CN112782924A

CN112782924A - Reflective color wheel

Info

Publication number: CN112782924A
Application number: CN202110069044.XA
Authority: CN
Inventors: 张克苏; 周彦伊; 陈琪; 吕俊贤
Original assignee: Delta Electronics Inc
Current assignee: Delta Electronics Inc
Priority date: 2015-08-11
Filing date: 2016-01-08
Publication date: 2021-05-11
Also published as: CN106449947A; TWI614917B; TW201707243A

Abstract

A reflective color wheel comprises a substrate, a reflective element and a wavelength conversion element. The substrate is made of glass, metal, ceramic or semiconductor material, and the reflecting element is arranged on the substrate and comprises a continuous phase material and a plurality of first sub-nanoparticles. The wavelength conversion element is disposed on the reflection element, wherein the reflection element is configured to reflect the light transmitted by the wavelength conversion element away from the wavelength conversion element. Wherein the refractive index of the plurality of first sub-nanoparticles is higher than that of the continuous phase material and the difference between the refractive indices is 0.5 or more, the particle diameter of the first sub-nanoparticles is 50 to 500 nm, and the concentration of the first sub-nanoparticles in the reflective element is 30 to 95 wt%.

Description

Reflective color wheel

The application is as follows: 2016, month 01, and day 8; the application numbers are: 201610013911.7, respectively; the invention has the name: divisional application of the invention application of the wavelength conversion device.

Technical Field

The present invention relates to a reflective color wheel, and more particularly to a wavelength conversion device and a color wheel device.

Background

In a conventional reflective color wheel, a high reflective layer is coated on a substrate, and then fluorescent powder is coated on the high reflective layer, so that the reflective layer reflects the light emitted from the fluorescent powder excited by laser to the front. The high reflection layer is usually designed by an optical reflection layer structure such as a Metal reflection layer, a Multi-layer Dielectric (Dielectric Multi-layer) reflection film, or a Metal/Dielectric composite (Metal/Dielectric Multi-layer) reflection film.

However, the performance of the reflective color wheel is greatly affected by the reflectivity of the substrate. Therefore, the angle and wavelength of the incident light are often considered when designing the highly reflective layer. The design of a reflecting structure with multiple dielectric layers requires the challenge of the design of the reflecting spectrum of full-angle incidence and full visible light wave bands, so that the number of the film layers is greatly increased, the film coating process is complicated and time-consuming, the reliability of the film layers is reduced, and the cost is greatly increased. Therefore, the multilayer dielectric reflective film is often greatly affected by incident light conditions. Although the metal reflective layer has no consideration of the incident angle, it is easy to be oxidized and corroded, and thus the stability is not good.

Furthermore, the phosphor is coated on the surface of the high reflective layer by glue material, so that the light photons emitted from the phosphor are incident to the high reflective layer from the glue environment with refractive index of about 1.4 to 1.5, which is different from the environment design of ordinary air (n ═ 1). Under the influence of the Brewster Angle Effect, a part of polarized light of the incident light with large Angle penetrates through the high reflection layer to the bottom substrate for absorption, so that the light output of the fluorescent powder color wheel is reduced.

Disclosure of Invention

In view of the above, an object of the present invention is to provide a wavelength conversion device that can meet the reflection requirements of a full incident angle and a full wavelength spectrum.

In order to achieve the above object, according to one embodiment of the present invention, a wavelength conversion device includes a substrate, a reflective element and a wavelength conversion element. The reflecting element is arranged on the substrate and comprises a continuous phase material and a plurality of nano-particles. The nanoparticles are distributed within the continuous phase material. The refractive index of the continuous phase material is different from the refractive index of the nanoparticles. The wavelength conversion element is disposed on the reflective element. The reflective element is configured to reflect light transmitted from the wavelength converting element away from the wavelength converting element.

In one or more embodiments of the present invention, the continuous phase material is an organic dielectric material or an inorganic dielectric material.

In one or more embodiments of the present invention, the organic dielectric material is acrylic resin, silicone rubber, or glass rubber.

In one or more embodiments of the present invention, the refractive index of the organic dielectric material is 1.3 to 1.55.

In one or more embodiments of the present invention, the inorganic dielectric material is a transparent oxide-based glass.

In one or more embodiments of the present invention, the inorganic dielectric material includes an oxide of a combination of at least one of silicon, phosphorus, boron, bismuth, aluminum, zirconium, zinc, an alkali metal element, and an alkaline earth element.

In one or more embodiments of the present invention, the refractive index of the inorganic dielectric material is 1.4 to 1.6.

In one or more embodiments of the present invention, the wavelength conversion element includes an inorganic dielectric material.

In one or more embodiments of the present invention, the thickness of the reflective element is 10 μm to 3 mm.

In one or more embodiments of the present invention, the thickness of the reflective element is further 30 to 500 micrometers.

In one or more embodiments of the present invention, the material of the nanoparticles includes at least one of silicon dioxide, bubbles, tantalum oxide, titanium oxide, magnesium fluoride, and barium sulfate.

In one or more embodiments of the present invention, the nanoparticle has a particle size of 50 nm to 500 nm.

In one or more embodiments of the present invention, the particle size of the nanoparticle is 100 nm to 400 nm.

In one or more embodiments of the present invention, the concentration of the nanoparticles in the reflective element is 30 wt% to 95 wt%.

In one or more embodiments of the present invention, the concentration of the nanoparticles in the reflective element is further 50 wt% to 90 wt%.

In one or more embodiments of the present invention, a difference between the refractive index of the continuous phase material and the refractive index of the nanoparticles is greater than or equal to 0.5.

In one or more embodiments of the present invention, the nanoparticle includes a plurality of first sub-nanoparticles and a plurality of second sub-nanoparticles. The refractive index of the first sub-nanoparticles is greater than the refractive index of the continuous phase material, and the refractive index of the second sub-nanoparticles is less than the refractive index of the continuous phase material.

In one or more embodiments of the present invention, the wavelength conversion element is a phosphor layer.

In summary, the reflective element of the wavelength conversion device of the present invention distributes the nanoparticles in the continuous phase material, and the refractive index of the continuous phase material is different from the refractive index of the nanoparticles, so that the light can be reflected at the interface between the two. Moreover, the particle size and concentration of the nano particles can be adjusted to simulate the reflection mechanism of the existing multilayer dielectric layer, so that the reflection requirements of the full incident angle and the full wavelength spectrum can be easily met. Moreover, the wavelength conversion device of the present invention can effectively increase the overall output brightness of the wavelength conversion device by only preparing the reflective element with a proper formula on the substrate, and therefore, the present invention has the advantages of simple manufacturing process, low price, etc.

The foregoing is merely illustrative of the problems, solutions to problems, and technical effects that can be produced by the present invention, and the detailed description of the present invention will be described in detail in the following detailed description and the related drawings.

Drawings

In order to make the aforementioned and other objects, features, and advantages of the invention, as well as others which will become apparent, reference is made to the following description taken in conjunction with the accompanying drawings in which:

fig. 1 is a schematic diagram illustrating a wavelength conversion device according to an embodiment of the invention.

Fig. 2 is a graph showing normalized output power-laser power curves of a wavelength conversion device and an aluminum plate according to an embodiment of the present invention.

Fig. 3 is a graph showing the luminance-laser power curve of the wavelength conversion device and the aluminum plate according to an embodiment of the invention.

Fig. 4 is a schematic view illustrating a wavelength conversion device according to another embodiment of the present invention.

Description of reference numerals:

1. 2: wavelength conversion device

10: substrate

12. 22: reflective element

120: continuous phase material

122. 222: nanoparticles

14: wavelength conversion element

140: binder

142: fluorescent powder particle

222 a: first sub-nanoparticles

222 b: second sub-nanoparticles

Detailed Description

In the following description, numerous implementation details are set forth in order to provide a thorough understanding of the present invention. It should be understood, however, that these implementation details are not to be interpreted as limiting the invention. That is, in some embodiments of the invention, such implementation details are not necessary. In addition, some conventional structures and elements are shown in simplified schematic form in the drawings.

Fig. 1 is a schematic diagram illustrating a wavelength conversion device 1 according to an embodiment of the invention.

As shown in fig. 1, in the present embodiment, the wavelength conversion device 1 includes a substrate 10, a reflective element 12, and a wavelength conversion element 14. The reflective element 12 is disposed on the substrate 10 and includes a continuous phase material 120 and a plurality of nanoparticles 122. Nanoparticles 122 are distributed within the continuous phase material 120. The refractive index of the continuous phase material 120 is different from the refractive index of the nanoparticles 122. The wavelength conversion element 14 is disposed on the reflective element 12. That is, the substrate 10, the reflective element 12 and the wavelength conversion element 14 form a sandwich structure. In some embodiments, the wavelength conversion element 14 is a phosphor layer, but the invention is not limited thereto. The phosphor layer can emit light when excited by light (e.g., laser) to serve as the light emitting layer of the wavelength conversion device 1. The reflective element 12 is configured to reflect light transmitted from the wavelength converting element 14 away from the wavelength converting element 14.

According to the above structure configuration, the reflective element 12 of the wavelength conversion device 1 has a structure in which the nanoparticles 122 are distributed in the continuous phase material 120, and the refractive index of the continuous phase material 120 is different from the refractive index of the nanoparticles 122, so that light can be reflected at the interface between the two. Also, the greater the difference between the refractive index of the continuous phase material 120 and the refractive index of the nanoparticles 122, the greater the reflectivity of the interface of the light rays between the two, and the greater the reflection angle.

In some embodiments, the difference between the refractive index of the continuous phase material 120 and the refractive index of the nanoparticles 122 is greater than or equal to 0.5, but the invention is not limited thereto.

In general, in designing a conventional multilayer dielectric reflective film, when light having a certain wavelength is to be reflected, the thickness of the film is set to be a quarter wavelength (quartz wavelength) of the light to be reflected. According to this concept, if the conventional multilayer dielectric reflective film is required to be suitable for the reflection requirement of the full incident angle and the full wavelength spectrum, the number of the film layers is often approaching to hundreds.

In contrast, the nano discontinuous reflective element 12 used in the wavelength conversion device 1 according to the embodiments of the present invention is to distribute the nanoparticles 122 with high refractive index into the continuous phase material 120 with low refractive index (or vice versa), and adjust the particle size and concentration of the nanoparticles 122 to achieve the reflection mechanism simulated by the conventional multilayer dielectric reflective film, and to more easily meet the reflection requirement of the full incident angle and the full wavelength spectrum than the conventional multilayer dielectric reflective film. Furthermore, the wavelength conversion device 1 according to the embodiments of the present invention can effectively increase the overall output brightness of the wavelength conversion device 1 by only preparing the reflective element 12 with a proper formulation on the substrate 10, and thus has the advantages of simple manufacturing process and low cost.

More specifically, the concentration of the nanoparticles 122 is used to adjust the distance between any two nanoparticles 122 and the particle size of the nanoparticles 122 can easily achieve various thickness combinations with a very thin thickness, thereby effectively achieving the reflection of various wavelength spectrums.

In some embodiments, the nanoparticles 122 have a particle size of 50 nanometers to 500 nanometers. More specifically, the nanoparticles 122 have a particle size of 100 nm to 400 nm. When the size of the nanoparticle 122 is smaller than 400 nm, visible light can be invisible and can penetrate through the nanoparticle 122. When the particle size of the nanoparticle 122 is larger than 100 nm, the resonant absorption of the surface plasmon and the visible light of the nanoparticle 122 can be avoided.

In some embodiments, the concentration of nanoparticles 122 in reflective element 12 is 30 wt% to 95 wt%. More specifically, the concentration of nanoparticles 122 in reflective element 12 is further from 50 wt% to 90 wt%.

In some embodiments, the continuous phase material 120 is an organic dielectric material. For example, the organic dielectric material is acrylic resin, silicone rubber, or glass-based rubber. In some embodiments, the organic dielectric material has a refractive index of 1.3 to 1.55. To increase the difference between the refractive index of the continuous phase material 120 and the refractive index of the nanoparticles 122, the nanoparticles 122 having a high refractive index material (e.g., TiOx, TaOx, etc.) may be added to the continuous phase material 120, or the nanoparticles 122 having a low refractive index material (e.g., air, magnesium fluoride, silicon dioxide, etc.) may be introduced.

In some embodiments, the continuous phase material 120 made of the organic dielectric material may be deposited by a dip-coating (dip-coating) process, a dropping (dropping) process, a printing (printing) process, or the like.

In some embodiments, the material of the nanoparticles 122 includes at least one of silicon dioxide, bubbles, tantalum oxide, titanium oxide, magnesium fluoride, and barium sulfate, but the invention is not limited thereto.

In some embodiments, reflective element 12 has a thickness of 10 micrometers to 3 millimeters. More specifically, the thickness of the reflective element 12 is further 30 to 500 micrometers, but the invention is not limited thereto.

Fig. 2 is a graph showing a normalized output power-laser power curve of the wavelength conversion device 1 and the aluminum plate according to an embodiment of the invention.

As shown in fig. 2, in the present embodiment, an aluminum plate having an aluminum content of 95% was compared with the wavelength conversion device 1, and both were subjected to a luminance test of reflected light under a laser light source of the same power. The continuous phase material 120 used in the reflective element 12 of the wavelength conversion device 1 is silica gel (refractive index of about 1.5). The material of the nanoparticles 122 used in the reflective element 12 is hollow glass beads (refractive index of about 1.0), the thickness of the nanoparticles 122 is about 200 nm, and the concentration of the nanoparticles 122 is about 10 wt% to 30 wt%. As is clear from fig. 2, the experimental results show that the luminance (i.e., normalized output power) of the reflected light of the wavelength conversion device 1 in the present embodiment is higher than the luminance of the reflected light of the aluminum plate by about 5%.

Fig. 3 is a graph showing a luminance-laser power curve of the wavelength conversion device 1 and the aluminum plate according to an embodiment of the invention.

As shown in fig. 3, in the present embodiment, an aluminum plate having an aluminum content of 95% was used as compared with the wavelength conversion device 1, and the luminance test of the reflected light was performed under a laser light source having the same power. The continuous phase material 120 used in the reflective element 12 of the wavelength conversion device 1 is silica gel (refractive index of about 1.5). The material of the nanoparticles 122 used in the reflective element 12 is titanium dioxide (refractive index of about 2.4), the thickness of the nanoparticles 122 is about 300 nanometers, and the concentration of the nanoparticles 122 is about 30 wt% to 50 wt%. As is clear from fig. 3, the experimental results show that the brightness of the reflected light of the wavelength conversion device 1 in the present embodiment is higher than that of the aluminum plate by about 10%.

In addition, compared to the embodiment shown in fig. 2, since the difference between the refractive indexes of the continuous phase material 120 and the nanoparticles 122 is larger (about 0.9), the gain of the reflectivity and the gain of the brightness both exceed those of the embodiment shown in fig. 2, and thus the operation principle claimed by the present invention is verified (i.e., the operation principle that the larger the difference between the refractive index of the continuous phase material 120 and the refractive index of the nanoparticles 122, the larger the reflectivity of the interface between the two is).

As can be seen from the experimental graphs shown in fig. 2 and fig. 3 and the above-mentioned experimental data, the wavelength conversion device 1 according to the embodiments of the present invention can effectively improve the overall output brightness compared to the conventional aluminum plate.

In some embodiments, the continuous phase material 120 of the reflective element 12 may also be an inorganic dielectric material. For example, the inorganic dielectric material may be a ceramic oxide, such as a transparent oxide-based glass. More specifically, the inorganic dielectric material includes an oxide of a combination of at least one of silicon, phosphorus, boron, bismuth, aluminum, zirconium, zinc, an alkaline metal group element, and an alkaline earth group element, but the present invention is not limited thereto. In some embodiments, the inorganic dielectric material has a refractive index of 1.4 to 1.6. The wavelength conversion device 1 of the present invention can be applied to higher power products by bonding the nanoparticles 122 with the continuous phase material 120 made of the above-mentioned inorganic dielectric material.

In some embodiments, the wavelength converting element 14 also comprises the aforementioned inorganic dielectric materials. Specifically, as shown in fig. 1, the wavelength conversion element 14 includes a binder (binder)140 and phosphor particles 142, and the binder 140 may be made of the inorganic dielectric material. Therefore, the wavelength conversion device 1 of the present invention can be made more suitable for higher power products.

In some embodiments, the continuous phase material 120 and/or the binder 140 made of the inorganic dielectric material can be deposited by a coating process and then sintered or fused by a high temperature process.

In some embodiments, the substrate 10 may be made of glass, metal (e.g., aluminum), ceramic or semiconductor material, but the invention is not limited thereto.

In some embodiments, the wavelength conversion device 1 is a reflective color wheel, but the invention is not limited thereto.

Fig. 4 is a schematic diagram illustrating a wavelength conversion device 2 according to another embodiment of the invention.

As shown in fig. 4, in the present embodiment, the wavelength conversion device 2 includes a substrate 10, a reflective element 22 and a wavelength conversion element 14, wherein the substrate 10 and the wavelength conversion element 14 are the same as those in the embodiment shown in fig. 1, and therefore, the description thereof is omitted. It should be noted that, compared to the embodiment shown in fig. 1, the nanoparticle 222 in this embodiment further includes a plurality of first sub-nanoparticles 222a and a plurality of second sub-nanoparticles 222 b. The refractive index of the first sub-nanoparticles 222a is greater than the refractive index of the continuous phase material 120, and the refractive index of the second sub-nanoparticles 222b is less than the refractive index of the continuous phase material 120. That is, in the present embodiment, the first sub-nanoparticles 222a and the second sub-nanoparticles 222b are uniformly distributed in the same continuous phase material 120 (i.e., share the same continuous phase material 120). In contrast, for the conventional multilayer dielectric reflective film, the film layers can only be stacked, and the thickness of the stacked film layers is necessarily larger than that of the reflective element 22 of the present embodiment to achieve the reflective effect similar to that of the present embodiment. Therefore, the reflective element 22 of the present embodiment can be reduced in thickness compared to the conventional multilayer dielectric reflective film.

As is apparent from the above detailed description of the specific embodiments of the present invention, the reflective element of the wavelength conversion device of the present invention is formed by distributing nanoparticles within a continuous phase material, and by making the refractive index of the continuous phase material different from that of the nanoparticles, light can be reflected at the interface between the two. Moreover, the particle size and concentration of the nano particles can be adjusted to simulate the reflection mechanism of the existing multilayer dielectric layer, so that the reflection requirements of the full incident angle and the full wavelength spectrum can be easily met. Moreover, the wavelength conversion device of the present invention can effectively increase the overall output brightness of the wavelength conversion device by only preparing the reflective element with a proper formula on the substrate, and therefore, the present invention has the advantages of simple manufacturing process, low price, etc.

Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention.

Claims

1. A reflective color wheel, comprising:

a substrate made of glass, metal, ceramic or semiconductor material;

a reflective element disposed on the substrate, the reflective element comprising: a continuous phase material and a plurality of first sub-nanoparticles; and

a wavelength conversion element disposed on the reflection element, wherein the reflection element is configured to reflect the light transmitted from the wavelength conversion element away from the wavelength conversion element;

Wherein, the refractive index of the first sub-nanoparticles is higher than the refractive index of the continuous phase material and the difference between the refractive indices is greater than or equal to 0.5,

Wherein, the particle size of the first sub-nanoparticles is 50 nanometers to 500 nanometers, and the concentration of the first sub-nanoparticles in the reflective element is 30 wt % to 95 wt %.

2 . The reflective color wheel of claim 1 , wherein the reflective element further comprises a plurality of second sub-nanoparticles, and the refractive index of the second sub-nanoparticles is smaller than that of the continuous phase material. 3 .

3 . The reflective color wheel of claim 2 , wherein the second sub-nanoparticles are air or hollow glass beads, and the particle size of the second sub-nanoparticles is 50 nm to 500 nm. 4 .

4. The reflective color wheel of claim 2, wherein the concentration of the nanoparticles in the reflective element is 30wt% to 95wt%.

5. The reflective color wheel of claim 1, wherein the continuous phase material is an inorganic dielectric material, comprising at least one of silicon, phosphorus, boron, bismuth, aluminum, zirconium, zinc, alkali metals and alkaline earth elements A combination of oxides.

6. The reflective color wheel of claim 5, wherein the inorganic dielectric material has a refractive index of 1.4 to 1.6.

7. The reflective color wheel of claim 1, wherein the reflective element has a thickness of 10 micrometers to 3 millimeters.

8. The reflective color wheel as claimed in claim 7, wherein the thickness of the reflective element is further from 30 microns to 500 microns.

9 . The reflective color wheel of claim 1 , wherein the materials of the first sub-nanoparticles comprise at least one of tantalum oxide, titanium oxide and barium sulfate. 10 .

10. A reflective color wheel, comprising:

a substrate made of glass, metal, ceramic or semiconductor material;

a reflective element disposed on the substrate, the reflective element comprising: a continuous phase material, a plurality of first sub-nanoparticles and a plurality of second sub-nanoparticles; and

Wherein, the first sub-nanoparticles and the second sub-nanoparticles are distributed in the continuous phase material and share the continuous phase material, and the refractive index of the first sub-nanoparticles is greater than that of the continuous phase material rate, and the refractive index of the second sub-nanoparticles is less than the refractive index of the continuous phase material,

Wherein, the difference between the refractive index of the first sub-nanoparticles and the refractive index of the continuous phase material is greater than or equal to 0.5,

11. A reflective color wheel, comprising:

a substrate made of glass, metal, ceramic or semiconductor material;

a reflective element disposed on the substrate, the reflective element comprises: a continuous phase material and a plurality of nanoparticles; and

Wherein, the refractive index of the continuous phase material is higher than the refractive index of the nanoparticles and the difference between the refractive indices is greater than or equal to 0.5,

Wherein, the nanoparticles are air or hollow glass beads, the particle size of the nanoparticles is 50 nm to 500 nm, and the concentration of the nanoparticles in the reflective element is 10 wt % to 30 wt %.