KR20150028634A - LED module operable with various power - Google Patents

Abstract

In the preset invention, disclosed is an LED module which includes an LED mounting board which maximally mounts N LED packages and the N LED packages which are mounted on the LED mounting board, are operated by an AC power source and are serially connected. The number of LED chips included in a first LED package is different from the number of LED chips included in a second LED package among the LED packages.

Description

[0001] The present invention relates to an LED module,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to an LED power source for an AC power source in which a plurality of LED packages are combined, and more particularly, to a technique for arranging LED packages and a technique for improving the uniformity of light emitted from LED lights.

With the development of LED technology, LEDs have been used not only in liquid crystal displays but also in general illumination fields, and non-DC power sources such as AC power sources can be used as a power source for driving LED lighting. The LED lighting for the AC power source may be configured to include an LED array and a part for controlling the LED array. In order for LED lighting to operate efficiently at a given AC voltage, the configuration and connection relationships of the plurality of LED packages included in the LED lighting must be well designed.

However, home AC voltages provided in different regions may have different peak values. For example, when LED lighting designed to operate at 220V is used in a region where a 110V commercial power supply is provided, some LED packages included in the LED lighting may not emit light at all. Also, if LED lighting designed to operate at a voltage of, for example, 110V is used in an area where commercial power of 220V is provided, the LED lighting may fail due to overheating. That is, there is a need to provide a technique that improves both the efficiency and durability of the LED lighting operated by the AC power source.

LED packages are arranged on the PCB board to provide LED illumination. At this time, the number and layout of LED packages that can be mounted on a specific PCB board are predetermined according to design conditions. In the present invention, a technique for designing various LED lights optimized for various AC power sources having different peak voltages using one kind of PCB board having a predetermined layout is provided.

The scope of the present invention is not limited by the above-mentioned problems.

According to an aspect of the present invention, there is provided an LED module comprising: an LED mounting board adapted to mount a maximum of np LED packages; And np LED packages mounted on the LED mounting board and operated by an AC power source and connected in series with each other.

The LED lighting provided according to another aspect of the present invention includes the above LED module and a power supply unit.

In the above-described LED module and LED illumination, the number of LED chips included in the first LED package of the plurality of LED packages may be different from the number of LED chips included in the second LED package. At this time, each of the LED packages is composed of one or more LED chips connected to each other in series, and the sum of the forward voltages of all the LED chips included in the LED module may be smaller than the peak voltage inputted to the LED module. At this time, all the LED chips included in the LED module may have the same forward voltage.

According to another aspect of the present invention, there is provided an LED package comprising: an LED mounting board adapted to mount a maximum np LED package; And np LED packages mounted on the LED mounting board and operated by electric power supplied from a power source of the input / output loss ratio x and connected in series to each other. In this case, the AC power source having the peak voltage V _p is input to the power supply unit, and the number of LED chips n _k (where k = 1 to np) constituting each of the LED packages is expressed by Equation 1 and Equation 2 together Satisfies.

[Equation _{1] n t * V f <} (1-x) * V p: However, V _f is the forward voltage, n _t is the total number of the LED chip included in the LED light of the LED chip.

; 단, n_k는 각각의 LED 패키지에 포함되는 LED 칩의 개수.[Formula 2]

; Where n _k is the number of LED chips included in each LED package.

The LED light provided according to another aspect of the present invention is connected to the above LED module.

In the LED module and the LED lighting described above, all of the LED chips included in the np LED packages may have the same forward voltage. The number of LED chips included in the first LED package may be different from the number of LED chips included in the second LED package.

The above LED mounting board may be a PCB board.

According to the present invention, there can be provided a structure of an LED array for providing LED lights of different configurations operating on AC power of different voltages by using one kind of PCB board of the same standard.

The scope of the present invention is not limited by the above-mentioned effects.

1 is a diagram for explaining the concept of an LED array, an LED package, and an LED chip used in an embodiment of the present invention.
2A and 2B show the mounting structure of an LED package that can be used in various embodiments of the present invention.
3A is a diagram for explaining an LED lighting system that can be used in an embodiment of the present invention. FIG. 3B is a diagram for explaining a configuration of each channel of the LED illumination including a plurality of channels according to an embodiment of the present invention. FIG. 3C illustrates the configuration of each channel of the LED illumination according to an embodiment of the present invention, using the reference numerals shown in FIGS. 2A and 3A.
FIG. 4 is a graph illustrating an operation state of an LED array according to time of an AC voltage according to an exemplary embodiment of the present invention. Referring to FIG.
5 (a), 5 (b), and 5 (c) show the same LED array input voltages (first LED illumination to third LED illumination) having different configurations designed using the layout of the LED package shown in FIG. 400 shown in Fig.

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

Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art. The following embodiments can be modified into various other forms, and the scope of the present invention is not limited by these embodiments. Further, the relationship of the constituent elements shown in the drawings may be exaggerated for convenience and clarity of explanation.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the" include singular forms unless the context clearly dictates otherwise. Also, &quot; comprise "and / or" comprising "when used herein should be interpreted as specifying the presence of stated shapes, numbers, steps, operations, elements, elements, and / And does not preclude the presence or addition of one or more other features, integers, operations, elements, elements, and / or groups.

Hereinafter, embodiments of the present invention will be described with reference to the drawings schematically showing ideal embodiments of the present invention. In the figures, for example, variations in the shape shown may be expected, depending on manufacturing techniques and / or tolerances. Accordingly, the embodiments of the present invention should not be construed as limited to the particular shapes of the regions shown herein, but should include, for example, changes in shape resulting from manufacturing.

1 is a diagram for explaining the concept of an LED array, an LED package, and an LED chip used in an embodiment of the present invention.

As shown in FIG. 1 (a), the LED array 100 may have a configuration in which a plurality of LED packages 200 are connected in series. At this time, each LED package 200 may be one in which a plurality of LED chips 300 shown in FIG. 1 (c) are coupled in series as shown in FIG. 1 (b). At this time, the forward voltages of the respective LED chips 300 included in the LED array 100 may be all the same, or some or all of them may be different from each other.

2A and 2B show the mounting structure of an LED package that can be used in various embodiments of the present invention.

In the case where the LED lighting for the AC power source is in the shape of a globe, the LED packages 201 to 212 may be arranged at predetermined positions on the PCB board 101 as shown in FIG. 2A.

As another example, in the case where the AC power source LED illumination has a shape of a substantially long rod, the LED packages 201 to 212 may be disposed at predetermined positions on the PCB board 101 as shown in FIG. 2B.

The LED packages 201 to 212 may be sequentially connected to each other in series and may be grouped into four LED channels 31 to 34. When LED lights are driven by an AC power source, each LED channel can be controlled to have different light emission characteristics. And one or more LED chips contained in each LED package 200 may not be visually identified.

There are a variety of prior art techniques in which LED packages operate in series with each other using LED lamps with an alternating current source. When the LED array 100 shown in FIGS. 2A and 2B is controlled in accordance with the operation principle of the prior art by an AC power source, some of the twelve LED packages 200 have a sine wave form, (Ex: 30V), but the other part is configured to emit light only in a time period in which the AC transient voltage is greater than the second voltage level (ex: 60V), which is larger than the first voltage level. At this time, if AC voltage of a sufficient magnitude is not applied to the AC power LED lighting, the one or more LED packages 200 may not emit light at all. Or if the voltage is too high, the possibility of LED light failure is increased.

3A is a diagram for explaining an LED illumination that can be used in an embodiment of the present invention. FIG. 3B is a diagram for explaining a configuration of each channel of the LED illumination including a plurality of channels according to an embodiment of the present invention. FIG. 3C illustrates the configuration of each channel of the LED illumination according to an embodiment of the present invention, using the reference numerals shown in FIGS. 2A and 3A.

The power supply unit 20, the LED driver IC 40, and the resistor 50 in Fig. 3A can be collectively referred to as a power module. The LED array 100 of FIG. 3A and the PCB board 101 for mounting the LED array 100 together can be referred to as an LED module. In an embodiment of the present invention, the LED module and the power module may be provided integrally. In another embodiment of the present invention, the LED module and the power module are separately provided and may be coupled to each other by a cable.

Hereinafter, an embodiment according to the present invention will be described with reference to Figs. 2A, 3A, 3B, and 3C.

The LED illumination may be configured to include a power source 20, an LED array 100, an LED driver IC 40, and a resistor 50. And the LED illumination can be driven by an external AC power source 10. [

The power supply unit 20 of FIG. 3A can provide a half-wave rectified or full-wave rectified waveform to the commercial AC power source 10 received from the outside. For this purpose, the power supply unit 20 may include a bridge diode. Alternatively, the power supply section 20 may provide a waveform in which the sinusoidal waveform is formed in an arbitrary shape. For example, the power supply unit 20 may provide a square waveform. The power supply unit 20 may have an input / output loss ratio x. For example, when x = 5%, the peak voltage of the waveform rectified by the power supply unit 20 may be 141 * 0.95V when the AC power supply 10 having the peak voltage of 141V is input.

The LED array 100 of FIG. 3A is expressed by dividing the LED array 100 shown in FIG. 1 (a) by the channel unit 30. That is, in this embodiment, a total of twelve LED packages 201 to 212 included in the LED array 100 are divided into n (ex: n = 4) LED channels 31 to 34 connected in series . Each of the LED channels 31 to 34 may include one or a plurality of LED packages 200 as shown in FIG. 3B. Specifically, in one embodiment, the channel 31, the channel 32, the channel 33, and the channel 34 each include three LED packages 201-203, three LED packages 204 206, three LED packages 207-209, and three LED packages 210-212.

The LED driving IC 40 includes n (ex: n = 4) switches 41 to 44. The m-th switch is connected to the cathode of the m-th LED channel (30, where m is a natural number less than or equal to n). Each of the switches 41 to 44 of the LED driving IC 40 may be constituted by a field effect transistor (FET), particularly an NMOS FET. The resistor 50 may be constituted by a variable resistor. One terminal of the resistor 50 is connected to each of the switches 41 to 44 included in the LED driver IC 40. Therefore, the current flowing through the resistor 50 becomes the sum of the currents flowing through the switches 41 to 44.

The LED driver IC 40 according to the present embodiment operates as follows.

Initially, all the switches 41 to 44 of the LED driver IC 40 are set to the on state, which is the on state. The switches 41 to 44 of the LED driving IC 40 are turned on by the sensing voltage Vr applied to the resistor 50 through the LED array 100 according to the magnitude of the input voltage Vd output from the power supply unit 20, 44) can be automatically switched.

In this embodiment, the resistor 50 can be set to, for example, 10 ohms (Ω).

The following Table 1 shows the saturation current values Id1 to Id4 of the switches 41 to 44 and the saturation current values Id1 to Id4 of the saturation current Id1 to Id4 flowing to the resistors 50 when the saturation currents Id1 to Id4 flow through the switches 41 to 44, And the sensing voltage Vr.

Id (mA) Vr Switch 41 Id1 = 20 0.2 Switch 42 Id2 = 40 0.4 Switch 43 Id3 = 60 0.6 Switch 44 Id4 = 80 0.8

At this time, the forward voltages Vf1 to Vf4 of the LED channels 31 to 34 are 50 V, respectively.

When the input voltage Vd rises to reach around 50 V, the LED channel 31 operates and the current I1 flows slowly through the switch 41. [

When the input voltage Vd becomes 50 V or more, a saturation current of 20 mA flows through the switch 41 and a sensing voltage Vr applied to the resistor 50 becomes 0.2V.

When the input voltage Vd rises to reach about 100 V, the LED channel 32 operates and the current I2 flows slowly through the switch 42. [ At this time, in the resistor 50, the current flows by the sum of the current flowing through the switch 41 and the current I2 flowing through the switch 42. When the input voltage Vd gradually increases and the current I2 flowing through the switch 42 gradually increases, the sensing voltage Vr applied to the resistor 50 gradually rises and relatively increases to the gate of the switch 41 The input voltage Vgs1 is lowered and the switch 41 enters a switching condition in which it is changed from the ON state to the OFF state.

When the input voltage Vd becomes 100 V or more, a saturation current of 40 mA flows through the switch 42 and the switch 41 is completely turned off. The sensing voltage Vr applied to the resistor 50 is 0.4V.

When the input voltage Vd rises to reach about 150 V, the LED channel 33 operates and the current I3 gradually flows through the switch 43. [ At this time, the current flows through the resistor 50 by the sum of the current flowing through the switch 42 and the current I3 flowing through the switch 43. When the input voltage Vd gradually increases and the current I3 flowing through the switch 43 gradually increases, the sensing voltage Vr applied to the resistor 50 gradually rises and relatively increases to the gate of the switch 42 The input voltage Vgs2 is lowered and the switch 42 enters a switching condition in which it is changed from the on state to the off state.

When the input voltage Vd exceeds 150V, saturation current of 60mA flows through the switch 43 and the switch 42 is completely turned off. The sensing voltage Vr applied to the resistor 50 is 0.6V.

When the input voltage Vd rises to reach about 200 V, the LED channel 34 operates and currents I3 and I4 flow through the switch 43 and the switch 44. [ At this time, the current flows through the resistor 50 by the sum of the current flowing through the switch 43 and the current flowing through the switch 44.

When the input voltage Vd becomes 200 V or more, a saturation current of 80 mA flows through the switch 44 and the switch 43 is completely turned off. The sensing voltage Vr applied to the resistor 50 is 0.8V.

As described above, as the input voltage Vd rises, when a current begins to flow through the (k + 1) th switch sequentially among n switches (ex: n = 4), the kth switch is turned off ex: k = 1).

FIG. 4 is a graph illustrating an operation state of an LED array according to time of an AC voltage according to an exemplary embodiment of the present invention. Referring to FIG.

The LED array input voltage 400 represents only a part of the voltage curve, that is, the LED array input voltage Vd, which is half-wave or full-wave rectified by the power source 20, for example. The LED array input voltage 400 may be a waveform of, for example, 1/2 of the commercial power waveform of 60 Hz and 220 V. [

In the example of FIG. 4, the LED array input voltage 400 is horizontally symmetrical, and in this case, the periods T0, T1, T2, and T3 have the same length of time as the periods T8, T7, T6, and T5.

In the periods T0 and T8, since the LED array input voltage 400 is smaller than the forward voltage Vf1 of the LED channel 31, all the four LED channels 31 to 34 do not emit light.

(= Vf1 + Vf2) of the two LED channels 31 and 32 although the LED array input voltage 400 is higher than the forward voltage Vf1 of the LED channel 31 in the periods T1 and T7 small. Therefore, only one LED channel 31 of the four LED channels 31 to 34 emits light. At this time, a current I1 flows through the LED channel 31.

In the sections T2 and T6, the LED array input voltage 400 is equal to or greater than the sum of the forward voltages of the two LED channels 31 and 32 (= Vf1 + Vf2), but the forward voltage of the three LED channels 31 to 33 (= Vf1 + Vf2 + Vf3). Therefore, only two of the four LED channels 31 to 34 emit light. At this time, a current I2 flows through the LED channels 31 and 32.

The LED array input voltage Vd 400 is greater than the sum of the forward voltages of the three LED channels 31 to 33 (= Vf1 + Vf2 + Vf3) in the periods T3 and T5, (= Vf1 + Vf2 + Vf3 + Vf4) of the first, Therefore, only three LED channels 31 to 33 among the four LED channels 31 to 34 emit light. At this time, a current I3 flows through the LED channels 31 to 33.

In the period T4, the LED array input voltage Vd, 400 is equal to or greater than the sum of the forward voltages of the four LED channels 31 to 34 (= Vf1 + Vf2 + Vf3 + Vf4). Therefore, all of the four LED channels 31 to 34 emit light. At this time, a current I4 flows through the LED channels 31 to 34.

On the other hand, the amount of light emitted from each LED channel during the time interval T9 in FIG. 4 can be approximated as in Equation (1) below.

At this time, if I1 = I2 = I3 = I4 = I, the amount of light emitted by the LED array during the 1/2 cycle of the LED array input voltage 400 shown in FIG. And the width of the area. And the area A between the graph 500 of FIG. 4 and the LED array input voltage 400 may be proportional to the power consumed by the switching elements or resistors included in the LED illumination, not the LED array.

Increasing the number of LED channels can reduce the area occupied by area A. For example, although FIG. 4 shows an example in which the number of LED channels is four, when the number of LED channels is 10, the area occupied by the area A can be further reduced, thereby increasing the efficiency of the LED illumination.

Thus, the efficiency of the LED illumination is determined at least by the design of the LED array input voltage 400, the number of LED channels determining the shape of the graph 500, the design of the forward voltage of each LED channel, and the magnitude of the currents I1 - Lt; RTI ID = 0.0 &gt; of &lt; / RTI &gt;

One embodiment of the present invention relates to the design of the forward voltage of each LED channel to determine the shape of the graph 500 therebetween.

FIGS. 5A, 5B and 5C are diagrams for explaining the same LED array input voltage 400 (FIG. 5A and FIG. 5B) for the first to third LED lights of different structures designed using the layout of the LED package shown in FIG. ) Is applied to the drive signal.

The forward voltage of the first LED channel 31 to the fourth LED channel 34 of the first LED light, the second LED light, and the third LED light is Vf1 to Vf4, Vf1 'to Vf4', Vf1 ' ''to be. 5 shows an example in which Vf1 '<Vf1 <Vf1' ', Vf2' <Vf2 <Vf2 '', Vf3 '<Vf3 <Vf3', and Vf4 '<Vf4 <Vf4'.

The widths of the hatched portions in FIGS. 5 (a) and 5 (b) may be different from each other. Therefore, assuming that a current value when a current flows through each of the LED channels 31 to 34 of the LED illumination has a constant (= I) value, the LED illumination shown in FIGS. 5A and 5B Efficiency can be different.

The value of Vf1 '' + Vf2 '' + Vf3 '' + Vf4 '' = Vft is larger than the maximum value Vmax of the LED array input voltage 400 in the LED illumination of FIG. 5 (c) The fourth LED channel of Vf4 &quot; is in a state in which it can not emit light.

Therefore, when the operation of FIG. 5 (c) is implemented in the layout as shown in FIG. 2A, the LED packages 210 to 212 included in the fourth LED channel 34 do not emit light. As a result, there arises a problem that the uniformity of the distribution of the surface emission of the LED illumination is lowered.

5, when designing the LED lighting using the PCB board providing a given number of LED channels, the total sum of the forward voltages of the LED arrays is the maximum value of the LED array input voltage 400 Vmax). Hereinafter, a method of designing an LED lighting that can be applied to different commercial power sources having various peak values using one type of PCB board and which can improve the light uniformity on the basis of the operation principle of the LED lighting Explain.

As described above, the PCB board 101 shown in FIG. 2A can be determined by designing the number of channels of the LED array, the number of the LED packages, and the layout of the PCB board for mounting the LED packages. For example, high efficiency LED lighting for use in AC 100V, AC 120V, and AC 220-240V areas should be designed differently. An example of this design result is shown in [Table 2].

LED type LED chip number Vft Vft and ac voltage peak-to-peak ratio Applied AC voltage 3-chip packages * 6 + 4-chip packages * 6 42 124V 87% 100V Four-chip package * 12 48 144V 85% 120V 8-chip package * 12 96 288V 85% to 92% 220-240V

In Table 2, Vft represents the total forward voltage of the LED array as a whole. As shown in FIG. 4, if Vft is smaller than the peak voltage of the LED array input voltage (Vd), all the LED channels belonging to the LED array are allowed to emit light. In the design according to [Table 2], only LED chips with a forward voltage of 3V were used. As a result of the design, a total of 42 LED chips are required for the LED lighting used in the AC 100V area, a total of 48 LED chips are required for the LED lighting used for the AC 120V area, and the LED lighting used for the AC 220 ~ A total of 96 LED chips are required.

In order to mount 42 LED chips, 48 LED chips, and 96 LED chips using a total of 12 LED package mounting regions provided on a single type PCB board designed as shown in FIG. 2A, The number should be a good combination.

As a result, in Table 2, for the LED lighting for the AC 100V region, a total of 42 LED chips are provided using six LED packages composed of three LED chips and six LED packages composed of four LED chips can do.

And for LED lighting for the AC 120V area, a total of 48 LED chips can be provided using 12 LED packages consisting of four LED chips.

Finally, for LED lighting for the AC 220-240V region, a total of 96 LED chips can be provided using twelve LED packages consisting of eight LED chips.

Generally, when the forward voltage per LED chip is Vf, it is possible to design an LED module satisfying the following equations (2) and (3).

Max (V _d ) is the maximum value of the input voltage to the LED array 100, V _p is the peak value of the AC power source, x is the loss factor of the power supply unit 2, V _{max ,} The maximum efficiency voltage, V _f is the forward voltage of the LED chip, and n _t is the number of LED chips.

Here, np is the number of LED packages mounted on the PCB board 101, and n _k is the number of LED chips included in each LED package.

Because Equation 2 and Equation 3] on the x, V _p, V _f is, np, and n _k is a pre-given value by the various elements and characteristics of the device which is provided to make the LED light, the formula 2] and [3], the values of the natural numbers n _t and n _k can be calculated. For example in Figure 2 and Table 2 applies an AC voltage of = 100V, np = 12, V f = 3.0V, n k = 3 ( single, k = natural number of _{1 ~ 6), n k =} 4 ( stage, k Is a natural number of 7 to 12), n _t = 42, and V _p = 100 * 1.414.

Although the example of the case of four channels has been described so far, embodiments of the present invention can be applied to an LED illumination designed with an arbitrary number of channels.

In this specification, a channel may mean a collection of LED chips or LED packages whose light emitting conditions are distinguished within one LED illumination. For example, LED chips or LED packages having different start and end points of light emission, as shown in FIG. 4, may belong to different channels.

3A, the LED driving IC is connected to each channel 30 of the LED array 100 to form any type of LED array having the same or similar function as that of FIG. 3A It is easily understood that a driving device can be combined with the embodiments of the present invention.

The fact that two LED channels, two LED packages, or two LED chips are connected in series with each other means that when current flows simultaneously through the two LED channels, the package or the chip, the two LED channels, Package, or chip may be substantially equal to one another.

The configuration of the LED array according to the present invention can not be applied to a power source in the form of a sinusoidal wave. That is, the waveform of the power source directly inputted to the LED array may have a waveform of any shape of a non-direct current type. Preferably, the size of the upper power source may have only one polarity. Accordingly, the term 'ac power' described herein may be replaced by the term 'non-DC power source' as the case may be.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

10: external power source 20: power source part
30, 31 ~ 34: LED channel 40: LED driving IC (current switching circuit)
41 to 44: Switch 50: Resistance
100: LED array 200, 201 - 212: LED package
300: LED chip 400: LED array input voltage
500: total forward voltage of LED channels in operation
Vmax: maximum value of LED array input voltage (400)

Claims (10)

An LED mounting board adapted to mount up to np LED packages; And
Np LED packages mounted on the LED mounting board and operated by an AC power source and connected in series with each other;
/ RTI &gt;
Wherein the number of LED chips included in the first LED package of the plurality of LED packages is different from the number of LED chips included in the second LED package.
LED module. 2. The LED module according to claim 1, wherein each of the LED packages is composed of one or more LED chips connected in series with each other, wherein a sum of forward voltages of all the LED chips included in the LED module is smaller than a peak voltage input to the LED module Features, LED module 3. The LED module of claim 2, wherein all the LED chips included in the LED module have the same forward voltage. An LED mounting board adapted to mount up to np LED packages;
Np LED packages mounted on the LED mounting board and operated by an AC power source and connected in series with each other; And
Power supply
/ RTI &gt;
Wherein the number of LED chips included in the first LED package of the plurality of LED packages is different from the number of LED chips included in the second LED package.
LED lighting. 5. The LED lighting of claim 4, wherein all the LED chips included in the LED module have the same forward voltage. An LED mounting board adapted to mount a maximum np LED package; And
A plurality of np LED packages mounted on the LED mounting board and operated by electric power supplied from a power source of an input / output loss ratio x,
/ RTI &gt;
An AC power source having a peak voltage Vp is input to the power source unit,
The number nk of LED chips constituting each of the LED packages (where k = a natural number of 1 to np) satisfies Equation 1 and Equation 2 together.
LED module.
[Equation _{1] n t * V f <} (1-x) * V p: However, V _f is the forward voltage, n _t is the total number of the LED chip included in the LED light of the LED chip.
[Formula 2]

; Where n _k is the number of LED chips included in each LED package. 7. The LED module of claim 6, wherein all of the LED chips included in the np LED packages have the same forward voltage. 7. The LED module of claim 6, wherein the number of LED chips included in the first LED package of the np LED packages is different from the number of LED chips included in the second LED package. An LED mounting board adapted to mount a maximum np LED package;
An input / output loss factor x power supply unit to which an AC power supply having a peak voltage Vp is input; And
Np LED packages mounted on the LED mounting board and operated by electric power supplied from the power supply unit and connected to each other in series;
/ RTI &gt;
The number n _k of LED chips constituting each of the LED packages (where _k is a natural number from 1 to np) satisfies Equation 1 and Equation 2 together.
LED lighting.
[Equation _{1] n t * V f <} (1-x) * V p: However, V _f is the forward voltage, n _t is the total number of the LED chip included in the LED light of the LED chip.
[Formula 2]

; Where n _k is the number of LED chips included in each LED package. 10. The LED lighting according to claim 9, wherein the number of LED chips included in the first LED package of the np LED packages is different from the number of LED chips included in the second LED package.

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