KR101079133B1

KR101079133B1 - LED light source

Info

Publication number: KR101079133B1
Application number: KR1020090061045A
Authority: KR
Inventors: 주원돈
Original assignee: 주식회사 옵티코
Priority date: 2009-07-06
Filing date: 2009-07-06
Publication date: 2011-11-02
Also published as: KR20110003666A

Abstract

The present invention relates to an LED light source with improved light efficiency. The LED light source according to the present invention includes an LED chip, a light concentrator, and a packaging part. The light concentrator concentrates the light emitted from the LED chip to lower the etendue or increase the light efficiency. The light concentrator may be a plurality of optical fibers, elliptical mirrors or parabolic mirrors.

According to the present invention, it is possible to provide an LED light source having a low etendue or an LED light source having high light efficiency using the light concentrator.

LEDs, light concentrators, etendues, optical fibers, curved facets, elliptical mirrors

Description

LED light source {LED light source}

The present invention relates to an LED light source having improved light efficiency, and more particularly, to an LED light source having increased light efficiency by concentrating light emitted from an LED chip using a light concentrator.

In the current optical system, the tendency to use a light emitting diode (LED) as a light source is increasing. In particular, LEDs are essential for miniaturization of light sources. In addition, in accordance with the demand for green technology (LED), LED is widely used as a light source.

Light emitting diodes (LEDs) are also called light emitting diodes. The LED produces a small number of carriers (electrons or holes) injected using the p-n junction structure of the semiconductor, and emits light by recombination thereof. Suitable materials for LED are to satisfy the conditions such as high luminous efficiency and the possibility of manufacturing p-n junction. Accordingly, the materials of the LED are mainly gallium arsenide (GaAs), gallium phosphide (GaP), gallium-arsenide-phosphorus (GaAs1-x Px), gallium-aluminum-arsenic (Ga1-xAlxAs), indium phosphide (InP), indium 2-element or 3-element compound semiconductors of Groups 3B and 5B, such as -gallium-phosphorus (ln1-xGaxP), are used. In recent years, research has been made on the use of 2B, 6B, 4A, and 4B as LED materials.

When using the LED as a light source there is a problem that the light efficiency is low. LEDs are basically limited in light efficiency because of high etendue. To solve this problem, the power of the LED is being used up, but this is not a fundamental solution. Therefore, in order to use an LED as a light source, it is necessary to be able to improve the light efficiency of a given power LED.

An object of the present invention is to provide an LED light source that can lower the etendue or improve the light efficiency using the light concentrator.

In order to achieve the above objects, the LED light source according to the embodiment of the present invention includes an LED chip, a light concentrator. The light concentrator is located in front of the light emitting surface of the LED chip. The light concentrator concentrates the light emitted from the LED chip.

In the LED light source according to the embodiment of the present invention, the light concentrator may be a plurality of optical fibers. One end of the plurality of optical fibers is disposed radially in front of the light emitting surface of the LED chip, and the ends are concentrated in one place.

LED light source according to an embodiment of the present invention may further include a curved surface forming portion. The curved portion allows one end of the plurality of optical fibers to be disposed radially. The curved surface forming portion may be a curved shape, a spherical shape, a multi-sided dome shape or a honeycomb shape.

In the LED light source according to the embodiment of the present invention, a plurality of optical fibers may be grouped into at least two optical fiber bundles. Inside each fiber bundle are optical fibers located side by side.

In the LED light source according to the exemplary embodiment of the present invention, the light concentrator may be an elliptical mirror or a parabolic mirror. The elliptical mirror or parabolic mirror is arranged such that the LED chip is located at the first focal point.

The light concentrator of the LED light source according to the exemplary embodiment of the present invention may further include a rod lens. The rod lens passes light reflected from an elliptic mirror or parabolic mirror.

LED light source according to another embodiment of the present invention includes a plurality of LED chips, a plurality of optical fibers. One end of a plurality of optical fibers is disposed radially in front of the light emitting surface of each of the plurality of LED chips, the ends are concentrated in one place.

The present invention can concentrate the light emitted from the LED chip using the light concentrator. Therefore, the light efficiency of an LED light source can be improved.

The light concentrator can also be packaged integrally with the LED chip. Therefore, the size of the LED light source can be reduced, and manufacturing is easy.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that, in the drawings, the same components are denoted by the same reference symbols as possible. In addition, detailed descriptions of well-known functions and configurations that may blur the gist of the present invention will be omitted. For the same reason, in the accompanying drawings, some components are exaggerated, omitted or schematically illustrated.

1 is a view conceptually showing an LED light source according to an embodiment of the present invention.

As shown in FIG. 1, the LED light source 100 according to the embodiment of the present invention includes an LED chip 110 and a light concentrator 120. The LED chip 110 converts electrical energy into light energy. The LED chip 110 emits light at 180 ° from the light emitting surface. The light concentrator 120 concentrates the light emitted from the LED chip 110.

By concentrating the light at the light concentrator 120, etendue is lowered and light is reduced. Etendu is proportional to the area and solid angle at which light is emitted. Therefore, if the area or solid angle at which light is emitted is small, the etendue is also reduced. For example, if the area of the light emitting surface of the LED chip 110 is 0.25 mm 2 and the emission angle of light is 180 °, the etendue is

to be. At this time, if the area where the light is emitted from the light concentrator 120 is 1.0 mm 2 and the light emission angle is 25 °, the etendue is

to be. That is, the etendue is lowered to about 1/10 by the light concentrator 120. When the etendue is lowered to 1/10, the light efficiency is improved by 10 times.

The LED chip 110 and the light concentrator 120 may be integrally packaged. The packaging can be made of epoxy or the like.

2 is a view showing that the light concentrator is a plurality of optical fibers in the LED light source according to an embodiment of the present invention.

As shown in FIG. 2, the LED light source 200 according to the exemplary embodiment of the present invention includes an LED chip 210 and a plurality of optical fibers 220. In this embodiment, the plurality of optical fibers 220 serves as a light concentrator. The plurality of optical fibers 220 are positioned in front of the light emitting surface of the LED chip 210.

Each of the optical fibers in the plurality of optical fibers 220 is located in the angle range where one end of the light of the LED chip 210 is emitted. That is, one end of the plurality of optical fibers 220 is disposed radially in front of the light emitting surface of the LED chip 210. To this end, one end of the optical fiber 220 may be fixed by the curved surface forming portion 221.

The shape of the curved surface forming portion 221 may be a curved surface, a spherical shape, a multi-faced dome shape or a honeycomb shape. The shape of the curved surface forming portion 221 may vary depending on the light emission and the optical fiber of the LED chip 210. In order to fix one end of the optical fiber 220, a groove may be formed in the curved surface forming portion 221. The curved surface forming portion 221 may fix one end of the optical fiber 220 by using the groove. In another embodiment, a hole may be formed in the curved surface forming unit 221, and one end of the optical fiber 220 may be inserted into and fixed to the hole. In particular, when the curved surface forming portion 221 has a honeycomb shape, the optical fiber 220 may be inserted into and fixed to a honeycomb-shaped hole. If one end of the optical fiber 220 is fixed by forming a groove or a hole in the curved surface forming portion 221, the manufacturing process is simple and easy. In another embodiment, one end of the optical fiber 220 may be fixed to the curved surface forming portion 221 using a jig.

Ends of the plurality of optical fibers 220 are concentrated in one place. In this case, at one end of the plurality of optical fibers 220, one end of the optical fiber that is the center of the light emitting surface of the LED chip 210 and one end of the optical fiber that is the periphery of the light emitting surface of the LED chip 210 (mix) properly, 220) light distribution at the ends can be adjusted.

The ability to receive light in an optical fiber is represented by numerical aperture (NA). That is, the larger the numerical aperture, the easier the coupling with the light source. When light is emitted from the optical fiber, it is emitted within the numerical aperture. For example, if the numerical aperture of the optical fiber is 0.2, the angle of light emitted at the end of the optical fiber is 11.54 ° (

)to be.

In the present embodiment, if the area of the light emitting surface of the LED chip 210 is 0.25 mm 2 and the light emission angle is 180 °, the etendue is

to be. At this time, if the numerical aperture of the optical fiber is 0.2 and the area of the ends of the plurality of optical fibers 220 is 1 mm 2, the etendue is

to be. Therefore, the etendue is lowered to 1/12, and the light efficiency is 12 times. Since there is some light loss at one end of the fiber, the overall efficiency may be slightly reduced. However, optical fiber efficiency will be at least six times higher.

The LED chip 210 and the plurality of optical fibers 220 may be integrally packaged. By packaging, the LED light source 200 may include a packaging unit 230. The packaging unit 230 allows the ends of the plurality of optical fibers 220, one end of which is disposed in a radial shape, to naturally concentrate in one place. In addition, the packaging unit 230 fixes the plurality of optical fibers 220 not to move. Ends of the plurality of optical fibers 220 may be located inside or outside the packaging unit 230. In the present embodiment, the packaging unit 230 may have various shapes.

3 is a view showing that a plurality of optical fibers are grouped into an optical fiber bundle in an LED light source according to an embodiment of the present invention.

As shown in FIG. 3, in the LED light source 300 according to the exemplary embodiment, the plurality of optical fibers may be grouped into a plurality of optical fiber bundles 320a, 320b, 320c, and 320d. In the present embodiment, four optical fiber bundles 320a, 320b, 320c, and 320d are grouped, but are not limited thereto. The optical fibers are located side by side inside each of the optical fiber bundles 320a, 320b, 320c, and 320d. One end of each of the optical fiber bundles 320a, 320b, 320c, and 320d is radially disposed by the curved surface forming portion 3210 in front of the light emitting surface of the LED chip 310. The ends of the optical fiber bundles 320a, 320b, 320c, and 320d are concentrated in one place.

When the plurality of optical fibers are grouped and arranged into a plurality of optical fiber bundles, the manufacturing process of the LED light source 300 is simplified. Radially arranging a plurality of optical fibers in front of the light emitting surface of the LED chip 310 takes a lot of effort and time. However, by arranging a plurality of optical fibers in groups of a plurality of optical fiber bundles, it is easy to arrange them radially.

4 is a view showing that the curved surface forming portion is a multi-sided dome shape in the LED light source according to an embodiment of the present invention.

As shown in FIG. 4, in the LED light source 400 according to the exemplary embodiment, the curved surface forming unit 421 may have a multi-sided dome shape. The plurality of optical fibers 420 are grouped into a plurality of open fiber bundles. One end of each of the plurality of optical fiber bundles is vertically coupled to each surface of the curved surface forming unit 421.

If the curved surface forming portion 421 is formed in a multi-sided dome shape and the optical fiber bundles are vertically coupled to each surface, it is easy to radially arrange the plurality of optical fibers 420 in front of the light emitting surface of the LED chip 410. Can be.

5 is a view showing that the light concentrator in the LED light source according to an embodiment of the present invention is an elliptical mirror.

As shown in FIG. 5A, the LED light source 500 according to the exemplary embodiment of the present invention includes an LED chip 510 and an elliptical mirror 520. In this embodiment, the elliptical mirror 520 serves as a light concentrator. The elliptical mirror 520 is arranged such that the LED chip 510 is positioned at the first focal point. Light emitted from the LED chip 310 is reflected by the elliptical mirror 520 and concentrated at the second focus, thus improving the light efficiency of the LED light source 500.

The LED chip 510 and the elliptical mirror 520 may be integrally packaged. By packaging, the LED light source 500 may include a packaging unit 530.

In another embodiment of the present invention, as shown in FIG. 5B, the LED light source 500 may further include a rod lens 540 through which the light reflected from the elliptical mirror 520 passes. By providing the rod lens 540, it is possible to form uniform light at the end of the rod lens 540. In addition, by adjusting the cross section of the rod lens 540, it is possible to adjust the cross section of the light emitted from the LED light source (500).

The rod lens 540 may be integrally packaged with the elliptical mirror 520. In this case, all of the load lens 540 may be located inside the packaging part. Alternatively, one end of the rod lens 540 may be located inside the packaging part 330, and the end may be located outside the packaging part 340.

In other embodiments, the LED light source may be provided with an LED chip and a parabolic mirror. The parabolic mirror is positioned so that the LED chip is located at the first focal point. The light emitted from the LED chip is reflected by a parabolic mirror, producing parallel rays, and the scattered light is collected. Thus, the light efficiency of the LED light source is improved. The LED chip and the parabolic mirror can be packaged integrally. By packaging, the LED light source may have a packaging part.

In another embodiment, the LED light source may further include a rod lens through which the light reflected from the parabolic mirror passes. By providing the rod lens, it is possible to form uniform light at the end of the rod lens. The rod lens can be packaged integrally with a parabolic mirror. In this case, all the rod lenses may be located inside the packaging part. Alternatively, one end of the rod lens may be located inside the packaging part, and the end may be located outside the packaging part.

6 is a view showing an LED light source according to another embodiment of the present invention.

As shown in FIG. 6, the LED light source 600 according to another embodiment of the present invention includes a plurality of LED chips 610a, 610b, and 610c. In the present embodiment, three LED chips 610a, 610b, and 610c are not limited thereto. A plurality of optical fibers 620a, 620b, and 620c are disposed radially in front of the light emitting surface of each LED chip. A plurality of optical fibers (620a, 620b, 620c) are all concentrated in one end. Each of the plurality of LED chips 610a, 610b, and 610c is packaged with the plurality of optical fibers 620a, 620b, and 620c, respectively.

The LED light source 600 according to the present embodiment may facilitate color mixing using a plurality of optical fibers 620a, 620b, and 620c. For example, when the first LED chip 610a is red, the second LED chip 610b is green, and the third LED chip 610c is blue. If it is, the color emitted from each LED chip (610a, 610b, 610c) should be properly mixed. For color mixing, by using a plurality of optical fibers 620a, 620b, 620c positioned in front of each LED chip 610a, 610b, 610c, it is possible to easily mix colors at a desired position. The position can be adjusted according to the length of the optical fiber, and the degree of color mixing can be adjusted according to the number of optical fibers located in front of each LED chip (610a, 610b, 610c). Therefore, the LED light source 600 can easily implement the desired color. Also in the case of the LED light source 600 according to the present embodiment may have the features as described in Figures 2 to 4.

It should be noted that the embodiments of the present invention disclosed in the present specification and drawings are only illustrative of the present invention in order to facilitate description of the present invention and to facilitate understanding of the present invention and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention can be carried out in addition to the embodiments disclosed herein.

1 is a view conceptually showing an LED light source according to an embodiment of the present invention;

2 is a view showing that the light concentrator is a plurality of optical fibers in the LED light source according to one embodiment of the present invention;

Description of the main parts of the drawing

100, 200, 300, 400, 500: LED light source

LED chip: 110, 210, 310, 410, 510, 610a, 610b, 610c

120: light concentrator 220, 620a, 620b, 620c: a plurality of optical fibers

221, 321, 421: curved surface forming portion 230, 430: packaging portion

520: elliptical mirror 540: rod lens

Claims

LED chip;

A light concentrator having a plurality of optical fibers positioned in front of a light emitting surface of the LED chip to concentrate light emitted from the LED chip; And

Includes; curved surface forming portion for fixing the plurality of optical fibers,

One end of the plurality of optical fibers are fixed to the curved surface forming portion is disposed radially in front of the light emitting surface of the LED chip, the ends are concentrated in one place,

The end of the plurality of optical fibers is one LED light source, characterized in that the end of the center of the light emitting surface of the LED chip is mixed with the optical fiber is one end of the peripheral surface of the LED chip.

The method of claim 1,

LED light source, characterized in that further comprising a packaging for fixing the plurality of optically arranged one end radially.

The method of claim 1,

LED curved light source, characterized in that the groove is formed in the curved portion.

The method of claim 3,

The curved surface forming portion is a LED light source, characterized in that the curved surface, spherical shape, multi-faceted dome shape or honeycomb shape.

The method according to any one of claims 1 to 4,

And the plurality of optical fibers are grouped into at least two optical fiber bundles.

delete

A plurality of LED chips; And

One end is disposed radially in front of the light emitting surface of each of the plurality of LED chips, the end is concentrated in one place,

And the end includes a plurality of optical fibers, one end of which is disposed by mixing an optical fiber, which is the center of the light emitting surface of the LED chip, and an optical fiber, which is one end of the light emitting surface of the LED chip.