KR20110054428A - Lighting device using led - Google Patents

Abstract

PURPOSE: An LED lighting device is provided to increase light efficiency and make a ceiling look clean. CONSTITUTION: A heat sink(10) includes a heat radiating fin and a connection unit. The connection unit is integrated with the heat radiating fin and the connection unit has a first coupling unit. An LED light source(20) is installed in the heat sink. A shade(30) sets the emitting orientation angle of light emitted from the LED light source and includes an opening and a second coupling unit. The second coupling unit is coupled with a first coupling unit.

Description

LED lighting device {Lighting device using LED}

The present invention relates to an LED lighting device, and more particularly, to an LED lighting device that can be installed embedded in the ceiling.

In general, a down light is a lighting method that drills a hole in a ceiling and embeds a light source therein, and is widely used as an architectural lighting technique for integrating lighting and buildings.

Such a buried light is a structure that is embedded in the ceiling, and there is almost no exposure of the lighting fixture, so the ceiling surface looks neat and moreover, the ceiling surface is dark, which makes it suitable for creating an atmosphere indoor space. .

The technical problem to be achieved by the present invention is to provide an illumination device using an LED that is excellent in heat emission, and efficiently focuses the light emitted from the LED which is a point light source, has a certain directivity angle, and can improve the light efficiency.

In order to achieve the above technical problem, the present invention, a heat sink comprising a heat dissipation fin and a connecting portion integral with the heat dissipation fin and having a first fastening portion; An LED light source installed in the heat sink; And a shade that sets the emission directing angle of the light emitted from the LED light source, has an opening through which the light is emitted, and has a second fastening portion fastened to the first fastening portion.

The present invention uses an eco-friendly, long-life, high-efficiency LED, low power consumption, efficient heat dissipation, and has excellent illuminance and uniformity, while preventing glare from LED light and further improving light transmittance. It can be effective.

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

While the invention allows for various modifications and variations, specific embodiments thereof are illustrated by way of example in the drawings and will be described in detail below. However, it is not intended to be exhaustive or to limit the invention to the precise forms disclosed, but rather the invention includes all modifications, equivalents, and alternatives consistent with the spirit of the invention as defined by the claims.

It will be appreciated that when an element such as a layer, region or substrate is referred to as being present on another element "on," it may be directly on the other element or there may be an intermediate element in between .

The terms first, second, etc. may be used to describe various elements, components, regions, layers and / or regions, but such elements, components, regions, layers and / or regions may be It will be understood that it should not be limited by terminology.

As shown in FIG. 1, the lighting apparatus includes a heat sink 10, a light emitting diode (LED) light source 20 provided in the heat sink 10, and light emitted from the LED light source 20. It is comprised including the shade 30 which sets an exit directivity angle.

The heat sink 10 includes a plurality of heat dissipation fins 11, which protrude integrally with the heat dissipation fins 11 to form a connection portion 12 having a first fastening portion 13.

As shown in FIG. 2, the connection part 12 may form a cylindrical shape protruding with respect to the heat dissipation fin 11, and the first fastening part 13 of the connection part 12 may be formed of an outer circumferential part of the cylindrical shape described above. It may be a single thread.

The heat sink 10 is formed by integrally forming a plurality of heat radiation fins 11 in order to discharge the heat generated by the LED light source 20 to the outside.

The LED light source 20 may include at least one LED 22 provided on a printed circuit board (PCB) 21 attached to and installed on the connection part 12 of the heat sink 10. A plurality of LEDs 22 may be arranged on the circuit board 21.

The shade 30 focuses the light emitted from the LED light source 20 so that the shade 30 may be emitted through the opening with a predetermined direction angle, and may have a mirror surface 32 on the inner surface thereof.

The shade 30 may be coupled to the heat sink 10 by a second fastening portion 31 fastened to the first fastening portion 13 of the heat sink 10, and the second fastening portion 31 may be coupled to the heat sink 10. May be a second screw thread formed inside the upper end of the shade 30 and coupled to the first screw thread of the first fastening portion 13.

Meanwhile, the diffusion substrate 40 may be provided in an opening through which the light of the shade 30 is emitted.

As described above, the lighting device may be used as a lamp for concentrating a plurality of LEDs 22 to obtain light. In particular, the lighting device may be embedded in a ceiling or a wall of a building to expose the opening side of the shade 30. It is available by purchase lights (downlight) to let you do it.

The above-described lighting apparatus is formed in the LED light source 20 without any additional mechanism such as a cooling fan by forming a plurality of heat dissipation fins 11 to increase the contact area with the outside in order to increase the emission efficiency of heat emitted from the LED light source 20. It is possible to dissipate sufficient heat, and also a through hole 14 for connecting the power applied from the outside with the circuit board 21 of the LED light source 20 bonded to the upper portion of the heat sink 10 can be formed. have.

In addition, the first fastening portion 13 of the heat sink 10 is formed to protrude from the heat dissipation fin 11 forming the body of the heat sink 10 so that the light emitted from the LED 22 is the first fastening portion. It is possible to minimize the reduction in the total amount of light due to reflection and absorption by hitting (13), which can greatly improve the luminous efficiency of the lighting device.

The heat sink 10 described above may be manufactured by an extrusion molding method, a die casting method, an injection molding method, or the like. As the representative materials capable of forming the heat sink 10, There is aluminum.

In addition, the heat dissipation efficiency may be further improved by coating or oxidizing the nanomaterial on the surface of the heat sink 10 to increase the contact area with the outside.

For optimal optical design of such a lighting device, first, the LED 22 package as a light source may be modeled. The software for LED package modeling and light simulation used LightTools from ORA. Modeling with LightTools should be designed based on accurate data for reliable results.

Based on the data sheet provided by the LED package manufacturer, design a three-dimensional LED package similar to the structure and size of the actual product, select the appropriate material for each characteristic such as the reflective cup and silicon lens, and adjust the refractive index, Modeling was done by inputting data such as transmittance and reflectance.

The modeled LED package has a typical Lambertian distribution with a luminous flux of 87lm, a color temperature of 3490K, and an angle of emission of 110 ° FWHM.The LED package used for prototyping uses the LED package (Cree, XLamp XP-E P4) The optical characteristic was satisfied.

In addition, the modeled LED package may be used to model the components of the lighting device to compare the light extraction efficiency according to the mounting position of the LED 22 package of the circuit board 21.

As shown in the downlight modeling example, the body length of the shade 30 has a streamlined curved surface of 105 mm and a maximum internal diameter of Φ 114 mm, and the circuit board 21 has a size of about Φ 70 mm as shown in the downlight modeling example. Designed for light.

In addition, the center of the circuit board 21 and the center of the body of the shade 30 were matched to simulate the change in the position of the LED 22 in the state coupled with the concave heat sink 10 to which the heat dissipation design was applied.

FIG. 3 simulates light extraction efficiency by changing the position of the LED 22 by 5mm in the outer direction from the center when the LED 22 is positioned at the center of the circuit board 21 (PCB). The result is.

As such, the LED downlight may be important in shape design to maximize the lighting efficiency by lowering the light emitted from the LED 22 to the bottom without interference or continuous overlapping reflection in the body of the shade 30.

In addition, luminaires made by combining a small point light source and a high directivity of the LED 22 may cause glare to the user, which may cause discomfort and fatigue, and thus, it is advantageous to alleviate the occurrence of glare.

For this purpose, the LED package 12EA required for the 15W class LED downlight is uniformly arranged on the circuit board 21 and simulated according to the shade 30 length, reflectivity, and reflectance change in the far distance ( luminosity at farfield receiver) was compared and the results are shown in FIG. 4.

At this time, the maximum internal diameter of the shade 30 was the same, and the reflective properties were divided into Lambertian reflection and mirror reflection, and the reflectances were 95% and 70%, respectively. Compared to the state in which the shade 30 is not fastened (Shade length: 0mm), as the length of the shade 30 increases, light extraction efficiency decreases under all conditions, and in the case of the Lambertian reflective property having a 70% reflectance, the shade 30 As the length increases, the light extraction efficiency decreases significantly, while the 95% mirror reflection property does not show a significant decrease in the light extraction efficiency.

Also, in order to solve the illumination glare according to the change in the length of the shade 30, the length of the shade 30 was further subdivided in 5 mm units to compare the raster charts. At this time, the reflective property of the inner surface reflective film 32 of the shade 30 was made into the conditions of 95% mirror reflection property. As a result, when the shade 30 length is 45mm, the uniformity of illuminance was excellent and the luminance distribution at that time is shown in FIG.

As a result of the downlight simulation, the shade 30 has excellent reflectivity of the mirror reflection property, and when the length of the shade 30 is 45 mm from the light source, the light extraction efficiency is excellent as well as a uniform illuminance distribution. It can be seen that glare can be solved.

On the other hand, it is important to prevent deterioration of the LED chip itself or the packaging resin by the design of the heat sink 10 that can effectively emit heat of the LED chip.

Heat sink heat dissipation design for high reliability of LED down light. The heat sink's heat dissipation design is not only suitable for 15W class LED downlights, but also designed for common use in 20W class LED downlights.

In the 20W LED downlight, about 18W is applied to the LED in consideration of the drive efficiency, and considering the light efficiency, the heat generation power is about 15.3W. It was.

Simulation conditions are as follows.

Boundary: 202mm * 202mm * 202mm Natural Air convection

Flow: Laminar Flow

-Semi-closed space or opened space

Room Temperature: 25 ℃

-Conduction, Convection, Radiation considered

Source: Equivalent Thermal Resistance

Power: 20W

Reflector Emissivity ~ 0.77 (Anodized surface)

In this condition, the simulation results in the opened space using the XP-E package having a thermal resistance (Rth) of about 9K / W are shown in FIG. 6.

In consideration of design conditions through simulation as described above, the LED 22 used in the LED light source 20 may be a high power package of 1W or more, and a white LED package having a color temperature of 3000K to 7000K. It is advantageous to apply.

As an example of the arrangement of the LED 22 installed on the circuit board 21 in the LED light source 20, a plurality of virtual concentric circles or concentric polygonal lines may be arranged on the circuit board 21.

In particular, as shown in FIG. 7, a plurality of LEDs 22 may be arranged on the circuit board 21 on a virtual concentric square line where edges and sides contact each other.

That is, it can arrange | position to a virtual rhombus or a corner part of a square, and can also install in the image. In addition, the heat dissipation may be considered, but the LED 22 may be disposed in the central portion of the circuit board 21 where possible.

In addition, as shown in FIG. 8, the LEDs 22 may be disposed on a plurality of virtual concentric circles on the circuit board 21.

Such LED 22 and IC elements (not shown) for driving the LED 22 may be bonded to the circuit board 21 by surface mounted technology (SMT) surface mount technology, and may be connected to the upper surface of the circuit board 21. The joining surface of the connection part 12 of the heat sink 10 is bonded to the center of the circuit board 21 so that the center of the heat sink 10 may be matched using the adhesive agent which is excellent in thermal conductivity.

As shown in FIG. 9, the position of the LED 22 bonded to the circuit board 21 is farther from the center of the circuit board 21, that is, the LED 22 is located closer to the fastened shade 30. Since the number of times that the light emitted from the LED 22 collides with the shade 30 increases, the amount of light of the LED 22 emitted to the outside tends to decrease, so the circuit board 21 is located at the outermost position. The light emitting efficiency of the downlight can be further improved by placing the LED 22 packages evenly spaced at a distance of 10 mm or more from the inner surface (second fastening portion) of the bottom surface of the LED 22 and the shade 30. It can be made to have a uniform illuminance.

 10 shows a shade 30 that not only collects the light emitted from the LED 22 package disposed as described above but also has a predetermined directivity angle.

Shade 30 as shown in Figure 10 is for fastening the lighting device to the second fastening portion 31 and the ceiling of the spiral to the portion that is engaged with the first fastening portion 13, which is the heat sink 10 fastening portion. It is a cylindrical shape having an opening structure for facilitating mounting of the fixing hole 35 and the diffusion plate 40, and can be manufactured by a die casting method and an injection molding method.

In particular, the cylindrical inner reflecting surface 32 of the shade 30 collides with the light emitted from the LED 22 package, which is highly related to the efficiency emitted to the outside by the optical characteristics of the inner reflecting surface 32. . Therefore, the cylindrical inner reflection surface 32 of the shade 30 can be formed as a mirror surface having a mirror (mirror) characteristics.

As a method for forming a mirror surface having such a mirror property, an optical sheet having a mirror property may be attached to the inside, or a silver (Ag) material may be formed by electroless plating on the surface. In addition, in order to have a uniform illuminance, it is advantageous if the height H of the shade 30 is equal to or greater than a certain height.

Thus, as in FIG. 10, it is advantageous to set the height H of the shade 30 in the range of 30 mm to 50 mm. In addition, the diffuser flat 40 may not only prevent glare of light emitted from the LED 22 package but also diffuse the light to uniformly irradiate the subject.

In addition, since the diffusion substrate 40 advantageously has excellent light transmittance, a polycarbonate (PC) substrate, an acrylic substrate, or the like may be used.

As a specific example, by attaching the optical diffusion sheet 42 having excellent light transmittance on the transparent substrate 41, it is possible not only to prevent glare caused by the light of the LED 22 but also to further improve the light transmittance.

The above embodiment is an example for explaining the technical idea of the present invention in detail, and the present invention is not limited to the above embodiment, various modifications are possible, and various embodiments of the technical idea are all protected by the present invention. It belongs to the scope.

1 is an exploded cross-sectional view showing an embodiment of a lighting device.

2 is a perspective view showing an embodiment of a lighting device.

3 is a graph showing the light extraction rate of the lighting apparatus.

4 is a graph showing the light extraction rate according to the length of the shade.

5 is an intensity chart when the shade is 45 mm.

6 is a simulation diagram illustrating a heat radiation simulation.

7 is a schematic diagram illustrating an example of an LED array.

8 is a schematic diagram illustrating another example of the LED arrangement.

9 is a schematic view showing the positional relationship between the light source and the shade.

10 is a schematic view showing an example of installation of shades.

Claims (12)

A heat sink comprising a heat dissipation fin and a connection portion integral with the heat dissipation fin and having a first fastening portion; An LED light source installed in the heat sink; And LED shade device comprising a shade having an emission directing angle of the light emitted from the LED light source, having an opening through which the light is emitted, and having a second fastening portion fastened to the first fastening portion. . The LED lighting apparatus of claim 1, wherein the connection part has a cylindrical shape protruding from the heat dissipation fin. The LED illuminating device according to claim 2, wherein the first fastening portion is a first screw thread formed on an outer peripheral portion of the cylindrical shape. The LED lighting apparatus of claim 3, wherein the second fastening portion is a second screw thread which is fastened to the first screw thread and formed inside the end of the shade. The method of claim 1, wherein the LED light source, A circuit board attached to the connection portion; And LED lighting device, characterized in that at least one LED arranged on the circuit board. The LED lighting apparatus according to claim 5, wherein a plurality of the LEDs are arranged on a virtual circular or polygonal line on the circuit board. The LED lighting apparatus according to claim 5, wherein the LEDs are arranged on the circuit board in a plurality of virtual concentric circles or concentric polygonal lines. 8. The LED lighting apparatus according to claim 7, wherein the LEDs are arranged on the circuit board in a plurality of virtual concentric square lines whose edges and sides are in contact with each other. The LED illuminating device according to any one of claims 6 to 8, wherein a distance between the LED located at the outermost part of the circuit board and the second fastening part among the LEDs is 10 mm or more. The LED illuminating device according to claim 1, wherein the opening portion further includes a diffusion substrate. The method of claim 10, wherein the diffusion substrate, A transparent substrate; LED lighting device comprising a diffusion sheet located on the transparent substrate. According to claim 1, The height of the shade, LED lighting device, characterized in that 30mm to 50mm.

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