CN110131596B - Light emitting device and illumination module - Google Patents
Light emitting device and illumination module Download PDFInfo
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- CN110131596B CN110131596B CN201910600183.3A CN201910600183A CN110131596B CN 110131596 B CN110131596 B CN 110131596B CN 201910600183 A CN201910600183 A CN 201910600183A CN 110131596 B CN110131596 B CN 110131596B
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- 238000005286 illumination Methods 0.000 title claims description 9
- 239000000463 material Substances 0.000 claims abstract description 128
- 239000010410 layer Substances 0.000 claims abstract description 114
- 238000012216 screening Methods 0.000 claims abstract description 98
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- 239000002096 quantum dot Substances 0.000 claims description 15
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- 230000005284 excitation Effects 0.000 claims description 14
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- 230000003247 decreasing effect Effects 0.000 description 1
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21K—NON-ELECTRIC LIGHT SOURCES USING LUMINESCENCE; LIGHT SOURCES USING ELECTROCHEMILUMINESCENCE; LIGHT SOURCES USING CHARGES OF COMBUSTIBLE MATERIAL; LIGHT SOURCES USING SEMICONDUCTOR DEVICES AS LIGHT-GENERATING ELEMENTS; LIGHT SOURCES NOT OTHERWISE PROVIDED FOR
- F21K2/00—Non-electric light sources using luminescence; Light sources using electrochemiluminescence
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
- F21V9/00—Elements for modifying spectral properties, polarisation or intensity of the light emitted, e.g. filters
- F21V9/30—Elements containing photoluminescent material distinct from or spaced from the light source
- F21V9/32—Elements containing photoluminescent material distinct from or spaced from the light source characterised by the arrangement of the photoluminescent material
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
- F21Y2115/00—Light-generating elements of semiconductor light sources
- F21Y2115/10—Light-emitting diodes [LED]
Abstract
The light-emitting device comprises a first adhesive layer, a second adhesive layer, a wavelength screening layer and a light-emitting wafer. The first adhesive layer has a light emitting surface and is filled with a first wavelength conversion material. The wavelength screening layer is arranged on one surface of the first adhesive layer opposite to the light emitting surface, and the second adhesive layer is arranged on one surface of the wavelength screening layer opposite to the first adhesive layer. The second adhesive layer is filled with a second wavelength conversion material; wherein the emission band of the first wavelength converting material partially overlaps the absorption band of the second wavelength converting material and has an overlap region. The light-emitting wafer is arranged on one side, opposite to the wavelength screening layer, of the second adhesive layer, and the second adhesive layer covers the light-emitting wafer.
Description
Technical Field
The invention relates to a light-emitting device and an illumination module; in particular, the present invention relates to a light emitting device and a lighting module having a layered design of light emitting materials.
Background
The light emitting diode is mainly used in the prior art to provide backlight with light-activated material (such as phosphor). In order to improve color rendering, a plurality of different light-receiving excitation materials are usually mixed and distributed with the light-emitting diode. Generally, different light-receiving materials are excited by light of the light-emitting diode to generate light of different colors. However, some of the photo-excitable materials may have a larger absorption wavelength range and thus may emit light from other sources, such as different photo-excitable materials, in addition to the light emitted by the led. For example, for a light emitting diode with red quantum dots and green quantum dots mixed, the red quantum dots will absorb blue light and emit red light, and will also absorb green light generated by the green quantum dots and emit red light. Therefore, the intensity of some color lights will become less than expected, resulting in poor light emitting efficiency. In addition, the light-receiving excited material emits light by converting the different light-receiving excited materials (in the above example, the red quantum dots absorb the green light generated by the green quantum dots to emit red light), and the heat energy generated by the light-receiving excited material is more than that generated by directly absorbing the light of the light source (for example, the red quantum dots absorb the blue light to emit red light), and the heat energy will shorten the service life of the light-receiving excited material. Therefore, the existing display device still needs to be improved.
Disclosure of Invention
The invention aims to provide a light-emitting device with a design of prolonging service life and an illumination module.
An object of the present invention is to provide a light emitting device and an illumination module, which can improve light emitting efficiency.
The light-emitting device comprises a first adhesive layer, a second adhesive layer, a wavelength screening layer and a light-emitting chip. The first adhesive layer has a light emitting surface and is filled with a first wavelength conversion material. The wavelength screening layer is arranged on one surface of the first adhesive layer opposite to the light emitting surface, and the second adhesive layer is arranged on one surface of the wavelength screening layer opposite to the first adhesive layer. The second adhesive layer is filled with a second wavelength conversion material; wherein the emission band of the first wavelength converting material partially overlaps the absorption band of the second wavelength converting material and has an overlap region. The light-emitting wafer is arranged on one side, opposite to the wavelength screening layer, of the second adhesive layer, and the second adhesive layer covers the light-emitting wafer. The light generated by the light-emitting chip penetrates through the wavelength screening layer to reach the first adhesive layer, and excites the first wavelength conversion material to generate excitation light, wherein the part of the excitation light with the wavelength in the overlapping region is at least partially reflected by the wavelength screening layer.
The illumination module comprises an optical film and a light source. The optical film comprises a first adhesive layer, a wavelength screening layer and a second adhesive layer. The first adhesive layer has a light emitting surface and is filled with a first wavelength conversion material. The wavelength screening layer is arranged on one surface of the first adhesive layer opposite to the light emitting surface, and the second adhesive layer is arranged on one surface of the wavelength screening layer opposite to the first adhesive layer. The second adhesive layer is filled with a second wavelength conversion material; wherein the emission band of the first wavelength converting material partially overlaps the absorption band of the second wavelength converting material and has an overlap region. The light source is arranged on one side of the second adhesive layer opposite to the wavelength screening layer. The light source generates light which penetrates through the wavelength screening layer to reach the first adhesive layer and excites the first wavelength conversion material to generate excitation light, and the part of the excitation light with the wavelength in the overlapping area is at least partially reflected by the wavelength screening layer. The wavelength screening layer can prevent different wavelength conversion materials from converting to emit light, thereby reducing heat energy generated in the light emitting process and prolonging the service life of the wavelength conversion materials.
The invention is described in detail below with reference to the drawings and specific examples, but the invention is not limited thereto.
Drawings
Fig. 1 is a schematic view of a light emitting device according to an embodiment of the invention.
Fig. 2 is a schematic diagram of the emission/absorption spectra of different wavelength converting materials.
Fig. 3 is a schematic view of an embodiment of a light emitting device generating different color lights.
Fig. 4 is a schematic diagram of the reflection spectrum of the wavelength screening layer and the luminous intensity of the light-emitting device.
FIG. 5 is a schematic diagram of another embodiment of the reflection spectrum of the wavelength screening layer and the luminous intensity of the light-emitting device.
Fig. 6 is a graph showing the emission intensity of a light-emitting device using quantum dots.
Fig. 7 is a graph showing the luminous intensity of a light-emitting device using a phosphor.
Fig. 8 is a schematic view of an embodiment of the lighting module of the present invention.
Wherein the reference numerals
1 light emitting device
2 Lighting module
20 optical film
30 light source
100 first adhesive layer
110 light-emitting surface
120 first wavelength converting material
130 surface
200 second adhesive layer
220 second wavelength converting material
300 wave length screening layer
400 luminous wafer
C1, C12 first color light
Color C2 light of second color
C3 light of third color
D1 light-emitting direction
M1 overlap region
Reflection ranges of N1, N2, N3, N4
Peak P1, P2, P3
Local minimum of Q
Detailed Description
The following detailed description of the embodiments of the present invention with reference to the drawings and specific examples is provided for further understanding the objects, aspects and effects of the present invention, but not for limiting the scope of the appended claims.
It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "connected to" another element, it can be directly on or connected to the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, there are no intervening elements present.
It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a "first element," "component," "region," "layer," or "color light" discussed below could be termed a second element, component, region, layer, or color light without departing from the teachings herein.
As used herein, "about", "approximately", or "substantially" includes the stated value and the average value within an acceptable range of deviation of the specified value as determined by one of ordinary skill in the art, taking into account the measurement in question and the specified amount of error associated with the measurement (i.e., the limitations of the measurement system). For example, "about" may mean within one or more standard deviations of the stated value, or within ± 30%, ± 20%, ± 10%, ± 5%. Further, as used herein, "about", "approximately" or "substantially" may be selected based on optical properties, etch properties, or other properties, with a more acceptable range of deviation or standard deviation, and not all properties may be applied with one standard deviation.
Fig. 1 is a schematic view of a light-emitting device 1 according to an embodiment of the present invention. As shown in fig. 1, the light emitting device 1 includes a first adhesive layer 100, a second adhesive layer 200, a wavelength screening layer 300, and a light emitting chip 400. The first adhesive layer 100 has a light emitting surface 110, and a first wavelength conversion material 120 is filled therein. The wavelength screening layer 300 is disposed on a surface (i.e., the surface 130) of the first adhesive layer 100 opposite to the light emitting surface 110. The second adhesive layer 200 is disposed on a surface of the wavelength screening layer 300 opposite to the first adhesive layer 100, and the second wavelength conversion material 220 is filled therein. The light emitting chip 400 is disposed on a side of the second adhesive layer 200 opposite to the wavelength screening layer 300, and the second adhesive layer 200 covers the light emitting chip 400.
When the first wavelength conversion material 120 and the second wavelength conversion material 220 are excited by the light from the light emitting chip 400, they may be converted into different colors of light. The wavelength-screening layer 300 is preferably a composite optical film formed by laminating or otherwise forming a plurality of media having different refractive indexes, and allows light of a certain wavelength band to pass therethrough and reflects light of another specific wavelength band. In the example of fig. 1, most or all of the light generated by the light emitting wafer 400 and the light generated by the excitation of the second wavelength conversion material 220 may pass through the wavelength screening layer 300, and most or all of the light generated by the excitation of the first wavelength conversion material 120 may be substantially reflected by the wavelength screening layer 300.
The light generated by the light emitting chip 400 penetrates through the wavelength screening layer 300 to reach the first adhesive layer 100, and excites the first wavelength conversion material 120 to generate excitation light. Generally, the emission band of the first wavelength converting material 120 at least partially overlaps the absorption band of the second wavelength converting material 220. Specifically, please refer to fig. 2. Fig. 2 is a schematic diagram of the emission/absorption spectra of different wavelength converting materials. In fig. 2, curve L1 (dashed line) is the emission spectrum of the first wavelength converting material 120 (see fig. 1) and curve L2 (solid line) is the absorption spectrum of the second wavelength converting material 220.
As shown in fig. 2, the emission wavelength band of the first wavelength conversion material 120 overlaps with the absorption wavelength band of the second wavelength conversion material 220, and the two wavelength bands have an overlapping region M1. In other words, the second wavelength conversion material 220 can emit light by the light generated by the first wavelength conversion material 120 as well as the light emitted by the light emitting chip 400. To reduce the occurrence of the latter, the light-emitting device 1 reflects at least part of the light having the wavelength in the overlapping region M1, which is generated by the excitation of the first wavelength converting material 120, by the wavelength screening layer 300. In other words, the wavelength screening layer 300 is designed to reflect most or all of the light generated by the first wavelength conversion material 120 whose wavelength band falls within the overlapping region M1. In the example of fig. 2, the absorption spectrum of the second wavelength converting material 220 covers the entire range of the emission spectrum of the first wavelength converting material 120, so the wavelength screening layer 300 is preferably designed to reflect all of the light generated by the first wavelength converting material 120. By this design, the chance that the light generated by the first wavelength conversion material 120 is absorbed by the second wavelength conversion material 220 and converted into different color lights can be reduced, so as to improve the overall light emitting efficiency.
Fig. 3 is a schematic diagram of an embodiment of the light emitting device 1 corresponding to fig. 1 for generating different color lights. As shown in fig. 1 and fig. 3, the first adhesive layer 100 and the second adhesive layer 200 are disposed on two opposite sides of the wavelength screening layer 300, and the second adhesive layer 200 is closer to the light emitting chip 400 than the first adhesive layer 100. As described above, the wavelength screening layer 300 may allow light emitted from the light emitting chip 400 and light excited by the second wavelength conversion material 220 to pass through and substantially reflect light excited by the first wavelength conversion material 120.
Referring to fig. 3, the light emitting chip 400 emits light, and the first wavelength conversion material 120 and the second wavelength conversion material 220 can be respectively converted into different colors of light after being excited by the light from the light emitting chip 400. In the example of fig. 3, a portion of the light emitted from the light emitting chip 400 maintains the original color, and another portion of the light is converted to a different color by the wavelength conversion material. Specifically, a portion of the light from the light emitting chip 400 is converted into color light (C1, C12) and color light C2 by the first wavelength conversion material 120 and the second wavelength conversion material 220, respectively, and another portion of the light from the light emitting chip 400 is color light C3 generated by the light emitting chip 400. As shown in fig. 3, the color light C3 directly exits from the light-emitting surface after penetrating through the wavelength screening layer 300 and the first adhesive layer 100, the color light C1 exits from the light-emitting surface after being generated by the first wavelength conversion material 120, the color light C2 exits from the light-emitting surface after passing through the wavelength screening layer 300 after being generated by the second wavelength conversion material 220, and the color light C12 exits after being reflected by the wavelength screening layer 300.
The color lights (C1, C12) and C2 are different wavelengths of light. In one embodiment, the wavelength of the color light (C1, C12) generated by the first wavelength conversion material 120 is smaller than the wavelength of the color light C2 generated by the second wavelength conversion material 220. For example, the light emitting chip 400 is a blue light emitting diode, and the wavelength screening layer 300 allows blue light to pass through. The first adhesive layer 100 and the second adhesive layer 200 are quantum dot film layers, and the first wavelength conversion material 120 and the second wavelength conversion material 220 filled therein are quantum dots, which can respectively generate green light and red light. Taking fig. 3 as an example, the color light (C1, C12) is green light, and the color light C2 is red light. The wavelength selective layer 300 is, for example, a multilayer film structure or a Distributed Bragg Reflector (DBR) of cholesteric liquid crystal material, and reflects green light. In other words, the wavelength screening layer 300 has a reflection range with respect to the wavelength, and the light having the wavelength within the reflection range is reflected by the wavelength screening layer 300. In the foregoing example, the reflection range of the wavelength screening layer 300 includes the wavelength band of green light.
As shown in fig. 3, for the converted color light (C1, C12), the color light C1 goes toward the light emitting direction D1 and directly emits, and the color light C12 originally goes toward the direction opposite to the light emitting direction D1, and the wavelength screening layer 300 reflects the color light C12 and then emits along the light emitting direction D1. The foregoing proceeding in the light-emitting direction preferably means the direction in which light can leave the wavelength screening layer 300 from the light-emitting side of the wavelength screening layer 300, and is not limited to the direction perpendicular to the surface of the wavelength screening layer 300. The design can improve the light emitting efficiency. In other words, by the design of separating the first wavelength conversion material 120 and the second wavelength conversion material 220 in different glue layers by the wavelength screening layer 300, the second wavelength conversion material 220 with a larger light absorption band is disposed near one side of the light emitting chip 400 and is separated from the first wavelength conversion material 120 by the wavelength screening layer 300, i.e. the second wavelength conversion material 220 is limited to be only excited by the light of the light emitting chip 400 and converted into different color lights. On the other hand, the first adhesive layer 100 with the first wavelength conversion material 120 is located on a side of the light emitting chip 400 away from the second adhesive layer 200. Therefore, the color light generated by the first wavelength conversion material 120 can be directly emitted from the light emitting surface 110 or reflected by the wavelength screening layer 300 to be prevented from being absorbed by the second wavelength conversion material 220, thereby improving the light emitting efficiency.
In addition, since the design of separating different glue layers by the wavelength screening layer 300 can prevent different wavelength conversion materials from converting into light (the second wavelength conversion material 220 is excited by the color light emitted from the first wavelength conversion material 120 to generate light), the heat energy generated during the process of exciting and converting into light can be reduced, and the service life of the wavelength conversion material can be prolonged.
In view of the amount of the wavelength conversion material, since the design of the present invention can avoid the occurrence of the light emission conversion between different wavelength conversion materials, it is not necessary to add more wavelength conversion material to compensate the loss of the light emission efficiency caused by the above situation. In other words, the light-emitting device of the present invention can save the amount of the wavelength conversion material to be doped, thereby reducing the manufacturing cost. In addition, the incorporation of more wavelength conversion material may cause the wavelength conversion material in the adhesive layer to be clustered, which may cause spectral shift of the light of each color of the light emitting device after mixing. The light-emitting device of the invention can avoid the problems caused by the clustering of the wavelength conversion materials.
Fig. 4 is a schematic diagram of the reflection spectrum of the wavelength screening layer and the luminous intensity of the light-emitting device. In fig. 4, a curve L3 shows a light emission spectrum of the light emitting device, and a curve L4 shows a reflection spectrum of the wavelength screening layer. As shown by the curve L3, the light emitting device has the color light generated by the excited wavelength conversion materials in the first adhesive layer and the second adhesive layer, which is green light and red light, respectively, and the blue light from the light emitting chip, which has the peak values P1, P2, and P3, respectively. The wavelength value corresponding to the peak P1 of the green light is smaller than the wavelength value corresponding to the peak P2 of the red light. In addition, the green light is the color light with a shorter wavelength corresponding to the color light peak value in the color light after conversion.
Taking the wavelength band of green light as an example of the overlapping area, the wavelength screening layer has different reflectances for different wavelength light, and has a reflection range N1 corresponding to the wavelength band of green light, as shown by a curve L4. Since the wavelength band of the green light falls within the reflection range N1 of the wavelength screening layer, the wavelength screening layer may reflect the green light. In other words, of the converted color lights, the color light having the color light peak corresponding to the shorter wavelength (i.e., green light) is reflected by the wavelength-screening layer.
Further, the reflection range N1 preferably has upper and lower limits. In the embodiment of fig. 4, the wavelength value of the peak P1 lies between the wavelength values of the upper and lower limits of the reflection range. The wavelength value of the peak value P2 is larger than the wavelength value of the upper limit of the reflection range. The wavelength value of the peak value P3 is smaller than the wavelength value of the lower limit of the reflection range. In other words, the upper and lower limits of the reflection range N1 preferably cover the entire green wavelength band.
The lower limit of the reflection range N1 may be defined by, for example, the lowest point of the rising edge of the reflectance curve of the wavelength-selective layer. As shown in FIG. 4, the curve L4 climbs from an average lower reflectivity to an average higher reflectivity along the rising edge between the wavelengths 450nm and 500nm, and the reflection range N1 has the wavelength corresponding to the lowest point of the rising edge as its lower limit (about 475 nm). Similarly, the upper limit of the reflection range N1 is based on, for example, the lowest point of the lower edge of the reflectance curve of the wavelength screening layer. As shown in fig. 4, the curve L4 falls from an average high reflectance to an average low reflectance along the falling edge in the vicinity of the wavelength of 600nm, and the reflection range N1 has a wavelength value corresponding to the lowest point of the falling edge as its upper limit value (about 600 nm).
In another embodiment, the upper and lower limits of the reflection range may also be defined according to the wavelength value corresponding to the peak value (i.e. P1) of the color light with shorter wavelength in the converted color light. Taking fig. 5 as an example, a curve L5 is a light emitting device light emission spectrum, and a curve L6 is a wavelength screening layer reflection spectrum. In the converted color light, the color light with the color light peak value corresponding to the shorter wavelength is green light, the lower limit of the reflection range N2 has a wavelength value not more than the wavelength value corresponding to the short wavelength side of 10% of the green light peak value P1, and the upper limit of the reflection range N2 has a wavelength value not less than the wavelength value corresponding to the long wavelength side of 10% of the green light peak value P1. In other words, the wavelength-screening layer reflects light having a wavelength value between about 10% of the peak value P1 of green light among the wavelength values of the converted color light.
It should be noted that the lower limit of the reflection range N2 corresponds to the side where the intensity of the color light in the shorter wavelength band decreases with decreasing wavelength value after conversion, i.e., the side where the peak P1 faces the short wavelength. The upper limit of the reflection range N2 corresponds to the side where the intensity of the converted color light in the shorter wavelength band decreases with increasing wavelength value, i.e., the side where the peak P1 is toward the longer wavelength.
Fig. 6 is a graph showing the emission intensity of a light-emitting device using quantum dots. In fig. 6, a curve L7 is a light emission spectrum of the light emitting device of the embodiment using quantum dots as the first wavelength converting material and the second wavelength converting material, and a curve L8 is a reflection spectrum of the wavelength screening layer of the embodiment. As shown by the curve L7, the light emitting device has the color lights (including green light and red light) converted by the first adhesive layer and the second adhesive layer, and the blue light from the light emitting chip, each having peak values of P1 (green light), P2 (red light), and P3 (blue light).
Taking the green wavelength band as an overlapping region for example, as shown by the curve L8, the wavelength-screening layer has different reflectances for different wavelengths of light and has a reflection range N3 corresponding to the green wavelength band. As shown in fig. 6, for a light emitting device using quantum dots, the reflection range N3 of the wavelength screening layer may preferably be less than 100 nm. In other words, the size of the reflection range can be adjusted according to the kind of wavelength conversion material to be used.
On the other hand, the reflection waveform of the wavelength-screening layer is related to the incident angle of the light. For the first adhesive layer, the light generated by excitation in the first adhesive layer may proceed in various directions. Of these light rays, light rays incident toward the wavelength-screening layer (i.e., traveling in a direction opposite to the light-exiting direction) may have different magnitudes of incident angles. For incident light with a large angle of incidence on the wavelength screening layer in the first glue layer, the waveform of the reflection spectrum of the wavelength screening layer is slightly shifted toward the short wavelength direction (for example, the reflection range of the wavelength screening layer for light with a small angle of incidence is 500nm to 580nm, and the reflection range of the wavelength screening layer for light with a large angle of incidence is 480nm to 560 nm). To ensure that the wavelength band of the target color light (here, green light) falls largely within the reflection range of the wavelength-screening layer, the upper wavelength limit of the reflection range is preferably close to the color light having a longer wavelength among the converted color lights. Taking fig. 6 as an example, the wavelength band of red light has a local minimum value Q (about 575nm) close to the wavelength band of green light in the emission spectrum, and the wavelength value of the upper limit of the reflection range N3 is not less than the wavelength value corresponding to the local minimum value Q. It should be understood that the emission spectra of different wavelength conversion materials are different, so that the wavelength values corresponding to the local minimum values Q are different, and the upper limit of the reflection range can be adjusted according to the kind of wavelength conversion material to be used.
Fig. 7 is a graph showing the luminous intensity of a light-emitting device using a phosphor. In fig. 7, a curve L9 shows the emission spectra of the light emitting device of the embodiment using the phosphors generating green light and the KSF phosphor as the first wavelength conversion material and the second wavelength conversion material, and a curve L10 shows the reflection spectra of the wavelength selective layer of the embodiment. As shown by the curve L9, the light emitting device has the color lights (including green light and red light) converted by the first adhesive layer and the second adhesive layer, and the blue light from the light emitting chip, each having peak values of P1 (green light), P2 (red light), and P3 (blue light).
Also taking the wavelength band of green light as an example of the overlapping area, as shown by the curve L10, the wavelength-screening layer has different reflectances for different wavelengths of light and has a reflection range N4 corresponding to the wavelength band of green light. As shown in fig. 7, for a light emitting device employing phosphors, an embodiment of the reflection range N4 of the wavelength screening layer may be substantially equal to or greater than 100 nm. Further, as described above, in consideration of the case of the incident light of a large angle, the upper limit of the reflection range N4 is preferably close to the color light having a longer wavelength among the color lights after conversion. As shown in fig. 7, the red band has a local minimum Q (about 600nm) near the green band in the emission spectrum. For the case of using the phosphor to form a plurality of continuous peaks distributed in a long wavelength direction in a red wavelength band as shown in fig. 7, the local minimum value Q is based on a peak closest to a green wavelength band among the plurality of continuous peaks. As shown in fig. 7, the upper limit of the reflection range N4 has a wavelength value not smaller than the wavelength value corresponding to the local minimum value Q.
Fig. 8 is a schematic view of an embodiment of the lighting module 2 of the present invention. The lighting module 2 of the present invention can be used as a general lamp or a backlight module in a display. As shown in fig. 8, the illumination module 2 includes an optical film 20 and a light source 30. The optical film 20 includes a first adhesive layer 100, a second adhesive layer 200, and a wavelength-screening layer 300. The first adhesive layer 100 has a light emitting surface 110, and a first wavelength conversion material 120 is filled therein. The wavelength screening layer 300 is disposed on a surface (i.e., the surface 130) of the first adhesive layer 100 opposite to the light emitting surface 110. The second adhesive layer 200 is disposed on a surface of the wavelength screening layer 300 opposite to the first adhesive layer 100, and the second wavelength conversion material 220 is filled therein. In this embodiment, the first glue layer 100 and the second glue layer 200 are disposed on opposite sides of the wavelength screening layer 300. The light source 30 is disposed on a side of the second adhesive layer 200 opposite to the wavelength screening layer 300. The light source 30 provides light to the optical film 20. The difference from the embodiment of fig. 1 is that the first adhesive layer 100, the second adhesive layer 200, and the wavelength screening layer 300 of fig. 1 are formed inside the package of the light emitting device, and the first adhesive layer 100, the second adhesive layer 200, and the wavelength screening layer 300 of fig. 8 are formed outside the light source 30.
When the first wavelength conversion material 120 and the second wavelength conversion material 220 are excited by light from the light source 30, they may be converted into different colors of light. The wavelength-screening layer 300 is preferably a composite optical film formed by laminating or otherwise forming a plurality of media having different refractive indexes, and allows light of a certain wavelength band to pass therethrough and reflects light of another specific wavelength band. In the example of fig. 8, most or all of the light from the light source 30 and the light from the second wavelength conversion material 220 may pass through the wavelength screening layer 300, while most or all of the light from the first wavelength conversion material 120 may be substantially reflected by the wavelength screening layer 300.
As mentioned above, the emission wavelength band of the first wavelength converting material 120 and the absorption wavelength band of the second wavelength converting material 220 at least partially overlap, and the two wavelength bands have an overlapping region. To avoid the second wavelength conversion material 220 from being excited by the light generated by the first wavelength conversion material 120 to emit light, the wavelength screening layer 300 is designed to reflect the light generated by the first wavelength conversion material 120 with a wavelength band falling within the overlapping region. By this design, the chance that the light generated by the first wavelength conversion material 120 is absorbed by the second wavelength conversion material 220 and converted into different color lights is reduced, so as to improve the overall light emitting efficiency. In other words, the design of separating different glue layers by the wavelength-screening layer 300 can improve the light-emitting efficiency. In addition, since the wavelength screening layer 300 can prevent different wavelength conversion materials from converting into light, the heat energy generated during the light emitting process can be reduced, and the service life of the wavelength conversion materials can be prolonged.
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it should be understood that various changes and modifications can be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (8)
1. A light emitting device, comprising:
a first adhesive layer having a light-emitting surface, the first adhesive layer being filled with a first wavelength conversion material;
the wavelength screening layer is arranged on one surface of the first adhesive layer opposite to the light emitting surface;
the second adhesive layer is arranged on one surface of the wavelength screening layer opposite to the first adhesive layer and is filled with a second wavelength conversion material, wherein the light emission waveband of the first wavelength conversion material is partially overlapped with the absorption waveband of the second wavelength conversion material and is provided with an overlapping area;
the light-emitting wafer is arranged on one side, opposite to the wavelength screening layer, of the second adhesive layer, and the second adhesive layer covers the light-emitting wafer; wherein, the light-emitting chip generates a light ray which penetrates through the wavelength screening layer to reach the first adhesive layer and excites the first wavelength conversion material to generate an excitation light ray, and the part of the excitation light ray with the wavelength in the overlapping area is at least partially reflected by the wavelength screening layer;
the first wavelength conversion material generates first color light, the second wavelength conversion material generates second color light, and the wavelength of the first color light is smaller than that of the second color light;
the wavelength screening layer has a reflection range corresponding to the overlapping region, and the light of the first color light, the second color light and the light of the light-emitting chip respectively have a first peak value, a second peak value and a third peak value in a light-emitting spectrum; the wavelength value of the first peak is between the upper limit and the lower limit of the reflection range, the wavelength value of the second peak is greater than the upper limit of the reflection range, and the wavelength value of the third peak is less than the lower limit of the reflection range;
the wavelength value of the upper limit of the reflection range is not less than the wavelength value corresponding to 10% of the first peak value; or
The second color light has a local minimum value close to the first color light band in the emission spectrum, and the wavelength value of the upper limit of the reflection range is not less than the wavelength value of the local minimum value.
2. The light-emitting device according to claim 1, wherein the first color light is green light and the second color light is red light.
3. The light-emitting device according to claim 1, wherein the first wavelength converting material and the second wavelength converting material are quantum dots, and the wavelength screening layer has a reflection range with respect to wavelength, the reflection range being less than 100 nm.
4. The light-emitting device according to claim 1, wherein the first wavelength conversion material and the second wavelength conversion material are phosphors, and the wavelength screening layer has a reflection range with respect to a wavelength, the reflection range being equal to 100 nm.
5. An illumination module, comprising:
an optical film, comprising:
a first adhesive layer having a light-emitting surface, the first adhesive layer being filled with a first wavelength conversion material;
the wavelength screening layer is arranged on one surface of the first adhesive layer opposite to the light emitting surface;
the second adhesive layer is arranged on one surface of the wavelength screening layer opposite to the first adhesive layer and is filled with a second wavelength conversion material, wherein the light emission waveband of the first wavelength conversion material is partially overlapped with the absorption waveband of the second wavelength conversion material and is provided with an overlapping area;
the light source is arranged on one side of the second adhesive layer opposite to the wavelength screening layer; wherein the light source generates a light beam which penetrates through the wavelength screening layer to reach the first adhesive layer and excites the first wavelength conversion material to generate an excitation light beam, and the part of the excitation light beam with the wavelength in the overlapping area is at least partially reflected by the wavelength screening layer;
the first wavelength conversion material generates first color light, the second wavelength conversion material generates second color light, and the wavelength of the first color light is smaller than that of the second color light;
the wavelength screening layer has a reflection range corresponding to the overlapping region, and the light of the first colored light, the second colored light and the light of the light source respectively have a first peak value, a second peak value and a third peak value in a light emission spectrum; the wavelength value of the first peak is between the upper limit and the lower limit of the reflection range, the wavelength value of the second peak is greater than the upper limit of the reflection range, and the wavelength value of the third peak is less than the lower limit of the reflection range;
the wavelength value of the upper limit of the reflection range is not less than the wavelength value corresponding to 10% of the first peak value; or
The second color light has a local minimum value close to the first color light band in the emission spectrum, and the wavelength value of the upper limit of the reflection range is not less than the wavelength value of the local minimum value.
6. The illumination module as recited in claim 5 wherein the first color light is green light and the second color light is red light.
7. The lighting module of claim 5, wherein the first and second wavelength converting materials are quantum dots, the wavelength screening layer having a reflection range with respect to wavelength that is less than 100 nm.
8. The lighting module of claim 5, wherein the first and second wavelength converting materials are phosphors, the wavelength screening layer having a reflection range with respect to wavelength equal to 100 nm.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| TW108100391A TWI717674B (en) | 2019-01-04 | 2019-01-04 | Light-emitting device and lighting module |
| TW108100391 | 2019-01-04 |
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| Publication Number | Publication Date |
|---|---|
| CN110131596A CN110131596A (en) | 2019-08-16 |
| CN110131596B true CN110131596B (en) | 2021-02-26 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910600183.3A Active CN110131596B (en) | 2019-01-04 | 2019-07-04 | Light emitting device and illumination module |
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| CN (1) | CN110131596B (en) |
| TW (1) | TWI717674B (en) |
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|---|---|---|---|---|
| KR100691143B1 (en) * | 2003-04-30 | 2007-03-09 | 삼성전기주식회사 | Light emitting diode device with multi-layered phosphor |
| TW201123548A (en) * | 2009-12-25 | 2011-07-01 | Ind Tech Res Inst | A multi-layer stacked LED package |
| CN102237477A (en) * | 2010-04-29 | 2011-11-09 | 财团法人工业技术研究院 | Multilayer stack-packaged light- emitting diode |
| CN106935576A (en) * | 2010-09-29 | 2017-07-07 | 皇家飞利浦电子股份有限公司 | The luminescent device of wavelength convert |
| CN106058015B (en) * | 2016-06-16 | 2019-02-26 | 青岛海信电器股份有限公司 | Quantum dot light emitting device, backlight module and liquid crystal display device |
| TWI643363B (en) * | 2016-10-20 | 2018-12-01 | 晶元光電股份有限公司 | Wavelength conversion element, manufacturing method thereof and light-emitting device using the same |
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| Publication number | Publication date |
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| TWI717674B (en) | 2021-02-01 |
| CN110131596A (en) | 2019-08-16 |
| TW202027301A (en) | 2020-07-16 |
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