KR20120055194A - Lighting device - Google Patents

Abstract

PURPOSE: A lighting device is provided to optimize a color temperature and the speed of light. CONSTITUTION: A light excitation plate(130) includes a substrate and a coating layer. The coating layer is coated on the surface of one side of the substrate and has fluorescent substances. A light emitting device is separated from the light excitation plate. The light excitation plate is separated from a light emitting device corresponding to a distance of an overlapped saturation section of a color temperature and a peak section of the speed of light according to a gap between the light excitation plate and the light emitting device. A reflector(170) surrounds the light emitting device.

Description

LIGHTING DEVICE

An embodiment of the present invention relates to a lighting device, and more particularly, to a lighting device using a light emitting diode (LED).

Light emitting diodes (LEDs) are a type of semiconductor device that converts electrical energy into light. Light emitting diodes have the advantages of low power consumption, semi-permanent life, fast response speed, safety and environmental friendliness compared to conventional light sources such as fluorescent and incandescent lamps. Accordingly, many researches are being conducted to replace the existing light sources with light emitting diodes, and the light emitting diodes are increasingly used as light sources for light units such as various lamps, display devices, electronic signs, and street lamps that are used indoors and outdoors.

An embodiment of the present invention provides a lighting device having an optimized luminous flux and color temperature.

Moreover, it provides the lighting apparatus which can improve the optical excitation efficiency.

According to one or more exemplary embodiments, a lighting apparatus includes: a light excitation plate having a surface having roughness on one surface and a coating layer coated on a surface of one surface of the substrate and having at least one phosphor; And a light emitting element disposed to be spaced apart from the light excitation plate, wherein the light excitation plate includes a peak section of the luminous flux according to the interval between the light excitation plate and the light emitting element and a color temperature according to the interval. The saturation sections are spaced apart by the distance to the overlapping sections.

Using the lighting apparatus according to the embodiment of the present invention, there is an advantage that can have an optimized luminous flux and color temperature.

In addition, there is an advantage that can improve the optical excitation efficiency.

1 is a perspective view of a lighting apparatus according to an embodiment of the present invention,
FIG. 2 is a perspective view when the optical excitation plate is removed from the lighting device shown in FIG. 1; FIG.
3 is a cross-sectional view taken along line AA ′ in the lighting device shown in FIG. 1, FIG.
4 is a perspective view of the optical excitation plate shown in FIG.
5 and 6 are cross-sectional views of B-B 'of the optical excitation plate shown in FIG.
7 is a view showing the appearance of the coating layer when having a roughness and the appearance of the coating layer when not having a roughness,
8 is an actual picture of FIG.
FIG. 9 is a comparative photograph for confirming adhesion performance of the optical excitation plate illustrated in FIG. 4; FIG.
FIG. 10 is a graph illustrating a luminous flux curve and a color temperature curve according to a distance between a light excitation plate and a light emitting device. FIG.

In the drawings, the thickness or size of each layer is exaggerated, omitted, or schematically illustrated for convenience and clarity of description. Also, the size of each component does not necessarily reflect its actual size.

In the description of the embodiment according to the present invention, when one element is described as being formed on the "on or under" of the other element, the above (up) Or on or under includes both elements in which two elements are in direct contact with each other or one or more other elements are formed indirectly between the two elements. In addition, when expressed as “on” or “under”, it may include the meaning of the downward direction as well as the upward direction based on 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 perspective view of a lighting apparatus according to an embodiment of the present invention, Figure 2 is a perspective view when the optical excitation plate is removed from the lighting device shown in Figure 1, Figure 3 is A- in the lighting device shown in Figure 1 It is sectional drawing to A '.

1 to 3, a lighting apparatus according to an embodiment of the present invention may include a housing 110, a light excitation plate 130, a light source module 150, and a reflector 170.

The housing 110 forms the exterior of a lighting device according to an embodiment of the present invention. The housing 110 houses the light excitation plate 130, the light source module 150, and the reflector 170. The housing 110 may have a hole through which the wire 190 passes. The wire 190 transfers external power to the light source module 150.

The housing 110 is preferably made of a material that is easy to receive heat generated from the light source module 150 to be discharged to the outside. For example, it is preferable that it is aluminum or an aluminum alloy.

The light excitation plate 130 is disposed at the upper end of the housing 110 and is disposed on the light source module 150. The light excitation plate 130 excites the light emitted from the light source module 150. That is, the wavelength of the light emitted from the light source module 150 is changed. The optical excitation plate 130 will be described in detail with reference to the accompanying drawings.

4 is a perspective view of the light excitation plate 130 shown in FIG. 3, and FIGS. 5 and 6 are cross-sectional views taken along line BB ′ of the light excitation plate 130 shown in FIG. 4. 5 and 6 are another embodiment.

4 to 6, the optical excitation plate 130 includes a substrate 131 and a coating layer 133.

The substrate 131 is preferably made of a resin material capable of transmitting light. For example, polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), acrylic resin, polystyrene (polystyrene) , PS) and the like. In particular, when heat resistance and chemical resistance of the substrate 131 are required, the substrate 131 is preferably polycarbonate (PC).

The substrate 131 may diffuse light as well as transmit light. For example, the substrate 131 may be a translucent diffuser plate or a translucent substrate including a diffuser. Here, the diffusion agent, for example, silicon oxide (SiO 2), titanium oxide (TiO 2), zinc oxide (ZnO), barium sulfate (BaSO 4), calcium carbonate (CaSO 4), magnesium carbonate (MgCO 3), aluminum hydroxide (Al (OH) 3), synthetic silica, glass beads, and diamond, but may include at least one. In addition, the particle size of the diffusion agent may be selected to a size suitable for the diffusion of light, for example, may have a diameter of 5 ~ 7μm.

As illustrated in FIGS. 5 and 6, the substrate 131 has a predetermined roughness on one surface thereof. Here, one surface is preferably a surface in contact with the coating layer 133. In addition, one surface of the substrate 131 may have a predetermined roughness, as shown in FIG. 5, in which fine irregularities are uniformly distributed, or as illustrated in FIG. 6, in which fine irregularities are uniformly distributed. do.

The coating layer 133 is coated on the surface of one surface of the substrate 131. The coating layer 133 may be formed of at least one of a resin material and a silicon material, and preferably, may be silicon resin.

The coating layer 133 has at least one phosphor 135. The phosphor 135 excites light. The phosphor 135 may be included in the coating layer 133 by being mixed with the liquid coating layer 133 and stirred using a stirrer, for example.

The phosphor 135 excites light from a light source to emit excited light. The phosphor 135 may be, for example, at least one of silicate series, sulfide series, YAG series, TAG series, and Nitride series.

The phosphor 135 may include at least one of yellow, red, green, and blue phosphors emitting yellow, red, green, and blue light, but is not limited to the type of the phosphor 135.

Meanwhile, CaS: Eu may be used as a representative sulfide-based inorganic phosphor for emitting deep red light. As the orange phosphor, at least one of sulfide-based SrS: Eu and MgS: Eu may be used. As the green phosphor, sulfide-based SrGa 2 S 4 and Eu 2+ may be used.

The phosphor 135 may be included in the coating layer 133 in a different kind and amount depending on a light source. For example, when the light source is a white light source, the coating layer 133 may include green and red phosphors. In addition, when the light source is a blue light source, the coating layer 133 may include green, yellow and red phosphors. As such, the type and amount of the phosphor 135 included in the coating layer 133 may vary depending on the type of light source, but is not limited thereto.

Meanwhile, the coating layer 133 may further include at least one or more of a diffusing agent, an antifoaming agent, an additive, and a curing agent.

The diffusion agent may be diffused by scattering light incident on the coating layer 133. Examples of the diffusion agent include silicon oxide (SiO 2), titanium oxide (TiO 2), zinc oxide (ZnO), barium sulfate (BaSO 4), calcium carbonate (CaSO 4), magnesium carbonate (MgCO 3), aluminum hydroxide (Al (OH)). 3), but may include at least one of synthetic silica, glass beads, diamond.

The antifoaming agent can secure reliability by removing bubbles in the coating layer 133. In particular, when the coating layer 133 is applied on the substrate 131 by a screen printing method, a problem of bubbles may be solved. Examples of the antifoaming agent may include, but are not limited to, at least one of octanol, cyclohexanol, ethylene glycol, or various surfactants.

The curing agent may cure the coating layer 133.

The additive may be used to evenly distribute the phosphor 135 in the coating layer 133.

Meanwhile, the coating layer 133 may include a layer having a red phosphor, a layer having a green phosphor, and a layer having a yellow phosphor, in addition to mixing various kinds of phosphors. For example, the coating layer 133 may be formed of at least one of a first coating film having a red phosphor, a second coating film having a green phosphor, and a third coating film having a yellow phosphor. The coating layer 133 may be formed on or below the substrate 131, or a coating layer 133 including different phosphors may be simultaneously formed on and below the substrate 131.

As such, the optical excitation plate 130 including the substrate 131 and the coating layer 133 may be emitted to the outside by changing the wavelength of light emitted from the light emitting element 153 of the light source module 150. Accordingly, the light excitation plate 130 is applied to light sources such as various lighting devices, backlight units, light emitting devices, and display devices, and used to generate light having various wavelengths, or the color rendering index (CRI) of the light sources. It can be used for the purpose of improving.

In addition, since one surface of the substrate 131 has a predetermined roughness, the photoexcitation plate 130 may ensure coating uniformity when the coating layer 133 is coated on one surface of the substrate 131. Specifically, reference is made to FIGS. 7 and 8.

FIG. 7 is a diagram illustrating the appearance of the coating layer 133 when not having a roughness and the appearance of the coating layer 133 when having a roughness. The left figure is a state of the coating layer when there is no predetermined roughness, and the right figure is a state of the coating layer 133 when there is a predetermined roughness. 8 is an actual picture of FIG. 7.

Referring to FIGS. 7 and 8, when a predetermined roughness is present on the substrate 131, it may be confirmed that a coating line does not occur in the coating layer 133.

In addition, the optical excitation plate 130 is excellent in adhesion. This will be described with reference to FIG. 9.

FIG. 9 is a comparison photograph for confirming adhesion performance of the optical excitation plate 130 illustrated in FIG. 4. The photo on the left is a photo showing a state after a predetermined time elapses after attaching 25 1 mm square materials to the photo excitation plate having no predetermined roughness using a tape, and the photo on the right shows the photo excitation plate 130 shown in FIG. 4. 25 is a photograph showing the state after a predetermined time after attaching the 25 square materials using a tape.

Comparing the two photographs of FIG. 9, it can be seen that the adhesion of the optical excitation plate 130 shown in FIG. 4 is better.

In addition, since the photoexcitation plate 130 has a predetermined roughness, the content of the phosphor 135 included in the coating layer 133 has the same thickness, and the coating layer is coated on a general substrate having the same roughness. Higher than the phosphor content contained in the photoexcitation plate.

On the other hand, when the substrate 131 of the optical excitation plate 130 is a diffuser substrate with a further diffuser function, the luminous flux decrease (approximately 60% or less) of the diffuser substrate can be compensated for (about 30%). . Specifically, it will be described with reference to <Table 1> and <Table 2> below. The experiments of Tables 1 and 2 below were performed with the same light emitting diodes.

Board Application number Lm CIE CCT Power Eff. PC


One 353.8 0.2040 0.1114 - 8.64 39.6 2 514.4 0.2401 0.1758 - 8.64 63 3 628.8 0.3001 0.2759 8469 8.68 69.5 4 603 0.3337 0.3324 5438 8.67 72.5

Table 1 above is a coating of the coating layer 133 shown in FIG. 4 on a general polycarbonate (PC) substrate having no predetermined roughness, and the luminous flux when the coating layer 133 is coated one to four times. (Lm), color coordinate system (CIE), color temperature (CCT), power, efficiency (Eff.).

Board Application number Lm CIE CCT Power Eff. Diffiffuser
Substrate

One 455.3 0.2231 0.1822 - 8.51 53.5 2 635.9 0.3040 0.3248 7043 8.65 73.5 3 646.6 0.3617 0.4240 4741 8.75 73.9 4 603.8 0.3980 0.4809 4190 8.73 69.2

Table 2 shows the luminous flux Lm and color when the coating layer 133 is coated one to four times when the substrate 131 is a diffuser substrate in the optical excitation plate 130 illustrated in FIG. 4. It shows the coordinate system (CIE), color temperature (CCT), power and efficiency (Eff.).

Comparing <Table 1> and <Table 2>, for example, when comparing the luminous flux when one coating layer 133 was coated on each substrate, it was 353.8 (Lm) for the PC (0.5T) and the diffuser substrate. It was 455.3 (Lm) for Diffuser Substrate. It was confirmed through this experiment that the transmittance of the diffuser substrate is lower than that of a general PC, so that the luminous flux is lowered compared to a general PC. However, since the diffuser substrate has a predetermined roughness, the luminous flux can be compensated for. I could confirm it. This is because the surface area of the phosphor 135 included in the coating layer 133 increases due to the roughness.

In the method of manufacturing the optical excitation plate 130 shown in FIG. 4, a light transmissive substrate 131 having a predetermined roughness is first provided. Here, the light transmissive substrate 131 may be a diffuser substrate 131 which further adds a light diffusing function.

Next, the phosphor 135 is mixed with the coating liquid. Mixing of the coating liquid and the phosphor 135 is preferably performed through an ultrasonic disperser.

Next, the coating liquid including the phosphor 135 is coated on one surface of the light transmissive substrate 131 having a predetermined roughness.

Through the above process, the optical excitation plate 130 may be manufactured.

In addition, the optical excitation plate 130 may use a polymer plate containing a phosphor.

The photoexcitation plate 130 is manufactured by including the above-mentioned phosphor and a diffusing agent in a polymer plate, or a mixture of plastics, phosphors, and additives is used to produce the photoexcitation plate (injection molding). 130)

Meanwhile, the relationship between the light excitation plate 130 and the light emitting element 153 will be described with reference to FIG. 4.

Referring to FIG. 4, the photoexcitation plate 130 and the light emitting element 153 may have a peak section of the luminous flux according to the distance D between the photoexcitation plate 130 and the light emitting element 153, and It is preferable that the saturation sections of the color temperature are spaced apart by an overlapping interval. Specifically, this will be described with reference to FIG. 10.

FIG. 10 is a graph of a luminous flux curve 1100 and a color temperature (CCT) curve 1500 according to a distance (D) between the light excitation plate 130 and the light emitting element 153. Although the graph shown in FIG. 10 varies slightly depending on the light emitting element 153 and the light excitation plate 130, the tendencies of the curves 1100 and 1500 are almost similar. The photoexcitation plate 130 used in the experiment was 2T5% DP. Here, 2T5% DP means that the thickness is 2T (mm), the phosphor content is 5%, and the substrate of the photoexcitation plate is a diffusion plate DP. The experiment was performed in an integrating sphere.

Here, when the graph shown in FIG. 10 is expressed in a table, it is as shown in Table 3 below.

Distance
(mm) 0 5 10 15 20 25 Luminous Flux (lm) 115 121 121 119 114 112 CCT (k) 10857 9874 9859 9721 9614 9717

Referring to the luminous flux curve 1100 illustrated in FIG. 10, the luminous flux according to the distance D between the light excitation plate 130 and the light emitting element 153 is determined from the light emitting element 153 when the distance is greater than or equal to a certain degree. Radiated radiations show light loss due to collisions between them. Looking at the luminous flux curve 1100, the luminous flux has a peak section between the distance D of 5 mm to 10 mm. Here, the peak period of the luminous flux is greater than or equal to a distance of less than 3 mm and less than a greater than 3 mm from the distance at which the luminous flux reaches the maximum value when the light emitted from the light emitting element 153 reaches the optical excitation plate 130. Or the like.

Referring to the color temperature curve 1500 illustrated in FIG. 10, the color temperature according to the distance D between the optical excitation plate 130 and the light emitting element 153 does not decrease when the distance is greater than a certain distance. That is, the color temperature curve 1500 has a saturation section. Looking at the color temperature curve 1500, it can be seen that the saturation section appears from about 5 mm or more.

Therefore, the optimal distance D between the light excitation plate 130 and the light emitting element 153 is preferably spaced apart by the distance to the light emitting element 153 in a section where the peak section of the luminous flux and the saturation section of the color temperature overlap each other.

1 to 3 again, the light source module 150 is disposed at the lower end of the housing 110. The light source module 150 may include a PCB 151 and a light emitting device 153.

A plurality of light emitting devices 153 may be disposed on one surface of the PCB 151, and the other surface may be disposed on the reflector 170. Here, the PCB 151 may be disposed on the housing 110. That is, when the reflector 170 is disposed only on the inner side surface of the housing 110, the PCB 151 may be disposed so as to be in direct surface contact with the housing 110.

The PCB 151 may be electrically connected to the wire 190 to receive external power.

The light emitting device 153 is disposed in plurality on one surface of the PCB 151. The light emitting element 153 is preferably a light emitting diode (LED), but is not limited thereto. The light emitting diodes may be red, green, blue, or white light emitting diodes emitting red, green, blue, or white light, respectively, but are not limited thereto.

The reflector 170 is disposed on the housing 110. Here, the reflector 170 may be disposed only on the inner side surface of the housing 110.

The reflector 170 reflects the light emitted from the light emitting element 153 of the light emitting module 150 to the light excitation plate 130. Therefore, the reflector 170 is preferably a material that can reflect light.

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 exemplary 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: housing
130: optical excitation plate
150: light source module
170: reflector
190; wire

Claims (13)

An optical excitation plate having a roughness of one surface and a substrate for transmitting light and a coating layer coated on a surface of one surface of the substrate and having at least one phosphor; And
A light emitting element spaced apart from the optical excitation plate;
Including,
The optical excitation plate is spaced apart from the light emitting element by a distance from the peak section of the luminous flux according to the interval between the light excitation plate and the light emitting element and the section where the saturation section of the color temperature according to the interval overlap each other.
The method of claim 1,
And a reflector arranged to surround the light emitting element.
The method of claim 2,
And a housing accommodating the optical excitation plate, the light emitting element, and the reflector, and dissipating heat from the light emitting element.
The method of claim 1,
And the substrate has a diffuser function to diffuse the light.
The method of claim 1,
The coating layer is a lighting device comprising at least one or more of a diffusing agent, an antifoaming agent, an additive, a curing agent.
The method of claim 1,
The coating layer is a lighting device comprising at least one of yellow, red, green and blue phosphor.
The method of claim 1,
Illumination device in which fine irregularities are uniformly or nonuniformly formed on one surface of the substrate.
The method of claim 1,
The coating layer includes at least one or more of a first coating film having a yellow phosphor, a second coating film having a red phosphor, and a third coating film having a blue phosphor.
The method of claim 1,
And a distance between the peak section of the luminous flux according to the distance between the optical excitation plate and the light emitting element and the saturation section of the color temperature according to the interval are approximately 5 to 10 mm from the light emitting element.
An optical excitation plate having at least one phosphor; And
A light emitting element spaced apart from the optical excitation plate;
Including,
The distance between the light emitting element and the optical excitation plate is greater than or equal to 3 mm and less than 3 mm greater than the distance at which the luminous flux reaches the maximum when light from the light emitting element reaches the optical excitation plate. Such lighting device.
11. The method of claim 10,
The distance between the optical excitation plate and the light emitting element is related to a section in which a color temperature curve according to the distance between the light emitting element and the optical excitation plate is saturated.
11. The method of claim 10,
Illumination device between the optical excitation plate and the light emitting element is approximately 5 ~ 10mm
11. The method of claim 10,
The optical excitation plate is composed of a coating layer coated with a phosphor on the substrate or a lighting device consisting of a polymer plate having a phosphor.

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