Light source device and vehicle lamp
阅读说明：本技术 光源装置及车灯 (Light source device and vehicle lamp ) 是由 陈彬 李屹 于 2018-06-27 设计创作，主要内容包括：本发明保护一种光源装置,包括,激发光源,用于出射激发光；导光管,包括内管壁面、外管壁面、入射端面和底端面,入射端面与底端面相对设置,入射端面连接内管壁面和外管壁面；发光体,设置于导光管的管壁上,能够吸收激发光并出射受激光,其靠近导光管的面为光入射面；散热体,设置于导光管远离发光体一侧,与导光管热耦合；激发光源出射的激发光从导光管的入射端面入射,经导光管内传导后,从发光体的光入射面入射于发光体。本发明通过将原本光导的导光和导热功能分离,由独立的导光管的管壁负责导光,由独立的散热体负责导热,避免了选择同时具备高导热、高导光性能的光导的高成本问题,而且能够以更短的传输距离实现匀光。(The invention protects a light source device, comprising an excitation light source, a light source control unit and a control unit, wherein the excitation light source is used for emitting excitation light; the light guide pipe comprises an inner pipe wall surface, an outer pipe wall surface, an incident end surface and a bottom end surface, wherein the incident end surface is arranged opposite to the bottom end surface and is connected with the inner pipe wall surface and the outer pipe wall surface; the luminous body is arranged on the tube wall of the light guide tube, can absorb exciting light and emit excited light, and the surface of the luminous body close to the light guide tube is a light incidence surface; the heat radiation body is arranged on one side of the light guide pipe, which is far away from the luminous body, and is thermally coupled with the light guide pipe; the excitation light emitted from the excitation light source enters from the entrance end face of the light guide tube, is conducted in the light guide tube, and then enters the luminous body from the light entrance face of the luminous body. According to the invention, the light guide and heat conduction functions of the original light guide are separated, the tube wall of the independent light guide tube is responsible for light guide, and the independent heat radiator is responsible for heat conduction, so that the problem of high cost of selecting the light guide with high heat conduction and high light conduction performance at the same time is avoided, and the uniform light can be realized in a shorter transmission distance.)
1. A light source device is characterized by comprising,
an excitation light source for emitting excitation light;
the light guide pipe comprises an inner pipe wall surface, an outer pipe wall surface, an incident end surface and a bottom end surface, wherein the incident end surface is arranged opposite to the bottom end surface, and the incident end surface is connected with the inner pipe wall surface and the outer pipe wall surface;
the luminous body is arranged on the wall surface of the inner tube or the wall surface of the outer tube of the light guide tube, can absorb exciting light and emits excited light, and the surface of the luminous body close to the light guide tube is a light incident surface;
the heat radiation body is arranged on one side of the light guide pipe, which is far away from the luminous body, and is thermally coupled with the light guide pipe;
the exciting light emitted by the exciting light source is incident on the light guide pipe from the incident end face of the light guide pipe, and is incident on the luminous body from the light incident face of the luminous body after being conducted in the light guide pipe.
2. The light source device according to claim 1, wherein the length of the light guide tube is greater than the length of the light emitting body along the axial direction of the light guide tube, and the light emitting body is away from the incident end face of the light guide tube.
3. The light source device of claim 1, wherein the light-emitting body is disposed on a wall surface of an outer tube of the light guide tube, and the heat sink is disposed on a tube core of the light guide tube.
4. The light source device according to claim 3, wherein the light emitter does not completely cover the light guide in a circumferential direction of the light guide in at least a partial region of the light guide.
5. The light source device according to claim 4, wherein the circumferential angle at which the light-emitting body covers the light guide pipe at different positions along the light guide pipe is monotonically not decreased with increasing distance from the incident end surface of the light guide pipe.
6. The light source device according to any one of claims 1 to 3, wherein the light emitting surface of the light emitting body is disposed opposite to the light incident surface.
7. The light source device according to any one of claims 1 to 3, wherein a light emitting surface of the light emitting body is disposed adjacent to a light incident surface, and an area of the light emitting surface is smaller than an area of the light incident surface.
8. The light source device according to claim 1 or 2, wherein the light emitting body is disposed on the inner wall surface of the light guide tube, the light emitting body is a solid block structure, and the light emitting surface of the light emitting body is disposed adjacent to the light incident surface.
9. The light source device according to any one of claims 1 to 3, wherein the excitation light source includes at least two light emitting units, and incident light spots of the at least two light emitting units on the incident end face are not coincident.
10. The light source device according to any one of claims 1 to 3, comprising a light guide device disposed between the excitation light source and the light guide tube, wherein the excitation light is incident on an incident end surface of the light guide tube via the light guide device, and the light guide device comprises a lens, a lens group, or an optical fiber.
11. The light source device according to any one of claims 1 to 3, wherein the bottom end surface of the light guide tube is provided with a reflective layer or a reflective structure.
12. The light source device according to any one of claims 1 to 3, wherein the bottom end surface of the light guide pipe is provided with a wavelength conversion material.
13. The light source device according to any one of claims 1 to 3, wherein a reflective layer or a reflective structure is provided between the light guide tube and the heat sink.
14. The light source device according to any one of claims 1 to 3, wherein the heat sink includes a heat pipe, or the heat sink includes a flowing heat-conducting medium.
15. The light source device according to claim 3, wherein the heat sink includes a first heat sink portion and a second heat sink portion arranged in an axial direction of the light guide, a size of the first heat sink portion in a radial direction of the light guide is smaller than a size of the second heat sink portion in the radial direction of the light guide, the heat sink is thermally coupled to the light guide through the second heat sink portion, the first heat sink portion is not in contact with the light guide, and the second heat sink portion is close to the light emitter with respect to the first heat sink portion.
16. A vehicular lamp comprising the light source device according to any one of claims 1 to 15, and further comprising a light collecting device disposed on an exit light path of the light emitting body for collecting exit light of the light emitting body and emitting the collected exit light.
Technical Field
The invention relates to the technical field of illumination, in particular to a light source device and a car lamp.
Background
With the increasing demand for illumination brightness, solid-state light sources are highly desired. The existing LED lighting is gradually improved toward the combination of a plurality of light emitting elements with high power, however, due to the characteristics of the LED, the improvement of the lighting brightness is increasingly hindered by the heat dissipation problem along with the improvement of the electric power and the densification of the light emitting elements.
The laser diode belonging to the solid-state light source has the advantages of high luminous brightness under large current, long irradiation distance and the like, and the white light is obtained by exciting the fluorescent powder through the laser diode. The technical proposal adopted by the technical proposal is that the laser light source and the fluorescent luminescent material are separated, so that the superposition of the laser light source and the fluorescent luminescent material caused by heat is avoided, and the brightness of the whole light source is further improved.
However, with the further demand for brightness, heat dissipation of fluorescent light-emitting materials is becoming a problem in the industry. For this reason, the industry has focused on finding materials having both good light-guiding properties and good thermal conductivity, but it is expected that even if such materials are developed, the material cost problem cannot be solved in a short period of time. Therefore, a simple and economical light emitting structure is in need of the invention.
Disclosure of Invention
Aiming at the defects of high cost and difficult heat dissipation in the prior art, the invention provides a light source device with low cost and good heat dissipation, which comprises: an excitation light source for emitting excitation light; the light guide pipe comprises an inner pipe wall surface, an outer pipe wall surface, an incident end surface and a bottom end surface, wherein the incident end surface is arranged opposite to the bottom end surface, and the incident end surface is connected with the inner pipe wall surface and the outer pipe wall surface; the luminous body is arranged on the wall surface of the inner tube or the wall surface of the outer tube of the light guide tube, can absorb exciting light and emits excited light, and the surface of the luminous body close to the light guide tube is a light incident surface; the heat radiation body is arranged on one side of the light guide pipe, which is far away from the luminous body, and is thermally coupled with the light guide pipe; the exciting light emitted by the exciting light source is incident on the light guide pipe from the incident end face of the light guide pipe, and is incident on the luminous body from the light incident face of the luminous body after being conducted in the light guide pipe.
Compared with the prior art, the invention has the following beneficial effects:
the light guide between the excitation light source and the luminous body is set to be the light guide pipe, so that the excitation light is incident and conducted between the inner pipe wall surface and the outer pipe wall surface of the light guide pipe (namely, in the pipe wall surface), and no matter the luminous body is arranged on the inner pipe wall surface or the outer pipe wall surface of the light guide pipe, the heat radiation body can be arranged on the other pipe wall surface, so that the heat generated by the luminous body is radiated. The invention separates the light guide and heat conduction functions of the original light guide, the tube wall of the independent light guide tube is responsible for light guide, and the independent heat radiator is responsible for heat conduction, thereby avoiding the problem of high cost of selecting the light guide with high heat conduction and high light conduction performance.
Meanwhile, the exciting light is conducted in the tube wall of the light guide tube, so that the reflection distance of light in each time when the light is conducted in the light guide tube is reduced, and the light homogenization is realized at a shorter distance under the condition of the same outer tube diameter of the light guide tube; or, compared with a light pipe or a solid light guide rod for guiding light in a pipe core (namely, in the inner wall surface), under the condition of the same light pipe size, the invention realizes more uniform emergent light distribution. Compared with a flat-plate light guide, the light guide conducts light in two dimensional directions, so that the comprehensive volume of the light guide is reduced, and uniform light can be realized at a shorter transmission distance.
In the present invention, the actual light guiding structure of the light pipe is the pipe wall rather than the pipe core, and the pipe wall of the light pipe can be in various structures. For example, the cross section of the light guide tube may be a closed ring (such as a circular ring, a square ring, a polygonal ring, etc.), the excitation light is reflected back and forth in the closed ring to fill the whole closed ring in the cross section, and is axially transmitted along the light guide tube; the cross section of the light guide pipe can also be an open ring (such as an arc ring and the like), in the cross section, the exciting light is reflected for multiple times to fill the open ring, and the exciting light is reflected at two tail ends of the open ring, so that the light beam is prevented from leaking.
In one embodiment, further, along the axial direction of the light guide, the length of the light guide is greater than the length of the light emitter, and the light emitter is far away from the incident end face of the light guide. This embodiment makes, the exciting light evenly reachs the whole cross section of light pipe through the transmission of a distance before reaching the luminous body, has guaranteed that the light beam has all had even illuminance in every position that reaches the luminous body, avoids the light beam to get into the luminous body too early and arouses the too high heat production problem of luminous body local exciting light power density.
In one embodiment, the light emitter is disposed on a wall surface of an outer tube of the light guide tube, and the heat sink is disposed on a tube core of the light guide tube. On one hand, the embodiment ensures that the light emitted by the luminous body does not need to pass through the light guide pipe, is favorable for the emergent light of the luminous body to be directly emitted, and has thinner luminous bodies with the same quantity; on the other hand, the heat dissipation body can be concentrated on the core part of the light guide pipe, and the heat dissipation body is provided with a wider heat dissipation channel, so that heat can be rapidly conducted out.
In one embodiment, further, in at least a partial region of the light guide, the light emitter does not completely cover the light guide along a circumferential direction of the light guide. In this embodiment, the outer wall surface of the light guide tube not covered with the light emitter is a total reflection surface or a reflection layer/reflection structure is provided. This embodiment enables the light beam to exit in a certain direction with directivity.
In one embodiment, further, at different positions along the light guide, the circumferential angle of the light emitter covering the light guide is monotonically not decreased with increasing distance from the incident end face of the light guide. In this embodiment, the number of the light emitters covering the light guide pipe is gradually increased or unchanged as the light emitters are away from the incident end face of the light guide pipe, so that more light can reach the light emitters at a far position, and the improvement of the light emitting uniformity of the light emitters is facilitated.
In one embodiment, the light exit surface of the luminous body is arranged opposite to the light entry surface.
In one embodiment, the light emitting surface of the light emitting body is disposed adjacent to the light incident surface, and the area of the light emitting surface is smaller than the area of the light incident surface. In this embodiment, the excitation light homogenized by the light guide enters the light incident surface of the light emitter in a large area (i.e., a small excitation light power density), and the laser beam exits from the end surface of the light emitter in a small area, thereby forming the emission light with a high lumen density, which can be applied to various high lumen lighting/display fields.
In one embodiment, the light emitter is disposed on the inner wall surface of the light guide tube, the light emitter is a solid block structure, and the light emitting surface of the light emitter is disposed adjacent to the light incident surface. Unlike the aforementioned "the light emitter is outside the light pipe and the heat sink is inside the tube core", in this embodiment, the block light emitter is placed on the tube core, so that a large area of the light incident surface receives the excitation light with uniform and low lumen density from the light pipe, and emits the received laser light with high lumen density from a small area of the light exit surface of the end surface. On the one hand, the local heat generation of the luminous body is reduced, the thermal quenching of luminous body materials is prevented, and on the other hand, emergent light with high lumen density is obtained.
In one embodiment, the excitation light source includes at least two light-emitting units, and incident light spots of the at least two light-emitting units on the incident end face are not coincident. Because the incident end face of the whole light guide pipe is difficult to cover by the exciting light spots, the incident light spots are not uniformly distributed on the incident end face of the light guide pipe, and the cross section of the whole light guide pipe can be covered only by conducting the exciting light spots for a certain distance. In this embodiment, the number of the light emitting units of the excitation light source is increased, and the light spots of different light emitting units on the incident end surface are not overlapped, so that the coverage range of the incident light spots is enlarged in advance, and the excitation light can cover the cross section of the whole light guide pipe in a shorter distance. Preferably, the light emitting units are distributed uniformly in space around the axis of the light guide tube at the positions of the light spots on the incident end surface of the light guide tube.
In one embodiment, the light source device further includes a light guide device disposed between the excitation light source and the light guide, the excitation light is incident on the incident end surface of the light guide through the light guide device, and the light guide device includes a lens, a lens group, or an optical fiber.
In one embodiment, the bottom end surface of the light pipe is provided with a reflective layer or a reflective structure. In this embodiment, by providing the reflective layer/reflective structure, the remaining excitation light reaching the bottom end surface can be reflected back to the light guide tube for reuse, and the distribution of the excitation light in the light guide tube can be improved.
In one embodiment, the reflective layer on the bottom end surface of the light guide tube may be a specular reflective layer, such as an aluminum film or a silver film, a dichroic sheet, such as a wavelength filter, or a diffuse reflective structure, such as a diffusion sheet coated with a reflective film, a metal reflective substrate with a glass reflective powder layer, a reflective glue layer, or the like.
In one embodiment, the bottom end face of the light pipe is provided with a wavelength converting material. In this embodiment, the surplus excitation light reaching the bottom end surface of the light guide can also be emitted from the bottom end surface side of the light guide by the light conversion action of the wavelength conversion material of the bottom end surface.
In one embodiment, a reflective layer or a reflective structure is disposed between the light pipe and the heat sink. This embodiment enables light incident to the interface between the light pipe and the heat sink to be reflected back into the light pipe.
In one embodiment, the light pipe and the heat sink are connected by a heat conductive adhesive. This embodiment can increase the thermal contact interface between the two and relieve stress between the two.
In one embodiment, the heat sink comprises a heat pipe or the heat sink comprises a flowing heat conducting medium. Because the radiator does not need to consider the problem of light guide, in the embodiment, a heat pipe and a liquid cooling structure with higher heat dissipation efficiency can be selected, the problem of thermal quenching of the luminous body is further avoided, and the luminous body can bear excitation light irradiation with higher power density.
In one embodiment, the heat sink includes a first heat sink portion and a second heat sink portion arranged along an axial direction of the light pipe, a radial dimension of the first heat sink portion along the light pipe is smaller than a radial dimension of the second heat sink portion along the light pipe, the heat sink is thermally coupled to the light pipe through the second heat sink portion, the first heat sink portion is not in contact with the light pipe, and the second heat sink portion is close to the light emitting body relative to the first heat sink portion. In the invention, the luminous body is a real 'heat source', in the embodiment, the heat radiation body is divided into the first heat radiation part and the second heat radiation part, so that the second heat radiation part close to the luminous body is used as a main heat radiation structure of the luminous body, and on the premise of not obviously reducing the heat radiation effect of the heat radiation body, the first heat radiation part does not need to be in thermal contact with the light guide pipe, so that a reflection structure does not need to be arranged between the first heat radiation part and the light guide pipe, the conduction of exciting light can be realized only by the total reflection function of the wall surface of the inner pipe of the heat guide pipe, the light transmission efficiency is improved.
The invention also provides a vehicle lamp, which comprises the light source device and a light collecting device, wherein the light collecting device is arranged on the light path of the emergent light of the luminous body and is used for collecting the emergent light of the luminous body and then emitting the collected emergent light.
In one embodiment, the light collecting device is at least one of a reflector, a total reflection lens and a lens group.
According to the technical scheme, the light shape of the filament bulb of the existing halogen car lamp can be simulated through the light source device, so that the simple replacement of the halogen car lamp is realized, the brightness of the car lamp is improved, the energy consumption of the car lamp is reduced, and the cost for replacing the car lamp is reduced.
Drawings
FIG. 1a is a schematic view showing a structure of a light source device according to a comparative example of the present invention;
FIG. 1b is a cross-sectional view of the light guide and the light emitter of the light source device shown in FIG. 1 a;
fig. 2a is a schematic structural diagram of a light source device according to a first embodiment of the invention;
FIG. 2b is a schematic cross-sectional view A-A of the light source device shown in FIG. 2 a;
fig. 2c is a schematic cross-sectional view of a light pipe according to a variation of the first embodiment of the present invention;
FIG. 2d is a cross-sectional view of a light pipe according to another variation of the first embodiment of the present invention;
fig. 3a is a schematic structural diagram of a light source device according to a second embodiment of the invention;
FIG. 3B is a schematic cross-sectional view B-B of the light source device shown in FIG. 3 a;
FIG. 3C is a schematic cross-sectional view of the light source device shown in FIG. 3 a;
fig. 4 is a schematic structural diagram of a light source device according to a third embodiment of the present invention;
fig. 5 is a schematic structural diagram of a light source device according to a fourth embodiment of the invention;
fig. 6 is a schematic structural diagram of a light source device according to a fifth embodiment of the present invention;
fig. 7 is a schematic structural diagram of a light source device according to a sixth embodiment of the present invention;
fig. 8 is a schematic structural diagram of a light source device according to a seventh embodiment of the present invention;
FIG. 9 is a schematic structural diagram of a vehicular lamp according to an embodiment of the present invention
Detailed Description
The invention is mainly characterized in that the light guide adopted by the invention adopts different prior structures, and realizes great improvement on the aspects of optics and heat. Firstly, the tube wall of a tubular light guide is utilized to conduct light instead of a tube core, and the light guide and the heat conduction functions of the light guide are separated, so that the special purpose is achieved; secondly, the transmission distance of the light beam in the radial direction of the light guide is reduced by utilizing the shape of the tubular light guide, the reflection times of the light beam are increased by shortening the average reflection distance of the light beam, so that the light beam is more quickly homogenized and diffused to the whole cross section of the light guide, and the reduction of the length size of the light guide and the improvement of the uniformity of the exciting light are facilitated.
Referring to fig. 1a and fig. 1b, fig. 1a is a schematic structural diagram of a light source device according to a comparative example of the present invention, and fig. 1b is a cross-sectional view of a light guide and a light emitter of the light source device shown in fig. 1 a. The light source device comprises an excitation light source 1, a light guide 2 and a luminophor 3, wherein the light guide 2 is a solid light guide rod, and the luminophor 3 is covered on the surface of the light guide 2 in a surrounding way. Excitation light emitted from the excitation light source 1 is incident on the incident end surface of the light guide 2 in the axial direction of the light guide 2, and is homogenized by the light guide 2, and then is incident on the light incident surface of the light emitting body 3, that is, the surface of the light emitting body 3 in contact with the light guide 2, with uniform light distribution.
In this comparative example, the light emitting body 3 absorbs the excitation light and emits the excited light, there is an energy loss inevitable in this conversion process due to the stokes shift, and the lost energy is converted into heat energy, so that the light emitting body 3 is the most dominant heat source. On one hand, the light guide 2 is used as a light homogenizing device to convert incident exciting light with high lumen density into light with large area and low energy density; on the other hand, the heat sink is used for conducting and dissipating heat emitted by the luminous body 3. The functional requirements of the light guide 2 result in the need to select materials with low light absorption and high thermal conductivity.
In addition, in this comparative example, the incident excitation light is reflected and propagated in the light guide 2, and a uniform distribution is formed by multiple reflection. When the size of the light emitter 3 is determined, the number of reflections of the incident excitation light in the light guide 2 is limited, and when the position of the incident light spot incident on the light guide 2 is deviated from the center of the light guide 2 (i.e., the spatial distribution of the incident light is not uniform), insufficient number of reflections causes the excitation light in the light guide to be not uniformly distributed, thereby affecting the spatial uniformity of the outgoing light from the light emitter 3. Therefore, after dimensioning the luminary, it is desirable that the light guide is as long as possible to achieve light uniformity.
Different from the comparative example, the light source device comprises an independent excitation light source, a light guide pipe, a luminous body and a heat radiation body, wherein excitation light emitted by the excitation light source is homogenized through the light guide pipe and then enters the luminous body from a light incident surface of the luminous body; the luminous body absorbs the exciting light and emits excited light, heat is generated at the same time, and the heat enters the heat radiation body through the light guide pipe and is conducted and radiated by the heat radiation body. The respective components of the light source device are described in detail below.
< excitation light source >
The excitation light source is used for emitting excitation light and converting electric energy into light energy. In the invention, the excitation light source is used for providing at least part of excitation light for the luminophor to absorb and then emit the stimulated light, and the final stimulated light or the combination of the stimulated light and the residual excitation light is the output light of the light source device which is wanted.
The excitation light source may be a solid-state light source, such as an LED light source or an LD (laser diode) light source of a semiconductor light emitting technology, which has high light emitting efficiency, is energy-saving and environment-friendly. Especially, the light emitting efficiency of the laser diode light source under heavy current is far higher than that of an LED, and the divergence angle of emergent light is small, so that the emergent light can conveniently enter the light guide pipe after being collected.
The excitation light source may have only a single light-emitting unit, or may have two or more light-emitting units. When the excitation light source comprises more than two light-emitting units, the light-emitting units can be combined into one beam of light to enter the light guide pipe, and the technical scheme can increase the brightness of the beam of light, for example, a plurality of LEDs are used for combining light to obtain excitation light with high lumen density.
In another technical scheme, different light emitting units are incident into the light guide pipe at different positions, that is, incident light spots of different light emitting units on the incident end face of the light guide pipe are not coincident. It is understood that when the incident light spot of the light guide can cover the whole incident end surface, uniform light distribution can be obtained at the shortest distance, but if the incident light spot is to cover the whole incident end surface, the incident light spot is made larger than the incident end surface, resulting in light loss. Therefore, the technical scheme is balanced, the total incident light spot area of the incident end face is enlarged by utilizing the different light emitting units to be incident at different positions on the premise of not exceeding the incident end face of the light guide pipe, and therefore the exciting light can realize dodging in a shorter distance. In a preferred embodiment, the incident light spots of the light emitting units on the incident end face of the light guide pipe are uniformly distributed in space around the axis of the light guide pipe, the light uniformizing performance can be further improved, and when the number of the light emitting units is gradually increased, the technical scheme gradually approaches to the technical scheme that the incident light spots cover the whole incident end face.
< light pipe >
The light pipe is used for receiving exciting light from the excitation light source, and carries out even light to it through multiple reflection, then conducts the exciting light to the light incident surface of luminous body, and wherein, the face that is close to the light pipe of luminous body is the light incident surface. The exciting light is conducted in the wall of the light guide pipe, the light guide pipe comprises an inner pipe wall surface, an outer pipe wall surface, an incident end surface and a bottom end surface, the incident end surface and the bottom end surface are arranged oppositely, and the incident end surface is respectively connected with the inner pipe wall surface and the outer pipe wall surface. The excitation light is reflected on the outer tube wall and the inner tube wall.
The invention is not limited to the specific shape of the light pipe. For example, the light pipe may be a circular pipe or a square pipe, and at this time, the cross section of the light pipe is a circular ring or a square ring, the outer ring corresponds to the wall surface of the outer pipe, and the inner ring corresponds to the wall surface of the inner pipe. Of course, the cross-section of the light pipe may be a closed ring with other shapes, such as a hexagonal ring, etc. When exciting light incides to the incident terminal surface of light pipe, along the direction of keeping away from the incident terminal surface, the facula area of cross section enlarges gradually, until being full of whole cross section, realizes the evenly distributed of light beam in the light pipe.
In some embodiments of the present invention, the cross section of the light guide is in the shape of an open ring, and in this case, the light guide is added with two side end faces that simultaneously connect the inner tube wall surface, the outer tube wall surface, the incident end face, and the bottom end face, in addition to the inner tube wall surface, the outer tube wall surface, and the incident end face and the bottom end face, and the two side end faces prevent the excitation light from leaking from the opening of the open ring by the light reflection function.
The main function of the light guide is to guide light, and the material is selected from transparent materials with low light absorption, such as glass.
In some embodiments, the light guide tube is preferably made of a material with a high refractive index, for example, a material with a refractive index greater than 1.8, and this technical solution can utilize the principle of total reflection, so that the excitation light can be efficiently conducted in the light guide tube.
In other embodiments, the light guide does not use the total reflection principle, but a reflective layer is disposed on the wall surface of the light guide, so that the light guide can also achieve the light conduction function.
In some technical schemes of the invention, in order to prevent the exciting light from being transmitted to the bottom end surface in the light guide pipe and still not being completely absorbed, the bottom end surface is provided with a reflecting layer or a reflecting structure, the residual exciting light reaching the bottom end surface is reflected by the reflecting layer/the reflecting structure to be reused by the light guide pipe, and the light distribution of the exciting light in the light guide pipe along the length direction of the light guide pipe is improved to a certain extent. Specifically, the reflective layer may be a specular reflective layer, such as an aluminum film or a silver film, or a dichroic sheet, such as a wavelength filter, or a diffuse reflective structure, such as a diffusion sheet coated with a reflective film, a metal reflective substrate provided with a glass reflective powder layer, a reflective adhesive layer, or the like.
In order to avoid the leakage of the exciting light propagating in the light guide pipe at the bottom end face, the wavelength conversion material can be arranged at the bottom end face of the light guide pipe, so that the residual exciting light reaching the bottom end face of the light guide pipe can be emitted from one side of the bottom end face of the light guide pipe through the light conversion effect of the wavelength conversion material at the bottom end face, and the light safety is improved.
In order to increase the efficiency of exciting light entering the light guide, an antireflection film may be provided on the incident end face of the light guide to improve light transmittance.
In order to prevent the excitation light from leaking from the incident end surface after being reflected in the light guide tube, an angle selection diaphragm may be provided at the incident end surface so that the excitation light at a predetermined incident angle is transmitted and the light at other incident angles is reflected. Other filter membranes can be selected to realize various dichroic functions.
< light-emitting body >
The light emitting body can absorb the excitation light and emit the excited light with different wavelengths. The light-emitting body can be a fluorescent layer formed by fluorescent powder and adhesive, such as an organic fluorescent powder layer bonded by silica gel/resin and a fluorescent glass layer bonded by glass powder, wherein the silica gel, the resin and the glass powder play a role of the adhesive. The luminophores may also be quantum dot films.
The luminophor may also be a fluorescent ceramic, such as a pure phase fluorescent ceramic, a complex phase fluorescent ceramic.
The pure-phase fluorescent ceramic can be various oxide ceramics, nitride ceramics or oxynitride ceramics, and a luminescent center is formed by doping a trace of activator elements (such as lanthanide) in the preparation process of the ceramic. Because the doping amount of the activator element is generally small (generally less than 1%), the fluorescent ceramic is generally transparent or semitransparent luminescent ceramic. In one embodiment of the invention, the luminescent ceramic layer is a Ce-doped YAG ceramic; in another embodiment of the present invention, the luminescent ceramic layer is a Ce-doped LuAG ceramic.
Generally, the pure-phase fluorescent ceramic is of a polycrystalline structure, and in some embodiments of the invention, the luminophor can also be a fluorescent single crystal, which has better light transmission performance, is generally colored and transparent, has high thermal conductivity, and can generate total reflection on the surface.
The complex phase fluorescent ceramic takes transparent/semitransparent ceramic as a matrix, and fluorescent ceramic particles (such as fluorescent powder particles) are distributed in the ceramic matrix. The transparent/translucent ceramic matrix can be a variety of oxide ceramics (e.g., alumina ceramics, Y)3Al5O12Ceramics), nitride ceramics (such as aluminum nitride ceramics) or oxynitride ceramics, the ceramic matrix is used for conducting light and heat, so that exciting light can be incident on the fluorescent ceramic particles, and excited light can be emitted from the complex phase fluorescent ceramics; the fluorescent ceramic particles assume the main light emitting function of the fluorescent ceramic for absorbing the excitation light and converting it into stimulated light. The grain size of the fluorescent ceramic particles is larger, and the doping amount of the activator element is larger (such as 1-5%), so that the luminous efficiency is high; and the fluorescent ceramic particles are dispersed in the ceramic substrate, so that the condition that the fluorescent ceramic particles positioned at the deeper position of the fluorescent ceramic cannot be irradiated by exciting light is avoided, and the condition that the concentration of an activator element is poisoned due to the large integral doping amount of the pure-phase fluorescent ceramic is also avoided, thereby improving the luminous efficiency of the fluorescent ceramic.
In an embodiment of the present invention, scattering particles may be further added to each of the above luminescent bodies, so that the scattering particles are distributed in the luminescent bodies. The scattering particles are used for enhancing the scattering of the exciting light in the luminescent ceramic layer, so that the optical path of the exciting light in the luminescent body is increased, the light utilization rate of the exciting light is greatly improved, and the light conversion efficiency is improved. The scattering particles may be scattering particles such as alumina, yttria, zirconia, lanthana, titania, zinc oxide, barium sulfate, etc., and may be either single-material scattering particles or a combination of two or more kinds, and the scattering particles are characterized by apparent white color, ability to scatter visible light, stable material, ability to withstand high temperature, and particle size in the same order of magnitude or one order of magnitude lower than the wavelength of the excitation light. In other embodiments, the scattering particles may be replaced by air holes with the same size, and the difference between the refractive index of the air holes and the refractive index of the matrix or the adhesive is used to realize total reflection so as to scatter the excitation light or the stimulated light.
The fluorescent ceramic may also be another composite ceramic layer that differs from the above-described complex phase fluorescent ceramic only in the ceramic matrix. The ceramic matrix is pure-phase fluorescent ceramic, namely the ceramic matrix is provided with an activator and can emit stimulated light under the irradiation of exciting light. The technical scheme integrates the advantages of high luminous efficiency of the luminescent ceramic particles of the complex phase fluorescent ceramic and the advantages of luminous performance of the pure phase fluorescent ceramic, and utilizes the luminescent ceramic particles and the fluorescent ceramic matrix to emit light, so that the luminous efficiency is further improved. In this luminophore, scattering particles or pores can likewise be added to enhance internal scattering.
The light-emitting material (e.g., phosphor) in the light-emitting body is not limited to a single material, and may be a combination of a plurality of materials, or may be a stacked combination of a plurality of material layers. The volume distribution of the luminescent centers in the luminescent body is not limited to the uniform distribution, and may be non-uniform distribution such as gradient distribution.
In the invention, the luminous body is arranged on the light guide pipe, and can be arranged on the wall surface of the outer pipe of the light guide pipe or the wall surface of the inner pipe of the light guide pipe.
Whether the light emitter is disposed on the outer wall surface or the inner wall surface of the light pipe, the length of the light emitter is preferably smaller than the length of the light pipe. This is because the excitation light emitted from the excitation light source cannot form uniform light just after entering the light guide tube, and the uniform light can be formed only after the cross section of the light guide tube is filled by conducting and reflecting the excitation light for a certain distance. Therefore, in some preferred technical solutions of the present invention, the length of the light guide is greater than the length of the light emitter, and the light emitter is far away from the incident end surface of the light guide, so that the excitation light has a sufficient distance to realize uniform light. Of course, the present invention does not preclude sacrificing some of the uniformity in some embodiments, such that the length of the light emitters is equal to the length of the light pipe, or even greater than the length of the light pipe. For the luminophor which exceeds the length part of the light guide pipe, the conduction can be realized by utilizing the total reflection or reflection of the exciting light on the surface of the luminophor. In addition, even the length of luminous body is less than the light pipe, still can make partial luminous body surpass the length scope of light pipe for this partial luminous body corresponding light pipe "unsettled" sets up, and this technical scheme can increase the light-emitting area of luminous body, obtains more emergent light type.
When the light emitter is disposed on the outer tube wall surface of the light guide tube, the heat sink is disposed at the tube core position of the light guide tube, and the excitation light in the light guide tube enters the light emitter through the outer tube wall surface optically coupled to the light incident surface of the light emitter. In the technical scheme, the light emitted by the luminous body does not need to be emitted through the light guide pipe, the direct emission of the emitted light of the luminous body is facilitated, and for the same light guide pipe and the same quantity of luminous bodies, the scheme has thinner luminous body than the scheme that the luminous body is arranged on the wall surface of the inner pipe of the light guide pipe; on the other hand, the technical scheme enables the heat radiator to be concentrated on the core part of the light guide pipe, has a wider heat radiation channel and is beneficial to quickly guiding out heat.
When the luminous body is arranged on the wall surface of the inner tube of the light guide tube, the luminous body is of a solid block structure, namely the luminous body is arranged on the tube core of the light guide tube. Under this technical scheme, the light that the luminous body sent is difficult to pass the light pipe outgoing, therefore in an embodiment, the light emergence face of luminous body sets up with the light incidence face is adjacent, and the emergent light direction of the light emergence face of luminous body is along the length direction of light pipe. The exciting light homogenized by the light guide pipe is incident around the luminous body in a large area and is absorbed by the luminous body at a lower luminous lumen density, so that the uniformity of heat generation is improved, and material thermal quenching caused by local overheating is avoided; and finally emergent light is emitted from the end face of the luminous body, the luminous area is small, the brightness is high, and emergent light with high lumen density is obtained.
In the scheme that the outer pipe wall of the light guide pipe covers the luminous body, the luminous body can completely cover the pipe wall surface of the light guide pipe along the circumferential direction of the light guide pipe for the part of the pipe wall of the light guide pipe covering the luminous body, and the luminous body can emit light in all directions along the circumferential direction. In other technical scheme, at least partial region of light pipe, the luminous body has restricted the emergent light orientation of luminous body along the circumference of light pipe not completely cover the light pipe.
Further, the circumferential angle at which the light emitter covers the light pipe varies at different positions along the length of the light pipe. Especially in a scheme, the circumferential angle of the light-emitting body covering the light guide pipe is monotonous and does not decrease along with the increase of the distance from the incident end face of the light guide pipe.
In the present invention, the light emitting surface of the light emitting body may be a surface opposite to the light incident surface thereof, or may be an adjacent surface to the light incident surface. In the technical scheme that the luminous body is arranged on the wall surface of the inner tube of the light guide tube, the light emitting surface opposite to the light incident surface is not provided, and only the adjacent surface of the light incident surface can be used as the light emitting surface, namely the end surface of the luminous body. In the technical scheme that the luminous body is arranged on the wall surface of the outer tube of the light guide tube, the light emergent surface of the luminous body can be an opposite surface similar to the area of the light incident surface, and an adjacent surface with a smaller area can also be selected. When a linear or planar illumination light source having a large area is required, a surface provided opposite to the light incident surface is selected as the light emitting surface. When a small-area light source with a high lumen density is required, the adjacent surface of the light entrance face is selected as the light exit face. Of course, the opposite surface of the light incident surface and the adjacent surface may be used as the light emitting surface of the light emitting body at the same time.
In the invention, the light emitting surface of the luminous body can be added with an optical film to obtain light with specific optical characteristics. For example, by providing a wavelength filter, only light in a certain wavelength range is transmitted to obtain outgoing light with high color purity, or by reflecting excitation light, the light utilization efficiency of the excitation light is improved. An analyzer membrane may also be provided to obtain light of a single polarization state. An angle selection membrane can be arranged to obtain emergent light with a small divergence angle.
< Heat dissipating body >
The heat radiation body is used for conducting and radiating heat emitted by the luminous body. The heat radiator is contacted with the light pipe and is positioned on the wall surface of one side of the light pipe far away from the luminous body, so that heat emitted by the luminous body firstly passes through the wall of the light pipe and then is conducted to the heat radiator.
The heat radiating body may be any known heat radiating structure, such as a metal heat radiating member. In one aspect, the heat sink includes a heat pipe. In one aspect, the heat sink includes a flowing heat conducting medium. Because the radiator does not need to consider the problem of light guide, in the embodiment, a heat pipe and a liquid cooling structure with higher heat dissipation efficiency can be selected, the problem of thermal quenching of the luminous body is further avoided, and the luminous body can bear excitation light irradiation with higher power density.
In order to prevent the contact between the heat sink and the light pipe from affecting the optical performance of the light pipe, a reflective layer or a reflective structure, such as a reflective film, may be disposed between the light pipe and the heat sink.
Most of the radiators are made of metal, and the light guide pipe is made of glass or ceramic, so that the thermal expansion coefficients of the radiator and the light guide pipe are greatly different, and in order to eliminate stress and ensure the thermal contact area of the radiator and the light guide pipe, heat-conducting glue for connection can be arranged between the light guide pipe and the radiators.
The structure of the heat radiator can be improved to realize improvement of volume and cost. In the technical scheme that the radiator is arranged on the tube core of the light guide tube, the radiator comprises a first radiating part and a second radiating part which are arranged along the axis of the light guide tube, the radial size of the first radiating part along the light guide tube is smaller than that of the second radiating part along the light guide tube, the radiator is thermally coupled with the light guide tube through the second radiating part, the first radiating part is not in contact with the light guide tube, and the second radiating part is close to the luminous body relative to the first radiating part (preferably, the projection of the second radiating part on the light guide tube is coincident with the projection of the luminous body on the light guide tube). According to the technical scheme, unnecessary heat dissipation structures can be reduced, the heat dissipation body can conduct heat dissipation on the luminous body in a targeted mode, and cost is reduced.
The embodiments of the present invention will be described in detail below with reference to the drawings and the embodiments.
Referring to fig. 2a, fig. 2a is a schematic structural diagram of a light source device according to a first embodiment of the invention. The light source apparatus 10 includes an excitation light source 110, a
The excitation light source 110 is used to emit excitation light. As described above, it may be an LED, a laser diode light source, or the like.
In this embodiment, the
The
The
In the overall optical path, the excitation light emitted from the excitation light source 110 enters the light guide from the entrance end surface 123 of the
For further clarity of describing the structure of the
The shape of the light pipe of the present invention is not limited to the circular pipe shape shown in fig. 2b, and the cross section may be other closed ring shapes. Fig. 2c is a schematic cross-sectional view of a light guide tube according to a variation of the first embodiment of the present invention, which shows a
Moreover, the cross section of the light guide pipe is not limited to be in a closed ring shape, and can be in an open ring shape. Fig. 2d is a schematic cross-sectional view of a light guide tube according to another modified embodiment of the first embodiment of the present invention, which shows a
Referring back to fig. 2a, in the embodiment, along the axial direction of the
In this embodiment, the light incident surface of the
In this embodiment, in addition to the excitation light source 110, the
In this embodiment, the heat sink may be a metal structure with fins, a heat dissipation structure including a heat pipe, or an active heat dissipation structure, such as a refrigeration chip. The radiator does not need to bear optical action, and various light-absorbing, light-transmitting and light-reflecting materials can be selected without limitation. The heat sink can therefore also be a flowing heat-conducting medium, such as cooling water. In this embodiment, since the excitation light is incident on the light pipe by remote irradiation, the light pipe, the light emitting body, and the heat radiating body are configured without electrical connection, and there is no fear of an electric shock safety problem in the technical solution using cooling water.
Referring to fig. 3a, fig. 3a is a schematic structural diagram of a light source device according to a second embodiment of the present invention, wherein the light source device 20 includes an
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