KR102322319B1 - Led lighting apparatus - Google Patents

Abstract

The present invention discloses a lighting device. The lighting device includes two or more lighting units including a plurality of light emitting diode groups that sequentially emit light in response to a rise in a rectified voltage, and at least one of the two or more lighting units has the same light emitting order and has a different light emission timing compared to other lighting units. is configured to include a group of light emitting diodes. Accordingly, current harmonics can be reduced, and power efficiency can be improved.

Description

lighting device {LED LIGHTING APPARATUS}

The present invention relates to a lighting device, and more particularly, to a lighting device with improved current harmonics.

A lighting device has been developed to use a light source having high luminous efficiency with a small amount of energy in order to save energy. A representative light source used in the lighting device may be a light emitting diode (LED).

Light emitting diodes have advantages that differentiate them from other light sources in various factors such as energy consumption, lifetime, and light quality. The light emitting diode has a characteristic of being driven by an electric current. Therefore, a lighting device using a light emitting diode as a light source has a problem in that a lot of additional circuits for driving current are required.

In order to solve the above problems, lighting devices have been developed to provide AC power to light emitting diodes in an AC direct type (AC DIRECT TYPE). The lighting device is configured to convert AC power into a rectified voltage, and a light emitting diode emits light by driving a current using the rectified voltage. The lighting device has a good power factor because it uses a rectified voltage without using an inductor and a capacitor. The rectified voltage means a voltage obtained by full-wave rectification of an AC voltage by full-wave rectification of the rectifier.

The above-described lighting device is driven non-linearly in an alternating current direct method. Therefore, current harmonics can occur. The current harmonic may cause a problem of reducing the power efficiency of the lighting device.

Accordingly, there is a need for a method for reducing current harmonics and improving power efficiency of a lighting device.

Korean Patent Laid-Open Patent Publication No. 10-2012-0079831 (Title of the invention: Spectral shift control for AC LED with dimming function)

An object of the present invention is to improve power efficiency by driving a lighting device including a light emitting diode in an AC direct method and improving current harmonics.

Another object of the present invention is to provide a lighting device including a light emitting diode capable of improving current harmonics due to nonlinear driving.

A lighting device of the present invention for solving the above technical problem includes: a rectifying circuit for providing a rectified voltage; two or more lighting units including a plurality of light emitting diode groups that sequentially emit light in response to a rise in the rectified voltage; and two or more driving circuits configured to correspond to the two or more lighting units, respectively, and regulating the current of the corresponding lighting units; characterized.

In addition, the lighting device of the present invention, a power supply for providing a rectified voltage; a lighting unit including a plurality of light emitting diode groups that sequentially emit light in response to a change in the rectified voltage; and two or more driving circuits sharing at least a portion of the plurality of light emitting diode groups, wherein the two or more driving circuits independently control a driving current for sequential light emission, and a portion of the current amount change timing of the driving currents Control to be different, and the number of current amount change timings of the total driving current corresponding to sequential light emission is set to exceed the number of the current amount change timings among the two or more driving circuits.

Accordingly, according to the present invention, it is possible to improve current harmonics that may occur due to AC direct driving, and to improve power efficiency by improving current harmonics caused by nonlinear driving.

1 is a circuit diagram of a lighting device according to a preferred embodiment of the present invention;
FIG. 2A is a circuit diagram illustrating an example of the lighting unit 200 of FIG. 1 .
FIG. 2B is a circuit diagram illustrating an example of the lighting unit 210 of FIG. 1 .
3 is a detailed circuit diagram of the driving circuit of FIG. 1;
4 is a graph for explaining the operation of each driving unit of FIG. 1 ;
5 is a current waveform diagram corresponding to a rectified voltage change in the embodiment of FIG. 1;
6 is a circuit diagram of a lighting device according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The terms used in the present specification and claims are not limited to a conventional or dictionary meaning, and should be interpreted in a meaning and concept consistent with the technical matters of the present invention.

The configuration shown in the embodiments and drawings described in this specification is a preferred embodiment of the present invention, and does not represent all of the technical spirit of the present invention, so various equivalents and modifications that can be substituted for them at the time of the present application are provided. there may be

The lighting device of the present invention may use a light source having semiconductor light emitting characteristics that converts electrical energy into light energy, and the light source having semiconductor light emitting characteristics may include a light emitting diode.

An embodiment of the present invention may be started using a lighting device driven in an AC direct manner as shown in FIG. 1 . The lighting device of the embodiment of FIG. 1 is configured such that the light source emits light by the AC power source, and current regulation for regulating the current is performed in response to the light emission of the light source.

1, an embodiment of the present invention will be described. The embodiment of the present invention includes a power supply circuit 100 , lighting units 200 and 210 , driving units 300 and 310 , and current sensing resistors Rs1 and Rs2 .

In the above configuration, the power circuit 100 provides the rectified power, the lighting units 200 and 210 emit light by the rectified power, and the driving units 300 and 310 are the lighting units 200 and 210 . A current regulation for regulating a current corresponding to light emission is performed and a current path for light emission is provided. In addition, the current sensing resistors Rs1 and Rs2 provide a current path and provide a sensing voltage for current regulation of the drivers 300 and 310 .

Among them, the power circuit 100 includes a power source Vs and a rectifier circuit 20 . Here, the power source Vs may be a commercial AC power supply providing AC power.

The rectifier circuit 20 converts the negative voltage of the AC voltage into a positive voltage. That is, the rectifier circuit 20 outputs a rectified voltage obtained by full-wave rectification of an AC voltage having a sinusoidal waveform of AC power provided from the AC power source Vs. The rectified voltage has a characteristic of having a ripple in which the voltage level rises and falls in units of half a period of a commercial AC voltage. In the embodiment of the present invention, the change (rising or falling) of the rectified voltage may be understood to mean the rise or fall of the ripple component of the rectified voltage.

The power circuit 100 may include a dimmer (not shown) to control brightness. The dimmer may control the phase of the AC voltage provided to the rectifier circuit 20 . By controlling the phase of the dimmer, the total amount of driving current provided to the lighting units 200 and 210 may be controlled, and as a result, the brightness of the lighting device may be controlled.

Meanwhile, in the embodiment of the present invention, the lighting units 200 and 210 configured as light sources emit light by the rectified voltage provided by the rectifier circuit 20 . The total driving current provided by the rectifier circuit 20 may be expressed as Irec, and the driving currents distributed from the total driving current Irec and provided to the lighting units 200 and 210, respectively, may be expressed as Irs1 and Irs2. The driving current provided to the lighting units 200 and 210, respectively, is the same as the current flowing through the respective current sensing resistors Rs1 and Rs2.

Each of the lighting units 200 and 210 may include a plurality of light emitting diodes, and the plurality of light emitting diodes may be divided into a plurality of groups to sequentially emit or extinguish light. In FIG. 1, each of the lighting units 200 and 210 is divided into four light emitting diode groups (LED11 to LED14, and LED21 to LED24). Each of the light emitting diode groups (LED11 to LED14 and LED21 to LDE24) may include one or more light emitting diodes, and for convenience of description in FIG.

A driving circuit is configured in each of the lighting units 200 and 210 . The driving circuit corresponding to the lighting unit 200 includes the driving unit 300 and the current sensing resistor Rs1 , and the driving circuit corresponding to the lighting unit 210 includes the driving unit 310 and the current sensing resistor Rs2 .

The drivers 300 and 310 regulate the driving current and induce the flow of a constant current in response to the light emission of the lighting units 200 and 210 . To this end, the drivers 300 and 310 perform current regulation for light emission of each light emitting diode group (LED11 to LED14, LED21 to LED24), and emit light together with each current sensing resistor Rs1 and Rs2 whose one end is grounded. is configured to provide a current path for

In the embodiment of FIG. 1 , the light emitting diode groups LED11 to LED14 and LED21 to LED24 of the lighting units 200 and 210 are sequentially emitted or extinguished in response to the rise or fall of the rectified voltage.

The drivers 300 and 310 provide a current path for light emission when the rectified voltage rises to sequentially reach the light emitting voltage of each of the light emitting diode groups (LED11 to LED14 and LED21 to LED24).

Here, the light emitting voltage V14 for emitting light from the light emitting diode group LED14 is defined as a voltage for emitting light from all of the light emitting diode groups LED11 , LED12 , LED13 , and LED14 . The light emitting voltage V13 for emitting light from the light emitting diode group LED13 is defined as a voltage for emitting light from all of the light emitting diode groups LED11 , LED12 , and LED13 . The light emitting voltage V12 for emitting light from the light emitting diode group LED12 is defined as a voltage for emitting light from all of the light emitting diode groups LED11 and LED12. The light emitting voltage V11 for emitting light from the light emitting diode group LED11 is defined as a voltage for emitting light from only the light emitting diode group LED11 .

In addition, the light emitting voltage V24 for emitting light from the light emitting diode group LED24 is defined as a voltage for all of the light emitting diode groups LED21 , LED22 , LED23 , and LED24 to emit light. The light emitting voltage V23 for emitting light from the light emitting diode group LED23 is defined as a voltage for emitting light from all of the light emitting diode groups LED21 , LED22 , and LED23 . The light emitting voltage V22 for emitting light from the light emitting diode group LED22 is defined as a voltage for emitting light from all of the light emitting diode groups LED21 and LED22. In addition, the light emitting voltage V21 for emitting light from the light emitting diode group LED21 is defined as a voltage for emitting light from the light emitting diode group LED21 .

The drivers 300 and 310 receive sensing voltages by current sensing resistors Rs1 and Rs2, respectively. The sensing voltage may be varied by a current path formed at a variable position in the driving units 300 and 310 according to the light emitting state of each light emitting diode group of the lighting units 200 and 210 . In this case, the driving current flowing through the current sensing resistors Rs and Rs2 may be a constant current.

In the above configuration, the light emission timing of at least one light emitting diode group having the same light emission order in the lighting units 200 and 210 may be different. In the lighting units 200 and 210 of the embodiment of the present invention, the light emitting order of the light emitting diode group LED11 and the light emitting diode group LED21 is the same, and the light emitting order of the light emitting diode group LED12 and the light emitting diode group LED22 is the same, and the light emitting diode group LED31 and The light emitting order of the light emitting diode group LED23 is the same, and the light emitting order of the light emitting diode group LED14 and the light emitting diode group LED24 is the same.

According to an embodiment of the present invention, as described above, at least one pair of light emitting diode groups among the light emitting diodes having the same light emitting order may be configured to have different light emitting timings.

As described above, a pair of light-emitting diode groups having the same light-emitting order and different light-emitting timings may be configured to emit light corresponding to different light-emitting voltages having a difference of at least 10% or more.

In addition, as described above, the light emitting diode groups having the same light emitting order and different light emission timings may be configured to emit light corresponding to different phases of the rectified voltage having a difference of at least 10% or more.

In addition, the total emission voltage of each of the lighting units 200 and 210 may be set to have a difference of less than 20 percent based on the total emission voltage of any one lighting unit.

In an embodiment of the present invention, the lighting units 200 and 210 are configured such that the light emission timings of a pair of light emitting diode groups in the last light emitting order are substantially the same, and pairs of different light emitting diode groups have different light emission timings.

To this end, the first light emitting diode groups LED11 and LED21 of the lighting units 200 and 210 may be configured to have different numbers of light emitting diodes connected in series.

2A and 2B , the light emitting diode group LED11 of the lighting unit 200 includes two light emitting diodes connected in series, and the light emitting diode group LED21 of the lighting unit 210 includes three light emitting diodes connected in series. includes a diode. The light emitting diode group LED12 of the lighting unit 200 and the light emitting diode group LED22 of the lighting unit 210 exemplify that two light emitting diodes are connected in series, and the light emitting diode groups LED13 and LED14 of the lighting unit 200 . The light emitting diode groups LED23 and LED24 of the lighting unit 210 are exemplified as including one light emitting diode. Here, the light emitting diode groups LED11 , LED12 , LED21 , and LED22 may be configured to include a plurality of parallel-connected columns.

2a and 2b, the light emitting diode groups (LED12, LED13, LED14) of the lighting unit 200 include the same number of light emitting diodes as the light emitting diode groups (LED22, LED23, LED24) of the lighting unit 210 . can be set.

In addition, the light emitting diode group LED21 of the lighting unit 210 may include a larger number of series-connected light emitting diodes than the light emitting diode group LED11 of the lighting unit 200 . That is, the light emitting diode group LED21 of the lighting unit 210 has a higher light emission voltage than the light emitting diode group LED11 of the lighting unit 200 . As a result, the light emission timing of the light emitting diode group LED21 is formed later than that of the light emitting diode group LED11 . In addition, the number of the light emitting diode group LED21 of the lighting unit 210 and the light emitting diode group LED11 of the lighting unit 200 may be adjusted in parallel to include the same number of light emitting diodes.

As described above, as the pairs of the light emitting diode groups LED11 and LED21 have different light emitting timings, the light emitting timings of the light emitting diode groups LED12 : LED22 and LED13 : LED23 may also be formed differently.

According to an embodiment of the present invention, the light emitting diode group LED24 may be configured to have a light emitting voltage lower than that of the light emitting diode group LED14 so that the light emitting timing of the light emitting diode groups LED14 and LED24 may be identically formed. More specifically, the light emitting diode group LED11 may be configured to have a light emitting voltage lower than the light emitting voltage of the light emitting diode group LED11 by the difference between the light emitting voltages of the light emitting diode groups LED11 and LED21 . Accordingly, the light emitting diode group LED14 and the light emitting diode group LED24 may have the same emission timing.

Meanwhile, the detailed configuration and operation of the driving units 300 and 310 for driving the above-described lighting units 200 and 210 will be described with reference to FIG. 3 , and the driving unit 300 will be representatively described. Since the driving unit 310 may have the same configuration as the driving unit 300 , a redundant description thereof will be omitted.

The driver 300 provides a plurality of switching circuits 31 , 32 , 33 , 34 providing current paths for the light emitting diode groups LED11 to LED14 and reference voltages VREF1 , VREF2 , VREF3 , and VREF4 as shown in FIG. 3 . It may include a reference voltage supply unit 30 for the following, and may be configured as a single chip.

The reference voltage supply unit 30 may be implemented by providing reference voltages VREF1, VREF2, VREF3, and VREF4 of various different levels according to the intention of the manufacturer.

The reference voltage supply unit 30 may be configured to output reference voltages VREF1, VREF2, VREF3, and VREF4 of different levels for each node between the resistors, including a plurality of series-connected resistors to which a constant voltage is applied. It can be configured to include independent voltage sources providing different levels of reference voltages VREF1, VREF2, VREF3, and VREF4.

Here, GND indicates a ground, and the ground GND may be commonly applied to the reference voltage supply unit 30 and the current sensing resistor Rs. In the reference voltage supply unit 30 , the ground GND may be applied to a plurality of series-connected resistors that output reference voltages VREF1 , VREF2 , VREF3 , and VREF4 of the level.

Reference voltages VREF1, VREF2, VREF3, and VREF4 of different levels may be provided such that the reference voltage VREF1 has the lowest voltage level and the reference voltage VREF4 has the highest voltage level.

Here, the reference voltage VREF1 has a level for turning off the switching circuit 31 when the light emitting diode group LED12 emits light. More specifically, the reference voltage VREF1 may be set to a level lower than the sensing voltage formed in the current sensing resistor Rs1 in response to light emission of the light emitting diode group LED12 .

In addition, the reference voltage VREF2 has a level for turning off the switching circuit 32 when the light emitting diode group LED13 emits light. More specifically, the reference voltage VREF2 may be set to a level lower than the sensing voltage formed in the current sensing resistor Rs1 in response to light emission of the light emitting diode group LED13 .

In addition, the reference voltage VREF3 has a level for turning off the switching circuit 33 when the light emitting diode group LED14 emits light. More specifically, the reference voltage VREF3 may be set to a level lower than the sensing voltage formed in the current sensing resistor Rs1 in response to light emission of the light emitting diode group LED14 .

In addition, the reference voltage VREF4 is preferably set to maintain the current path through the switching circuit 34 in the region of the upper limit level of the rectified voltage.

Meanwhile, the switching circuits 31 , 32 , 33 , and 34 are commonly connected to a sensing resistor Rs1 that provides a sensing voltage for current regulation and formation of a current path.

The switching circuits 31 , 32 , 33 , and 34 compare the sensing voltage sensed by the current sensing resistor Rs1 with the respective reference voltages VREF1 , VREF2 , VREF3 , and VREF4 of the reference voltage generating circuit 30 to compare the lighting unit 200 . ) to form a selective current path for emitting light.

The switching circuits 31, 32, 33, and 34 of the driving unit 300 induce a regulated constant current flow in response to the light emission of each light emitting diode group (LED11, LEED12, LED13, LED14), and each light emitting diode group ( In response to the sequential light emission of LED11, LED12, LED13, and LED14), current regulation is performed so as not to exceed the set current.

That is, the switching circuits 31 , 32 , 33 , and 34 do not perform a current regulation operation with respect to a driving current less than the regulated current value set therein, and exceed the regulated level for a driving current greater than or equal to the regulated current value set therein. To prevent this from happening, a current regulation operation is performed.

The switching circuits 31 , 32 , 33 , and 34 receive a higher level of reference voltage as they are connected to the light emitting diode groups LED11 , LED12 , LED13 , and LED14 that are farther from the position to which the rectified voltage is applied.

Each of the switching circuits 31 , 32 , 33 , and 34 includes a comparator 36 and a switching element 37 , and the switching element 37 is preferably composed of an NMOS transistor.

The comparator 36 of each of the switching circuits 31, 32, 33, 34 has a reference voltage applied to a positive input terminal (+), a sensing voltage applied to a negative input terminal (-), and a reference voltage and a sensing voltage to an output terminal. Print the comparison result.

In addition, the switching element 37 of each of the switching circuits 31 , 32 , 33 , and 34 performs a switching operation according to the output of each comparator 36 applied to the gate.

The operation of the driving unit 300 of FIG. 3 may be described with reference to FIG. 4 .

The power circuit 100 provides a rectified voltage corresponding to AC power to the lighting unit 200 , wherein the rectified voltage is as illustrated in FIG. 4 .

When the rectified voltage is in an initial state, each of the switching circuits 31 , 32 , 33 , and 34 senses the reference voltages VREF1 , VREF2 , VREF3 , and VREF4 applied to the positive input terminal (+) are applied to the negative input terminal (-). Since it is higher than the sensing voltage across both ends of the resistor Rs1, all are maintained in the turned-on state. At this time, the driving current flowing through the switching circuit 31 is equal to or less than the current value regulated by the switching circuit 31 . Therefore, the switching circuit 31 does not regulate the flowing driving current. That is, the current regulation operation by the switching circuit 31 is not performed.

After that, when the rectified voltage rises to reach the emission voltage V11 , the light emitting diode group LED11 of the lighting unit 200 emits light. When the LED group LED11 emits light, the switching circuit 31 of the driving unit 300 connected to the LED group LED11 provides a current path.

As described above, when the rectified voltage reaches the light emitting voltage V11, the light emitting diode group LED11 emits light and a current path through the switching circuit 31 is formed, the level of the sensing voltage of the current sensing resistor Rs1 increases. However, since the level of the sensing voltage at this time is low, the turn-on state of the switching circuits 31 , 32 , 33 , and 34 is not changed. And, the driving current flowing through the switching circuit 31 is regulated by the current regulation operation of the switching circuit 31 .

Thereafter, the rectified voltage may rise above the emission voltage V11. At this time, the driving current flowing through the switching circuit 32 is equal to or less than the current value regulated by the switching circuit 32 . Therefore, the switching circuit 32 does not regulate the flowing driving current. That is, the current regulation operation by the switching circuit 31 is performed, and the current regulation operation by the switching circuit 32 is not performed.

After that, when the rectified voltage continues to rise to reach the emission voltage V12 , the LED group LED12 of the lighting unit 200 emits light. When the LED group LED12 emits light, the switching circuit 32 of the driving unit 300 connected to the LED group LED12 provides a current path. At this time, the light emitting diode group LED11 also maintains the light emitting state.

As described above, when the rectified voltage reaches the light emitting voltage V12 so that the light emitting diode group LED12 emits light and a current path through the switching circuit 32 is formed, the level of the sensing voltage of the current sensing resistor Rs1 increases. At this time, the level of the sensing voltage is higher than the reference voltage VREF1. Therefore, the switching element 37 of the switching circuit 31 is turned off by the output of the comparator 36 . That is, the switching circuit 31 is turned off, and the switching circuit 32 provides a selective current path corresponding to the light emission of the light emitting diode group LED12 . At this time, the driving current flowing through the switching circuit 32 is regulated by the current regulation operation of the switching circuit 32 .

After that, when the rectified voltage continues to rise to reach the emission voltage V13 , the light emitting diode group LED13 of the lighting unit 200 emits light. And, when the light emitting diode group LED13 emits light, the switching circuit 33 of the driving unit 300 connected to the light emitting diode group LED13 provides a current path. At this time, the light emitting diode groups LED11 and LED12 also maintain a light emitting state.

As described above, when the rectified voltage reaches the light emitting voltage V13 and the light emitting diode group LED13 emits light and a current path through the switching circuit 33 is formed, the level of the sensing voltage of the current sensing resistor Rs1 increases. At this time, the level of the sensing voltage is higher than the reference voltage VREF2. Therefore, the switching element 37 of the switching circuit 32 is turned off by the output of the comparator 36 . That is, the switching circuit 32 is turned off, and the switching circuit 33 provides a selective current path corresponding to the light emission of the light emitting diode group LED13 . At this time, the driving current flowing through the switching circuit 33 is regulated by the current regulation operation of the switching circuit 33 .

After that, when the rectified voltage reaches the emission voltage V14 , the light emitting diode group LED14 of the lighting unit 200 emits light. In addition, when the light emitting diode group LED14 emits light, the switching circuit 34 of the driving unit 300 connected to the light emitting diode group LED14 provides a current path. At this time, the light emitting diode groups LED11 , LED12 , and LED13 also maintain a light emitting state.

As described above, when the rectified voltage reaches the light emitting voltage V14, the light emitting diode group LED14 emits light and a current path through the switching circuit 34 is formed, the level of the sensing voltage of the current sensing resistor Rs1 increases. At this time, the level of the sensing voltage is higher than the reference voltage VREF3. Therefore, the switching element 37 of the switching circuit 33 is turned off by the output of the comparator 36 . That is, the switching circuit 33 is turned off, and the switching circuit 34 provides a selective current path corresponding to the light emission of the light emitting diode group LED14 . At this time, the driving current flowing through the switching circuit 34 is regulated by the current regulation operation of the switching circuit 34 .

Thereafter, the rectified voltage may rise above the emission voltage V14. In this case, the switching circuit 34 may regulate the flowing driving current. In addition, even when the rectified voltage continues to rise, the switching circuit ( 34) remains turned on.

As described above, when the light emitting diode groups LED11 to LED14 sequentially emit light in response to the rise of the rectified voltage, the driving current in the current path also increases stepwise to have a step current waveform as shown in FIG. 4 .

The driving unit 300 performs the constant current regulation operation as described above. Therefore, the driving current corresponding to light emission for each light emitting diode group maintains a constant level, and when the number of light emitting diode groups increases, the level increases accordingly.

On the other hand, the rectified voltage starts to fall after rising to the upper limit level as described above. When the rectified voltage falls below the emission voltage V14, the light emitting diode group LED14 of the lighting unit 200 is extinguished.

When the light emitting diode group LED14 is extinguished, the lighting unit 200 maintains the light emitting state by the light emitting diode group nulls LED13, LED12, and LED11, and accordingly a switching circuit 33 connected to the light emitting diode group LED13 A current path is formed by

After that, when the rectified voltage is sequentially lowered to below the emission voltages V13, V12, and V11, the LED groups LED13, LED12, and LED11 of the lighting unit 200 are sequentially extinguished.

In response to the sequential extinction of the light emitting diode groups LED13, LED12, and LED11 of the lighting unit 200, the driving unit 300 shifts the selective current path formed by the switching circuits 33, 32, and 31. while providing In addition, the driving current on the current path is also gradually decreased to have a step current waveform in response to the extinction state of the light emitting diode groups LED11 , LED12 , and LED13 .

On the other hand, the lighting unit 210 also emits and emits light sequentially as in the operation of the lighting unit 200 in response to the rise and fall of the rectified voltage, and the driver 310 also provides a shifted current path in response to light emission. .

Here, some light emitting diode groups of the lighting unit 210 have different light emission timings from those of the light emitting diode groups having the same light emitting order of the lighting unit 200 . Therefore, the lighting units 200 and 210 may be operated to alternately and sequentially increase the number of light emitting diode groups in response to the increase of the rectified voltage. In addition, the driving units 300 and 310 may regulate the driving current to have step current waveforms at different current change times in response to the light emission of the respective lighting units 200 and 210 .

The embodiment of the present invention exemplifies that each of the lighting units 200 and 210 includes four light emitting diode groups, and illustrates that the light emitting diode groups except for the last light emitting diode are configured to have different light emission timings for each light emission order.

This will be described in more detail.

A voltage emitted by all the light emitting diode groups LED11 to LED14 included in the lighting unit 200 may be defined as the total emission voltage of the lighting unit 200 , and the total emission voltage of the lighting unit 200 corresponds to the emission voltage V14 . can do. In addition, the voltage emitted by all the light emitting diode groups LED21 to LED24 included in the lighting unit 210 may be defined as the total emission voltage of the lighting unit 210 , and the total emission voltage of the lighting unit 210 is the emission voltage V24 . can correspond to

In this case, it is preferable that one lighting unit is set to have a difference of less than 20 percent based on the total emission voltage of the other lighting unit.

Based on the sequential light emission order of the lighting units 200 and 210 , the light emitting diode group LED11 and the light emitting diode group LED21 correspond to each other, and the light emitting diode group LED12 and the light emitting diode group LED22 correspond to each other The light emitting diode group LED13 and the light emitting diode group LED23 correspond to each other, and the light emitting diode group LED14 and the light emitting diode group LED24 correspond to each other.

In addition, the light emitting diode groups LED11 to LED13 of the lighting unit 200 and the light emitting diode groups LED21 to LED23 of the lighting unit 210 may have a light emitting voltage having the same potential difference for each group corresponding to the light emitting order. The light emitting voltage difference may be determined by series-connected light emitting diodes further included in the light emitting diode group LED21, and it is preferable that the light emitting voltages between the light emitting diode groups having the same light emitting order have a difference of 10% or more.

More specifically, the light emitting diode group (LED11 to LED13) of the lighting unit 200 and the light emitting diode group (LED21 to LED23) of the lighting unit 210 may be configured to have a light emitting voltage having a potential difference of 64V for each channel, The light emitting diode group LED21 may be configured to have a light emitting voltage 32V higher than that of the light emitting diode group LED11 .

As described above, the emission voltage V11 of the lighting unit 200 is 64V, the emission voltage V12 is 128V, the emission voltage V13 is 192V, and the emission voltage V14 is 256V, and the potential difference for each group may be set to 64V. In addition, the emission voltage V21 of the lighting unit 210 may be 96V, the emission voltage V22 may be 160V, and the emission voltage V23 may be 224V. Here, the light emitting voltage V24 of the last light emitting diode group LED24 of the lighting unit 210 may be formed to be substantially the same as the light emission voltage V14 of the last light emitting diode group LED14 of the lighting unit 200, To this end, the light emitting voltage V24 is formed to be 256V, and the potential difference between the light emitting voltages of the light emitting diode group LED23 and the light emitting diode group LED24 may be set to 32V.

As described above, when the rectified voltage rises to reach 64V corresponding to the emission voltage V11, the light emitting diode group LED11 emits light, and when the rectified voltage rises to reach 96V corresponding to the emission voltage V21, the light emitting diodes The group LED21 emits more light, and when the rectified voltage reaches 128V corresponding to the emission voltage V12, the LED group LED12 further emits light, and when the rectified voltage reaches 160V corresponding to the emission voltage V22, the LED group ( LED22) emits more light, and when the rectified voltage reaches 192V corresponding to the emission voltage V13, the light emitting diode group (LED13) further emits light, and when the rectified voltage reaches 224V corresponding to the emission voltage V23, the light emitting diode group (LED23) The light is further emitted, and when the rectified voltage reaches 256V corresponding to the light-emitting voltages V14 and V24, the light-emitting diode groups LED14 and LED24 further emit light.

That is, the number of light emitting diode groups emitting light of the lighting units 200 and 210 may be alternately sequentially increased.

Corresponding to the light emission of the lighting units 200 and 210, the driving units 300 and 310 regulate the driving current corresponding to the light emission of each of the lighting units 200 and 210 so that the current change points have different step current waveforms. current regulation for

The driving units 300 and 310 regulate the driving current by performing current regulation corresponding to the light emission of the corresponding lighting units 200 and 210 , respectively, and are regulated by the driving unit 300 corresponding to the light emission of the illumination unit 200 . The used driving current has a step current waveform equal to Irs1, and the driving current regulated by the driving unit 310 corresponding to the light emission of the lighting unit 210 has a step current waveform equal to Irs2.

The lighting units 200 and 210 and the drivers 300 and 310 act as a load from the viewpoint of the power circuit 100, and the current supplied to the load, that is, the total driving current Irec supplied to the lighting units 200 and 210 is It has a step current waveform that is the sum of the driving current Irs1 and the driving current Irs2.

That is, the total driving current Irec may have a plurality of constant current sections, and it is preferable that the constant current sections are divided by (the number of the light emitting diode groups × the number of the lighting units)-(the number of the lighting units - 1). To this end, it is preferable that the last light emitting diode groups of each of the lighting units 200 and 210 have substantially the same light emitting voltage to form the same constant current period.

Although the present invention exemplifies an embodiment including two lighting units, the present invention is not limited thereto and may include three or more lighting units.

In this case, it is preferable that the total emission voltage of each lighting unit is set to have a difference of less than 20 percent based on the total emission voltage of any one lighting unit.

In addition, it is preferable that the plurality of light emitting diode groups of the lighting units are configured to have light emission voltages having different light emission timings.

In addition, it is preferable that the light emitting voltages of the light emitting diode groups of the lighting units corresponding to each other based on the light emission order have a difference of 10% or more with respect to the light emitting diode group of any one lighting unit.

As described above, it is shown that nonlinearity is alleviated in the change of the total driving current Irec according to the embodiment of the present invention, and as the number of lighting units increases, the total driving current Irec for lighting may have a relaxed nonlinearity waveform.

Therefore, according to the embodiment of the present invention, current harmonics can be reduced by alleviating nonlinearity of the entire driving current, and as a result, power efficiency can be improved.

The lighting device of the present invention may be implemented to include a lighting unit including a plurality of light emitting diode groups that sequentially emit light in response to a change in a rectified voltage, and two or more driving circuits sharing at least a portion of the plurality of light emitting diode groups.

Here, the two or more driving circuits may independently control a driving current for sequential light emission and may control a portion of a current amount change time point of the driving currents to be different from each other.

In addition, the number of current amount change timings of the total driving current corresponding to sequential light emission may be set to exceed the number of current amount change timing points of the driving circuit having the largest amount of current change timing among the two or more driving circuits.

Here, the total driving current may be set as the sum of driving currents controlled by the two or more driving circuits, and the number of current amount change timings of the total driving current is the sum of the current amount change timing points of each of the two or more driving circuits. It can be determined as follows.

The above-described embodiment of the present invention may be presented as shown in FIG. 6 .

6 includes a power circuit 100 , a lighting unit 230 , drivers 300 and 310 , and current sensing resistors Rs1 and Rs2 . Here, the power circuit 100 , the drivers 300 and 310 , and the current sensing voltages Rs1 and Rs2 have the same configuration as the embodiment of FIG. 1 , and thus a redundant description thereof will be omitted.

The lighting unit 230 of FIG. 6 emits light by the rectified voltage provided by the rectifier circuit 20 . The total driving current provided by the rectifier circuit 20 may be expressed as Irec, and the driving currents distributed from the total driving current Irec and provided to the lighting units 200 and 210, respectively, may be expressed as Irs1 and Irs2. The driving current provided to the lighting units 200 and 210, respectively, is the same as the current flowing through the respective current sensing resistors Rs1 and Rs2.

The lighting unit 230 may include a plurality of light emitting diodes, and the plurality of light emitting diodes may be divided into a plurality of groups to sequentially emit or extinguish light. In FIG. 6 , the lighting unit 230 is illustrated as including seven light emitting diode groups (LED11 to LED14 and LED21 to LED23). Each of the light emitting diode groups (LED11 to LED14 and LED21 to LDE23) may include one or more light emitting diodes, and in FIG.

The lighting unit 230 includes LED groups connected in series in the order of LED11, LED21, LED12, LED22, LED13, LED23, and LED14. , and the light emitting diode group LED14 emits light in response to the highest light emitting voltage, and may be defined as the last light emitting diode group.

One driving circuit is configured in the odd-numbered light emitting diode groups (LED11 to LED14) of the lighting unit 230, and different from the even-numbered light emitting diode groups (LED21 to LED23) and the last light emitting diode group (LED14) of the lighting unit 230 . One driving circuit is constituted. Here, the output terminal of the last light emitting diode group LED14 is shared by the two driving circuits. That is, in the embodiment of the present invention, two driving circuits are configured in parallel in the lighting unit 230 , and the two driving circuits share at least a portion of a plurality of light emitting diode groups.

The driving circuit corresponding to the odd-numbered light emitting diode groups LED11 to LED14 of the lighting unit 230 includes the driving unit 300 and the current sensing resistor Rs1 , and the even-numbered light emitting diode groups LED21 of the lighting unit 230 . ~LED23) and the driving circuit corresponding to the last light emitting diode group LED14 includes a driving unit 310 and a current sensing resistor Rs2.

The driving units 300 and 310 regulate driving currents and induce a flow of a constant current in response to light emission of the lighting units 200 and 210 . To this end, the drivers 300 and 310 perform current regulation for light emission of each light emitting diode group (LED11 to LED14, LED21 to LED24), and emit light together with each current sensing resistor Rs1 and Rs2 whose one end is grounded. is configured to provide a current path for

The drivers 300 and 310 may have the same structure or provide the same reference voltage. Also, the current sensing resistors Rs1 and Rs2 having the same value may be used. For convenience of description, the embodiment of the present invention will be described on the assumption that the reference voltages of the drivers 300 and 310 are the same and the resistance values of the current sensing resistors Rs1 and Rs2 are the same. However, the manufacturer may set the reference voltages of the drivers 300 and 310 differently or set the resistance values of the current sensing resistors Rs1 and Rs2 differently in a range that maintains sequential light emission as needed.

In the embodiment of FIG. 6 configured as described above, the light emitting diode groups (LED11 to LED14, LED21 to LED23) of the lighting unit 230 are sequentially emitted or extinguished in response to a change (rising or falling) of the rectified voltage.

Here, the light emitting voltage V14 for emitting light from the light emitting diode group LED14 is defined as a voltage for all of the light emitting diode groups LED11 , LED21 , LED12 , LED22 , LED13 , LED23 , and LED14 to emit light. The light emitting voltage V23 for emitting light from the light emitting diode group LED23 is defined as a voltage for emitting light from all of the light emitting diode groups LED11, LED21, LED12, LED22, LED13, and LED23. The light emitting voltage V13 for emitting light from the light emitting diode group LED13 is defined as a voltage for emitting light from all of the light emitting diode groups LED11 , LED21 , LED12 , LED22 , and LED13 . The light emitting voltage V22 for emitting light from the light emitting diode group LED22 is defined as a voltage for all of the light emitting diode groups LED11 , LED21 , LED12 , and LED22 to emit light. The light emitting voltage V12 for emitting light from the light emitting diode group LED12 is defined as a voltage for all of the light emitting diode groups LED11 , LED21 , and LED12 to emit light. The light emitting voltage V22 for emitting light from the light emitting diode group (LED 21) is defined as a voltage for emitting all of the light emitting diode groups (LED11 and LED21). The light emitting voltage V11 for emitting light from the light emitting diode group (LED11) is the light emitting diode group ( It is defined as the voltage that only LED11) emits light.

The drivers 300 and 310 provide a current path for light emission when the rectified voltage rises to sequentially reach the light emitting voltage of each of the light emitting diode groups (LED11 to LED14 and LED21 to LED24).

The operation of the above-described embodiment of FIG. 6 may be described with reference to FIG. 5 .

When the rectified voltage is in an initial state, each of the switching circuits 31 , 32 , 33 , and 34 of the driving units 300 and 310 has a negative input terminal of reference voltages VREF1 , VREF2 , VREF3 , and VREF4 applied to a positive input terminal (+). Since it is higher than the sensing voltage of the current sensing resistors Rs1 and Rs2 applied to (-), all of them maintain the turned-on state.

After that, when the rectified voltage rises to reach the emission voltages V11, V21, V12, V22, V13, V23, and V14, respectively, the LED groups (LED11, LED21, LED12, LED22, LED13, LED23, LED14) are sequentially glow

When the rectified voltage reaches the light emitting voltage V11 and the light emitting diode group LED11 emits light, a current generated by the switching circuit 31 and the current sensing resistor Rs1 of the driving unit 300 in response to the light emission of the light emitting diode group LED11 path is provided. And, when the rectified voltage reaches the light emitting voltage V21 and the light emitting diode group LED21 emits light, the switching circuit 31 and the current sensing resistor Rs2 of the driving unit 310 correspond to the light emission of the light emitting diode group LED21. A current path is provided by And, when the rectified voltage reaches the light emitting voltage V12 and the light emitting diode group LED12 emits light, in response to the light emitting of the light emitting diode group LED12, the switching circuit 32 of the driving unit 300 and the current sensing resistor Rs1 A current path is provided by Then, when the rectified voltage reaches the light emitting voltage V22 and the light emitting diode group LED22 emits light, in response to the light emitting of the light emitting diode group LED22, the switching circuit 32 of the driving unit 310 and the current sensing resistor Rs2 A current path is provided by Then, when the rectified voltage reaches the light emitting voltage V13 and the light emitting diode group LED13 emits light, in response to the light emitting of the light emitting diode group LED13, the switching circuit 33 of the driving unit 300 and the current sensing resistor Rs1 A current path is provided by the Then, when the rectified voltage reaches the light emitting voltage V23 and the light emitting diode group LED23 emits light, in response to the light emitting of the light emitting diode group LED23, the switching circuit 33 of the driving unit 310 and the current sensing resistor Rs2 A current path is provided by Then, when the rectified voltage reaches the light emitting voltage V14 and the light emitting diode group LED14 emits light, in response to the light emitting of the light emitting diode group LED14, the switching circuit 34 of the driving unit 300 and the current sensing resistor Rs1 A current path by the switching circuit 34 of the driver 310 and a current path by the current sensing resistor Rs2 are provided.

The switching circuits 31 to 34 of the driving units 300 and 310 configured in the embodiment of the present invention are turned off when the sensing voltage is higher than the reference voltage, and after the light emitting diode group connected thereto emits light, the next light emitting diode group Until the light is emitted, a current regulation operation for regulating the driving current flowing through the current path is performed in response to the change in the rectified voltage. And, when the rectified voltage rises above the emission voltage V14, the switching circuit 34 of the drivers 300 and 310 regulates the driving current and maintains the turned-on state so that the driving current flowing through the current path becomes a predetermined constant current. do.

As described above, when the rectified voltage rises, the light emitting diode groups (LED11, LED21, LED12, LED22, LED13, LED23, LED14) are sequentially light-emitted, and correspondingly to each current path of the drivers 300 and 310 The driving currents Irs1 and Irs2 respectively flowing and the total driving current Irec provided to the lighting unit 230 are gradually increased to have a step current waveform. Here, the total driving current Irec is equal to the sum of the driving currents Irs1 and Irs2 flowing in each current path of the drivers 300 and 310 .

On the other hand, the rectified voltage starts to fall after rising to the upper limit level as described above. When the rectified voltage gradually drops to the light emitting voltages V14, V23 ... V11, the light emitting diode groups LED14, LED23, LED13, LED22, LED12, LED21, LED11 are sequentially extinguished. In response to the sequential extinction of the light emitting diode groups LED14, LED23, LED13, LED22, LED12, LED21, and LED11, the current path in the driving units 300 and 310 is shifted in the reverse order compared to the case of light emission. In addition, the driving current of the current paths is also decreased stepwise so as to have a step current waveform.

In the embodiment of FIG. 6, the light emitting diode groups are sequentially emitted in the order of LED11, LED21, LED12, LED22, LED13, LED23, and LED14. Correspondingly, a current path is provided by the switching circuit 31 of the driving unit 300 when the light emitting diode group LED11 emits light, and when the light emitting diode group LED21 emits light, a current path is provided to the driving units 300 and 310 when the light emitting diode group LED21 emits light. A current path is provided by the switching circuit 31 , and a current path is provided by the switching circuit 32 of the driving unit 300 and the switching circuit 31 of the driving unit 310 when the light emitting diode group LED12 emits light. A current path is provided by the switching circuit 32 of the driving units 300 and 310 when the light emitting diode group LED22 emits light, and a switching circuit of the driving unit 300 when the light emitting diode group LED13 emits light. A current path is provided by 33 and the switching circuit 32 of the driving unit 310, and the current path is changed by the switching circuit 33 of the driving units 300 and 310 when the light emitting diode group LED23 emits light. A current path is provided by the switching circuit 34 of the driving units 300 and 310 when the light emitting diode group LED14 emits light.

In the above-described embodiment of FIG. 6 , each of the light emitting diode groups LED11 to LED14 and LED21 to LED23 moves a current path corresponding to light emission in response to a change in rectified voltage, either or both of the driving units 300 and 310 . is provided by That is, the drivers 300 and 310 share the light emitting diode groups LED11 to LED14 and LED21 to LED23.

In addition, the current amount change timing of the driving currents on the current paths provided by the driving units 300 and 310 are controlled to be partially different from each other. More specifically, the driving units 300 and 310 have the same current amount change timing corresponding to the light emission of the shared light emitting diode group LED14, and the current amount change time point corresponding to the light emission of the other light emitting diode groups are different.

As described above, in the embodiment of the present invention, the number of current amount change timings of the total driving current Irec is set to exceed the number of current amount change timing points of the driver having the largest number of current amount change times among the driving units 300 and 310. and may be determined to be less than or equal to the sum of the number of current amount change points of each of the driving currents of the drivers 300 and 310 .

Therefore, many current amount change points may be formed in the total driving current Irec in response to a change in the rectified voltage in one period, and nonlinearity in the change in the total driving current Irec may be alleviated. In the present invention, as the number of light emitting diode groups increases, the total driving current Irec for illumination may have a relaxed non-linearity waveform.

More specifically, in the embodiment of FIG. 6 , the current amount change time of the total driving current Irec is formed seven times in response to the increase of the rectified voltage. The driving currents of the respective driving units 300 and 310 each have four current amount change times. Therefore, in the embodiment of the present invention, the number of times of change in the amount of current of the total driving current Irec exceeds the number of times when the amount of change in the amount of current of each of the driving units 300 and 310 and the driving current of each of the drivers 300 and 310 It is exemplified that it is determined to be smaller than the sum of the number of points of change of the amount of current.

As described above, according to the present invention, current harmonics can be reduced by alleviating nonlinearity of the entire driving current, and as a result, power efficiency can be improved.

100: power circuit 200, 210, 220: lighting unit
300, 310: driving unit 30: reference voltage supply unit
31~34: switching circuit

Claims (15)

a rectifier circuit providing a rectified voltage;
two or more lighting units including a plurality of light emitting diode groups that sequentially emit light in response to a change in the rectified voltage; and
Two or more driving circuits configured to correspond to the two or more lighting units one by one and regulating the driving current of the corresponding lighting units;
The lighting device according to claim 1, wherein the two or more lighting units each include at least one group of light emitting diodes having the same light emitting order and different light emission timings due to a difference in light emitting voltage. According to claim 1,
Each of the at least one light emitting diode group having the same light emitting order and different light emission timings of the two or more lighting units emit light in response to the different light emitting voltages having a difference of at least 10% or more. According to claim 1,
The two or more driving circuits are a lighting device for regulating current so that the total driving current supplied to the two or more lighting units has a constant current section divided by (number of light emitting diode groups × number of lighting units) - (number of lighting units - 1) . According to claim 1,
A lighting device configured to have a difference of less than 20 percent between the total emission voltages of each of the two or more lighting units based on the total emission voltages of any one of the lighting units. According to claim 1,
The light emitting order of the two or more lighting units is the same with respect to the light emitting diode groups except for the light emitting diode group having the last light emitting order, and the light emitting time is configured differently due to the difference in the light emitting voltage. According to claim 1,
The light emitting diode groups having the last light emitting order in the two or more lighting units have the same light emitting timing. According to claim 1,
The two or more lighting units include at least one light emitting diode group having the same light emitting order and different numbers of light emitting diodes connected in series. a power supply unit providing a rectified voltage;
a lighting unit including a plurality of light emitting diode groups that sequentially emit light in response to a change in the rectified voltage; and
a first driving circuit and a second driving circuit sharing at least a portion of the plurality of light emitting diode groups;
The first driving circuit independently controls a first driving current for sequential light emission of at least odd-numbered light emitting diode groups among the plurality of light emitting diode groups,
The second driving circuit independently controls a second driving current for sequential light emission of at least even-numbered light emitting diode groups among the plurality of light emitting diode groups,
The first driving current and the second driving current are controlled such that a portion of the current amount change timing is different from each other,
The number of current amount change timings of the total driving current corresponding to sequential light emission is set to exceed the number of the current amount change timing points in any one of the first driving current and the second driving current having a large number of current amount change timing points. lighting device with 9. The method of claim 8,
The total driving current is set as a sum of the first driving current and the second driving current. 9. The method of claim 8,
The number of times of change of the amount of current of the total driving current is determined to be less than or equal to the sum of the number of times of change of the amount of current of the first driving current and the second driving current. 9. The method of claim 8,
The first driving circuit regulates a current in response to light emission of the odd-numbered light emitting diode groups,
The second driving circuit regulates a current in response to light emission of the even-numbered light emitting diode groups,
and a current path for light emission of the lighting unit is provided by at least one of the first driving circuit and the second driving circuit. 12. The method of claim 11,
and the first driving circuit and the second driving circuit provide the current path in common in response to light emission of a last light emitting diode group. 9. The method of claim 8,
each of the first driving circuit and the second driving circuit,
a driving unit providing a current path by comparing a sensing voltage with reference voltages corresponding to the light emitting diode groups connected thereto; and
and a current sensing resistor connected to the current path of the driving unit and configured to provide the sensing voltage. 14. The method of claim 13,
and the reference voltages of the first driving circuit and the second driving circuit are set to be the same. 14. The method of claim 13,
and wherein the current sensing resistors of the first driving circuit and the second driving circuit have the same resistance value.

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