KR20120129685A - Light emitting device - Google Patents

Abstract

PURPOSE: A light-emitting device is provided to generate light of different wavelengths by changing positions of two light sources. CONSTITUTION: A wavelength converter(300) changes the light from a first light source(100) to a wavelength. The wavelength converter comprises at least one wavelength conversion layer. The wavelength conversion layer is to elongate the light from the first light source in a light traveling direction. The wavelength conversion layer comprises wavelength conversion particles. The wavelength conversion layer comprises a first wave length conversion layer and a second wavelength conversion layer.

Description

LIGHT EMITTING DEVICE}

The present invention relates to a light emitter.

Recently, various researches using light emission characteristics of quantum dots (QDs) have been actively conducted.

These quantum dots generate strong fluorescence in a narrow wavelength band. The light generated by the quantum dots is generated when electrons in an unstable state descend from the conduction band to the valence band. In this case, the smaller the particles of the quantum dots generate light having a shorter wavelength, and the larger the particles produce light having a longer wavelength.

Therefore, by adjusting the size of the quantum dot can be obtained the light of the desired wavelength band. In addition, when quantum dots of different sizes are present together, light can be emitted at one wavelength to produce various colors at once.

In particular, quantum dots can receive light of short wavelengths and shift the wavelength band to longer wavelengths.

Researches on light emitters that generate various light using the characteristics of the quantum dots are in progress.

The embodiment may generate light of various wavelength bands through the wavelength conversion particle.

The light emitter according to the embodiment includes a first light source; And a wavelength converting unit converting light emitted from the first light source into a wavelength, wherein the wavelength converting unit includes at least one wavelength converting layer, and the wavelength converting layer is configured to receive light emitted from the first light source. Extend in the direction.

The light emitter according to the embodiment includes a wavelength converter that converts light emitted from the light source. In particular, the wavelength conversion unit may include wavelength conversion particles such as quantum dots and nanocrystals. The wavelength conversion particle can efficiently convert light emitted from the light source.

In particular, the wavelength converter may include a plurality of wavelength conversion layers. In addition, each wavelength conversion layer may include wavelength conversion particles having different sizes. As a result, various colors may be emitted from the respective wavelength conversion layers, and light having various colors may be mixed with each other to generate an unexpected new color.

In addition, the light emitter according to the embodiment may include two or more light sources. Thus, of the light source Depending on the location, light with different wavelengths can be generated. That is, depending on the light source to be driven, light having various colors may be generated or infrared rays may be generated. Therefore, it is possible to generate various light from one light emitter according to the consumer's preference or request.

1 is an exploded perspective view of a light-emitting body according to the first embodiment.
2 is a perspective view of a light emitter according to the first embodiment.
FIG. 3 is a cross-sectional view taken along the line AA ′ of FIG. 2.
4 is an enlarged perspective view of the lens unit of FIG. 3.
5 is an exploded perspective view of a light-emitting body according to the second embodiment.
6 is a perspective view of a light emitter according to a second embodiment.
FIG. 7 is a cross-sectional view taken along the line BB ′ in FIG. 6.

In the description of embodiments, each layer, region, pattern, or structure may be “on” or “under” the substrate, each layer, region, pad, or pattern. Substrate formed in ”includes all formed directly or through another layer. Criteria for the top / bottom or bottom / bottom of each layer will be described with reference to the drawings.

The thickness or the size of each layer (film), region, pattern or structure in the drawings may be modified for clarity and convenience of explanation, and thus does not entirely reflect the actual size.

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

A light emitter according to the first embodiment will be described in detail with reference to FIGS. 1 to 4. 1 is an exploded perspective view of a light-emitting body according to the first embodiment. 2 is a perspective view of a light emitter according to the first embodiment. FIG. 3 is a cross-sectional view taken along the line A-A 'of FIG. 2. 4 is an enlarged perspective view of the lens unit of FIG. 3.

1 to 3, the light emitter 10 according to the first exemplary embodiment may include a first light source 100, a case 200, a wavelength converter 300, a lens unit 400, and a protective device 500. ).

The first light source 100 generates light. The light emitted from the first light source 100 is incident to the wavelength converter 300. The first light source 100 may include, for example, a light emitting diode that generates light.

The case 200 accommodates the wavelength converter 300 and the lens unit 400. In addition, the case 200 may serve to protect the wavelength converter 300 and the lens unit 400 from external contamination. In addition, the case 200 may support the light source 100. The case 200 may include plastic or metal. In addition, the case 100 may accommodate the wavelength converter 300 and the protection device 500.

The wavelength converter 300 includes at least one wavelength converting layer 310 or 320. The wavelength conversion layers 310 and 320 include a plurality of wavelength conversion particles 311 and 321.

The wavelength conversion particles 311 and 321 are uniformly dispersed and included in the wavelength conversion layers 310 and 320. That is, the wavelength converting particles 311 and 321 may be dispersed in a host 312 and 322. The host 312 and 322 may stably disperse the wavelength converting particles 311 and 321.

For example, the hosts 312 and 322 may include a silicone-based resin.

The wavelength conversion particles 311 and 321 convert the wavelength of incident light. The wavelength conversion particles 311 and 321 may include, for example, nanocrystals.

Nanocrystal is a nanometer size crystal, and a display apparatus using this nanocrystal has attracted attention recently.

Nanocrystals can have various forms such as spheres, wires, and rods.

In particular, spherical quantum dots have attracted attention as nanomaterials. These quantum dots generate strong fluorescence in a narrow wavelength band. The light generated by the quantum dots is generated when electrons in an unstable state descend from the conduction band to the valence band. In this case, the smaller the particles of the quantum dots generate light having a shorter wavelength, and the larger the particles produce light having a longer wavelength.

Therefore, by adjusting the size of the quantum dot can be obtained the light of the desired wavelength band. In addition, when quantum dots of different sizes are present together, light can be emitted at one wavelength to produce various colors at once.

In addition, quantum dots generate very strong fluorescence because the extinction coefficient is 100-1000 times larger and the quantum yield is higher than that of general fluorescent dyes.

In particular, quantum dots can receive light of short wavelengths and shift the wavelength band to longer wavelengths.

The quantum dot may include a core nanocrystal and a shell nanocrystal surrounding the core nanocrystal. In addition, the quantum dot may include an organic ligand bound to the shell nanocrystal. In addition, the quantum dot may include an organic coating layer surrounding the shell nanocrystals.

The shell nanocrystals may be formed of two or more layers. The shell nanocrystals are formed on the surface of the core nanocrystals. The quantum dot may convert the wavelength of the light incident on the core core crystal into a long wavelength through the shell nanocrystals forming the shell layer and increase the light efficiency.

The quantum dot may include at least one of a group II compound semiconductor, a group III compound semiconductor, a group V compound semiconductor, and a group VI compound semiconductor. In more detail, the core nanocrystals may include CdSe, InGaP, CdTe, CdS, ZnSe, ZnTe, ZnS, HgTe or HgS. In addition, the shell nanocrystals may include CuZnS, CdSe, CdTe, CdS, ZnSe, ZnTe, ZnS, HgTe or HgS.

For example, when the core nanocrystals include CdSe and the diameter of the quantum dot is 1 nm to 3 nm, blue light may be generated. In addition, when the diameter of the quantum dot is 3 nm to 5 nm, green light may be generated, and when the diameter of the quantum dot is 7 nm to 10 nm, red light may be generated.

The wavelength of light emitted from the quantum dots can be controlled by the size of the quantum dots or the molar ratio of the molecular cluster compound and the nanoparticle precursor in the synthesis process. The organic ligand may include pyridine, mercapto alcohol, thiol, phosphine, phosphine oxide, and the like. The organic ligands serve to stabilize unstable quantum dots after synthesis. After synthesis, a dangling bond is formed on the outer periphery, and the quantum dots may become unstable due to the dangling bonds. However, one end of the organic ligand is in an unbonded state, and one end of the unbound organic ligand bonds with the dangling bond, thereby stabilizing the quantum dot.

Particularly, when the quantum dot has a size smaller than the Bohr radius of an exciton formed by electrons and holes excited by light, electricity or the like, a quantum confinement effect is generated to have a staggering energy level and an energy gap The size of the image is changed. Further, the charge is confined within the quantum dots, so that it has a high luminous efficiency.

The quantum dot can be synthesized by a chemical wet process. Here, the chemical wet method is a method of growing particles by adding a precursor material to an organic solvent, and the quantum dots can be synthesized by a chemical wet method.

Subsequently, the wavelength converter 300 may include wavelength converter layers 310 and 320. The wavelength conversion layers 310 and 320 may include a first wavelength conversion layer 310 and a second wavelength conversion layer 320.

The first wavelength converting layer 310 and the second wavelength converting layer 320 extend in a direction in which the light emitted from the first light source 100 travels. In detail, the first wavelength conversion layer 310 includes a first incidence portion 313 to which light emitted from the first light source 100 is incident, and the second wavelength conversion layer 320 is formed of the first wavelength conversion layer 320. And a second incidence part 323 to which light emitted from the first light source 100 is incident. The first incident part 313 and the second incident part 323 are disposed in one plane.

First wavelength conversion particles 311 may be included in the first wavelength conversion layer 310, and second wavelength conversion particles 321 may be included in the second wavelength conversion layer 320.

Diameters of the first wavelength converting particles 411 and the second wavelength converting particles 412 may be different from each other. Accordingly, the first wavelength conversion layer 310 and the second wavelength conversion layer 320 may emit light having different wavelengths. That is, the first wavelength conversion layer 310 and the second wavelength conversion layer 320 may emit light having different colors.

However, the embodiment is not limited thereto, and the wavelength conversion layers 310 and 320 may be formed in plural as shown in FIG. 3. As a result, various colors may be emitted from the wavelength conversion layers, and light having various colors may be mixed with each other to generate an unexpected new color.

In addition, although not shown in the drawings, the wavelength conversion layer may include a first wavelength conversion layer, a second wavelength conversion layer, and a third wavelength conversion layer. The first wavelength converting layer may include first wavelength converting particles, the second wavelength converting layer may include second wavelength converting particles, and the third wavelength converting layer may include third wavelength converting particles. Diameters of the first wavelength converting particle, the second wavelength converting particle, and the third wavelength converting particle may be different from each other. As a result, various colors can be generated.

 Subsequently, the lens unit 400 is disposed in the case 200. The lens unit 400 may further spread the light emitted from the wavelength converter 300.

Referring to FIG. 4, the lens unit 400 may include a flat entrance part 411 and an exit part 412 having irregularities.

 That is, in the lens unit 400, a surface facing the wavelength converter 300 may be flat. In addition, a plurality of protrusions may be formed on a surface of the lens unit 400 facing the protection device 500.

The lens unit 400 may include, for example, a microlens or a prism sheet.

In the drawing, although the lens unit 400 is positioned only between the wavelength converter 300 and the protection device 500, the embodiment is not limited thereto. Therefore, the lens unit 400 may be located between the first light source 100 and the wavelength converter 300. Through this, light emitted from the first light source 100 may be uniformly incident on the wavelength converter 300. For this reason, the conversion efficiency of the light which the wavelength conversion part 300 generate | occur | produces can be improved.

In the drawing, although the lens unit 400 is illustrated as being included, the embodiment is not limited thereto. Therefore, the lens unit 400 may be included in various numbers between the wavelength converter 300 and the protection device 500 or between the first light source 100 and the wavelength converter 300.

Subsequently, the protection device 500 is connected to the case 200. The protection device 500 may be fastened to the case 200 or integrally formed with the case 200.

In addition, the protection device 500 may extend downward from the outside of the wavelength converter 300.

The emitted light may be refracted through the protection device 500. That is, light may be effectively collected using the protection device 500. The protection device 500 may have a dome shape extending from the outside of the emission surface from which the light is emitted from the wavelength converter 300.

Hereinafter, the light emitter according to the second embodiment will be described with reference to FIGS. 5 to 7. Detailed descriptions of parts identical or similar to those of the first embodiment will be omitted for clarity and simplicity.

5 is an exploded perspective view of a light-emitting body according to the second embodiment. 6 is a perspective view of a light emitter according to a second embodiment. FIG. 7 is a cross-sectional view taken along the line BB ′ in FIG. 6.

5 to 7, the light emitter 20 according to the second embodiment includes a first light source 110 and a second light source 120.

The second light source 120 may have a form extending in the longitudinal direction of the wavelength converter 300. Light emitted from the second light source 120 is incident on the first wavelength conversion layer 310 and the second wavelength conversion layer 320 in order.

That is, the first wavelength conversion layer 310 is located close to the second light source 120, and the second wavelength conversion layer 320 is positioned adjacent to the first wavelength conversion layer 310 along the light propagation direction. can do.

The first wavelength conversion layer 310 may include a third incidence part 314 through which light emitted from the second light source 120 is incident, and the second wavelength conversion layer 320 may include the second light source ( And a fourth incidence part 324 to which light exiting from 120 is incident. The third incidence part 314 and the fourth incidence part 324 are sequentially disposed along the direction in which the light emitted from the second light source 120 travels.

Specifically, the light emitted from the second light source 120 is first incident on the first wavelength conversion particles 311 of the first wavelength conversion layer 310, and is shifted to a longer wavelength than the incident light. The shifted wavelength is incident on the second wavelength converting particles 321 of the second wavelength converting layer 320 to be shifted once more to become a longer wavelength band.

Therefore, infrared rays may be generated through the wavelength conversion layers 310 and 320 included in the wavelength conversion unit 300.

Light generated by the second light source 120 and the wavelength converter 300 may travel along the lens unit 420 and the protection device 520.

In the light emitter 20 according to the second exemplary embodiment, the first light source 110 and the second light source 120 are positioned at different portions. Therefore, when the light having various colors is to be generated, the first light source 110 can be driven, and when the infrared light is to be generated, the second light source 120 can be driven. That is, various lights can be generated from one light emitter according to the consumer's preferences and requirements.

The features, structures, effects and the like described in the foregoing embodiments are included in at least one embodiment of the present invention and are not necessarily limited to one embodiment. In addition, the features, structures, effects, and the like illustrated in the embodiments may be combined or modified with respect to other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the present invention. It can be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiments may be modified. It is to be understood that the present invention may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof.

Claims (13)

A first light source; And
A wavelength converter configured to convert light emitted from the first light source into wavelength;
The wavelength conversion unit includes at least one wavelength conversion layer,
The wavelength conversion layer extends in a direction in which the light emitted from the first light source proceeds. The method of claim 1,
The wavelength converting layer includes a light emitting body including wavelength converting particles. The method of claim 2,
The wavelength conversion layer includes a first wavelength conversion layer and a second wavelength conversion layer. The method of claim 3,
The first wavelength converting layer includes a first wavelength converting particle, the second wavelength converting layer includes a second wavelength converting particle,
The light emitter of which the diameters of the first wavelength conversion particle and the second wavelength conversion particle are different from each other. 5. The method of claim 4,
The first wavelength conversion layer includes a first incidence part to which light emitted from the first light source is incident,
The second wavelength conversion layer includes a second incidence portion to which light emitted from the first light source is incident.
The light emitter, wherein the first incident part and the second incident part are disposed in one plane. 5. The method of claim 4,
A second light source extending in the longitudinal direction of the wavelength converter;
The light emitted from the second light source sequentially enters the first wavelength conversion layer and the second wavelength conversion layer. The method according to claim 6,
The first wavelength conversion layer includes a third incidence portion to which light emitted from the second light source is incident,
The second wavelength conversion layer includes a fourth incidence part to which light emitted from the second light source is incident.
The light emitter of which the third incidence portion and the fourth incidence portion are sequentially disposed along a direction in which the light emitted from the second light source travels. The method of claim 2,
The wavelength conversion layer includes a first wavelength conversion layer, a second wavelength conversion layer, and a third wavelength conversion layer,
The first wavelength converting layer includes a first wavelength converting particle, the second wavelength converting layer includes a second wavelength converting particle, and the third wavelength converting layer includes a third wavelength converting particle,
A light emitter having different diameters of the first wavelength converting particle, the second wavelength converting particle, and the third wavelength converting particle, respectively. The method of claim 2,
The wavelength conversion particle comprises a nanocrystal (nanocrystal),
The nanocrystals have a shape of at least one of sphere, wire and rod. The method of claim 1,
And a lens unit for augmenting light emitted from the wavelength converter. The method of claim 1,
A light emitter comprising a protective device for refracting the light emitted from the wavelength converter. The method of claim 2,
The wavelength converter includes a host,
A light emitter in which the wavelength conversion particles are dispersed in the host. The method of claim 11,
The host is a light emitter containing a silicone-based resin.

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