WO2019153638A1

WO2019153638A1 - Wavelength conversion device

Info

Publication number: WO2019153638A1
Application number: PCT/CN2018/094729
Authority: WO
Inventors: 徐虎; 段银祥; 周萌; 田梓峰; 许颜正
Original assignee: 深圳光峰科技股份有限公司
Priority date: 2018-02-07
Filing date: 2018-07-06
Publication date: 2019-08-15
Also published as: CN110119058A

Abstract

Disclosed is a wavelength conversion device, comprising a heat-dissipation substrate of a disc shape, and at least one wavelength conversion module located on a light receiving surface of the heat-dissipation substrate, wherein the heat-dissipation substrate has a centrally symmetric stepped structure, and the at least one wavelength conversion module is arranged on a surface of a corresponding step of the stepped structure in a ring shape. The present invention can provide a wavelength conversion device which is improved in heat dispersion performance, stability and service life.

Description

Wavelength conversion device

Technical field

The present invention relates to the field of image display, and more particularly to a wavelength conversion device.

Background technique

In recent years, with the continuous development of technology, people are increasingly demanding image display devices. Laser light source has become one of the most promising technical research directions. In the technical field of laser light sources, a wavelength conversion device having a fluorescent color wheel mechanism is generally employed. Wherein, the fluorescent color wheel rotates around the central axis under the driving of the motor, and the laser light as the excitation light converges and illuminates the surface of the fluorescent color wheel to be coated or the like, so that the phosphor material is excited and emitted. The fluorescence of the color.

Fig. 1 is a block diagram showing the structure of a wavelength conversion device having a fluorescent color wheel mechanism in the prior art. It includes a heat dissipation substrate 100, a drive motor 200, and a light emitting layer 300. The heat dissipation substrate 100 has a circular surface, and the light-emitting layer 300 for emitting fluorescence of different colors is applied on the surface of the heat dissipation substrate in a circular arc or a fan shape, and the drive motor 200 is disposed at the center of the back surface of the heat dissipation substrate 100 to drive the entire device. Rotate around the center of the circle.

In order to obtain high-quality display images, small to portable micro projectors, as large as cinema projectors, are constantly improving the brightness of the light source, high-brightness display instruments are an inevitable trend in the future display industry development. However, as the brightness increases, it is bound to increase the power of the light source. In the case of using a high-power laser light source, the wavelength conversion device having the fluorescent color wheel mechanism shown in FIG. 1 has poor heat dissipation performance, which affects the stability and service life of the device.

Summary of the invention

In view of the above problems, the present invention is intended to provide a wavelength conversion device capable of improving heat dissipation performance, stability, and service life.

According to an embodiment of the present invention, a wavelength conversion device includes: a heat dissipation substrate having a disk shape; at least one wavelength conversion module, wherein the at least one wavelength conversion module is located on a light receiving surface of the heat dissipation substrate; The heat dissipation substrate has a centrally symmetrical step structure, and the at least one wavelength conversion module is respectively disposed in a ring shape on a corresponding step surface of the step structure.

Preferably, the wavelength conversion device further includes a driving motor at a center position of the non-light receiving surface of the heat dissipation substrate opposite to the light receiving surface, the driving motor driving the wavelength conversion device around the center Rotate.

Preferably, the light-receiving surface of the heat-dissipating substrate may be gradually recessed from the outside to the inside in a stepped form. Alternatively, the light-receiving surface of the heat-dissipating substrate may gradually protrude in a stepped form from the outside to the inside. Alternatively, the light-receiving surface of the heat-dissipating substrate is gradually recessed from the outside to the inside in a stepped manner and then gradually convex, so that the heat-dissipating substrate has a W-shaped cross section. Alternatively, the light-receiving surface of the heat-dissipating substrate is gradually convex and gradually recessed from the outside to the inside in a stepped manner, so that the heat-dissipating substrate has a W-shaped cross section.

Preferably, the wavelength conversion device includes a plurality of wavelength conversion modules, and the plurality of wavelength conversion modules are sequentially arranged from the inside to the outside in a sequence in which the amount of heat generation is small to large.

Preferably, the width of the wavelength conversion module is equal to the width of the corresponding step surface of the step structure.

Preferably, the widths of the step faces of the stepped structure of the heat dissipation substrate are the same or different.

Preferably, the non-light-receiving back surface of the heat dissipation substrate is provided with a heat dissipation fin, and a position of the heat dissipation fin corresponds to a position of the wavelength conversion module.

Preferably, each step sidewall of the stepped structure of the heat dissipation substrate is provided with a plurality of heat dissipation holes or additional heat dissipation fins.

As described above, at least the following advantages according to the present invention are as follows:

1. By providing a stepped heat dissipation substrate, the heat dissipation surface area is increased, so that the heat dissipation performance of the wavelength conversion device is greatly improved;

2. By specifically providing different phosphor layers in different annular step portions of the stepped heat dissipation substrate, it is possible to avoid the mutual influence of heat generation of different phosphor layers;

3. The phosphor layers of different colors are all arranged in a concentric annular shape, which increases the laser irradiation time of the phosphor layer in each wavelength range, and improves the luminous efficiency of the device.

4. Preferably, the heat dissipation performance can be further improved by additionally providing the heat dissipation fins and the heat dissipation holes.

5. Preferably, the disk-shaped heat dissipation substrate has a stepped structure in which the central portion of the non-light-receiving surface is gradually recessed, whereby the size of the device can be kept small.

It should be understood that the beneficial effects of the present invention are not limited to the above effects, but may be any of the advantageous effects described herein.

DRAWINGS

1 and b are respectively a side view and a plan view showing a structure of a wavelength conversion device in the related art;

2 shows a side view of a wavelength conversion device in accordance with an embodiment of the present invention;

3 shows a top view of a wavelength conversion device in accordance with an embodiment of the present invention;

4 shows a side view of a modification of the wavelength conversion device according to an embodiment of the present invention;

FIG. 5 is a side view showing an outline of a structure of a wavelength conversion device according to another embodiment of the present invention; FIG.

Figure 6 shows a side view of a modification of the wavelength conversion device according to another embodiment of the present invention;

Fig. 7 shows a side view of a modification of the wavelength conversion device according to still another embodiment of the present invention.

Detailed ways

Hereinafter, various embodiments in accordance with the present invention will be described in detail with reference to the accompanying drawings. It is to be emphasized that all the dimensions in the drawings are only schematic and are not necessarily illustrated in a true scale, and thus are not limiting. For example, it should be understood that the thickness, shape, size, and the like of the various components in the structure of the wavelength conversion device are not shown in actual size and scale, and are merely for convenience of illustration.

The wavelength conversion device according to the present invention includes at least a heat dissipation substrate and a wavelength conversion module. Further, a drive motor is also included. The drive motor and the wavelength conversion module are respectively disposed on both sides of the heat dissipation substrate. The wavelength conversion device is driven to rotate about the center of the circle. For example, the drive motor may be disposed at a center position of the heat dissipation substrate. It will be understood that a wavelength conversion device employing a drive motor in the art, also referred to as a color wheel, is not specifically distinguished in the present invention and should be considered as being included in the present invention.

Heat sink substrate

The heat dissipation substrate has a disk shape, and the radial cross section of the heat dissipation substrate has a center symmetrical step structure. In other words, the heat dissipation substrate has a plurality of stepped surfaces, each of which has a circular ring shape. The heat dissipation substrate may be, for example, a ceramic substrate, a metal substrate, or a ceramic metal mixed substrate. The heat dissipation substrate carries the wavelength conversion module and serves as a heat dissipation structure of the wavelength conversion module. The ceramic substrate is an alumina substrate, a sapphire substrate, an aluminum nitride substrate, a silicon nitride substrate, a silicon carbide substrate, or a boron nitride substrate. These ceramic materials have a thermal conductivity of 80 W/(m·K) or more and a melting point of substantially 1000 ° C or higher, so that they can withstand higher temperatures while achieving heat conduction and heat dissipation. The metal substrate includes, for example, a copper substrate, a copper alloy substrate, and an aluminum substrate. The ceramic metal mixed substrate includes, for example, an aluminum-aluminum nitride substrate.

Wavelength conversion module

The wavelength conversion module is directly or indirectly fixed on the heat dissipation substrate, and the number may be one or more. Each of the wavelength conversion modules is disposed on each of the annular stepped surfaces of the heat dissipation substrate, and also has a corresponding annular shape. Each of the wavelength conversion modules may have, for example, a multilayer laminated structure including at least a light-emitting layer and a diffuse reflection layer. For example, on the heat dissipation substrate, a diffuse reflection layer and a light-emitting layer are sequentially laminated.

The luminescent layer may comprise a luminescent material and a binder. The luminescent material comprises a phosphor, a quantum dot, etc., for absorbing light having a certain wavelength (for example, a laser), and then emitting light of another wavelength; the binder may include an organic binder such as silica gel or resin, and may also An inorganic binder such as glass may be included, and a transparent ceramic binder may also be included. Alternatively, the luminescent layer may be a fluorescent ceramic. The difference in luminescent material in the luminescent layer results in a difference in its absorption and emission spectra. For different wavelength conversion modules for emitting light of different wavelengths, different specific luminescent materials are required. For example, for the green segment wavelength conversion module, the fluorescent material may be a green phosphor such as a LuAG (yttrium aluminum garnet) phosphor; for the yellow segment wavelength conversion module, the fluorescent material may be a yellow phosphor such as YAG (yttrium aluminum). Garnet) phosphor; for the red segment wavelength conversion module, the fluorescent material can be red phosphor.

The diffuse reflective layer comprises, for example, scattering particles and a binder. The scattering particles are particles having a reflective function in the diffuse reflection layer, and the binder is used to bond the scattering particles to form a diffuse reflection layer. The scattering particles are usually apparently white powder/particles, which are salts, oxides or nitride powders, including, for example, alumina, titania, aluminum nitride, magnesium oxide, boron nitride, zinc oxide, zirconium oxide, barium sulfate, etc. Ultra-white monomer powder particles, or a mixture of at least two powder particles, for scattering/reflecting light. In addition, these scattering materials do not substantially absorb light and are stable in nature and do not oxidize or decompose at high temperatures. The binder may include an organic binder such as silica gel or resin, and may also include an inorganic binder such as glass. For the organic binder, the diffuse reflection layer is obtained by directly mixing the scattering particles with an organic binder and heating. For the inorganic binder, it is necessary to mix the scattering particles with the binder in proportion and then sinter to obtain a diffuse reflection layer.

The wavelength conversion function of the luminescent layer causes it to generate heat itself, and the heat dissipation properties of these materials are not good regardless of whether the binder is made of silica gel/resin, glass or ceramic particles. In the working state, the accumulation of heat in the luminescent layer causes an increase in temperature, affecting the activity of the luminescent material, and further causes a decrease in the luminous efficiency of the luminescent layer. Therefore, the diffuse reflection layer also functions as a heat conductive member that transfers heat from the light emitting layer to the heat dissipation substrate, so that heat can be dissipated from the heat dissipation substrate in time without forming heat accumulation.

In the wavelength conversion device according to the present invention, since the heat dissipation substrate has a stepped structure, the heat dissipation area is much larger than the heat dissipation area of the planar disk-shaped heat dissipation substrate of the same diameter, and thus has more excellent heat dissipation performance.

In the prior art, each wavelength conversion module is generally brushed on an air-dissipating substrate into an adjacent sector or arc shape. Therefore, when the amount of heat generated in a certain wavelength conversion module is large, the heat conducted from the module also affects the heat dissipation of other adjacent modules. In the wavelength conversion device according to the present invention, each of the wavelength conversion modules is disposed in a ring shape on each stepped surface of the stepped heat dissipation substrate. Therefore, it is possible to reduce the influence of the wavelength conversion module having a large amount of heat generation on the adjacent other wavelength conversion modules. Further, when the wavelength conversion device (color wheel) is rotated, the portion of the heat dissipation substrate at the outer ring is larger in line speed with respect to the heat dissipation medium (for example, air), and thus has better heat dissipation performance. Therefore, in the wavelength conversion device according to the present invention, the setting position of each wavelength conversion module can be determined according to the amount of heat generation of each wavelength conversion module. For example, the longer the wavelength of the fluorescing light, the more obvious the thermal effect of the luminescent layer, so that the wavelength converting module that emits the longer wavelength fluorescence can be disposed at the outer ring position of the heat dissipating substrate, thereby making the whole device as a whole better. heat radiation. In other words, the plurality of wavelength conversion modules can be sequentially arranged from the inside to the outside in order of their heat generation from small to large.

In addition, since each of the wavelength conversion modules in the wavelength conversion device of the present invention is provided in an annular shape, the time during which the excitation light of each wavelength conversion module is irradiated can be arbitrarily set and adjusted as needed during the rotation thereof. This improves the utilization efficiency of the excitation light and improves the light efficiency of the entire device. Illustratively, in the case where the wavelength conversion module that emits the red light with the lowest wavelength conversion efficiency (that is, the most thermal effect) is disposed at the position of the outermost circle, on the one hand, the sector segment is compared to the existing scheme. The setting method has a larger wavelength conversion angle (ie, the entire ring), and the outermost ring also has a larger area of the conversion area, reducing the power per unit area of the fluorescent material without reducing the overall luminous power of the red light. , which reduces the calorific value of the fluorescent material per unit area, improves the luminous efficiency per unit area, reduces the risk of failure of the fluorescent material (thermal quenching), and improves the reliability; on the other hand, the outermost circle of the wavelength conversion device has a higher The line speed increases heat dissipation efficiency and reduces the risk of fluorescent material failure (thermal quenching), ensuring reliability. Similarly, other color wavelength conversion modules are equally applicable.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific embodiment of a wavelength conversion device according to the present invention will be described below with reference to the accompanying drawings.

First embodiment

Fig. 2 shows a side view of a wavelength conversion device according to a first embodiment of the invention. Fig. 3 shows a plan view of a wavelength conversion device according to a first embodiment of the present invention.

As shown in FIGS. 2 and 3, the wavelength conversion device according to the present embodiment includes a heat dissipation substrate 10, a drive motor 20, and a wavelength conversion module 30. The heat dissipation substrate 10 is, for example, an aluminum nitride substrate. The drive motor 20 is disposed at a center position of a non-light-receiving surface (also referred to as a "back surface") of the heat dissipation substrate 10, and the wavelength conversion module 30 is disposed on a light-receiving surface (also referred to as a "front surface") of the heat dissipation substrate 10. The heat dissipation substrate 10 has a disk shape as a whole, and has a center-symmetric stepped structure in which the front surface is gradually recessed from the outside to the inside and the back surface is gradually convex from the outside to the inside. The wavelength conversion module 30 is disposed on the stepped surface of the stepped heat dissipation substrate 10 and has a corresponding annular shape. 2 and 3 show an example in which three wavelength conversion modules 30 are provided. In this case, for example, the outermost wavelength conversion module 30 may be a red wavelength conversion module that emits red light, the intermediate wavelength conversion module 30 may be a green wavelength conversion module that emits green light, and the innermost wavelength conversion module 30 may It is a blue wavelength conversion module that emits blue light.

It should be understood that the number and arrangement order of the wavelength conversion modules 30 are not limited thereto, and may be any settings as needed. For example, it is also possible to provide wavelength conversion modules of the same color on different step faces. Further, although the widths of the step faces illustrated in the drawings are the same, the width of each step face and the brush width of the wavelength conversion module 30 disposed thereon may be arbitrarily set as needed. In other words, the widths of the different step faces may be the same or different, and correspondingly, the widths of the different wavelength conversion modules may be the same or different. In addition, as shown in FIGS. 2 and 3, the set width of the wavelength conversion module 30 is smaller than the width of the corresponding step surface of the heat dissipation substrate 10, but it is obvious that the arrangement width of the wavelength conversion module 30 can also be set equal to that of the heat dissipation substrate 10. The width of the corresponding step surface. In this case, in the plan view of FIG. 3, the front surface of the heat dissipation substrate 10 is covered by each wavelength conversion module 30 except for the step surface of the innermost circumference.

Fig. 4 shows a modification of the wavelength conversion device according to the first embodiment of the present invention. As shown in FIG. 4, heat dissipation fins 40 are provided at positions on the back surface of the heat dissipation substrate 10 opposite to the wavelength conversion module 30. The heat dissipation fins 40 further increase the contact area of the heat dissipation substrate 10 with the heat dissipation medium (for example, air), thereby improving heat dissipation efficiency.

Second embodiment

Fig. 5 shows a side view of a wavelength conversion device in accordance with a second embodiment of the present invention. The wavelength conversion device according to the present embodiment includes the heat dissipation substrate 11, the drive motor 20, and the wavelength conversion module 30. For convenience of illustration, only two wavelength conversion modules 30 are shown in FIG. The wavelength conversion device according to the present embodiment is different from the wavelength conversion device of the first embodiment shown in FIG. 2 in that the heat dissipation substrate 11 has a light-receiving surface (front surface) that gradually protrudes from the outside to the inside and the non-light-receiving surface (back surface) from the outside to the outside. A centrally symmetrical stepped structure that gradually recesses inside.

Since the wavelength conversion device requires a drive motor for driving rotation, and the drive motor is usually disposed on the back surface of the heat dissipation substrate, the overall thickness of the wavelength conversion device includes the thickness of the drive motor. In the wavelength conversion device according to the first embodiment of the present invention, since the back surface of the disk-shaped heat dissipation substrate 10 gradually protrudes from the outside to the inside, the thickness of the entire wavelength conversion device (that is, in the left and right direction of FIG. 2) The total thickness is equal to the sum of the thickness of the drive motor 20 and the step heights of the stepped heat dissipation substrates 10. Therefore, the thickness of the wavelength conversion device according to the first embodiment of the present invention may increase with respect to the wavelength conversion device having the planar disk heat dissipation substrate. However, in the wavelength conversion device according to the second embodiment of the present invention, since the back surface of the disk-shaped heat dissipation substrate 11 is gradually recessed from the outside to the inside, the step structure of the heat dissipation substrate 11 makes full use of the installation space of the drive motor 20. Therefore, the thickness of the entire wavelength conversion device (i.e., the total thickness in the left-right direction of Fig. 5) is substantially the same as the thickness of the wavelength conversion device having the planar disk heat-dissipating substrate. In other words, the central portion of the non-light-receiving surface of the heat-dissipating substrate 11 is recessed inwardly to form a concave portion, and the drive motor 20 having a certain thickness can be accommodated in the concave portion. Here again, for the sake of clarity of illustration, in each of the drawings, the thickness of the heat dissipation substrate, the wavelength conversion module, and the thickness of the drive motor are not shown in true scale.

In addition to the above differences, the wavelength conversion device according to the second embodiment of the present invention may have the above various structures, functions, and variations of the wavelength conversion device of the first embodiment.

For example, Fig. 6 shows a modification of the wavelength conversion device according to the second embodiment of the present invention. As shown in FIG. 6, heat dissipation fins 40 are provided at positions on the back surface of the heat dissipation substrate 11 opposite to the wavelength conversion module 30. The heat dissipation fins 40 further increase the contact area of the heat dissipation substrate 11 with the heat dissipation medium (for example, air), thereby improving heat dissipation efficiency.

Third embodiment

Fig. 7 shows a side view of a wavelength conversion device in accordance with a third embodiment of the present invention. The wavelength conversion device according to the present embodiment includes the heat dissipation substrate 12, the drive motor 20, and the wavelength conversion module 30. For convenience of illustration, only four wavelength conversion modules 30 are shown in FIG. As shown in FIG. 7, the wavelength conversion device according to the present embodiment is different from the wavelength conversion device of the second embodiment shown in FIG. 6 in that the heat dissipation substrate 12 has a light receiving surface (front surface) which is gradually recessed from the outside to the inside and then gradually convex. And the non-light-receiving surface (back surface) gradually bulges from the outside to the inside and then gradually recesses the center-symmetric step structure. In other words, the heat dissipation substrate 12 in this embodiment has a W-shaped cross section.

In this embodiment, since the heat dissipation substrate has a W-shaped structure, the heat dissipation area of the heat dissipation substrate can be further increased, and a more excellent heat dissipation effect can be obtained.

It should be understood that in the present embodiment, the heat dissipation substrate may also be disposed opposite to the W-shaped structure shown in FIG. 7, that is, the light-receiving surface (front surface) gradually bulges from the outside to the inside and then gradually recesses, and the non-light-receiving surface The (back) is gradually recessed from the outside to the inside and then gradually bulges to a centrally symmetrical step structure. Further, according to the structure shown in FIG. 7, it is apparent to those skilled in the art that the heat dissipating substrate can be provided as a wavy step structure having more undulations as needed.

In addition, FIG. 7 shows that the heat dissipation substrate 12 is provided with heat dissipation fins 40. However, it should be understood that the heat sink fins 40 are not required. Here again, for the sake of clarity of illustration, in each of the drawings, the thickness of the heat dissipation substrate, the wavelength conversion module, and the thickness of the drive motor are not shown in true scale.

In addition to the above differences, the wavelength conversion device according to the third embodiment of the present invention may have various structures, functions, and variations that are the same or similar to the foregoing embodiments.

The specific embodiment of the wavelength conversion device according to the present invention has been described above with reference to the accompanying drawings, but it should be understood that the wavelength conversion device of the present invention is not limited to the specific embodiments described above, but may have other modifications. For example, in the wavelength conversion devices according to the first to third embodiments of the present invention, the step side walls of the heat dissipation substrates 10 to 12 having the stepped structure are not provided with the wavelength conversion module 30 (in FIGS. 2 and 4). In the 5th to 7th, the portion of the heat dissipation substrate extending along the horizontal surface may be provided with a plurality of heat dissipation holes and/or additional heat dissipation fins to further improve the heat dissipation performance of the heat dissipation substrate, and reduce the heat generation of each wavelength conversion module. The effect of the wavelength conversion module. For example, it is also possible to have only the light-receiving surface of the heat-dissipating substrate have a stepped structure as needed, and the non-light-receiving surface is kept in the same plane. In addition, the various features and structures disclosed in the various embodiments of the present invention can be variously combined without departing from the spirit of the invention.

Although the wavelength conversion module according to the present invention has been described above with reference to the accompanying drawings, the present invention is not limited thereto, and those skilled in the art should understand that, without departing from the spirit or scope defined by the appended claims Various changes, combinations, sub-combinations, and variations can be made.

Claims

A wavelength conversion device comprising:

a heat dissipation substrate, wherein the heat dissipation substrate has a disk shape;

At least one wavelength conversion module, the at least one wavelength conversion module being located on a light receiving surface of the heat dissipation substrate;

The heat dissipation substrate has a centrally symmetrical step structure, and the at least one wavelength conversion module is respectively disposed in a ring shape on a corresponding step surface of the step structure.
The wavelength conversion device according to claim 1, wherein the light-receiving surface of the heat dissipation substrate is gradually recessed in a stepped form from the outside to the inside.
The wavelength conversion device according to claim 1, wherein the light-receiving surface of the heat dissipation substrate is gradually convex in a stepped form from the outside to the inside.
The wavelength conversion device according to claim 1, wherein the light-receiving surface of the heat-dissipating substrate is gradually recessed from the outside to the inside in a stepped manner and then gradually convex, so that the heat-dissipating substrate has a W-shaped cross section. ;

Alternatively, the light-receiving surface of the heat-dissipating substrate is gradually convex in a stepwise manner from the outside to the inside and then gradually recessed, so that the heat-dissipating substrate has a W-shaped cross section.
The wavelength conversion device according to any one of claims 1 to 4, wherein the wavelength conversion device further includes a driving motor, the driving motor being located at a non-light receiving side of the heat dissipation substrate opposite to the light receiving surface At a central position of the surface, the drive motor drives the wavelength conversion device to rotate about the center.
The wavelength conversion device according to any one of claims 1 to 4, wherein the wavelength conversion device comprises a plurality of wavelength conversion modules, and the plurality of wavelength conversion modules are arranged in descending order of heat generation Arranged inside and outside.
The wavelength conversion device according to any one of claims 1 to 4, wherein a width of the wavelength conversion module is equal to a width of a corresponding one of the step faces of the step structure.
The wavelength conversion device according to any one of claims 1 to 4, wherein a width of each of the step faces of the stepped structure of the heat dissipation substrate is the same or different.
The wavelength conversion device according to any one of claims 1 to 4, wherein the non-light-receiving back surface of the heat dissipation substrate is provided with a heat dissipation fin, a position of the heat dissipation fin and the wavelength conversion module The location corresponds.
The wavelength conversion device according to any one of claims 1 to 4, wherein each of the step sidewalls of the stepped structure of the heat dissipation substrate is provided with a plurality of heat dissipation holes and/or additional heat dissipation fins.