CN113671781B

CN113671781B - Light emitting unit, light source system, and laser projection apparatus

Info

Publication number: CN113671781B
Application number: CN202111016358.XA
Authority: CN
Inventors: 张勇
Original assignee: Qingdao Hisense Laser Display Co Ltd
Current assignee: Qingdao Hisense Laser Display Co Ltd
Priority date: 2021-08-31
Filing date: 2021-08-31
Publication date: 2023-03-14
Anticipated expiration: 2041-08-31
Also published as: CN113671781A

Abstract

The application discloses luminescence unit, light source system and laser projection equipment belongs to projection technical field. The light emitting unit includes: the LED package comprises a heat conduction substrate, a package shell, a first reflection part, a second reflection part, a light emitting chip and a fluorescent part. Since the fluorescent moiety is in direct contact with the heat conducting substrate. Therefore, the heat generated by the fluorescent part can be quickly transferred to the whole heat conducting substrate to quickly dissipate the heat of the fluorescent part, so that the working temperature of the fluorescent part is lower. In this way, the fluorescence excitation efficiency of the fluorescent portion can be effectively improved, and the probability of damage to the fluorescent portion can be effectively reduced. Moreover, the light beam emitted by the light emitting chip is guided to the fluorescent part after being reflected for multiple times by the first reflecting part and the second reflecting part, so that the light loss of the light beam emitted by the light emitting chip in the process of being transmitted to the fluorescent part is low, the excitation efficiency of the fluorescent part on fluorescence is further improved, and the overall brightness of the light emitting unit is high.

Description

Light emitting unit, light source system, and laser projection apparatus

Technical Field

The present application relates to the field of projection technologies, and in particular, to a light emitting unit, a light source system, and a laser projection apparatus.

Background

At present, light sources of projection devices are mainly classified into three types, namely, a conventional bulb light source, a light-emitting diode (LED) light source, and a laser light source, wherein the laser light source is used as a light source of the projection device, and has the characteristics of high brightness, bright color, low energy consumption, long service life, and high picture contrast and clear imaging of the projection device.

A laser light source system comprising: laser, fluorescence wheel and light path subassembly. The laser includes a plurality of laser units for emitting monochromatic laser light. The fluorescent wheel comprises a substrate and a fluorescent layer positioned on the substrate. The substrate has a first partition and a second partition, the phosphor layer is located in the first partition of the substrate, and the second partition of the substrate is usually a transmission region or a reflection region. As the fluorescent wheel rotates, laser emitted by the laser can sequentially irradiate the first subarea and the second subarea. After laser emitted by the laser irradiates the first partition, the fluorescent layer in the first partition is excited by the laser and emits fluorescent light, and the emitted fluorescent light emits to the light path component; after the laser emitted by the laser irradiates the second partition, the second partition guides the laser to the optical path component. Thus, the optical path component can mix the fluorescence and the laser and output the mixed light.

However, in the above laser light source system, the fluorescent wheel is usually heat-dissipated by the rotation of the substrate and the fluorescent wheel itself. Since the phosphor layer in the phosphor wheel is usually bonded to the substrate by the adhesive, the adhesive is not conducive to heat dissipation of the phosphor layer. Therefore, the fluorescent wheel has a poor heat dissipation effect. Also, when the operating temperature of the fluorescent wheel is high, the efficiency of exciting the fluorescent light by the fluorescent layer in the fluorescent wheel is low, and the fluorescent layer may be damaged.

Disclosure of Invention

The embodiment of the application provides a light-emitting unit, a light source system and laser projection equipment. The technical scheme is as follows:

according to an aspect of the present application, there is provided a light emitting unit including: a heat conductive substrate;

the packaging shell is connected with the heat-conducting substrate, and one side, far away from the heat-conducting substrate, of the packaging shell is provided with a light outlet;

the first reflecting part is positioned between the light emitting chip and the fluorescent part, and the fluorescent part is in contact with the heat conducting substrate;

the second reflection part is positioned in the packaging shell and connected with the packaging shell;

the light emitting chip is used for emitting light beams to the first reflecting part;

the first reflector is used for guiding the light beam to the second reflector, and the second reflector is used for guiding the light beam to the fluorescent part;

the fluorescent part is used for emitting fluorescent light to the light outlet under the excitation effect of at least part of light rays in the light beams.

According to another aspect of the present application, there is provided a light source system comprising: the device comprises a light emitting component, a light path shaping component and a color filtering component;

the light emitting assembly includes: a plurality of light emitting units arranged in an array, each of the light emitting units being as claimed in any one of claims 1 to 9.

According to another aspect of the present application, there is provided a laser projection apparatus including: a light source system, at least one light valve and a projection lens; the light source system is the light source system.

The beneficial effects that technical scheme that this application embodiment brought include at least:

there is provided a light emitting unit including: the LED package comprises a heat conduction substrate, a package shell, a first reflection part, a second reflection part, a light emitting chip and a fluorescent part. Since the fluorescent moiety is in direct contact with the thermally conductive substrate, no colloid is present between the two. Therefore, the heat generated by the fluorescent part can be quickly transferred to the whole heat conducting substrate to quickly dissipate the heat of the fluorescent part, so that the working temperature of the fluorescent part is lower. Thus, the fluorescence excitation efficiency of the fluorescent part can be effectively improved, and the probability of damage to the fluorescent part can be effectively reduced. Moreover, the light beam emitted by the light emitting chip is guided to the fluorescent part after being reflected for multiple times by the first reflecting part and the second reflecting part, so that the light loss of the light beam emitted by the light emitting chip in the process of being transmitted to the fluorescent part is low, the excitation efficiency of the fluorescent part on fluorescence is further improved, and the overall brightness of the light emitting unit is high.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the description below are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic diagram of a light source system;

FIG. 2 is a schematic diagram of a fluorescent assembly of the light source system shown in FIG. 1;

fig. 3 is a schematic structural diagram of a light-emitting unit according to an embodiment of the present application;

FIG. 4 is a schematic diagram of an optical path of the light emitting unit shown in FIG. 3;

fig. 5 is a partial structural view of the light emitting unit shown in fig. 4;

fig. 6 is a schematic structural diagram of another light-emitting unit shown in the embodiment of the present application;

FIG. 7 is a schematic view showing the structure of a fluorescent moiety in the luminescent unit shown in FIG. 4;

fig. 8 is a schematic structural diagram of a light source system according to an embodiment of the present application;

fig. 9 is a schematic view of a color filter assembly in the light source system shown in fig. 8;

fig. 10 is a schematic structural diagram of a laser projection apparatus according to an embodiment of the present application.

Specific embodiments of the present application have been shown by way of example in the drawings and will be described in more detail below. The drawings and written description are not intended to limit the scope of the inventive concepts in any manner, but rather to illustrate the concepts of the application by those skilled in the art with reference to specific embodiments.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, the following detailed description of the embodiments of the present application will be made with reference to the accompanying drawings.

The laser light source system uses laser to excite fluorescent materials, generates fluorescence with different colors as a light source and is used for a projection display system.

Fluorescence is the emission of light from a substance after absorption of light or other electromagnetic radiation. When a certain normal temperature substance is irradiated by incident light (usually ultraviolet rays or X rays) with a certain wavelength, the substance enters an excited state after absorbing light energy, and immediately excites and emits emergent light (usually with the wavelength in a visible light waveband) which is longer than the wavelength of the incident light; many phosphors also exhibit a phenomenon of luminescence that immediately disappears as soon as the incident light stops. The emerging light having this property is called fluorescence.

As shown in fig. 1, fig. 1 is a schematic structural diagram of a laser light source system, which includes a laser 101, a fluorescent wheel 102, an optical path component 103, an output component 104, and a light focusing component 105. The laser 101 includes a plurality of laser units 1011 for emitting monochromatic laser light. Blue light wavelength is short in nature, and the cost of the blue laser unit is relatively low, and the blue laser unit is usually selected.

As shown in fig. 2, fig. 2 is a schematic structural diagram of a fluorescent component in the laser light source system shown in fig. 1. The fluorescent wheel 102 includes a substrate 1022 and a fluorescent layer 1021 on the substrate. Wherein the substrate has a first partition and a second partition. The phosphor layer 1021 is located in a first partition of the substrate 1022, and a second partition of the substrate 1022 is typically a transmissive region or a reflective region. As the fluorescent wheel 102 rotates, the laser light emitted from the laser device sequentially irradiates the first and second partitions. After the laser emitted by the laser irradiates the first partition, the fluorescent layer 1021 in the first partition is excited by the laser and emits fluorescent light, and the emitted fluorescent light is emitted to the light path component; after the laser emitted by the laser irradiates the second partition, the second partition guides the laser to the optical path component. Thus, the optical path component can mix the fluorescence and the laser and output the mixed light.

Due to the high energy density of the light beam irradiated to the fluorescent wheel 102, the fluorescent wheel 102 further includes a driving part 1023 for driving the fluorescent wheel 102 to rotate to prevent the fluorescent wheel 102 from being damaged by the high energy laser.

As shown in fig. 1, the optical path assembly 103 comprises a first lens assembly 1031 and a second lens assembly 1032, the first lens assembly 1031 is arranged in front of the incident surface of the fluorescence wheel 102 when the blue laser light reaches the fluorescence wheel 102, and the first lens assembly 1031 has the dual functions of focusing and collimating. When laser light enters the fluorescence wheel 102 through the first lens assembly 1031, the laser beam can be converged into a small spot, and when the fluorescence wheel 102 rotates to the position of the reflection portion, the blue laser spot irradiates on the fluorescent layer of the reflection portion of the fluorescence wheel 102 to excite the fluorescent light. The excited fluorescence is reflected by the wheel-shaped surface and passes through the first lens assembly 1031, and because the divergence angle of the fluorescence is relatively large, the fluorescence is collimated after passing through the first lens assembly 1031 and is converted into a parallel light beam to be emitted. When the fluorescent wheel 102 rotates to the transmissive part position, the blue laser spot is allowed to transmit through the transmissive part of the fluorescent wheel 102, and since the light travels in a straight line, the blue light is focused by the first lens assembly 1031 and then also diverges, so that the blue laser light reaches the back of the fluorescent wheel 102 and needs to be collimated by the second lens assembly 1032 again according to the reversible light path, so as to travel as a parallel light beam. The blue laser passes through the optical loop and outputs blue light. The light path component 103 is used for providing light paths of different color fluorescent light, so that the fluorescent light and the blue light in the laser light source system form primary colors required by laser display.

The output component 104 may be a color filter wheel. The laser Light source system can be used for a Digital Light Processing (DLP) display system to output three primary colors of red, green and blue in a required time sequence, wherein the blue primary color is provided by a blue laser beam, and the red and green primary colors are filtered out from a fluorescent beam by a color filter wheel.

However, the above laser light source system has the following problems: in the laser light source system, the fluorescent wheel generally relies on the rotation of the substrate and the fluorescent wheel to dissipate heat. Since the phosphor layers in the phosphor wheel are usually bonded to the substrate by the glue, the glue is not conducive to heat dissipation of the phosphor layers. Therefore, the fluorescent wheel has a poor heat dissipation effect. The heat of the fluorescent layer cannot be rapidly dissipated and is gathered on the fluorescent layer, so that the heat of the fluorescent layer is high, the conversion efficiency of the fluorescent is poor, and the display effect of the display system is poor. Moreover, when the operating temperature of the fluorescent wheel is high, the fluorescent layer in the fluorescent wheel has low excitation efficiency for fluorescent light, and the fluorescent layer is damaged.

The embodiment of the application provides a light-emitting unit, a light source system and a laser projection device, which can solve the problems existing in the related art.

As shown in fig. 3, fig. 3 is a schematic structural diagram of a light emitting unit shown in the embodiment of the present application, and the light emitting unit 20 may include: a heat conductive substrate 21, a package case 22, a first reflection part 23, a light emitting chip 24, a fluorescent part 25, and a second reflection part 26.

The package housing 22 is connected to the heat conductive substrate 21, and a light outlet 221 is formed on a side of the package housing 22 away from the heat conductive substrate 21.

The first reflector 23, the light emitting chip 24 and the fluorescent part 25 are all located in the package housing 22 and connected to the heat conductive substrate 21. The first reflection portion 23 is located between the light emitting chip 24 and the fluorescent portion 25, and the second reflection portion 26 is located in the package housing 22 and connected to the package housing 22. The fluorescent portion 25 is in contact with the heat conductive substrate 21. In this case, since the fluorescent portion 25 is in direct contact with the heat conductive substrate 21, no colloid exists therebetween. Therefore, the heat generated by the fluorescent part 25 can be quickly transferred to the whole heat conducting substrate 21 to quickly dissipate the heat of the fluorescent part 25, so that the operating temperature of the fluorescent part 25 is low.

In the embodiment of the present application, as shown in fig. 4, fig. 4 is a schematic optical path diagram of the light emitting unit shown in fig. 3, wherein the light emitting chip 24 can be used for emitting a light beam to the first reflection portion 23. The light emitting chip 24 may include a semiconductor light emitting element, which may emit a laser beam having a wavelength ranging from 420nm to 470nm (i.e., a blue light band), for example. It should be noted that the light emitting chip 24 in the embodiment of the present application may also emit light beams in another wavelength range, for example, the light emitting chip 24 may also emit light beams in a wavelength range of 410nm to 450 nm. The embodiments of the present application are not limited thereto.

The first reflector 23 may be used to direct the light beam to the second reflector 26, and the second reflector 26 may be used to direct the light beam to the fluorescent part 25. The light beam emitted from the light emitting chip 24 is guided to the fluorescent part 25 by the multiple reflection of the first and second reflecting

parts

23 and 26, so that the light loss of the light beam emitted from the light emitting chip 24 in the process of being transmitted to the fluorescent part 25 is low, and the fluorescence excitation efficiency of the fluorescent part 25 can be improved. The fluorescent portion 25 can be used to emit fluorescent light towards the light outlet 221 under excitation of at least part of the light in the light beam.

In summary, the embodiment of the present application provides a light emitting unit, including: the LED package comprises a heat conduction substrate, a package shell, a first reflection part, a second reflection part, a light emitting chip and a fluorescent part. Since the fluorescent moiety is in direct contact with the thermally conductive substrate, no colloid is present between the two. Therefore, the heat generated by the fluorescent part can be quickly transferred to the whole heat conducting substrate to quickly dissipate the heat of the fluorescent part, so that the working temperature of the fluorescent part is lower. Thus, the fluorescence excitation efficiency of the fluorescent part can be effectively improved, and the probability of damage to the fluorescent part can be effectively reduced. Moreover, the light beam emitted by the light emitting chip is guided to the fluorescent part after being reflected for multiple times by the first reflecting part and the second reflecting part, so that the light loss of the light beam emitted by the light emitting chip in the process of being transmitted to the fluorescent part is low, the excitation efficiency of the fluorescent part on fluorescence is further improved, and the overall brightness of the light emitting unit is high.

For example, the energy of the light beam irradiated to the fluorescent portion 25 by the light emitting chip 24 in the light emitting unit 20 may be less than or equal to 20W. And the energy of the laser beam irradiated to the fluorescent assembly by the laser in the related art is 60W to 100W. Therefore, in the embodiment of the present application, the energy received by the fluorescent portion 25 is small, and the problem of high temperature of the fluorescent portion 25 can be avoided, so that the fluorescence excitation efficiency of the fluorescent portion 25 is high.

Alternatively, the energy of the light beam irradiated to the fluorescent portion 25 by the light emitting chip 24 in the light emitting unit 20 may be more than 20W. Due to the faster heat dissipation of the fluorescent part 25 in the embodiment of the present application, the fluorescent part 25 can maintain a higher excitation efficiency when receiving higher energy.

Alternatively, as shown in fig. 4, the region of the heat conductive substrate 21 in contact with the fluorescent part 25 is a reflective region. The fluorescent part 25 can be used to emit fluorescence under the excitation of a part of the light beams emitted by the light emitting chip 24 and transmit another part of the light beams. That is, the fluorescent part 25 may be used to emit fluorescent light toward the light outlet 221 of the package case 22 by excitation of a part of light rays in the light beam emitted from the light emitting chip 24. The fluorescent portion 25 also serves as a reflective area for transmitting light beams emitted from the light emitting chip 24 to the heat conductive substrate 21. The reflective region of the heat conductive substrate 21 is used to reflect at least part of the light transmitted from the fluorescent portion 25 of the light beam toward the light outlet 221.

The other part of the light beam emitted from the light emitting chip 24 may refer to the light of the light beam emitted from the light emitting chip 24 that does not excite the fluorescent part 25. That is, the fluorescent light emitted from the fluorescent portion 25 may be mixed with the light reflected by the reflective region of the heat conductive substrate 21 and not exciting the fluorescent portion 25, and then guided to the light outlet 221 of the package housing 22. Illustratively, the light beam emitted from the light emitting chip 24 is a blue laser, the fluorescent portion 25 emits yellow fluorescent light under the excitation of a part of the blue light beam, and the reflective region of the heat conductive substrate 21 reflects at least a part of the blue light beam to the light outlet 221. That is, the yellow fluorescence and the blue light not exciting the fluorescence part 25 can be emitted to the light outlet 221 of the package case 22 together, and the light outlet 221 outputs a white light beam.

In general, when the fluorescent portion 25 is made of the same material, the thicker the fluorescent portion 25 is, the higher the proportion of fluorescence generated by the fluorescent portion 25 under excitation of light rays emitted from the light emitting chip 24 becomes, and the lower the proportion of light rays emitted from the light emitting chip 24 directly passing through the fluorescent portion 25 becomes. The ratio of the excited fluorescence to the directly reflected light beam can be determined by the color matching of the red, green and blue color modes, and the color temperature of the light beam is different in different ratios. When the set color temperature is low, the thickness of the fluorescent portion 25 can be increased to increase the fluorescence excited by the fluorescent portion 25 and reduce the reflected light. The red green blue color mode is a color standard in the industry, and various colors are obtained by changing three color channels of red, green and blue and superimposing the three color channels on each other, wherein the red, green and blue are colors representing the three channels of red, green and blue, the standard almost includes all colors which can be perceived by human vision, and the standard is one of the most widely used color systems.

The color temperature is a unit of measure representing the color component contained in the light. Exemplarily, the color temperature of red is the lowest, and then orange, yellow, white and blue are gradually increased, and blue is the highest color temperature; the higher the color temperature, the more blue and the less red components of the spectrum.

Illustratively, the fluorescent part 25 can be used to excite yellow fluorescence, and the light beam emitted by the light emitting chip 24 is blue laser; the yellow fluorescence emitted by the fluorescence part 25 and part of the blue laser beam emitted by the light emitting chip 24 converge at the light outlet to generate a white light beam. When the color temperature of the white light beam formed by the part of the blue laser beam and the yellow fluorescent light does not meet the requirement of the color temperature ratio, the ratio of the blue laser beam not exciting the fluorescent part 25 can be adjusted by adjusting the thickness of the fluorescent layer 252 in the fluorescent part 25.

In an alternative example, the reflective region of the heat conductive substrate 21 may include a white diffuse reflective layer or a metal reflective layer. The white diffuse reflection layer or the metal reflection layer may be connected to the heat conductive substrate 21. Wherein, the white diffuse reflection layer can play a role of dodging the reflected light beams. The metal reflective layer can be made of aluminum or silver, and the metal reflective layer has a good reflective effect. Alternatively, the heat conductive substrate 21 may have a reflective function, and thus, a white diffuse reflection layer or a metal layer may be provided on the heat conductive substrate 21 to perform a reflective function.

Alternatively, the metal reflective layer may be formed on the heat conductive substrate 21 by means of plating. The fluorescent portion 25 may be fixed to the heat conductive substrate by bonding or high temperature sintering. In this way, a part of the light beams emitted by the light emitting chip 24 directly passes through the fluorescent portion 25 and then irradiates the reflective area of the heat conducting substrate 21, and then irradiates the light outlet after being reflected by the reflective area.

In an exemplary implementation, as shown in fig. 4, a side of the first reflection part 23 close to the light emitting chip 24 has a first reflection surface 231, and a side of the second reflection part 26 close to the fluorescent part 25 has a second reflection surface 261. The first and second reflecting

surfaces

231 and 261 may be flat reflecting surfaces or curved reflecting surfaces.

Alternatively, as shown in fig. 4, at least one of the first reflecting surface 231 of the first reflecting portion 23 and the second reflecting surface 261 of the second reflecting portion 26 is a curved reflecting surface, which can be used to converge the light beam emitted by the light emitting chip and change the transmission direction of the light beam emitted by the light emitting chip to reduce the diffusion degree of the light beam emitted by the light emitting chip 24 during transmission, so that the fluorescent portion 25 can excite fluorescence with higher efficiency.

In an alternative example, as shown in fig. 5, fig. 5 is a partial structural view of the light emitting unit shown in fig. 4. The first reflecting surface 231 of the first reflecting portion 23 and the second reflecting surface 261 of the second reflecting portion 26 are both curved reflecting surfaces, and the curved reflecting surfaces are parabolic reflecting surfaces. The light parallel to the main optical axis of the parabolic reflecting surface is converged at the focus of the parabolic reflecting surface after being reflected by the parabolic reflecting surface. The incident light passing through the focus of the parabolic reflecting surface is parallel to the main optical axis of the parabolic reflecting surface after being reflected by the parabolic reflecting surface. The parabolic reflecting surface can be used for collimating or converging the light beam emitted by the laser.

Optionally, as shown in fig. 5, a central point A1 of the light emitting surface of the light emitting chip 24 coincides with the focal point A2 of the first reflecting surface 231. In this way, a plurality of light rays in the light beam emitted by the light emitting chip 24 are transmitted to the first reflecting surface 231, and after being reflected by the first reflecting surface 231, the plurality of light rays in the light beam are transmitted to the second reflecting surface 261 in parallel.

Alternatively, the focal point A3 of the second reflecting surface 261 coincides with the center point A4 of the fluorescent portion 25. A plurality of parallel light rays in the light beam reflected by the first reflecting surface 231 are parallel to the main optical axis of the second reflecting surface 261. The second reflecting surface 261 receives the plurality of parallel light rays reflected by the first reflecting surface 231, and then reflects and converges a plurality of light rays parallel to the main optical axis of the second reflecting surface 261 to the focal point A3 of the second reflecting surface 261. That is, the light beam emitted from the light emitting chip 24 may be collimated by the first reflecting surface 231 and condensed by the second reflecting surface 261 to enter the central point A4 of the fluorescent portion 25. In this way, a large amount of light can be incident on the fluorescent portion 25, and the fluorescence excitation efficiency of the fluorescent portion 25 can be increased.

Moreover, because the curved surface reflecting surface is a reflection imaging surface, chromatic aberration can not occur, the light beams emitted by the light emitting chip are collimated and converged by the curved surface reflecting surface, and reflection of different refractive indexes on the light beams due to different wavelengths can be avoided, so that the consistency of the light beams emitted by the light emitting chip and the light beams irradiated to the fluorescent part can be favorably ensured.

It should be noted that, the positional relationship between the light emitting chip 24 and the first reflection portion 23 in the embodiment of the present application may also be set according to actual optical path requirements, and the embodiment of the present application is not limited herein.

Optionally, as shown in fig. 4, the first reflection portion 23 further has a first bottom surface 232, and the first bottom surface 232 is connected to the heat conductive substrate 21. The first bottom surface 232 and the heat conductive substrate 21 may be soldered by plating a metal film layer on the first bottom surface 232. In this way, the first reflection portion 23 can be fixed by the first bottom surface 232.

The second reflection portion 26 further has a second bottom surface 262, and the second bottom surface 262 is connected to the package housing 22. The second bottom surface 262 and the package housing 22 may be welded by plating a metal film layer on the second bottom surface 262. In this manner, the second reflection portion 26 can be fixed by the second bottom surface 262.

Alternatively, as shown in fig. 4, the package housing 22 may include: a side plate 222 connected to the heat conductive substrate 21, and a package plate 223 connected to a side of the side plate 222 remote from the heat conductive substrate 21. The light outlet 221 is located on the package board 223. The package case 22 may serve to protect the first and

second reflection parts

23 and 26, the light emitting chip 24, and the fluorescent part 25 located inside thereof.

The side of the package plate 223 close to the heat conductive substrate 21 is connected to the second reflection part 26. In this way, the second reflection portion 26 may be disposed opposite to the first reflection portion 23, and a propagation path of the light beam emitted from the light emitting chip may be reduced, so that loss of the light beam emitted from the light emitting chip during propagation may be reduced.

Optionally, the first reflecting portion may also include a first curved reflector and a first fixing structure, and the first fixing structure may be connected to the first curved reflector and the heat conducting substrate, and is configured to fix the first curved reflector on the heat conducting substrate. The second reflecting portion may also include a second curved reflector and a second fixing structure, and the second fixing structure may be connected to the second curved reflector and the package housing, for fixing the second curved reflector to the package housing. The first and second curved mirrors may function as the first and second reflective surfaces described above.

Alternatively, as shown in fig. 4, the light emitting unit 20 may further include: and an optical element 28 connected to the package housing 22 and located at the light outlet 221, wherein the optical element 28 may be used for collimating, converging and/or homogenizing the light beam emitted from the light outlet 221. The optical element 28 may include at least one of a fly-eye lens assembly, an aspheric lens, a fresnel lens, and a spherical mirror. Illustratively, the optical element 28 is a fly-eye lens, and can be used for receiving the light beam emitted from the fluorescent part 25, and performing beam homogenization and spot optimization on the received light beam.

Alternatively, as shown in fig. 6, fig. 6 is a schematic structural diagram of another light-emitting unit shown in the embodiment of the present application. The number of the light emitting chips 24, the first reflectors 23, and the second reflectors 26 in the light emitting unit 20 is two, the two light emitting chips 24 are respectively located at both sides of the fluorescent portion 25, the two first reflectors 23 are respectively located at both sides of the fluorescent portion 25, and the two second reflectors 26 are respectively located at both sides of the fluorescent portion 25. In general, the stronger the irradiation light, the greater the number of molecules excited to an excited state on the fluorescent material, and the stronger the intensity of the generated fluorescence. In this way, the brightness of the light beam emitted from the light emitting unit 20 can be enhanced.

Alternatively, as shown in fig. 4, the light emitting unit 20 may further include: and the chip base 27 is positioned on the heat conduction substrate 21, and one side of the chip base 27, which is far away from the heat conduction substrate 21, is connected with the light-emitting chip 24. The chip base 27 can increase the distance between the light emitting chip 24 and the heat conducting substrate 21, and can prevent the light beam emitted by the light emitting chip 24 from irradiating the heat conducting substrate 21 to cause the temperature of the heat conducting substrate 21 to be too high. Meanwhile, the chip base 27 may allow more light beams emitted from the light emitting chips 24 to be irradiated onto the fluorescent portion 25, so as to improve the utilization rate of the light beams emitted from the light emitting chips 24. The die pad 27 may be encapsulated on the heat conducting substrate 21 by means of adhesive bonding, mechanical fixing, silver sintering, soldering or bonding.

The heat-conducting substrate 21, the package housing 22 and the chip base 27 are made of heat-conducting materials. The material of the heat conductive substrate 21 may include: metals and their alloys, silicon carbide, aluminum nitride, ceramic materials or glass bodies, etc. The material of the package housing 22 may include a metal material or a ceramic material. The material of the die pad 27 may be silicon carbide, aluminum nitride, or silicon.

For example, the heat conducting substrate may be made of an aluminum alloy or a heat conducting ceramic sheet, the heat conducting ceramic sheet may be a ceramic sheet with good insulation and heat conduction, and heat generated after the fluorescent portion 25 is irradiated by the laser beam may be conducted to each region of the heat conducting substrate, so as to further reduce the temperature of the fluorescent portion 25. Therefore, the problem that the efficiency of converting fluorescence of the fluorescent part 25 is poor due to high heat of the area irradiated by the laser beam in the fluorescent part 25, and further the brightness of the light-emitting unit is influenced can be avoided. Alternatively, the thickness of the heat conductive substrate 21 may range from 0.2 mm to 10 mm.

The light emitting chip 24 is connected to the heat conductive substrate 21 through a chip pad 27. In this way, the heat generated by the light emitting chip 24 can be conducted to each region of the heat conductive substrate 21 through the chip pad 27, so that the heat dissipation efficiency of the light emitting chip 24 can be improved.

It should be noted that the materials of the heat conducting substrate 21, the package housing 22 and the chip base 27 in the embodiment of the present invention may also be other materials with heat conducting performance, which is not limited in the embodiment of the present invention.

Optionally, as shown in fig. 4, the light emitting unit 20 may further include a circuit (not shown) and a pin 211 for providing a driving current to the light emitting chip 24.

Alternatively, as shown in fig. 7, fig. 7 is a schematic structural view of a fluorescent moiety in the light-emitting unit shown in fig. 4. The fluorescent portion 25 may include a fluorescent layer 251 connected to a heat conductive substrate. The fluorescent layer 251 can generate fluorescence under the irradiation of the laser beam, and the reflection region of the heat conduction substrate can effectively reflect the fluorescence generated by the fluorescent layer 251. The fluorescent light can be reflected by the reflecting area of the heat conducting substrate and then emitted to the light outlet.

In an alternative example, the material of the fluorescent layer 251 may include: yttrium Aluminum Garnet (english: yttrium Aluminum Garnet; abbreviated: YAG) and a phosphor material derived therefrom or a single crystal phosphor material. The yttrium aluminum garnet and the derivative phosphor material thereof can comprise cerium-doped yttrium aluminum garnet (ce: YAG) phosphor.

The material of the fluorescent layer 251 may further include an inorganic composite wavelength conversion material formed by combining phosphor powder and silica gel, glass, or ceramic. Wherein, the silica gel can be inorganic silica gel.

Optionally, the fluorescent layer 251 is made of a fluorescent ceramic formed by sintering yttrium aluminum garnet crystal fluorescent powder and a ceramic material at a high temperature, or a single-crystal yttrium aluminum garnet fluorescent powder crystal.

That is, the yttrium aluminum garnet crystal phosphor and the ceramic may be used to form the phosphor layer 251 by crystal growth, and the phosphor layer 251 may also be referred to as a ceramic phosphor plate. Alternatively, the fluorescent layer 251 may be formed by crystal growth using only an yttrium aluminum garnet fluorescent powder, and the fluorescent layer 251 may also be referred to as a single crystal fluorescent layer. The yttrium aluminum garnet phosphor in the phosphor layer 251 can generate fluorescence with a wavelength range of 400nm to 780nm (i.e., visible light range) under the irradiation of the laser beam.

It should be noted that, in the embodiment of the present application, the phosphor in the phosphor layer 251 may also be made of other materials and have other colors. Illustratively, the material of the fluorescent layer 251 includes red yttrium aluminum garnet fluorescent powder, and the red yttrium aluminum garnet fluorescent powder in the fluorescent layer 251 can generate red fluorescent light under the irradiation of the laser beam emitted by the light emitting chip, that is, can generate fluorescent light with a wavelength range of 625nm to 740 nm. The embodiments of the present application do not limit this.

Illustratively, the thickness of the fluorescent layer 251 may range from 0.01 mm to 1 mm. Further, the thickness of the fluorescent layer 251 may range from 0.1 mm to 0.3 mm.

The fluorescent ceramic sheet can be packaged on the heat conducting substrate in a mechanical fixing, bonding or welding mode. Alternatively, the ceramic fluorescent material may be sintered and encapsulated on the heat conducting substrate by high temperature sintering. So that the ceramic fluorescent sheet is fixed on the heat conductive substrate. Therefore, the temperature generated on the fluorescent ceramic sheet can be transmitted to the heat-conducting substrate, so that the fluorescent ceramic sheet can quickly dissipate heat.

Optionally, as shown in fig. 7, the fluorescent part 25 may further include an optical antireflection film 252. The optical anti-reflection film 252 may be located on a surface of the fluorescent layer 251 away from the heat conductive substrate.

That is, when the laser beam emitted from the light emitting chip is irradiated to the fluorescent portion 25, the laser beam may be transmitted through the optical antireflection film 252 and then irradiated to the fluorescent layer 251. The optical antireflection film 252 can effectively reduce the reflection of the laser beam. For example, assuming that the laser beam is a blue laser beam, the optical anti-reflection film 252 may reduce the reflection of blue light, i.e., reduce the reflection of light having a wavelength ranging from 420nm to 470 nm.

In summary, the present application provides a light emitting unit, including: the LED package comprises a heat conduction substrate, a package shell, a first reflection part, a second reflection part, a light emitting chip and a fluorescent part. Since the fluorescent moiety is in direct contact with the thermally conductive substrate, no colloid is present between the two. Therefore, the heat generated by the fluorescent part can be quickly transferred to the whole heat conducting substrate to quickly dissipate the heat of the fluorescent part, so that the working temperature of the fluorescent part is lower. In this way, the fluorescence excitation efficiency of the fluorescent portion can be effectively improved, and the probability of damage to the fluorescent portion can be effectively reduced. Moreover, the light beam emitted by the light emitting chip is guided to the fluorescent part after being reflected for multiple times by the first reflecting part and the second reflecting part, so that the light loss of the light beam emitted by the light emitting chip in the process of being transmitted to the fluorescent part is low, the excitation efficiency of the fluorescent part on fluorescence is further improved, and the overall brightness of the light emitting unit is high.

As shown in fig. 8, fig. 8 is a schematic structural diagram of a light source system according to an embodiment of the present application. The light source system 30 may include: a light emitting assembly 31, a light path shaping assembly 32, and a color filtering assembly 33.

Among them, the light emitting assembly 31 may include: a plurality of light emitting units 20 arranged in an array, each light emitting unit 20 being the light emitting unit 20 described above, for example, the light emitting unit 20 shown in fig. 3, 4 or 6. The light emitting assembly 31 may further include an integrated base 311, and the plurality of light emitting units 20 may be distributed on the integrated base 311 in an array. The material of the integrated base 311 may be a metal or an alloy thereof, silicon carbide, aluminum nitride, or a heat conductive material such as a heat conductive ceramic. The integrated base 311 may have the function of providing structural support, heat dissipation, and electrical connections for the plurality of light emitting units 20.

When the light emitting unit 20 emits only fluorescence, a monochromatic light emitting element may be further included in the light emitting assembly 31, and the monochromatic light emitting element may be configured to emit a monochromatic light beam and mix with the fluorescence emitted by the light emitting unit 20 to generate a white light beam. For example, the light emitting unit 20 may emit color fluorescence, and the single color light emitting element may emit blue laser light.

When the light emitting unit 20 can emit the white mixed light beam, the light emitting assembly 31 may include a plurality of light emitting units 20 arranged in an array.

The light path shaping component 32 can be used for receiving the light beam emitted by the light emitting component 31, and after the light beam is condensed and homogenized, a small uniform-energy spot is formed and enters the color filter component 33.

As shown in fig. 9, fig. 9 is a schematic view of a structure of a color filter assembly in the light source system shown in fig. 8. The color filter assembly 33 may include a green color filter 331, a blue color filter 332, and a red color filter 333. The color filter assembly 33 may further include a driving part 334 for driving the color filter assembly 33 to rotate at a timing, and the light beam emitted from the light emitting assembly is filtered by the color filter assembly 33 to sequentially output three primary colors of red, green and blue.

Illustratively, when a control signal of the light source system indicates that red light is output, the filter assembly 33 may be rotated to the red filter 333, a light beam emitted from the light emitting assembly is irradiated to the red filter 333, a light beam other than the red light beam among the light beams is blocked, and the red light beam exits the light source system through the red filter 333.

In addition, the light source system 30 shown in fig. 8 may further include a condensing collimator lens 34, and the condensing collimator lens 34 may be located on the light-emitting side of the light path shaping assembly 32 and is configured to condense the light beam transmitted by the light path shaping assembly 32. The light source system 30 may further include a dodging assembly 35, and the dodging assembly 35 may be positioned at a side of the light beam output from the color filter assembly 33, for dodging the light beam output from the color filter assembly 33.

The dodging assembly 35 may be a fly eye lens or a light pipe. Fly-eye lenses are generally formed by combining a series of small lenses, two arrays of fly-eye lenses are arranged in parallel to divide the light spot of an input laser beam, and the divided light spots are accumulated by a subsequent focusing lens, so that the light beam is homogenized and the light spot is optimized. The light guide pipe is a tubular device formed by splicing four plane reflection sheets, namely a hollow light guide pipe, and light rays are reflected for multiple times in the light guide pipe to achieve the effect of light uniformity. The light guide pipe can also adopt a solid light guide pipe, the light inlet and the light outlet of the light guide pipe are rectangular with the same shape and area, light beams enter from the light inlet of the light guide pipe and then are emitted from the light outlet of the light guide pipe, and light beam homogenization and light spot optimization are completed in the process of passing through the light guide pipe.

Optionally, a plurality of light emitting components and/or light emitting diodes may be included in the light source system to increase the brightness of the light source system and obtain a better color display effect.

In the related art, as shown in fig. 1, the light path component 103 in the laser light source system is used to provide light paths of light beams with different colors, and it is obvious that the structure of the light path component 103 is complex and the volume is large, which further results in the complex structure and the large volume of the laser light source system.

The fluorescent part in the light source system provided by the embodiment of the application reduces more complex driving components and light path components, so that the light source system has a simpler structure and a smaller volume. And because the fluorescent part reduces the driving assembly, the fluorescent part can reduce the noise and friction during working, thereby improving the performance of the light source system.

Fig. 10 is a schematic structural diagram of a laser projection apparatus according to an embodiment of the present application. As can be seen with reference to fig. 10, the laser projection apparatus may include: a light source system 30, at least one light valve 40, and a projection lens 50. The light source system 30 emits a light beam, and the at least one light valve 40 processes the light beam and directs the processed light beam to the projection assembly 50, thereby implementing an imaging function.

At least one light valve 40 may be used to digitally modulate the light beam emitted by the light source device. The reflection of the beam color is achieved by the fast flipping of the micromirrors on at least one light valve 40. The resolution of the at least one light valve 40 may be 2k, 3k or 4k. The embodiments of the present application do not limit this.

The laser projection device may comprise at least two light valves and the light source system in the above embodiments.

Alternatively, the light source system in the laser projection device may refer to the light source system provided in the above-described embodiment, for example, the light source system shown in fig. 8, and the light source system may include a light emitting assembly, an optical path shaping assembly, and a color filtering assembly. The light emitting assembly may include a plurality of light emitting units arranged in an array, and each of the light emitting units may refer to the light emitting unit provided in the above-described embodiment.

Optionally, the number of the light valves is three, and three light valves are used for respectively processing the three color lights provided by the light source system. The light source system can directly emit white light, so that the light source system can be matched with an illumination system with three light valves. Namely, the light valve assembly comprises a light valve, a light valve and a light valve, and is used for respectively processing three color lights provided by the light source system.

The light valve may be a Digital Micromirror Device (DMD), a Liquid Crystal On Silicon (LCOS) or a Liquid Crystal Display (LCD).

The light valve assembly may include three LCDs, in which the LCDs generate images of different gray levels and colors by controlling the transmittance and reflectance of liquid crystal cells through circuits using the electro-optical effect of liquid crystals, and the main imaging devices of the LCDs are liquid crystal panels that transmit light from the liquid crystal panels of three colors of red, green, and blue through lenses and mirrors.

Illustratively, a three-chip LCD projector uses three liquid crystal panels of red, green and blue as control layers for three colors of light of red, green and blue, respectively. The white light emitted by the light source system is converged to the color separation lens group after passing through the lens group, the red light is firstly separated and projected onto a red liquid crystal plate, and the liquid crystal plate forms red light information in an image. The green light is projected on the green liquid crystal plate to form green light information in the image, the blue light is also passed through the blue liquid crystal plate to form blue light information in the image, the three colors of light are converged in the prism group, and projected on the projection screen by means of projection lens to form a full-color image.

Alternatively, the light valve assembly may include three LCOS, the LCOS is a matrix liquid crystal display device based on reflective mode and with very small size, the light valve is formed by filling liquid crystal between two substrates of the LCOS, and the liquid crystal molecules can be driven to rotate by the switch of the circuit to determine the brightness and darkness of the image.

The term "and/or" in this application is only one kind of association relationship describing the associated object, and means that there may be three kinds of relationships, for example, a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

In this application, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The term "plurality" means two or more unless explicitly defined otherwise.

The above description is only exemplary of the present application and should not be taken as limiting, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A light-emitting unit, comprising:

a thermally conductive substrate;

the packaging shell is connected with the heat-conducting substrate, one side, far away from the heat-conducting substrate, of the packaging shell is provided with a light outlet, the packaging shell comprises a side plate connected with the heat-conducting substrate and a packaging plate connected with one side, far away from the heat-conducting substrate, of the side plate, and the light outlet is located in the packaging plate;

an optical element located at the light exit;

the first reflecting part is connected with one side, close to the packaging plate, of the heat conducting substrate, the first reflecting part is located between the light emitting chip and the fluorescent part, the fluorescent part is in contact with the heat conducting substrate, the chip base is located on the heat conducting substrate, and one side, far away from the heat conducting substrate, of the chip base is connected with the light emitting chip;

the second reflecting part is positioned in the packaging shell and connected with the packaging shell, and the second reflecting part is connected with one side, close to the heat-conducting substrate, of the packaging plate;

the fluorescent part is used for emitting fluorescent light to the light outlet under the excitation action of at least part of light rays in the light beams;

one side of the second reflecting part, which is close to the fluorescent part, is provided with a second reflecting surface, one side of the second reflecting part, which is far away from the fluorescent part, is also provided with a second bottom surface, and the second bottom surface is connected with the packaging shell.

2. The light-emitting unit according to claim 1, wherein a region in contact with the fluorescent portion in the heat conductive substrate is a reflective region;

the fluorescent part is used for emitting the fluorescent light under the excitation action of part of light rays in the light beams and transmitting the other part of light rays in the light beams;

the reflecting area is used for reflecting at least part of light rays transmitted from the fluorescent part in the light beams to the light outlet.

3. The light-emitting unit according to claim 1, wherein a side of the first reflecting portion adjacent to the light-emitting chip has a first reflecting surface, and at least one of the first reflecting surface and the second reflecting surface is a curved reflecting surface.

4. The lighting unit of claim 3, wherein the curved reflective surface is a parabolic reflective surface.

5. The light-emitting unit according to claim 3 or 4, wherein the first reflection portion further has a first bottom surface connected to the heat conductive substrate.

6. The lighting unit according to any one of claims 1 to 4, wherein the optical element is connected to the package housing, and the optical element is configured to collimate, condense and/or homogenize the light beam emitted from the light outlet.

7. The light-emitting unit according to any one of claims 1 to 4, wherein the number of the light-emitting chips, the first reflecting portions, and the second reflecting portions is two, two of the light-emitting chips are respectively located on both sides of the fluorescent portion, two of the first reflecting portions are respectively located on both sides of the fluorescent portion, and two of the second reflecting portions are respectively located on both sides of the fluorescent portion.

8. The lighting unit of any one of claims 1 to 4, wherein the thermally conductive substrate, the package body and the die pad are made of thermally conductive material.

9. A light source system, comprising: the device comprises a light emitting component, a light path shaping component and a color filtering component;

the light emitting assembly includes: a plurality of light emitting units arranged in an array, each of the light emitting units being as claimed in any one of claims 1 to 8.

10. A laser projection device is characterized by comprising a light source system, at least one light valve and a projection lens;

the light source system is the light source system of claim 9.