KR20160027681A - Lighting device - Google Patents

Abstract

An embodiment relates to a lighting device. The lighting device according to an embodiment comprises: a light source including at least one first light emitting device for emitting blue light, at least one second light emitting device for emitting red light, and at least one third light emitting device for emitting green light; a power supply control part electrically connected to the light source for providing a first driving current to the first light emitting device, providing a second driving current to the second light emitting device, and providing a third driving current to the third light emitting device; and an optical unit arranged on the first to third light emitting devices of the light source, wherein the CRI of the light emitted from the optical unit is greater than or equal to 88, and according to the first to third driving currents and the light emitted from the optical unit has a predetermined color temperature between 2700K and 6500K. When the lighting device according to the embodiment is used, there are advantages in that a user can obtain the light having a specific color temperature that the user wants in the range between 2700K and 6500K, and that the CRI of the emitted light is greater than or equal to 88.

Description

LIGHTING DEVICE

An embodiment relates to a lighting device.

Light emitting diodes (LEDs) are a type of semiconductor devices that convert electrical energy into light. The light emitting diode has advantages of low power consumption, semi-permanent lifetime, fast response speed, safety, and environmental friendliness compared with conventional light sources such as fluorescent lamps and incandescent lamps. Therefore, much research has been conducted to replace conventional light sources with light emitting diodes. Light emitting diodes are increasingly used as light sources for various lamps used in indoor / outdoor, liquid crystal display devices, electric sign boards, streetlights, and the like .

The embodiment provides an illumination device capable of emitting light having a CRI of 88 or more and having a specific color temperature between 2700K and 6500K by external selection.

The embodiment provides an illumination device capable of maintaining the originally set target color coordinates of light emitted even when the operating time of a plurality of light emitting elements is increased and deteriorated.

A lighting device according to an embodiment includes a light source unit including at least one first light emitting device emitting blue light, at least one second light emitting device emitting red light, and at least one third light emitting device emitting green light; A second driving current is supplied to the first light emitting element, and a second driving current is supplied to the first light emitting element, and the third driving current is supplied to the second light emitting element. A power control unit; And an optical portion disposed on the first to third light emitting elements of the light source portion, wherein a CRI of light emitted from the optical portion is 88 or more, and in accordance with the first to third drive currents, The emitted light has a predetermined color temperature between 2700K and 6500K.

With the illumination device according to the embodiment, the user can obtain light having a specific color temperature desired by himself in a range from 2700K to 6500K, and the CRI of emitted light is advantageous to be 88 or more.

In addition, even if the operation time of a plurality of light emitting elements is increased, there is an advantage that the target color coordinate that was initially set can be maintained as it is.

1 is a view for explaining a lighting apparatus according to an embodiment;
2 is a plan view of the light source unit shown in FIG. 1 viewed from above;
FIG. 3 shows the color temperature of light that can be emitted in a lighting device according to the embodiment shown in FIG. 1 to FIG. 2 in the CIE 1931 chromaticity diagram.
Fig. 4 is a CIE 1931 chromaticity diagram showing enlargement of A shown in Fig. 3; Fig.
FIG. 5 is a graph showing the shift of a color coordinate according to the operation time when the color temperature of light emitted from the lighting apparatus according to the embodiment shown in FIG. 1 and FIG. 2 is set to 2700K.
FIG. 6 is a graph showing the shift of a color coordinate according to the operation time when the color temperature of light emitted from the lighting apparatus according to the embodiment shown in FIG. 1 and FIG. 2 is set to 5700K.
7 is a view for explaining a lighting apparatus according to another embodiment;

The thickness and size of each layer in the drawings are exaggerated, omitted, or schematically shown for convenience and clarity of explanation. Also, the size of each component does not entirely reflect the actual size.

In the description of the embodiments according to the present invention, in the case where an element is described as being formed "on or under" another element, the upper (upper) or lower (lower) (On or under) all include that the two elements are in direct contact with each other or that one or more other elements are indirectly formed between the two elements. Also, when expressed as "on or under", it may include not only an upward direction but also a downward direction with respect to one element.

Hereinafter, a lighting apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings.

1 is a view for explaining a lighting apparatus according to an embodiment.

Referring to FIG. 1, the lighting apparatus according to the embodiment may include a heat dissipating unit 110, a light source unit 130, a reflector 150, an optical unit 170, and a power control unit 190.

The heat discharging body 110 receives the heat from the light source unit 130 and can discharge the received heat to the outside.

The heat discharging body 110 may have one surface on which the light source unit 130 is disposed. Here, the one surface may be a flat one surface or a surface having a predetermined curvature.

The heat discharging body 110 may have a heat radiating fin 115. The radiating fin 115 may protrude or extend from one side of the heat discharging body 110 in the outward direction. The radiating fin (115) widens the radiating area of the radiator (110). Therefore, the lighting device according to the embodiment can improve the heat radiation efficiency by the heat radiating fin 115.

The heat discharging body 110 may be formed of a metal material or a resin material having excellent heat dissipation efficiency, but the present invention is not limited thereto. For example, the material of the heat sink 110 may include at least one of aluminum (Al), nickel (Ni), copper (Cu), silver (Ag), and tin (Sn).

The heat discharging body 110 may have a hole 119. A conductive member 195 for electrically connecting the power control unit 190 and the light source unit 130 may be disposed in the hole 119. [ The conductive member 195 may be a wire or an electrode pin.

The light source unit 130 is disposed on the heat emitting body 110 and emits predetermined light onto the heat emitting body 110.

The light source unit 130 may include a substrate 131 and a light emitting device 133.

The substrate 131 may be any one of a general PCB, a metal core PCB (MCPCB), a standard FR-4 PCB, or a flexible PCB. The substrate 131 may be in direct contact with the heat discharging body 110 or may be disposed with a separate member therebetween. The substrate 131 may be disposed on one side of the heat discharging body 110.

A plurality of light emitting devices 133 may be disposed on the upper surface of the substrate 131.

On the upper surface of the substrate 131, a light reflecting material can be coated or deposited to easily reflect light from the plurality of light emitting elements 133.

The substrate 131 may optionally have a heat dissipation tape or a heat dissipation pad or the like for structural purposes or to improve heat transfer to the heat dissipator 110.

The plurality of light emitting devices 133 may be disposed on the substrate 131. The plurality of light emitting devices 133 can emit light of the same wavelength and emit light of different wavelengths. In addition, the plurality of light emitting devices 133 may emit light of the same color, and may emit light of different colors. Referring to FIG. 2, a plurality of light emitting devices 133 will be described in detail.

2 is a top plan view of the light source unit shown in FIG.

Referring to FIG. 2, the plurality of light emitting devices 133 may include a first light emitting device 133a, a second light emitting device 133b, and a third light emitting device 133c. Here, each of the first light emitting device 133a, the second light emitting device 133b, and the third light emitting device 133c may be at least one.

The first light emitting device 133a, the second light emitting device 133b, and the third light emitting device 133c are disposed on the substrate 131. Specifically, one first light emitting device 133a is disposed at the center of the substrate 131, and two second light emitting devices 133b and two third light emitting devices 133a are disposed around the first light emitting device 133a 133c. The two second light emitting devices 133b may be arranged in the center of the first light emitting device 133a and the two third light emitting devices 133c may be disposed in the center of the first light emitting device 133a . The arrangement of the first light emitting device 133a, the second light emitting device 133b, and the third light emitting device 133c is not limited to this and can be arranged in various forms.

The first light emitting device 133a may be a blue light emitting device that emits blue light in the visible spectrum or may emit light having a peak wavelength Wp between 455 nm and 470 nm, And may emit light having a half width Wd.

The second light emitting device 133b may be a red light emitting device emitting red light in the spectrum of visible light, emitting light having a peak wavelength between 614 nm and 620 nm, emitting light having a full width from 607 nm to 614 nm You may.

The third light emitting device 133c may be a green light emitting device that emits green light in the visible spectrum or may emit light having a peak wavelength between 540 nm and 550 nm. The color coordinates of the light emitted from the third light emitting device 133c are represented by four color coordinates ((0.3726, 0.4885), (0.3853, 0.4930), (0.3646, 0.4708) and (0.3763, 0.4749)) in the CIE 1931 chromaticity diagram. Lt; / RTI >

Each of the first to third light emitting devices 133a, 133b and 133c may be a light emitting diode (LED) chip or an organic light emitting diode (OLED) chip.

The light source unit 130 may further include a heat sensor 135. The thermal sensor 135 may measure the current temperature of any one or more of the first through third light emitting devices 133a, 133b, and 133c. The thermal sensor 135 may output the measured temperature to the power control unit 190 shown in FIG.

The thermal sensor 135 is disposed on the upper surface of the substrate 131 and may be disposed closer to the second light emitting device 133b of the first to third light emitting devices 133a, 133b, and 133c. The thermal sensor 135 can measure the solder temperature Ts of the second light emitting device 133b. The reason why the thermal sensor 135 is disposed closer to the second light emitting device 133b than the other light emitting devices 133a and 133c to measure the solder temperature Ts of the second light emitting device 133b is that, This is because the element 133b is more sensitive to heat than the first or third light emitting elements 133a and 133c.

The thermal sensor 135 may be an NTC thermistor. The NTC thermistor is a sensor whose resistance decreases with increasing temperature and is a resistor with a negative temperature coefficient (α).

Referring again to FIG. 1, the reflector 150 reflects light from the light source 130.

The reflector 150 surrounds the light source unit 130 and can reflect the light emitted from the light source unit 130 to the optical unit 170.

The reflector 150 may have a reflecting surface that reflects light from the light source 130. The reflecting surface may be substantially perpendicular to the substrate 131 and may form an obtuse angle with the upper surface of the substrate 131. The reflective surface may be coated or vapor-deposited with a material capable of easily reflecting light.

The optical unit 170 may transmit the light emitted from the light source unit 130 as it is, condense it, or diffuse it. In addition, light having a wavelength different from that of the light emitted from the light source unit 130 may be emitted.

The optical unit 170 is disposed at a predetermined distance from the light source unit 130. The optical unit 170 may be disposed at the upper end of the reflector 150 to be spaced apart from the light source unit 130 by a predetermined distance.

A mixing space 160 may be formed by the optical unit 170, the reflector 150, and the heat discharging unit 110. The mixing space 160 is a space in which lights emitted from the light source unit 130 or emitted from the light source unit 130 and reflected from the reflector 150 are mixed.

The optical unit 170 may include at least one phosphor. Specifically, the optical section 170 may include at least one of a yellow phosphor, a green phosphor, and a red phosphor.

The power control unit 190 receives external power from the outside and provides a driving signal to the light source unit 130 to turn on the plurality of light emitting devices 133 of the light source unit 130. Here, the driving signal for turning on the plurality of light emitting devices 133 may be a current.

The driving current provided to the plurality of light emitting devices 133 in the power control unit 190 may be different from each other among the plurality of light emitting devices 133. [ Specifically, the power control unit 190 provides a first driving current of 30 mA to 280 mA to the first light emitting device 133a shown in FIG. 2, and a second driving current of 30 mA to 280 mA to the second light emitting device 133b shown in FIG. And the third light emitting device 133c shown in FIG. 2 may provide a third driving current of 430 mA to 500 mA.

Within the range of the first to third drive currents described above, the first to third drive currents can be adjusted by the user. For example, when the user selects a desired color temperature from the outside, the power control unit 190 supplies the first to third light emitting elements 133a, 133b, and 133c corresponding to the color temperature selected by the user, Respectively. Here, the ratio between the first to third driving currents provided by the first to third light emitting devices 133a, 133b, and 133c corresponding to the color temperature selected by the user and the color temperature is as shown in Table 1 below .

2700K 3000K 4000K 5000K 5700K 6500K
Current (mA)

The first driving current (%) 4 7 16 23 29 33 The second driving current (%) 40 33 20 14 9 7 The third driving current (%) 56 60 64 63 62 60 all(%) 100 100 100 100 100 100

In Table 1, the ratio of the first driving current, the second driving current, and the third driving current is 4-33: 7-40: 56-64, where the ratio of the first driving current, And the ratio of the third driving current is 100.

Here, the ratio of each of the first to third driving currents provided to the first to third light emitting devices 133a, 133b, and 133c in Table 1 is the same as that of the first to third light emitting devices 133a, 133b, There may be a predetermined error of +/- 5% according to the change of the peak wavelength Wp of the light receiving portions 133a and 133c.

The color temperature of the light that can be emitted from the lighting apparatus according to the embodiment is located between 2700 K and 6500 K according to the user's choice. Regardless of which color temperature the user selects, the CRI of the light emitted by the lighting device according to the embodiment is advantageously 88 or more. Here, when the CRI is required to be 90 or more, the color temperature of the light that can be emitted from the lighting apparatus according to the embodiment may be located between 2700 K and 5700 K, depending on the user's choice. More specifically, the description will be made with reference to Figs. 3 to 4. Fig.

FIG. 3 shows the color temperature of light that can be emitted by a lighting apparatus according to the embodiment shown in FIGS. 1 and 2 in a CIE 1931 chromaticity diagram, and FIG. 4 shows a CIE 1931 chromaticity diagram to be.

3 to 4, the illumination device according to the embodiment shown in Figs. 1 and 2 has a CRI of 88 or more and a plurality of specific color temperatures, for example, 2700K, 3000K, 4000K, 5000K, 5700K, and 6500K It is possible to emit light. Here, when the CRI is set to 90 or more, light having 2700K, 3000K, 4000K, 5000K, and 5700K can be emitted.

And, as shown in FIG. 4, the color temperature of the light that can be emitted from the illumination device according to the embodiment can be arranged on or very close to the black body locus like the 'CCT Tunable' line CRI is highly advantageous because it is located at or near the Ansi center.

1 and 2, the power supply control unit 190 may be disposed below the heat discharging unit 110. [ Further, although not shown in the drawing, the power control unit 190 may be disposed inside the heat discharging unit 110. In this case, the power control unit 190 may be disposed in a storage unit (not shown) formed inside the heat discharging unit 110.

The power supply control unit 190 may include a conductive member 195. The conductive member 195 may electrically connect the power control unit 190 and the light source unit 130. [ The conductive member 195 may be disposed in the hole 119 of the heat discharging body 110.

The power control unit 190 may further include a memory unit 197.

The memory unit 197 may receive the solder temperature data of the second light emitting device 133b from the heat sensor 135 shown in FIG. 2, and may output driving current control data corresponding to the supplied solder temperature data. Here, the memory unit 197 previously stores drive current control data corresponding to input solder temperature data. That is, it has an equation or algorithm (algorism) for outputting drive current control data according to input solder temperature data, or it obtains drive current control data corresponding to input solder temperature data in advance through experiments and stores it in a table form Can be. The memory unit 197 may be an EEPROM (Electrically Erasable Programmable Read-Only Memory).

The output drive current control data may be used when the power control section 190 controls the drive current supplied to the first to third light emitting devices 133a, 133b, and 133c. That is, the low power control unit 190 may adjust the amounts of the driving currents supplied to the first to third light emitting devices 133a, 133b, and 133c according to the driving current control data.

The reason why the driving current supplied to the first to third light emitting devices 133a, 133b, and 133c is adjusted using the thermal sensor 135 and the memory unit 197 will be described with reference to FIGS. 5 to 6 do.

5 is a graph showing a shift of a color coordinate according to an operation time when the color temperature of light emitted from the illumination apparatus according to the embodiment shown in Figs. 1 and 2 is set to 2700K, and Fig. 6 is a graph 2 is a graph showing the shift of the color coordinates according to the operation time when the color temperature of light emitted from the lighting apparatus according to the embodiment shown in FIG. 2 is set to 5700K.

Referring to FIGS. 5 to 6, when the plurality of light emitting devices 133a, 133b, and 133c illustrated in FIGS. 1 and 2 operate, the first through third light emitting devices 133a, 133b, 133c (solder temperature, Ts) gradually increases. When Ts increases gradually, the target color coordinate moves toward the upper left side at the initial (25 DEG C). That is, as the operation time of the plurality of light emitting devices 133a, 133b, and 133c increases, the light having the target color temperature set at the beginning is difficult to emit.

In order to solve such a problem, the above-described thermal sensor 135 and memory unit 197 are used. 1 and 2, when the thermal sensor 135 detects the temperature of the solder of the second light emitting device 133b that is most sensitive to heat among the first to third light emitting devices 133a, 133b, and 133c Ts in real time, and sends the measured solder temperature data to the memory unit 197. Then, the memory unit 197 generates drive current control data corresponding to the solder temperature data input using the formula, algorithm or data previously stored therein. The power control unit 190 adjusts the amount or value of the driving current provided to the first to third light emitting devices 133a, 133b, and 133c according to the driving current control data generated in the memory unit 197. [ As a result, the lighting apparatus according to the embodiment can emit light having a target color temperature set initially even if the operating time of the first to third light emitting devices 133a, 133b, and 133c increases and the solder temperature increases .

1 and 2, the memory unit 197 is illustrated as being included in the power control unit 190, but this is merely an example, and the memory unit 197 may be configured separately from the power control unit 190 Lt; / RTI > For example, the memory unit 197 may be disposed on the substrate 131 of the light source unit 130.

7 is a view for explaining a lighting apparatus according to another embodiment.

The illuminating device according to another embodiment shown in Fig. 7 differs from the illuminating device according to the embodiment shown in Fig. 1 in that there is no reflector 150 shown in Fig. 1, And an optical part 170 'that is different in shape from the optical part 170'. Since the other configurations are the same, the optical unit 170 'will be described below. Here, the optical part 170 'shown in FIG. 7 is the same as the optical part 170 shown in FIG. 1 except for the shape.

Referring to FIG. 2, the optical unit 170 'may have a spherical shape. This optical portion 170 'may be disposed on the inner surface or the outer surface of a globe of a bulb-type illumination device, or may replace the globe.

The optical portion 170 'is not limited to a spherical shape. For example, the optical portion 170 'may be hemispherical, ellipsoidal, or polygonal.

The optical unit 170 'is disposed on the heat discharging body 110 and can be coupled to the heat discharging body 110.

The lighting apparatus according to another embodiment shown in Fig. 7 can emit light having a specific color temperature from 2700K to 6500K and a CRI of 88 or more, regardless of the color temperature, like the lighting apparatus according to the embodiment shown in Fig. have. Here, when the CRI is set to 90 or more, light having a specific color temperature can be emitted from 2700K to 5700K.

When the illumination device according to another embodiment shown in Fig. 7 further includes the heat sensor 135 shown in Fig. 2 and the memory portion 197 shown in Fig. 1, the plurality of light emitting elements 133 are driven So that even if the solder temperature is increased, the light having the target color temperature set at the beginning can be continuously emitted.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

110:
130:
150: reflector
170, 170 ': optical part

Claims (9)

A light source unit including at least one first light emitting device emitting blue light, at least one second light emitting device emitting red light, and at least one third light emitting device emitting green light;
A second driving current is supplied to the first light emitting element, and a second driving current is supplied to the first light emitting element, and the third driving current is supplied to the second light emitting element. A power control unit; And
And an optical portion disposed on the first to third light emitting elements of the light source portion,
A CRI of light emitted from the optical portion is 88 or more,
Wherein the light emitted from the optical portion has a predetermined color temperature in a range of 2700K to 6500K according to the first to third driving currents. The method according to claim 1,
The first light emitting device emits light having a peak wavelength (Wp) between 455 nm and 470 nm, or light having a half width (Wd) from 459 nm to 474 nm,
The second light emitting device emits light having a peak wavelength between 614 nm and 620 nm, or light having a half-width from 607 nm to 614 nm,
And the third light emitting element emits light having a peak wavelength between 540 nm and 550 nm. The method according to claim 1,
The first light emitting device emits light having a peak wavelength (Wp) between 455 nm and 470 nm, or light having a half width (Wd) from 459 nm to 474 nm,
The second light emitting device emits light having a peak wavelength between 614 nm and 620 nm, or light having a half-width from 607 nm to 614 nm,
The color coordinates of the light emitted from the third light emitting device are represented by a first color coordinate (0.3726, 0.4885), a second color coordinate (0.3853, 0.4930), a third color coordinate (0.3646, 0.4708), and a fourth color coordinate 0.4749). ≪ / RTI > The method according to claim 1,
Wherein the first driving current is between 30 mA and 280 mA,
The second drive current is between 60mA and 320mA,
And the third driving current is between 430mA and 500mA. 5. The method of claim 4,
The ratio of the first driving current, the second driving current, and the third driving current is 4-33: 7-40: 56-64,
Wherein the sum of the ratio of the first driving current, the ratio of the second driving current, and the ratio of the third driving current is 100. 6. The method according to any one of claims 1 to 5,
Wherein the light source unit includes a substrate on which the first to third light emitting devices are disposed and a thermal sensor that is disposed closer to the second light emitting device than the first or third light emitting device and measures the temperature of the second light emitting device Further included,
Wherein the illumination device further comprises a memory unit for outputting drive current control data corresponding to temperature data of the second light emitting device measured by the heat sensor,
Wherein the power control unit adjusts each of the first to third driving currents according to the driving current control data output from the memory unit. The method according to claim 6,
Wherein the memory unit is disposed in the power source control unit or the light source unit. The method according to claim 1,
Further comprising a heat dissipater having the light source portion disposed therein,
Wherein the power control unit is disposed below the heat radiator,
Wherein the heat discharger has a hole in which a conductive member for electrically connecting the power source control unit and the light source unit is disposed. 9. The method of claim 8,
And a reflector disposed on the heat discharging body,
And the optical portion is disposed on the reflector.

Images