KR20140102966A - LED illumination device with energy conservation - Google Patents

Abstract

The purpose of the present invention is to operate most of LED light-emitting units even in a low voltage state by making a power unit change in voltages in an LED illumination system where the LED light-emitting units are connected to each other in series. To achieve this, an LED illumination system with energy storage characteristics is provided. The LED illumination system includes a power unit; a rectification circuit unit which receives alternating current power from the power unit and outputs a rectified voltage; a charge storage circuit unit which receives power from the rectification circuit unit, stores charges when the received power is a high voltage, and discharges stored charges when the received power is a low voltage; an LED light emitting circuit unit in which a first LED light emitting unit disposed at a front end of a separate diode and a second LED light emitting unit disposed at a rear end thereof are connected to each other in series, the first LED light emitting unit is connected to the power unit to receive power, and the second LED light emitting unit is connected to the charge storage circuit unit; a current detour switch which connects the charge storage circuit unit with the second LED light emitting unit; a current switch circuit unit which includes a plurality of current switches connected to the LED light emitting units to control operation thereof; and a control circuit unit which controls the current detour switch and the current switch circuit unit according to a power state to operate the LED light emitting units.

Description

[0001] The present invention relates to an LED illumination device,

The present invention relates to an LED (Light Emitting Diode) lighting apparatus, and more particularly to an LED lighting apparatus having an energy saving characteristic.

In recent years, LED diodes (hereinafter referred to as LEDs) have been widely used in lighting devices due to their low power, high efficiency and long service life.

In order to use the LED as a light source, it is necessary to have an LED driver circuit that controls LED on / off, brightness, and color of emitted light. Such conventional LED driving circuits are largely divided into a driving method and a linear driving method and a switch mode driving method called SMPS (Switched Mode Power Supply).

Since the SMPS operates in a switch mode using an inductor, the configuration of the circuit is complicated and a lot of components are required, which is costly. In addition, since the current flows discontinuously, an electromagnetic interference (EMI) problem arises. In addition, when the input voltage is changed while the input voltage is changed (that is, when the AC voltage is input), the brightness changes due to the flicker and the forward voltage Vf of the LED. In addition, a separate PFC (Power Factor Correction) circuit is required to meet the power factor due to the unstable power supply, and the lifespan is short due to the use of electrolytic capacitors.

On the other hand, the linear drive method does not use the inductor and the electrolytic capacitor compared to the SMPS, so the circuit configuration is simple. Therefore, low manufacturing cost, excellent stability and long life are the greatest advantages.

However, in the linear driving method, when the voltage difference between the input voltage and the LED load voltage is large, the power efficiency is deteriorated and there is a problem of energy waste. If the input voltage is AC power, the input voltage varies continuously with time, but the load of the connected LED is almost constant. Therefore, there is a limit to increase the efficiency by the above method. Of course, if the LED load voltage is increased close to the input maximum voltage, high efficiency can be obtained. However, when the LED lighting time is reduced and the plurality of LEDs are used, the amount of light that can be extracted is reduced there is a problem. In addition, there is a problem that the power factor is deteriorated due to a discontinuous current flow. That is, when a plurality of LEDs are connected in series, when the input power source changes, there arises a problem that a time period during which the LEDs connected to the subsequent stage do not operate occurs. The resulting flicker not only lowers the current efficiency, but also has a negative effect on the visual acuity.

U.S. Patent No. 6,989,807 discloses that a plurality of switches connected in parallel to a plurality of LED groups connected in series at an AC input voltage varying in voltage in real time can be controlled to drive a maximum LED at a voltage varying in real time However, it is only possible to operate the entire LED in a voltage section (time) in which the input voltage is higher than the threshold voltage of the entire LED group, and at a lower voltage, some of the LEDs connected to the rear end are turned off. Particularly when the input voltage is lower than the threshold voltage of the first LED group, all the LEDs are turned off and the average usage rate (average on time) of the LEDs connected to the circuit is low.

In order to solve the conventional problem of the present invention, in an LED lighting device in which a plurality of LED light emitting units are connected in series, most of the LED light emitting units operate in a low voltage state due to a fluctuation of the power supply unit.

It is a further object of the present invention to provide a light emitting diode which is connected to a light emitting diode by a separation diode, charges the electric charge while supplying a high electric power from the electric power source, discharges the electric charge stored in a low voltage state, The purpose is to supply.

It is a further object of the present invention to provide a method and apparatus for simultaneously varying (scattering) an LED forward voltage Vf inevitably generated in the mass production of LEDs and varying input voltages for various LED configurations required for various applications The aim is to select and operate the LED load that can have maximum LED power and power efficiency at that time.

Other objects of the present invention will become readily apparent from the following description of the embodiments.

According to an aspect of the present invention, there is provided a rectifier circuit comprising: a power supply unit; a rectifier circuit unit receiving AC power from the power supply unit and outputting a rectified voltage; A first LED light emitting unit at a front end of the isolation diode and a second LED light emitting unit at a rear end are connected in series and the first LED light emitting unit is connected to the power supply unit to receive power, The second LED light emitting unit includes an LED light emitting circuit unit connected to the charge storage circuit unit, a current bypass switch connecting the charge storage circuit unit and the second LED light emitting unit, and a plurality of currents A current switch circuit portion including a switch; And a control circuit unit controlling the current bypass circuit and the current switch circuit unit according to the power state to emit light to the LED light emitting unit.

Here, the charge storage circuit portion includes a first diode, a second diode, a third diode, and a first capacitor and a second capacitor, and the second diode is connected between the first capacitor and the second capacitor in a forward direction One end of the first capacitor is connected to the power supply voltage node of the power supply unit and the other end of the second capacitor is connected to the ground. The first diode is connected to the node between the first capacitor and the second diode, And the third diode is connected between the node to which the second capacitor and the second diode are connected and the current bypass switch so that the charge stored in the second capacitor is reverse- And is supplied to the second LED light emitting portion through a switch.

Here, the first LED light emitting unit and the second LED light emitting unit may include one or more LEDs, and each of the LEDs may be connected to the current switch.

Here, the first LED light emitting unit and the second LED light emitting unit each include at least one LED, and when the power supplied from the power source unit does not reach the power source for operating all the LEDs of the second LED light emitting unit The control circuit controls the current-bypass switch to be turned on so that the electric charge stored in the charge storage circuit portion is supplied to the second LED light-emitting portion.

At least one resistor is inserted between the first capacitor and the forward current path of the second capacitor to improve the peak current reduction and the input current waveform when the first capacitor or the second capacitor is charged, And improving the current harmonics.

A circuit section for improving the power factor and the current harmonic is connected between the rectifying circuit section and the charge storage circuit section. The circuit section for improving the power factor and the current harmonics includes two capacitors between the power supply voltage node of the rectifying circuit section and the ground, And a resistor is connected between the intermediate connection node of the two capacitors and the rectifying circuit portion.

Here, an isolation discharge prevention diode is connected between the first capacitor and the power supply voltage node, and the first condenser and the current bypass circuit are connected to each other so that all charges charged in the first and second capacitors 2 LED light emitting unit.

The charge storage circuit unit may further include a third LED light emitting unit connected to the LED light emitting circuit unit through a second isolation diode and a second current bypass switch for operating the third LED light emitting unit, A first diode, a first diode, a second diode, a third diode, a fourth diode, a fifth diode, a sixth diode and a first capacitor, a second capacitor, and a third capacitor, A second diode connected in a forward direction, one side of the first capacitor being connected to a power supply voltage node of the rectifying circuit portion, and a side of the second capacitor being connected in a reverse direction to a ground through a fourth diode, And the first diode is connected to a node between the first capacitor and the second diode, And the third diode is connected between a node to which the second capacitor and the second diode are connected and the current bypass switch so that the charge stored in the second capacitor is connected to the current bypass switch And the sixth diode is connected between the node to which the third capacitor and the fifth diode are connected and the second current-bypassing switch, and the charge stored in the third capacitor is supplied to an LED light- Is supplied to the third LED light-emitting portion through the second current-bypassing switch.

Here, the backflow prevention switch may be provided instead of the isolation diode.

When the input voltage of the power supply unit is high, the charge is charged. When the voltage of the power supply unit is low, the charge is emitted to supply the voltage to the inoperative LED light emitting unit. There is an effect that can operate.

Also, according to the changing input voltage, an LED load capable of having the maximum LED light output and power efficiency at that time can be selected, and the current switch can be adjusted to maintain the maximum light efficiency.

Further, the present invention has the effect of reducing power loss and increasing power efficiency.

In addition, the present invention has an effect of improving the power factor and the current harmonic by providing a circuit for improving the peak current and the input current waveform at the time of charging the capacitor.

Further, according to the present invention, the current of the LED drive device can flow continuously, not discontinuously, and the EMI and EMC characteristics are advantageous.

FIG. 1 is a diagram showing a configuration of an LED illumination device having an energy storage characteristic according to an embodiment of the present invention.
2 is a circuit diagram of a charge storage circuit portion according to an embodiment of the present invention.
3 is a diagram showing a circuit structure of an LED light-emitting circuit part and a current switch circuit part according to an embodiment of the present invention.
FIG. 4 to FIG. 7 are diagrams for explaining the operation principle of the present invention in an embodiment of the present invention.
FIG. 8 is a diagram illustrating a time during which the LED of the LED light emitting circuit unit 400 operates according to a rectified voltage according to an embodiment of the present invention.
9 is a graph illustrating brightness of light according to an input voltage according to an embodiment of the present invention.
FIG. 10 to FIG. 14 are views showing a modification of the charge storage circuit portion according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The first and second or the above terms are only used for the purpose of distinguishing one element from another. Also, the singular expressions may include plural expressions unless the context clearly dictates otherwise.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a diagram showing a configuration of an LED illumination device having an energy storage characteristic according to an embodiment of the present invention.

The LED lighting apparatus having the energy saving feature of the present invention includes a power supply unit 100, a rectifier circuit unit 200, a charge storage circuit unit 300, an LED light emitting circuit unit 400, a current switch circuit unit 500, a current bypass circuit 601, And a control circuit unit 700.

The power supply unit 100 performs a function of supplying power. In the present invention, the power supply unit 100 of the LED illumination device having the energy saving characteristic particularly receives and supplies AC power.

The rectifying circuit unit 200 receives the AC power from the power supply unit 100 and outputs a rectified voltage. To this end, the rectifying circuit section 200 includes a bridge rectifying circuit.

The charge storage circuit part 300 receives the rectified power from the rectifying circuit part 200 and stores the charge when the voltage is high and discharges the stored charge when the voltage is low. In the case of a low voltage, the charge storage circuit unit 300 supplies the charged charge to the LED light emitting circuit unit 400 through the current bypass switch 601. At this time, the current bypass switch 601 is turned on by the control of the control circuit unit 700, and the charged electric charge is supplied to the LED light emitting circuit unit 400.

To this end, the charge storage circuit unit 300 includes a capacitor capable of charging and discharging a charge, thereby constituting a circuit. A more detailed description of the charge storage circuit portion 300 will be described later with reference to FIG.

The LED light-emitting circuit unit 400 includes an LED and performs a function of emitting light when power is applied. In particular, the LED light emitting circuit unit 400 includes a first LED light emitting unit 410 and a second LED light emitting unit 420.

Here, the first LED light emitting unit 410 and the second LED light emitting unit 420 are connected in series through a separation diode 451.

The first LED light emitting unit 410 is directly connected to the rectifying circuit unit 200 and receives the rectified voltage from the rectifier circuit unit 200 to operate the second LED light emitting unit 420. The second LED light emitting unit 420 includes a first LED light emitting unit 410, or when the current bypass switch 601 is turned on, it may be operated by receiving the stored charge from the charge storage circuit unit 300. [

Here, the isolation diode 451 is connected in a forward direction to allow a current to flow from the first LED light emitting portion 410 to the second LED light emitting portion 420, and to prevent current from flowing in the opposite direction do. Accordingly, when the current bypass circuit 601 is turned on, the current supplied from the charge storage circuit portion 300 flows only to the second LED light emitting portion 420.

Here, the forward direction means a direction in which the current flows from the power supply voltage Vcc to the ground. Hereinafter, the term " connected in the forward direction " means that the current flows in the forward direction.

The first LED light emitting unit 410 and the second LED light emitting unit 420 may include a plurality of LEDs. In the present invention, the first LED light emitting unit 410 includes a first LED The second LED 411 and the second LED 412 and the second LED light emitting unit 420 includes the third LED 421 and the fourth LED 422. [

The current switch circuit unit 500 controls the operation of each of the LEDs 411, 412, 421, and 422 of the LED light emitting circuit unit 400.

To this end, the current switch circuit unit 500 includes a plurality of current switches 501, 502, 503, and 504. Here, the current switches 501, 502, 503, and 504 of the current switch circuit unit 500 are equal to the total number of LEDs included in the first LED light emitting unit 410 and the second LED light emitting unit 420. Each of the current switches 501, 502, 503, and 504 is connected to each of the LEDs to select and operate the LED according to the voltage state of the input power.

The current bypass circuit 601 is connected to the charge storage circuit unit 300 and the second LED light emitting unit 420. When the current bypass circuit 601 is turned on, the charge stored in the charge storage circuit unit 300 is input to the second LED light emitting unit 420.

The control circuit unit 700 controls the current switch circuit unit 500 and the current bypass circuit 601 according to the voltage state of the input power source to control the optimum LED to operate according to the input voltage state. That is, it controls the maximum LED to operate.

2 is a circuit diagram of a charge storage circuit portion according to an embodiment of the present invention.

1, the charge storage circuit unit 300 stores the rectified voltage inputted from the rectifying circuit unit 200 at a high voltage and stores the stored charge at a low voltage to the second LED light emitting unit 420, .

To this end, the charge storage circuit unit 300 includes a first capacitor 310 for storing charges, a second capacitor 320, and a first diode 301, a second diode 302, (303).

The first capacitor 310 and the second capacitor 320 are connected in series through a forward second diode 302 and the first diode 301 is connected to the first capacitor 310 and the second diode 302 It is connected in reverse between the connected node and ground. Thus, the first diode 301 allows current to flow through the first capacitor 310, the second diode 302, and the second capacitor 320 when the voltage is high.

The third diode 303 is connected between the node to which the second capacitor 320 and the second diode 302 are connected and the current bypass circuit 601 so that the charge stored in the second capacitor 320 And flows through the current bypass switch 601 to the second LED light emitting portion 420.

The operation of the charge storage circuit unit 300 according to the rectified voltage input from the rectifier circuit unit 200 will be described later with reference to FIG.

3 is a diagram showing a circuit structure of an LED light-emitting circuit part and a current switch circuit part according to an embodiment of the present invention.

The LED light-emitting circuit unit 400 includes a first LED light-emitting unit 410 and a second LED light-emitting unit 420.

The first LED light emitting unit 410 and the second LED light emitting unit 420 are connected in series through the isolation diode 451 as described above with reference to FIG. The first LED light emitting unit 410 and the second LED light emitting unit 420 may include a plurality of LEDs. In the present invention, if the order of the LEDs is determined in the forward direction of the current, The first LED 411, the second LED 412, the third LED 421, and the fourth LED 422. It is assumed that the first LED light emitting unit 410 includes the first LED 411 and the second LED 412 and that the second LED light emitting unit 420 includes the third LED 421 and the fourth LED 422 .

1, the current switch circuit unit 500 controls the operation of each of the LEDs 411, 412, 421 and 422 of the LED light-emitting circuit unit 400. As shown in FIG.

The first current switch 501 is connected to the rear end of the first LED 411 and the second current switch 502 is connected to the rear end of the second LED 412. The third current switch 503 is connected to the rear end of the third LED 421, And the fourth current switch 504 is connected to the rear end of the fourth LED 422. [

Therefore, only when the current switches 501, 502, 503, and 504 are kept in the ON state, the LED operates and emits light.

For example, when all of the LEDs 411, 412, 421 and 422 are operated to emit light, the fourth current switch 504 is turned on and the first current switch 501, the second current switch 502, (503) is turned off to allow current to flow through all the LEDs (411, 412, 421, 422).

For example, when only the first LED 411, the second LED 412 and the third LED 421 are operated, the first current switch 501, the second current switch 502 and the fourth current switch 504 are turned off The third current switch 503 is turned on so that current flows through the first LED 411, the second LED 412, and the third LED 421.

For example, when only the first LED 411 and the second LED 412 are operated, the first current switch 501, the third current switch 503, and the fourth current switch 504 are turned off, and the second current switch 502 are turned on so that current flows through the first LED 411 and the second LED 412.

For example, when only the first LED 411 is operated, the second current switch 502, the third current switch 503, and the fourth current switch 504 are turned off, and the first current switch 501 is turned on So that a current flows through the first LED 411.

That is, the current switch connected to the rear end of the LED to be operated is turned on and the remaining current switch is turned off, thereby emitting the LED to be operated.

Here, the control of each of the current switches 501, 502, 503, and 504 is performed in accordance with the magnitude of the input voltage in the control circuit unit 700.

That is, when the rectified voltage rectified by the rectifying circuit unit 200 is high enough to operate all the LEDs of the LED light-emitting circuit unit 400, the control circuit unit 700 controls the last LED (that is, the fourth LED 422 ) (That is, the fourth current switch 504) are turned on and the remaining current switches are turned off.

The third current switch 503 for operating the third LED 421 is turned on and the remaining current switch 501 is turned on when the voltage applied to the fourth LED 422 is lower than the threshold voltage 502, and 504 are turned off to control the current switch circuit unit 500 so that only the first LED 411, the second LED 412, and the third LED 421 operate.

The second current switch 502 for operating the second LED 412 is turned on and the remaining current switch 501 is turned on when the voltage input to the third LED 421 is lower than the threshold voltage, , 503, and 504 are turned off to control the current switch circuit unit 500 so that only the first LED 411 and the second LED 412 operate.

When the voltage applied to the second LED 412 is lower than the threshold voltage, the first current switch 501 for operating the first LED 411 is turned on and the remaining current switches 502 , 503, and 504 are turned off to control the current switch circuit unit 500 so that only the first LED 411 operates.

Although the above description has been made by taking the case where the current voltage decreases at the maximum value, the control circuit unit 700 can operate the rectified voltage rectified and outputted by the rectifying circuit unit 200 even when the rectified voltage increases from the minimum value to the maximum value And controls the current switch circuit unit 500 so that the LED of the LED light-emitting circuit unit 400 can operate.

The above description has been made on the assumption that only the first LED light emitting part 410 and the second LED light emitting part 420 are present in the LED light emitting circuit part 400. In addition to the third LED light emitting part 410 and the second LED light emitting part 420, Emitting portion 4N0, and each LED light emitting portion may include N first, second, third, fourth, and N-th LEDs. In this case, the current switch of the current switch circuit unit 500 includes N current switches equal to the number of all the LEDs included in the LED light-emitting circuit unit 400.

FIG. 4 to FIG. 7 are diagrams for explaining the operation principle of the present invention in an embodiment of the present invention.

4 is a diagram illustrating a method of storing charges in the charge storage circuit portion 300. FIG.

The rectified voltage outputted from the rectifying circuit part 200 is referred to as Vrec and the magnitude of the rectified voltage with time is shown in Fig. 5 (a).

5 (a), it can be seen that the rectified voltage Vrec is output between the maximum value Vpeak and the minimum value 0.

When the rectified voltage is input, the charge storage circuit part 300 is charged with the electric currents flowing in the first capacitor 310 and the second capacitor 320 as indicated by the dotted line in the arrow direction, V2. ≪ / RTI >

Here, when capacitors having capacitance values of C1, C2, C3, ..., CN are connected in series, the total capacitance value Ceq is calculated according to the capacitance relation as follows.

1 / Ceq = 1 / C1 + 1 / C2 + 1 / C3 + ... + 1 / CN

Here, the amount of charge charged in two or more capacitors connected in series is

Qeq = Ceq * V

.

Here, V is the maximum value of the input voltage, which in the present invention is the maximum value Vpeak of the rectified voltage Vrec.

The voltages (V1, V2, V3, ..., VN) charged in each capacitor connected in series are

V1 = Qeq / C1, V2 = Qeq / C2, V3 = Qeq / C3, ..., VN = Qeq / CN

.

In the present invention, the capacitance of the capacitor of the charge storage circuit unit 300 is assumed to be the same for convenience of explanation.

Then, the voltages charged in the first condenser 310 and the second condenser 320, respectively,

V1 = (1/2) * Vpeak

V2 = (1/2) * Vpeak

.

The voltages V1 and V2 charged in the first and second capacitors 310 and 320 are discharged when the input rectified voltage is lower than the charged voltage. In the present invention, V1 and V2 are respectively 1 / 2) Vpeak, the voltage V1 and the voltage V2 charged in the first condenser 310 and the second condenser 320 are discharged when the rectified voltage is (1/2) Vpeak.

5B is a diagram illustrating a voltage discharged from the first condenser 310 and input to the first LED light emitting unit 410. FIG.

The voltage input to the first LED light emitting unit 410 is expressed by the sum of the rectified voltage Vrec and the voltage V1 discharged from the capacitor 310. [

Therefore, the voltage value is displayed as shown in Fig. 5 (b).

5C is a diagram showing the voltage discharged from the second condenser 320 and input to the current bypass switch 601. FIG.

The voltage input to the current bypass switch 601 is expressed only by the voltage V2 discharged from the second condenser 320 because the rectified voltage is not directly connected.

Therefore, it is expressed as a voltage value ((1/2) * Vpeak) as shown in Fig. 5 (b).

In the present invention, two capacitors having the same capacitance value are exemplified for convenience of explanation, but they may include N capacitors having different capacitance values.

6 is a diagram showing an operation in the case where the rectified voltage is a high voltage section for operating the second LED light emitting portion.

Here, the meaning of the high voltage section means a voltage section in which the rectified voltage can operate all of the first LED light emitting part 410 and operate at least one LED of the second LED light emitting part 420. That is, a voltage output from the first LED light emitting unit 410 and input to the second LED light emitting unit 420 through the isolation diode 451 is applied to the LEDs located at the beginning of the second LED light emitting unit 420 (The third LED 421).

When the voltage input to the second LED light emitting unit 420 is equal to or higher than the threshold voltage of the third LED 421 and the voltage output through the third LED 421 is equal to or higher than the threshold voltage of the fourth LED 422, So that all the LEDs of the LED light-emitting circuit unit 400 can be operated. Here, the control circuit unit 700 controls the current switch circuit unit 500 to control the current to flow as I4 as described above.

If the voltage input to the second LED emission unit 420 is equal to or higher than the threshold voltage of the third LED 421 or the voltage output through the third LED 421 is equal to or lower than the threshold voltage of the fourth LED 422, So that all the LEDs of the LED light emitting circuit unit 400 except for the fourth LED 422 of the second LED light emitting unit 420 can be operated. Here, the control circuit unit 700 controls the current switch circuit unit 500 to control the current to flow as I3 as described above.

The high voltage section is a section during which the second LED light emitting section 420 can be operated only by the rectified voltage. The voltage charged in the charge storage circuit section 300 is not discharged through the bypass current switch 601.

7 is a diagram showing an operation in a case where the rectified voltage is a low voltage section in which the second LED light emitting unit can not operate.

The low voltage section refers to a voltage range in which the rectified voltage can be operated by the first LED light emitting unit 410 and the voltage range in which the second LED light emitting unit 420 can not operate. That is, a voltage output from the first LED light emitting unit 410 and input to the second LED light emitting unit 420 through the isolation diode 451 is applied to the LEDs located at the beginning of the second LED light emitting unit 420 The third LED 421). Therefore, in the low voltage period, the second LED emission unit 420 can not be operated only by the rectified voltage. In this low voltage period, the voltage charged in the charge storage circuit portion 300 may be inputted to the second LED light emitting portion 420 through the bypass current switch 601 to operate the second LED light emitting portion 420 .

7, the voltage charged in the charge storage circuit portion 300 (that is, the voltage charged in the second capacitor 320) is input to the second LED light emitting portion 420 through the bypass current switch 601, 2 LED light emitting unit 420 will be described.

When the rectified voltage is a low voltage, the rectified voltage can not operate the second LED emission unit 420, but the first LED emission unit 410 can operate according to the rectified voltage.

The input voltage input to the first LED light emitting portion is the sum of the rectified voltage Vrec and the voltage V1 stored in the first capacitor as described above with reference to FIG. 5 (b).

Therefore, the input voltage input to the first LED light emitting portion is always larger than V1. Here, when V1 is greater than the sum of the threshold voltage of the first LED 411 and the second LED 412, the first LED 411 and the second LED 412 always operate. Of course, in this case, the control circuit unit 700 controls the first current switch 501 of the current switch circuit unit 600 to be turned off and the second current switch 502 to be turned on to control the current to flow as I2, 411 and the second LED 412 are operated.

If V1 is smaller than the sum of the threshold voltage of the first LED 411 and the second LED 412 but larger than the threshold voltage of the first LED 411, the first LED 411 operates but the second LED 412 operates can not do it. Of course, in this case, the control circuit unit 700 controls the first current switch 501 of the current switch circuit unit 600 to be turned on and the second current switch 502 to be turned off to control the current to flow as I1, 411).

In the present invention, the second LED emission unit 420 may operate in response to a voltage stored in the charge storage circuit unit 300 during a low voltage period.

That is, when the rectified voltage fails to operate the second LED light emitting unit 420, the control circuit unit 700 controls the turn-off current switch 601 to be in the on-state so that the voltage charged in the charge storage circuit unit 300 The voltage V2 charged in the second capacitor 320 may be input to the second LED light emitting unit 420 to operate the second LED light emitting unit 420. [

Here, when V2 is greater than the sum of the threshold voltage of the third LED 421 and the threshold voltage of the fourth LED 422, the third LED 421 and the fourth LED 422 are both operated and the current flows as I4bypass. Of course, in this case, the control circuit unit 700 causes the third current switch 503 to be turned off and the fourth current switch 504 to be turned on to allow the current to flow through the second LED emission unit 420 as I4 bypass.

Here, when V2 is smaller than the sum of the threshold voltage of the third LED 421 and the threshold voltage of the fourth LED 422 but larger than the threshold voltage of the third LED 421, the third LED 421 operates, Flow. Of course, in this case, the control circuit unit 700 causes the third current switch 503 to be turned on and the fourth current switch 504 to be turned off so that the current flows to the second LED light emitting unit 420 as I3 bypass.

Here, the isolation diode 451 prevents the electric charge discharged from the charge storage circuit portion 300 from flowing to the first LED light emitting portion 410 through the current bypass switch 601 in the low voltage state.

FIG. 8 is a diagram illustrating a time during which the LED of the LED light emitting circuit unit 400 operates according to a rectified voltage according to an embodiment of the present invention.

8A is a diagram illustrating a time period in which the LEDs 411, 412, 421, and 422 of the LED light-emitting circuit unit 400 operate according to a rectified voltage in the prior art in which the charge storage circuit unit 300 is not provided.

The first LED 411 is turned on and the rectified voltage is increased so that the difference between the threshold voltage of the first LED 411 and the threshold voltage of the second LED 412, The second LED 412 is turned on until the sum of the threshold voltage of the first LED 411 and the threshold voltage of the third LED 421 exceeds the sum of the threshold voltage of the third LED 421 and the threshold voltage of the third LED 421 The threshold voltage of the second LED 412 and the threshold voltage of the third LED 421 and the threshold voltage of the third LED 421 are set to be higher than the threshold voltage of the second LED 421, The fourth LED 422 is turned on only when the sum of the threshold voltages is equal to or greater than the sum of the threshold voltages.

Therefore, in the prior art, each LED has a period in which each LED can not operate by the hatched time period.

However, in the present invention, the stored voltage V2 of the charge storage circuit unit 300 is supplied to the second LED unit 420 through the current bypass switch 601 in the low voltage period in which the third LED 421 and the fourth LED 422 are not operated. The second LED 420 can be operated. Here, if a half voltage of the maximum voltage Vpeak of the rectified voltage Vrec is a voltage capable of operating all the LEDs of the first LED light emitting unit 410 and the second LED light emitting unit 420, The voltage of the first LED light emitting unit 410 and the second LED light emitting unit 420 is equal to or greater than (1/2) * Vpeak, so that all the LEDs operate.

In the high voltage section, the rectified voltage is divided into a time interval in which the threshold voltage of the first LED 411, the threshold voltage of the second LED 412, the threshold voltage of the third LED 421 and the threshold voltage of the fourth LED 422 The fourth LED in the emulator does not work, and all the LEDs operate in all the other segments. That is, in the present invention, the fourth LED 422 does not operate only in the hatched time period of FIG. 8B, and all the LEDs are turned on in the input time interval of all other rectified voltages.

9 is a graph illustrating brightness of light according to an input voltage according to an embodiment of the present invention.

9 (a) is a graph showing the brightness of the LED light according to the rectified voltage in the conventional technique.

The brightness of light in an LED lighting device is proportional to the number of LEDs that operate. Thus, the brightness of light in the prior art is proportional to the LED operating as described above in Fig. 8 (a).

Likewise, the brightness of light in the present invention is proportional to the LED operating as described above in Fig. 8 (b).

9, it can be seen that the brightness of the light is uniform in all the input time intervals of the rectified voltage in the present invention.

That is, in the present invention, the change in brightness of light is reduced, so that the entire LED can be turned on even in a dark low-voltage period in which the conventional technology does not allow more than half of the LEDs, and the brightness of the LED light- The quality of light is very good. Also, the period of light brightness change was 100Hz to 120Hz in the prior art, but in the present invention, it is faster from 200Hz to 240Hz, and it becomes more difficult to detect the change of light by human eyes. That is, it is possible to make stable high quality light in the eye.

FIG. 10 to FIG. 14 are views showing a modification of the charge storage circuit portion according to an embodiment of the present invention.

10 is a view showing another modification of the charge storage circuit portion according to an embodiment of the present invention.

10, in the present invention, in order to reduce the peak current and the input current waveform during charge of the charge storage circuit portion 300, the forward current path of the first capacitor 310 and the forward current path of the second capacitor 320 the power factor and the current harmonic distortion (THD) of the charge storage circuit part 300 are improved by inserting one or more resistors R1, R2, R3 and R4 on the path as shown in FIG. .

11 is a view showing still another modification of the charge storage circuit portion according to an embodiment of the present invention.

11, a circuit unit 800 for improving the power factor and the current harmonic wave may be further connected between the rectifier circuit unit 200 and the charge storage circuit unit 300 according to the present invention.

The circuit part 800 for improving the power factor and the current harmonic has a structure in which two capacitors 802 and 803 are connected in series between a power supply voltage node of the rectifier circuit part 200 and the ground and an intermediate connection node B of two capacitors, The power factor and the current harmonic can be improved by the charging and discharging function of the two capacitors 802 and 803 with the circuit structure in which the resistor 801 is connected between the capacitor 200 and the capacitor A. [

12 is a circuit diagram illustrating a circuit for inputting all charges stored in the charge storage circuit portion to the second LED light emitting portion according to an embodiment of the present invention.

An isolation discharge prevention diode 309 is connected between the first capacitor 310 and the power supply voltage node and the first capacitor 310 and the current bypass circuit 601 are connected to each other, So that the charges charged in the first capacitor 310 and the second capacitor 320 are all input to the second LED light emitting portion 420 through the current bypass switch 601 can do.

Here, the separation-discharge prevention diode 309 functions to prevent the charge stored in the first condenser 310 from being input to the LED light-emitting circuit unit 400 when the charge is discharged in the charge storage circuit unit 300.

13 and 14 are diagrams showing a circuit modification of the charge storage circuit portion when a third LED light-emitting portion is added to the LED light-emitting circuit portion according to an embodiment of the present invention.

The LED light-emitting circuit unit 400 may further include an N-th LED light-emitting unit 4N0 of the third LED light-emitting unit 430 or more.

In this case, the charge storage circuit portion 300 may be modified to include N capacitors in order to supply charge to each of the N LED light-emitting portions 4N0 in the low-voltage section of the rectified voltage.

13 is a circuit diagram showing a circuit modification of the charge storage circuit part 300 including three capacitors 310, 320 and 330 when the third LED light emitting part 430 is added. In FIG. 13, the first capacitor 310 and the third capacitor 330, so that three capacitors 310, 320, and 330 are charged. The voltage stored in the first capacitor 310 is supplied to the first LED light emitting part 410 together with the rectified voltage and the charge stored in the second capacitor 320 is supplied to the second current- Emitting portion 420 and the charge stored in the third capacitor 330 is supplied to the third LED light-emitting portion 430 through the second current-

Here, a second isolation diode 452 is further provided between the second LED light emitting unit 420 and the third LED light emitting unit 430 so that the electric charge input to the third LED light emitting unit 430 is the second LED light (420).

In the present invention, the isolation diodes 451 and 452 are used to prevent the reverse flow of charges input to the LED light emitting units 420 and 430. However, the reverse current prevention switch may be used instead of the isolation diodes 451 and 452, It is possible to control the backflow prevention switch.

13, a third capacitor 330 is added to the charge storage circuit unit 300 to supply charge to the third LED light emitting unit 430. However, as shown in FIG. 14, the charge storage circuit unit 300_2 The charge storage circuit unit 300_2 may be supplied with electric charge from the added charge storage circuit unit 300_2.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the following claims And changes may be made without departing from the spirit and scope of the invention.

100: Power supply unit 200:
300: charge storage circuit part 310: first capacitor
320: second capacitor 400: LED light-emitting circuit
410: first LED emitting part 420: second LED emitting part
500: current switch circuit section 601: current-bypass switch
700: control circuit

Claims (9)

A power supply unit;
A rectifying circuit part receiving the AC power from the power supply part and outputting a rectified voltage;
A charge storage circuit part for receiving a power from the rectifying circuit part to store a charge when the voltage is a high voltage and discharging a stored charge when the voltage is a low voltage;
The first LED light-emitting unit of the front end of the isolation diode and the second LED light-emitting unit of the rear end are connected in series. The first LED light-emitting unit is connected to the power source unit to receive power, An LED light-emitting circuit connected to the LED;
A current bypass switch connecting the charge storage circuit portion and the second LED light emitting portion;
A current switch circuit part including a plurality of current switches connected to the LED light emitting part and controlling operation thereof;
And a control circuit unit controlling the current bypass circuit and the current switch circuit unit according to a power supply state to emit light of the LED light emitting unit.
The method according to claim 1,
The charge storage circuit portion
A first diode, a second diode, a third diode, and a first capacitor and a second capacitor, wherein the second diode is connected in a forward direction between the first capacitor and the second capacitor, One end of the first capacitor is connected to the power supply voltage node of the power supply unit and the other end of the second capacitor is connected to the ground, and the first diode is connected in a reverse direction between the node to which the first capacitor and the second diode are connected, And the third diode is connected between the node to which the second capacitor and the second diode are connected and the current bypass switch so that the charge stored in the second capacitor is supplied to the second LED light- And an energy storage characteristic of the light emitting diode is provided to the light emitting diode.
The method according to claim 1,
The first LED light emitting unit and the second LED light emitting unit may include one or more LEDs,
And each of the LEDs is connected to the current switch.
The method according to claim 1,
The first LED light emitting unit and the second LED light emitting unit each include at least one LED,
Wherein the control circuit unit turns on the current bypass switch to turn off the charge stored in the charge storage circuit unit when the power supplied from the power supply unit does not reach the power source for operating all the LEDs of the second LED light emitting unit, And the LED light emitting unit is controlled to be supplied to the LED light emitting unit.
3. The method of claim 2,
Wherein at least one resistance is inserted between the first capacitor and the forward current path of the second capacitor to improve a peak current reduction and an input current waveform when the first capacitor or the second capacitor is charged, And an improvement in harmonics is provided.
The method according to claim 1,
A circuit section for improving the power factor and the current harmonic is connected between the rectifying circuit section and the charge storage circuit section,
The circuitry for improving the power factor and current harmonics
Wherein two capacitors are connected in series between a power supply voltage node of the rectifying circuit section and the ground, and a resistor is connected between the intermediate connection node of the two capacitors and the rectifying circuit section.
3. The method of claim 2,
Wherein the first capacitor and the current bypass circuit are connected to each other so that the charges charged in the first capacitor and the second capacitor are all connected to the first and second capacitors, And the light is supplied to the light emitting unit.
The method according to claim 1,
And a third LED light emitting unit connected to the LED light emitting circuit unit through a second isolation diode,
And a second current bypass circuit for operating the third LED light emitting unit,
The charge storage circuit portion
A first diode, a second diode, a third diode, a fourth diode, a fifth diode, a sixth diode and a first capacitor, a second capacitor, and a third capacitor, and between the first capacitor and the second capacitor The second diode is connected in the forward direction, one side of the first capacitor is connected to the power supply voltage node of the rectifying circuit part, one side of the second capacitor is connected to the ground through the fourth diode connected in the reverse direction, Wherein the first diode is connected in a reverse direction between a node connected to the first capacitor and the second diode and the ground and the third diode is connected to the third capacitor through the second capacitor, And a second capacitor connected between the node to which the second diode is connected and the current bypass switch, And the sixth diode is connected between a node to which the third capacitor and the fifth diode are connected and the second current bypass switch and is stored in the third capacitor And an electric charge is supplied to the third LED light-emitting portion through the second current-bypassing switch.
The method according to claim 1,
And a reverse current prevention switch is provided instead of the isolation diode.

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