, but the present invention is not limited thereto.

Each of the plurality of light emitting device arrays (natural number of LED1 to LEDn, n> 1) may include one or more light emitting devices, for example, a light emitting diode or a light emitting device package. For example, each of the light emitting device arrays may include a zener diode for protecting the device, but the present invention is not limited thereto.

When the number of the light emitting elements included in the light emitting element array is plural, the plurality of light emitting elements may be connected to each other in series, parallel, or series and parallel.

The light emitting unit 101 includes a plurality of groups (e.g., G1 to G3) corresponding to the respective channels CH1 to CH3, and each of the plurality of groups (e.g., G1 to G3) includes at least one light emitting device array . ≪ / RTI >

For example, the light emitting unit 101 may include the first to third groups G1 to G3 corresponding to the three channels CH1 to CH3.

The light emitting unit 101 includes capacitors C1, C2 and C3 connected in parallel between the input and output terminals of the groups G1, G2 and G3, a capacitor C4 connected between the input terminal of the first group G1 and the ground, ), And diodes D1 and D2 connected between two adjacent groups G1 and G2, G2 and G3.

For example, the first capacitor C1 may be connected in parallel to the first group G1 including the first light emitting device array (LED1), and the second capacitor C2 may be connected in parallel to the second and third light emitting device arrays The third capacitor C3 may be connected in parallel with the second group G2 including the second light emitting element LED2 and the third group G3 including the fourth light emitting element array LED4, The fourth capacitor C4 may be connected between the input terminal (+ terminal) of the first light emitting device array (LED1) and the ground (GND).

For example, the first diode D1 may be connected between the adjacent first group G1 and the second group G2, and the second diode D2 may be connected between the adjacent second group G2 and the third group G2. (G3).

The first to third capacitors C1 to C3 and the first and second diodes D1 and D2 charge the rectification signal VR for driving the light emitting element arrays and apply the charged voltage to the light emitting element arrays LED1 to LED4 to prevent the flicker phenomenon caused by the turn-on and turn-off of the switches included in the control unit 130 for controlling the lighting of the light-emitting element arrays LED1 to LED4.

Further, the fourth capacitor C4 may serve to remove the noise from entering the light emitting portion 101.

The light emitting device driver 102 controls the lighting of the light emitting device arrays (LED1 to LEDn, n> 1) connected in series by using an AC power source, for example, a rectification signal VR.

The light emitting device driving unit 102 may include an AC power source 110, a rectifier 120, a switching controller 130, a sensing resistor Rsen, and a protection unit 140.

 The switching controller 130, the sensing resistor Rsen, and the protection unit 140 may constitute a control unit for controlling driving and lighting of the light emitting unit 101. [

The AC power supply unit 110 provides the AC signal to the rectifying unit 120.

The AC signal provided from the AC power source 110 may be a voltage in the form of a sine wave or a cosine wave, but is not limited thereto. For example, the alternating signal may be an alternating voltage having a frequency of 50 Hz to 60 Hz, and the maximum value may be about 100 to 250 volts (V), but is not limited thereto.

Although not shown in FIG. 1, the light emitting device driver 102 may include a surge protection unit, which may be implemented as a varistor or the like, for protecting a circuit from a surge voltage, and a fuse that can protect the circuit from an overcurrent. And may further include a fuse portion that can be implemented.

The rectifying unit 120 rectifies the AC signal supplied from the AC power supply unit 110 and outputs a rectified signal VR which is a ripple current according to the rectified result.

For example, the rectified signal VR may be a full-wave rectified AC voltage.

For example, the rectifying unit 120 may be implemented by various rectifying circuits such as a full-wave rectifying circuit or a half-wave rectifying circuit, but is not limited thereto.

For example, the rectifying unit 120 includes first and second input terminals 121a and 121b to which AC signals are supplied from the AC power source unit 110, and first and second output terminals 122a and 122b to which the rectified signal VR is output. , 122b.

The switching control unit 130 controls turning on and off of the light emitting element arrays LED1 to LED3 of the light emitting unit 101 connected in series based on the level of the rectified signal VR supplied from the rectifying unit 120. [

For example, the switching control unit 130 senses the level of the rectified signal VR and controls the first to third groups G1 and G3 of the light emitting unit 101 based on the level of the rectified signal VR. Can be sequentially turned on and off.

FIG. 2 shows an embodiment of the switching controller 130 shown in FIG.

2, the switching controller 130 senses the level of the rectified signal VR, and based on the level of the rectified signal VR, detects the level of the rectified signal VR through one of the channels CH1 to CH3, (101).

The sensing resistor Rsen is connected between the ground GND and the first node N1. Or the sensing resistor Rsen may be connected between the first output terminal 122a of the rectifying unit 120 and the first node N1.

The first output terminal 122a of the rectifying unit 120 may be connected to the ground GND and the second output terminal 122b may be connected to the input terminal IT1 of the light emitting unit 101. [ For example, the first node N1 may be a node to which one end of the sensing resistor Rsen and the switching controller 130 are connected.

For example, the switching control unit 130 senses the level of the rectified signal VR, and detects the level of the rectified signal VR between any one of the channels CH1 to CH3 and the first node N1 And can form a current path between the connected channel and the first node N1.

And a plurality of switching units 201-1 to 201-3 for controlling the driving of the light emitting device arrays included in the groups G1 to G3 of the light emitting unit 101. [

The channels CH1 to CH3 may be electrical paths between the output terminals of the groups G1 to G3 of the light emitting portion 101 and the corresponding switching portions 201-1 to 201-3.

Each of the plurality of switching units 201-1 to 201-3 is connected between the corresponding one of the output terminals of the light emitting device arrays LED1 to LED4 of the light emitting unit 101 and the first node N1 .

For example, each of the plurality of switching units 201-1 to 201-3 is connected to a corresponding one of the output terminals OT1 to OT3 of the groups G1 to G3 of the light emitting unit 101, Respectively.

For example, the output terminal of the group may be a negative terminal of the last light emitting element included in the last light emitting element array included in the group.

Each of the plurality of switching units 201-1 to 201-3 includes a transistor 210-1, 210-2 or 210-3, an amplifier 220-1, 220-2 or 220-3, and a diode 230-1, 230-2, or 230-3).

Each of the transistors 210-1, 210-2, and 210-3 of the plurality of switching units 201-1 to 201-3 is connected to any one of the output terminals of the amplifiers 220-1 to 220-3 And a source and a drain connected between the corresponding one of the output terminals OT1 to OT3 of the groups G1 to G3 of the light emitting portion 101 and the first node N1.

The transistors 210-1, 210-2, and 210-3 may be implemented as a field effect transistor, for example, a MOSFET or a bipolar junction transistor. For example, the transistors 210-1, 210-2, and 210-3 may be NMOS transistors, but the present invention is not limited thereto. In other embodiments, the transistors 210-1, 210-2, and 210-3 may be implemented as PMOS transistors.

Each of the amplifiers 220-1 to 220-3 includes a first input terminal (e.g., an - input terminal) connected to the first node N1, and a corresponding one of the reference voltages REF1 to REF3 A second input terminal (e.g., a + input terminal), and an output terminal for outputting the amplified signal CS1, CS2, or CS3. For example, the reference voltages REF1 to REF3 may be voltages of different magnitudes.

For example, each of the amplifiers 220-1 through 220-3 may be a differential amplifier, e.g., a differential operational amplifier, but is not limited thereto.

For example, the gates of the transistors 210-1, 210-2, or 210-3 may be connected to the output of the corresponding amplifier, the source may be connected to the first node N1, To G3 of the output terminals OT1 to OT3.

Each of the diodes 230-1, 230-2 and 230-3 may be connected in parallel to a corresponding one of the transistors 210-1 to 210-3, and may be connected to the switching units 201- 201-1) can be stably driven by a constant current.

The forward direction of each of the diodes 230-1, 230-2 and 230-3 may be a direction from the first node N1 to each of the channels CH1 to CH3.

For example, each of the diodes 230-1, 230-2, and 230-3 may be a PN junction diode, the P-type terminal may be connected to the source of the transistor, and the N-type terminal may be connected to the drain of the transistor have. For example, each of the diodes 230-1, 230-2, and 230-3 may be a zener diode, but is not limited thereto.

The switching controller 130 may further include a reference voltage generator (not shown) for generating reference voltages REF1 to REF3 having different sizes. For example, the reference voltage generator may include, but is not limited to, a voltage divider including a plurality of resistors.

The operation of the switching controller 130 is as follows.

When the voltage level of the rectified signal VR is lower than the first level, the transistors 210-1 to 210-3 of the switching units 201-1 to 201-3 are all turned off and the first to third All of the groups G1 to G3 are turned off and turned off.

For example, the first level may be the magnitude of the voltage capable of operating one group. For example, the first level may be the operating voltage of the first light emitting device array.

When the voltage level of the rectified signal VR is equal to or greater than the first level and smaller than the second level, only the first switching unit 201-1 can be turned on and a current can flow through the first channel CH1 And only the first group G1 is lighted up.

For example, the second level may be the magnitude of the voltage capable of operating the first and second groups G1 and G2. For example, the second level may be a sum of the operating voltages of the first through third light emitting device arrays.

When the voltage of the rectified signal VR is equal to or greater than the second level and smaller than the third level, only the second switching unit 201-2 can be turned on and a current can flow through the second channel CH2 , Only the first and second groups G1 and G2 may be turned on to emit light.

For example, the third level may be the magnitude of the voltage capable of operating the first to third groups G1 to G3. For example, the third level may be a sum of the operating voltages of the first through fourth light emitting device arrays.

When the voltage of the rectified signal VR is equal to or greater than the third level, only the third switching unit 201-3 can be turned on, the current can flow through the third channel CH3, All the three groups G1 to G3 can be turned on and emit light.

The protection unit 140 is connected between the second node NG and the output terminal or the input terminal of any one of the plurality of light emitting device arrays in the light emitting unit 101.

For example, the protection unit 140 may be connected to the output terminal of the second light emitting device array of the plurality of light emitting device arrays of the light emitting unit 101 and the second node NG.

For example, the protection unit 140 may be connected to the output terminal of any one of the plurality of groups G1 to G3 of the light emitting unit 101 and the second node NG.

For example, the protection unit 140 may be connected to the output terminal OT3 of the last group G3 of the plurality of groups G1 to G3 of the light emitting unit 101 and the second node NG, It is not.

For example, the second node NG may be a connecting portion of the sensing resistor Rsen and the ground GND. Or the second node NG may be a connection portion between the sensing resistor Rsen and the first output terminal 122a of the rectifying section 120. [

The surge voltage may be introduced into the second node NG through the substrate of the light emitting module or the substrate of the illumination device. When the surge voltage flows into the second node NG, And shields the switching units 201 - to 201 - 3 from the surge voltage by dispersing the inflow surge voltage to the light emitting unit 101.

The protection unit 140 may include a bypass diode 140a connected between the second node NG and the output or input terminal of any one of the plurality of light emitting device arrays in the light emitting unit 101. [

For example, the bypass diode 140a may be connected between the second node NG and the output terminal of any one of the plurality of groups G1 to G3 of the light emitting portion 101. [ For example, the bypass diode 140a may be connected between the second node NG and the output terminal OT3 of the last group G3 of the light emitting portion 101. [

The direction from the second node NG to the output end of any group of the light emitting units 101 may be the forward direction of the bypass diode 140a.

For example, the bypass diode 140a may be a PN junction diode, and the P-type terminal may be connected to the second node NG.

The N-type terminal of the bypass diode 140a may be connected to one of the plurality of light emitting device arrays of the light emitting unit 101. [ For example, the N-type terminal of the bypass diode 140a may be connected to the output terminal of any one of the plurality of groups G1 to G3 of the light emitting portion 101. [

For example, the N-type terminal of the bypass diode 140a may be connected to the output terminal OT3 of the last group G3 of the light emitting portion 101. [

The bypass diode 140a bypasses the surge voltage supplied to the second node NG to any one of the plurality of groups of the light emitting unit 101 such as the output terminal OT3 of the last group G3 , It is possible to prevent the surge voltage from flowing into the first node N1 of the switching control unit 130 and destroying the switching units 201-1 to 201-3.

The surge voltage can be prevented from flowing into the switching control unit 130 and the surge voltage can be output to the output terminal of any one of the groups G1 to G3 (e.g., G3) of the light emitting unit 101 through the bypass diode 140a , OT3) are as follows.

The operating voltage of the bypass diode 140a is lower than the voltage between the second node NG of the switching units 201-1 to 201-3 and the output terminal OT3 of each of the groups G1, G2 and G3.

For example, the operating voltage of the bypass diode 140a may be lower than the voltage between the second node NG and the output terminal OT3 of the last group G1.

For example, in order to prevent the surge voltage from flowing into the switching control unit 130 and to bypass the surge voltage to the bypass diode 140a, the resistance value at both ends of the bypass diode 140a is greater than the resistance value of the sensing resistor Can be small.

In addition, the bypass diode 140a may have a breakdown voltage higher than a clamping voltage of the varistor to protect the device from a surge voltage flowing through the power supply unit 110. [

5 shows the influence of the surge voltage on the switching control unit not having the protection unit 140. FIG.

5, the first node N1 and the switching units 201-1 to 201-N are turned on by the surge voltage flowing into the first node N1 of the switching controller 130 through the second node NG, 3) transistors 210-1 to 210-3, and diodes D1 to D3 may be damaged or broken.

6 is a view for explaining the role of the protection unit 140 according to the embodiment.

6, the surge voltage introduced into the second node NG is supplied to one of the plurality of groups G1 to G3 of the light emitting unit 101 by the bypass diode 140a of the protection unit 140, , E.g., the output of the last group G3 (e.g., OT3).

Since the surge voltage is bypassed to the output terminal OT3 of the last group G3, the surge voltage may not directly affect the switching units 201-1 to 201-3.

Also, the surge voltage is distributed or distributed to the plurality of light emitting device arrays LED1 to LDE4 connected in series through the bypass diode 140a, or bypassed through the switching units 201-1 to 201-3, The capacitor C1 to C4 and / or the Zener diode included in the light emitting device arrays.

Therefore, the embodiment can protect the switching units 201-1 to 201-3 from the surge voltage, and it is possible to prevent the lifetime of the light emitting element driving apparatus and the light emitting module including the same from being shortened due to the surge voltage.

FIG. 3 shows a schematic block diagram of a light emitting module 100-1 according to another embodiment. The same reference numerals as in Fig. 1 denote the same components, and a description of the same components will be simplified or omitted.

3, the protection unit 140-1 is connected to the input terminal of any one of the plurality of light emitting element arrays (e.g., LED4) of the light emitting unit 101 and the second node NG.

For example, the protection unit 140-1 may be connected to the input terminal of any one of the plurality of groups G1 to G3 of the light emitting unit 101 and the second node NG.

For example, the protection unit 140-1 may be connected to the input terminal IT3 of the last group G3 of the plurality of groups G1 to G3 of the light emitting unit 101 and the second node NG, But is not limited thereto.

For example, the input terminal of the group G1, G2, or G3 may be a positive terminal of the first light emitting element of the first light emitting element array belonging to the group.

The protection unit 140-1 includes a bypass diode 140b connected to the second node NG and the input terminal of any one of the plurality of light emitting device arrays in the light emitting unit 101. [

For example, the bypass diode 140b may be connected to the input terminal of any one of the plurality of groups G1 to G3 of the light emitting unit 101 and the second node NG.

For example, the bypass diode 104b may be connected between the second node NG and the input terminal IT3 of the last group G3 of the light emitting portion 101. [

The direction from the second node NG to the input terminal of any one group of the light emitting units 101 may be the forward direction of the bypass diode 140b.

For example, the bypass diode 140b may be a PN junction diode, and the P-type terminal may be connected to the second node NG.

The N-type terminal of the bypass diode 140b is connected to the input terminal of any one of the light emitting element arrays of the light emitting portion 101. [ For example, the N-type terminal of the bypass diode 140b may be connected to the input terminal of any one of the plurality of groups G1 to G3 of the light emitting portion 101. [

For example, the N-type terminal of the bypass diode 140b may be connected to the input terminal IT3 of the last group G3 of the light emitting portion 101. [

The bypass diode 140b bypasses the surge voltage supplied to the second node NG to any one of a plurality of groups of the light emitting unit 101, for example, the input terminal IT3 of the last group G3 , It is possible to prevent the surge voltage from flowing into the first node N1 of the switching control unit 130 and destroying the switching units 201-1 to 201-3.

The surge voltage is supplied to the switching control unit 130 and the surge voltage is supplied to the input terminal of one of the groups G1 to G3 of the light emitting unit 101 (for example, G3) through the bypass diode 140b , IT3) are the same as those described above with reference to FIG. 1 and FIG.

FIG. 4 shows a schematic block diagram of a light emitting module 100-2 according to another embodiment. The same reference numerals as in Fig. 1 denote the same components, and a description of the same components will be simplified or omitted.

Referring to FIG. 4, the protection unit 140-2 may include a first bypass diode 140c and a second bypass diode 140d.

The first bypass diode 140c is connected between the second node NG and the output or input terminal of any one of the plurality of light emitting device arrays.

The second bypass diode 140d is connected between the second node NG and the output or input of any one of the plurality of light emitting device arrays.

The first bypass diode 140c may be connected between the second node NG and the output or input terminal of any one of the plurality of groups G1 to G3 of the light emitting portion 101. [

The second bypass diode 140d may be connected between the second node NG and the output or input terminal of any one of the plurality of groups G1 to G3 of the light emitting unit 101. [

For example, the first bypass diode 140c may be connected between the second node NG and the output terminal OT3 of the last group G3 of the light emitting portion 101, and the second bypass diode 140d may be connected May be connected between the second node NG and the output terminal OT2 of the second group G2 of the light emitting portion 101, but the present invention is not limited thereto.

For example, each of the first bypass diode 140c and the second bypass diode 140d may be a PN junction diode. The P-type terminal of each of the first and second bypass diodes 140c and 140d may be connected to the second node NG.

The N-type terminal of the first bypass diode 140c may be connected to the output terminal or the input terminal of any one of the plurality of light emitting device arrays, and the N-type terminal of the second bypass diode 140d may be connected to the plurality of light emitting device arrays May be connected to any one of the output terminals or the input terminal.

For example, the N-type terminal of the first bypass diode 140c may be connected to the output or input terminal of any one of the plurality of groups G1 to G3 of the light emitting portion 101, and the second bypass diode 140d May be connected to any one of the output terminals or the input terminals of the plurality of groups G1 to G3 of the light emitting portion 101. [

The surge voltage flows into the first node N1 of the switching control unit 130 and the switching units 201-1 to 201-n are turned on as the surge voltage is bypassed through the first and second bypass diodes 140c and 140d. -3) can be prevented from being destroyed.

In order for the first and second bypass diodes 140c and 140d to bypass the surge voltage, the operating voltages of the first and second bypass diodes 140c and 140d are supplied to the switching units 201-1 to 201- -3) and the output terminal OT3 of each group G1, G2, G3.

Also, for example, the resistance value at both ends of each of the first and second bypass diodes 140c and 140d may be smaller than the resistance value of the sensing resistor Rsen.

Each of the first and second bypass diodes 140c and 140d may have a breakdown voltage higher than a clamping voltage of the varistor for protecting the device from a surge voltage flowing through the power supply unit 110. [

Further, the light emitting module according to the embodiment may be implemented as a display device, a pointing device, or a lighting device.

The features, structures, effects and the like described in the embodiments are included in at least one embodiment of the present invention and are not necessarily limited to one embodiment. Further, the features, structures, effects, and the like illustrated in the embodiments can be combined and modified by other persons having ordinary skill in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

101: light emitting portion 102: light emitting element driving portion
110: AC power supply unit 120:
130: switching control unit 140: protection unit.

Claims (14)

A light emitting element driving apparatus for controlling a light emitting unit including a plurality of light emitting element arrays connected in series,
A rectifier including a first output terminal and a second output terminal for outputting a rectified signal according to a result of rectifying the AC signal;
A sensing resistor connected between the first node and the second node;
And a plurality of switching units connecting the corresponding one of the output terminals of the light emitting device arrays to the first node based on the level of the rectified signal. And
And a first diode connected between the second node and the output or input of any one of the light emitting device arrays,
Wherein the first node is a connection node of the plurality of switching units and one end of the sensing resistor, and the second node is a connection node of the first output end of the rectifying unit and the other end of the sensing resistor. The method according to claim 1,
Wherein the first diode is connected to the output terminal of the last one of the light emitting device arrays. The method according to claim 1,
Wherein an operating voltage of the first diode is lower than a voltage between the second node and the corresponding one of the output terminals. The method according to claim 1,
Wherein a resistance value of both ends of the first diode is smaller than a resistance value of the sensing resistor. The method of claim 3,
Wherein the first diode is a PN junction diode, the P-type terminal of the first diode is connected to the second node, and the N-type terminal of the first diode is connected to the output terminal or the input terminal of any one of the light- Emitting device. 6. The method of claim 5,
And a second diode connected to an output terminal or an input terminal of any one of the second node and the light emitting device arrays. The method according to claim 6,
Type terminal of the second diode is connected to the second node and the N-type terminal of the second diode is connected to the output terminal or the input terminal of any one of the light-emitting element arrays, the second diode being a PN junction diode, And the light emitting element driving device is connected to the light emitting element. The apparatus of claim 1, wherein each of the plurality of switching units comprises:
An amplifier including a first input terminal connected to the first node, a second input terminal receiving a corresponding one of the reference voltages, and an output terminal; And
A gate connected to the output terminal of the amplifier, and a source and a drain connected between the corresponding one of the light emitting element arrays and the first node. The method according to claim 1,
And the first output terminal of the rectifying unit is connected to the ground. The method according to claim 6,
Wherein a resistance value of both ends of the second diode is smaller than a resistance value of the sensing resistor. 9. The apparatus of claim 8, wherein each of the plurality of switching units comprises:
And a third diode connected in parallel to a source and a drain of the transistor. A rectifier for outputting a rectified signal according to a result of rectifying the AC signal;
A light emitting unit including a plurality of groups, each of the plurality of groups including at least one light emitting element array;
A sensing resistor connected between the first node and the second node;
A switching controller for sensing the level of the rectified signal and for connecting the corresponding one of the plurality of groups to the first node based on the detected level of the rectified signal; And
And a first diode connected between the second node and an output or input of any one of the plurality of groups,
Wherein the first node is a connection node of the plurality of switching units and one end of the sensing resistor, and the second node is a connection node of the first output end of the rectifying unit and the other end of the sensing resistor. 13. The light-emitting device according to claim 12,
And a capacitor connected in parallel to each of the plurality of groups. 14. The light-emitting device according to claim 13,
And a fourth diode connected between two adjacent groups.

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