CN216526711U

CN216526711U - Color wheel assembly and projection device

Info

Publication number: CN216526711U
Application number: CN202122951668.2U
Authority: CN
Inventors: 江文豪; 向令; 朱金涛
Original assignee: Chengdu Jimi Technology Co Ltd
Current assignee: Chengdu Jimi Technology Co Ltd
Priority date: 2021-11-29
Filing date: 2021-11-29
Publication date: 2022-05-13
Anticipated expiration: 2031-11-29

Abstract

The application discloses a color wheel assembly and a projection device, wherein the color wheel assembly comprises a heat-conducting base material and a wavelength changing device which are fixedly connected, wherein the heat-conducting base material comprises a first surface and a second surface which are opposite, one or more through holes are arranged on the heat-conducting base material, and the through holes penetrate from the first surface to the second surface; the wavelength changing device comprises a wavelength changing layer and a heat conducting and light transmitting layer, wherein the wavelength changing layer can absorb exciting light and emit stimulated light, and the heat conducting and light transmitting layer is used for supporting the wavelength changing layer; the wavelength changing device covers the through holes of the heat-conducting base material and is arranged in one-to-one correspondence with the through holes. The heat that the wavelength changes the layer and produces in the color wheel subassembly that this application embodiment provided can transmit to the heat conduction substrate through the heat conduction stratum lucidum, outwards gives off the heat through the heat conduction substrate, has improved the heat dispersion on wavelength change layer.

Description

Color wheel assembly and projection device

Technical Field

The present application relates to the field of light emitting devices, and more particularly, to a color wheel assembly and a projection apparatus.

Background

In a projection display product, the brightness of a projection display picture is a very important performance parameter, wherein in order to improve the brightness of a projector, the power of a light source can be increased, which has a good effect on a projection system based on an LED light source. A method of using excitation light emitted from a solid-state light source such as an LD (Laser Diode) to excite a wavelength-changing material can obtain visible light of various colors, and this technique is increasingly used in illumination and display. The technology has the advantages of high efficiency, low energy consumption, low cost and long service life, and is an ideal alternative scheme of the existing white light or monochromatic light source. Two ways are commonly used for improving the projection display brightness, namely, improving the power of exciting light and improving the light emitting efficiency of the excited light of the color wheel component.

SUMMERY OF THE UTILITY MODEL

The demand of projection display is increasing day by day, and timely projection display especially when the ambient brightness is great, new demand is put forward to the luminance of projection display, so it is especially important to improve the luminance of projection display. Visible light of various colors can be obtained by irradiating the wavelength-changing material, and increasing the excitation efficiency of the wavelength-changing device and increasing the power of the excitation light are two ways to effectively increase the projection brightness. In view of this, embodiments of the present application provide a color wheel assembly and a projection apparatus, which can improve the heat dissipation efficiency of a wavelength-changing material, and can realize excitation of the wavelength-changing material with ultrahigh efficiency for excitation light (UV light, blue laser, etc.) with high power density.

In a first aspect, embodiments of the present application provide a color wheel assembly, including a thermally conductive substrate and a wavelength changing device, fixedly connected to each other,

the heat conduction substrate comprises a first surface and a second surface which are opposite, one or more through holes are arranged on the heat conduction substrate, and the through holes penetrate from the first surface to the second surface;

the wavelength changing device comprises a wavelength changing layer and a heat conducting and light transmitting layer, wherein the wavelength changing layer can absorb exciting light and emit stimulated light, and the heat conducting and light transmitting layer is used for supporting the wavelength changing layer;

the wavelength changing device covers the through holes of the heat-conducting base material and is arranged in one-to-one correspondence with the through holes.

In one possible implementation, the thermally conductive and light transmissive layer is a silicon carbide layer or an aluminum nitride layer or a silicon nitride layer or a diamond layer.

In a possible implementation manner, the wavelength changing device further includes a reflective layer or a transmissive layer, the thermally conductive and optically transmissive layer is located between the wavelength changing layer and the reflective layer or the transmissive layer, and the thermally conductive and optically transmissive layer is further configured to support the reflective layer or the transmissive layer.

In a possible implementation manner, the wavelength-changing device is disposed on the first surface of the heat-conductive substrate, and the wavelength-changing layer is located on a side of the heat-conductive and light-transmissive layer away from the first surface.

In a possible implementation manner, the wavelength changing device further includes a heat-conducting adhesive layer, and the heat-conducting adhesive layer is disposed between the wavelength changing device and the heat-conducting substrate, so that the wavelength changing device is fixed on the heat-conducting substrate.

In one possible implementation, the size of the heat-conducting and light-transmitting layer is larger than that of the through hole.

In a possible implementation manner, the heat conduction substrate further comprises a driving device fixedly connected with the heat conduction substrate, and the driving device is used for driving the heat conduction substrate to rotate;

the side surface of the heat conduction substrate is provided with a radiating fin, the radiating fin protrudes out of the side surface of the heat conduction substrate, the radiating fin and the heat conduction substrate are of an integral structure, and the side surface is connected with the first surface and the second surface.

In a possible implementation manner, the device further comprises a reflection device or a transmission device fixedly connected with the heat conduction substrate, and the reflection device or the transmission device is used for reflecting or transmitting the excitation light.

In a possible implementation manner, the heat dissipation device is fixedly connected with the heat conduction substrate, and the heat dissipation device is arranged on one side of the through hole close to the central axis of the heat conduction substrate.

In a second aspect, an embodiment of the present application provides a projection apparatus, where the projection apparatus includes the color wheel assembly described in the first aspect and possible implementation manners of the first aspect.

The color wheel assembly provided by the embodiment of the application comprises a wavelength changing device and a heat-conducting base material fixedly connected with the wavelength changing device, wherein the wavelength changing device comprises a wavelength changing layer and a heat-conducting transparent layer, so that heat generated by the wavelength changing layer can be transferred to the heat-conducting base material through the heat-conducting transparent layer, and the heat dissipation performance of the wavelength changing layer is improved by outwards dissipating the heat through the heat-conducting base material. And by utilizing the special heat dissipation structure design, the high-efficiency heat conversion with air is realized, and the stable brightness output of the projection display system is improved. In addition, in the embodiment of the application, materials (such as silicon carbide, aluminum nitride, silicon nitride and diamond) with high heat conductivity coefficient, high transmittance and low absorption rate are used as the substrate material of the wavelength changing device, so that the wavelength changing device excited by the wavelength changing material with high functional density and high efficiency is realized, meanwhile, the wavelength changing material cannot be heated to saturation, and the brightness output stability of projection display is greatly improved.

Drawings

The above and other objects, features and advantages of the present application will become more apparent by describing in more detail embodiments of the present application with reference to the attached drawings. The accompanying drawings are included to provide a further understanding of the embodiments of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application. In the drawings, like reference numerals generally refer to like parts. Wherein:

fig. 1 is a schematic cross-sectional view of a color wheel assembly according to an embodiment of the present disclosure;

fig. 2 is a schematic top view of a color wheel assembly according to an embodiment of the present disclosure;

fig. 3 is a schematic structural diagram of a color wheel assembly according to an embodiment of the present disclosure;

fig. 4 is a schematic cross-sectional view of another color wheel assembly provided in an embodiment of the present application.

101: a wavelength-changing layer; 102: a heat-conducting light-transmitting layer; 103: a reflective layer or a transmissive layer; 104: a heat conductive substrate; 105: a heat sink; 106: a rotating shaft; 107: reflective or transmissive means; 108: a heat sink; 201: a first surface; 202: a second surface; 203: a side surface; 204: and a through hole.

Detailed Description

In order to make those skilled in the art better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all the embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application. Moreover, while the disclosure herein has been presented in terms of exemplary one or more examples, it is to be understood that each aspect of the disclosure can be utilized independently and separately from other aspects of the disclosure to provide a complete disclosure. The embodiments described below and the features of the embodiments can be combined with each other without conflict.

In the embodiments of the present application, "at least one" means one or more, "a plurality" means two or more. The words "exemplary," "e.g.," and the like are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, the term using examples is intended to present concepts in a concrete fashion. The terminology used in the embodiments of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the examples of this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs. The use of "first," "second," and similar terms in this application do not denote any order, quantity, or importance, but rather the description is used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The term "and/or" includes any and all combinations of one or more of the associated listed items. It is to be understood that the terms "upper", "lower", "inner", "outer", "front", "back", and the like are used merely for convenience in describing the present application and for simplicity in description, and are not intended to imply or imply any limitations on the present application.

In order to thoroughly understand the present application, a detailed description will be provided below in order to explain the technical solution of the present application. The following detailed description of the preferred embodiments of the present application, however, will suggest that the present application may have other embodiments in addition to these detailed descriptions.

Fig. 1 is a schematic cross-sectional view of a color wheel assembly according to an embodiment of the present disclosure. As shown in fig. 1, the color wheel assembly includes a fixedly connected wavelength changing device and a heat conducting substrate 104, wherein the heat conducting substrate 104 includes a first surface 201 and a second surface 202 opposite to each other, one or more through holes 204 are formed in the heat conducting substrate 104, and the through holes 204 penetrate from the first surface 201 to the second surface 202; the wavelength changing device comprises a wavelength changing layer 101 and a heat-conducting and light-transmitting layer 102, wherein the wavelength changing layer 101 can absorb exciting light and emit stimulated light, and the heat-conducting and light-transmitting layer 102 is used for supporting the wavelength changing layer 101; the wavelength changing device covers the through holes 204 of the heat conducting substrate 104 and is disposed in one-to-one correspondence with the through holes 204. If only one wavelength changing device is needed, only one through hole 204 needs to be formed in the heat conducting substrate 104, and if two wavelength changing devices are needed, two through holes 204 need to be formed in the heat conducting substrate 104, and so on. In some embodiments, to better avoid the imbalance of the color wheel assembly, the wavelength-changing devices may be symmetrically disposed on the heat-conducting substrate 104, and the through holes 204 on the heat-conducting substrate 104 are also symmetrically disposed, as shown in fig. 1 to 3. It should be noted that the heat conducting substrate 104 in the embodiment of the present application is circular, and in other embodiments, the heat conducting substrate 104 may also be other shapes, such as rectangular.

The wavelength change device in the color wheel assembly provided by the embodiment of the application can dissipate heat through the heat conducting substrate, and is arranged at the through hole of the heat conducting substrate, so that the heat dissipation efficiency of the wavelength change device is greatly improved.

With continued reference to fig. 1, the wavelength-changing device may further include a reflective or transmissive layer 103, a thermally conductive and optically transmissive layer 102 disposed between the wavelength-changing layer 101 and the reflective or transmissive layer 103, the thermally conductive and optically transmissive layer 102 further supporting the reflective or transmissive layer 103. If the wavelength changing device includes a reflective layer, that is, the wavelength changing device is a reflective wavelength changing device, the received laser light emitted by the wavelength changing layer 101 will be returned by the reflective layer along the original path; if the wavelength changing device includes a transmissive layer, that is, the wavelength changing device is a transmissive wavelength changing device, the laser light emitted from the wavelength changing layer 101 is transmitted by the transmissive layer, and the embodiment of the present application takes a reflective layer as an example for detailed description, that is, in the embodiment of the present application, the wavelength changing device includes the wavelength changing layer 101, the thermally conductive and transparent layer 102, and the reflective layer 103, wherein the wavelength changing layer 101 is tightly connected to the thermally conductive and transparent layer 102 and the thermally conductive and transparent layer 102 is tightly connected to the reflective layer 103. Alternatively, the wavelength-changing layer 101 and the heat-conducting and light-transmitting layer 102 may be joined by using a bonding, coating, mechanical fixing, fastening, or the like, and the heat-conducting and light-transmitting layer 102 and the reflective layer 103 may be joined by using a coating, plating, adhering, or the like, which is not limited in this embodiment.

In the working state, after the excitation light irradiates the wavelength changing layer 101, the wavelength changing material is excited to emit excited light, the excited light and part of the excitation light which does not participate in the excitation pass through the wavelength changing layer 101, reach the reflecting layer 103 through the heat-conducting light-transmitting layer 102, are reflected by the reflecting layer 103, return to irradiate the wavelength changing layer 101 again, excite the wavelength changing material again, and finally emit.

The wavelength changing layer 101 is irradiated with excitation light and then excited to emit laser light, and common wavelength changing materials include phosphor, ceramic phosphor sheet, glass phosphor, and the like, and phosphor is preferable. The wavelength-changing layer 101 may further include a binder, and the wavelength-changing material and the binder form a layered structure, and the binder may be an inorganic binder, an organic binder, or a combination thereof. The organic adhesive is suitable for a low-power wavelength changing device, and the preparation process is simple; however, for high power wavelength conversion devices, the organic adhesive cannot withstand the high temperature caused by the high luminous intensity for a long time, and the present embodiment uses an inorganic adhesive, such as glass or transparent ceramic, as the adhesive, so that the wavelength conversion device can still be stable at high temperature. In some embodiments, the wavelength-changing layer 101 is prepared by sintering a mixed slurry of an inorganic binder and a wavelength-changing material on the thermally conductive and optically transparent layer 102 until the mixed slurry is softened, and a connection structure formed by sintering exists between the wavelength-changing layer 101 and the thermally conductive and optically transparent layer 102, so that the wavelength-changing layer 101 and the thermally conductive and optically transparent layer 102 are more tightly bonded to each other, thereby facilitating reduction of interface thermal resistance during heat conduction from the wavelength-changing layer 101 to the thermally conductive and optically transparent layer 102.

The heat-conducting transparent layer 102 is a transparent layer for supporting the wavelength-changing layer 101 and the reflective layer 103, has good heat resistance and high heat conductivity, and can bear excitation light irradiation with high power density, such as a silicon carbide (SiC) layer or an aluminum nitride (AIN) layer or a silicon nitride (SiN) layer or a diamond layer, and the like, specifically, can be a silicon carbide crystal, a silicon carbide ceramic, an aluminum nitride crystal, an aluminum nitride ceramic, a silicon nitride crystal, a silicon nitride ceramic, a diamond, and the like, wherein the silicon carbide, the aluminum nitride, and the silicon nitride material includes a single crystal material, a polycrystalline material, a ceramic (a material with a cubic crystal form can be used for preparing a transparent ceramic with high density and fewer internal pores); diamond includes both single crystal and polycrystalline materials.

The reflecting layer 103 is a metal reflecting film or a dielectric reflecting film, the metal reflecting film has the advantages of simple film coating, high reflectivity and good heat conductivity, the reflectivity of the dielectric reflecting film can be more than 99%, and the reflecting wavelength range of the dielectric reflecting film can be designed according to requirements. The medium reflecting film is designed to transmit the excited light and reflect the exciting light, so that the effect of obtaining the monochromatic excited light by using the wavelength changing device is achieved. Part of the excitation light transmitted through the wavelength changing layer 101 passes through the reflective layer 103 and then excites the wavelength changing layer 101 again, so that secondary excitation is realized, and the excited light of the wavelength changing layer 101 is reflected.

The wavelength changing device can be bonded to the heat conductive substrate 104 by a heat conductive adhesive material, and in other embodiments, the wavelength changing device can be connected to the heat conductive substrate 104 by other methods, such as clamping, etc. The heat-conducting adhesive material forms a heat-conducting adhesive layer (not shown) between the wavelength-changing device and the heat-conducting substrate 104, and the heat of the wavelength-changing layer 101 is transmitted to the heat-conducting substrate 104 through the heat-conducting transparent layer 102 and the heat-conducting adhesive layer in sequence to be dissipated. Preferably, the size of the thermally conductive transparent layer 102 is larger than the size of the through hole 204, so as to increase the contact area between the wavelength-changing device and the thermally conductive substrate 104, thereby enhancing the thermal conductivity of the color wheel assembly. Assuming that the contact area of the wavelength changing device with the heat-conducting substrate 104 through the heat-conducting adhesive layer is S, the heat flow transferred from the wavelength changing layer 101 to the heat-conducting transparent layer 102 is Q, the thickness of the heat-conducting adhesive layer is d, the heat conductivity of the adhesive material used in the heat-conducting adhesive layer is λ, and the temperature difference of the heat-conducting adhesive layer cannot exceed T (a preset threshold), the contact area S can be made to satisfy the formula

Thereby achieving better heat dissipation effect.

Optionally, the color wheel assembly may further include a heat dissipation device 108 fixedly connected to the heat conductive substrate 104, where the heat dissipation device 108 is disposed at a side of the through hole 204 close to the central axis of the heat conductive substrate 104, so as to enhance heat dissipation of the inner ring, as shown in fig. 4. The heat dissipation device 108 may be a heat dissipation fin, a fan blade, a boss, a bump, or the like, and the heat dissipation device 108 may be integrally formed with the heat conductive substrate 104, or may be a modular component that is fixed on the heat conductive substrate 104 by other methods such as bonding, for the selection of the high power wavelength changing device.

With continued reference to fig. 1-3, the color wheel assembly may further include a driving device (not shown) fixedly connected to the heat-conducting substrate 104, and the driving device is configured to drive the heat-conducting substrate 104 to rotate around the rotation axis 106. The side surface of the heat conducting substrate 104 is further provided with a heat sink 105, the heat sink 105 is arranged to protrude out of the side surface 203 of the heat conducting substrate 104, the heat sink 105 and the heat conducting substrate 104 can be of an integral structure, or the heat sink can be connected to the side surface of the heat conducting substrate 104 by welding, bonding or the like, and the side surface 203 is connected to the first surface 201 and the second surface 202. The heat sink 105 may be a heat sink fin, a fan blade, a boss, a bump, or the like. Preferably, the heat conducting substrate 104 is a metal substrate, such as an aluminum alloy substrate or the like. Through the radiating fins 105 arranged on the outer edge of the heat conducting substrate 104, the flow velocity of forced air is increased by utilizing the larger edge radius and the larger linear velocity, the heat exchange speed is increased, the heat source of the wavelength changing layer is closer to the radiating fins, the heat transfer path is shorter, the heat of the heat source can be quickly transferred to the air, and the high-speed heat exchange is realized.

The wavelength-changing layer 101 on the wavelength-changing device may include one or more wavelength-changing regions, and when the driving device is used to drive the heat-conducting substrate 104 to rotate the wavelength-changing device, the wavelength-changing layer 101 on the wavelength-changing device may include a plurality of wavelength-changing regions, or the wavelength-changing layers 101 of the plurality of wavelength-changing devices disposed on the heat-conducting substrate 104 include different wavelength-changing regions, so as to generate a plurality of different colors of stimulated light. Furthermore, the heat conducting substrate 104 may further be provided with a reflection device or a transmission device 107 for reflecting or transmitting the excitation light and the stimulated light to enter the light combining system, the reflection device 107 may be a metal substrate, a structure formed by adhering a reflection mirror or plating a reflection film on the metal substrate, or may directly use the heat conducting transparent layer 102 and the reflection layer 103 of the wavelength changing device as the reflection device 107, or directly use the heat conducting substrate 104, for example, polishing the surface of the heat conducting substrate 104 or plating a reflection film as the reflection device 107; the transmissive device 107 may be a notch of the heat conductive substrate 104, or may be a heat conductive and light transmissive layer 102 of the wavelength varying device or a heat conductive and light transmissive layer 102 and a transmissive layer 103 of the wavelength varying device, which are not limited in this embodiment.

In one embodiment, the wavelength-changing device is fixed on the first surface 201 of the heat-conducting substrate 104 through a heat-conducting adhesive layer, the wavelength-changing layer 101 is located on a side of the heat-conducting transparent layer 102 away from the first surface 201, the size of the wavelength-changing layer 101 is smaller than or equal to the size of the through hole 204 on the heat-conducting substrate 104 and the size of the reflective layer 103, the projection of the wavelength-changing layer 101 on the plane of the reflective layer 103 falls within the area of the reflective layer 103, and the heat dissipation device 108 is located on the second surface. In other embodiments, the wavelength changing device may be fixed in the through hole 204 instead of being disposed on the surface of the heat conducting substrate 104, such as a clamping structure for fixing the wavelength changing device is disposed on two wall surfaces of the through hole 204; wavelength-altering layer 101 may also be located on a side of thermally conductive, optically transparent layer 102 proximate to first surface 201; the wavelength-changing layer 101 and the reflective layer 103 may both have the same size as the thermally conductive, optically transmissive layer 102; the size of the reflective layer 103 may also be smaller than the size of the thermally conductive transparent layer 102 as long as the size of the reflective layer 103 is greater than or equal to the size of the wavelength-changing layer 101; the heat dissipation device 108 may also be disposed on the first surface, which is not limited in this application.

In this embodiment, in the operating state, the excitation light firstly excites the first outgoing light on the surface of the wavelength-changing layer 101, and then continues to propagate. After passing through the heat-conductive light-transmitting layer 102, the light is reflected on the surface of the reflective layer 103 to form first reflected light, and the first reflected light is reflected back to the wavelength-changing layer 101. The first reflected light excites the wavelength-changing material again, and part of the excited light is emitted together with the rest of the excitation light to form second emitted light. The stimulated light reflected to the inside of the heat-conducting light-transmitting layer is finally emitted after being reflected by the reflecting layer 103, so that third emergent light is formed.

The embodiment of the present application further provides a projection apparatus, including the color wheel assembly according to the above embodiment, and the projection apparatus further includes other assemblies, such as an excitation light source, and the arrangement of these assemblies may refer to related technologies, and is not described herein again.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A color wheel assembly comprising a thermally conductive substrate and a wavelength changing device fixedly attached thereto, wherein,

2. The color wheel assembly of claim 1 wherein the thermally conductive light transmitting layer is a silicon carbide layer or an aluminum nitride layer or a silicon nitride layer or a diamond layer.

3. The color wheel assembly of claim 1 wherein the wavelength changing device further comprises a reflective or transmissive layer, the thermally conductive and optically transmissive layer being positioned between the wavelength changing layer and the reflective or transmissive layer, the thermally conductive and optically transmissive layer further supporting the reflective or transmissive layer.

4. The color wheel assembly of claim 1 wherein the wavelength-altering device is disposed on the first surface of the thermally conductive substrate, the wavelength-altering layer being disposed on a side of the thermally conductive light-transmissive layer away from the first surface.

5. The color wheel assembly of claim 1 further comprising a thermally conductive adhesive layer disposed between the wavelength-altering device and the thermally conductive substrate to secure the wavelength-altering device to the thermally conductive substrate.

6. The color wheel assembly of claim 1 wherein the thermally conductive light transmitting layer has a size greater than the size of the through hole.

7. The color wheel assembly of claim 1, further comprising a driving device fixedly connected to the heat-conducting substrate, wherein the driving device is configured to drive the heat-conducting substrate to rotate;

8. The color wheel assembly of claim 7 further comprising a reflective or transmissive device fixedly attached to the thermally conductive substrate, wherein the reflective or transmissive device is configured to reflect or transmit the excitation light.

9. The color wheel assembly of claim 1 further comprising a heat sink fixedly attached to the thermally conductive substrate, wherein the heat sink is disposed on a side of the through hole near a central axis of the thermally conductive substrate.

10. A projection device comprising a color wheel assembly according to any of claims 1-9.