Laser white light source module capable of improving light color consistency

Abstract

The invention discloses a laser white light source module capable of improving light color consistency, which comprises a laser diode, a laser collimating lens, a reflecting prism, a micro lens array, a focusing lens, a fluorescent powder sheet, a radiator, a radiating copper pipe group and a reflector structure, and is characterized in that the laser diode is fixed in a radiating copper pipe, and the radiating copper pipe is fixed in the radiator; the micro lens array, the focusing lens and the fluorescent powder sheet are sequentially and oppositely arranged in the reflector structure. The collimating lens and the reflecting prism are adopted to collimate laser beams and reduce the distance between the laser beams, and meanwhile, the micro lens array and the focusing lens are utilized to enable the laser beams to uniformly irradiate the surface of the fluorescent powder sheet with the micro structure, so that fluorescent powder is excited to generate uniform yellow light, and the yellow light is mixed with blue light to form uniform white light. The light color consistency of the light source is improved, and the problem of fluorescent powder thermal quenching caused by overhigh local energy on the surface of the fluorescent powder sheet can be solved.

Description

Technical Field

[0001] This invention belongs to the field of laser white light illumination technology, and specifically relates to a laser white light source module that improves the uniformity of light color. Background Technology

[0002] In the field of high-power and high-brightness lighting, laser diodes can overcome the efficiency drop problem of traditional light-emitting diodes and have the characteristics of low energy consumption, fast response speed, and long lifespan, thus having a wider range of application prospects. Most laser white light sources adopt the technical route of using blue lasers to excite phosphors to generate white light. In high-power lighting applications such as automotive headlights, this can achieve higher brightness and luminous efficacy. Chinese utility model patent CN210567600U discloses "a transmissive laser white light source," which uses a transmissive remote excitation phosphor structure. A focusing lens concentrates blue laser light onto the phosphor sheet to excite the phosphor and generate white light, thereby achieving miniaturization and high luminous efficacy output of the light source. However, this solution still has the following shortcomings: (1) The laser beam has high directionality and its intensity is Gaussian. After the laser enters the phosphor layer, some of the yellow light generated by the blue light excites the phosphor and diffuses at a wide angle due to the scattering effect, while the unabsorbed blue light still maintains a small divergence angle and is emitted, resulting in uneven distribution of white light emitted by the light source module. (2) The center energy density of the laser beam is extremely high. During the laser excitation of the phosphor, the local temperature of the phosphor will rise sharply, causing thermal quenching and severely reducing the luminous stability and light conversion efficiency of the light source module.

[0003] Therefore, there is an urgent need for a laser white light source module with high luminous efficiency, high color consistency, and the ability to effectively avoid the problem of phosphor thermal quenching. Summary of the Invention

[0004] To address at least one of the problems existing in the prior art, this invention provides a laser white light source module that improves light color consistency. By combining a microlens array with a phosphor sheet with microstructures, the spatial intensity distribution of the laser is optimized, thereby meeting the multiple requirements of the laser white light source module for light efficiency, uniformity, and reliability.

[0005] To achieve the objective of this invention, this invention provides a laser white light source module for improving light color consistency, comprising a laser diode, a heat sink, a heat dissipation copper tube assembly, a collimating lens, a reflecting prism, a microlens array, a focusing lens, a reflector structure, and a phosphor sheet; The laser diode is fixedly installed inside the heat dissipation copper pipe assembly, and the heat dissipation copper pipe assembly is fixedly installed inside the heat sink. The collimating lens and the reflecting prism are positioned sequentially above the laser diode; The reflector structure is located above the heat sink. The reflector structure includes a reflector and a reflector cup. A microlens array and a focusing lens are arranged opposite each other inside the reflector, and the microlens array is opposite to the reflecting prism. A phosphor sheet is arranged inside the reflector cup. The phosphor sheet is provided with a pyramidal microstructure for diffusing laser light. The inner surface of the reflector and the lower surface of the reflector cup are coated with a reflective film to reflect the backlight scattered by the phosphor sheet back to the phosphor sheet, thereby improving the utilization rate of backlight generated by laser-excited phosphor.

[0006] Furthermore, the collimating lens is fixed above the laser diode; the reflecting prism is fixed above the collimating lens; the microlens array is fixed above the reflecting prism; and the focusing lens is fixed above the microlens array. Furthermore, the phosphor sheet is embedded in the groove at the center of the reflector cup.

[0007] Furthermore, the heat sink is provided with an encapsulation shell, and the reflector structure is fixed above the encapsulation shell.

[0008] Furthermore, both the reflector and the reflector cup are coated with a reflective film.

[0009] Furthermore, the heat dissipation copper pipe assembly includes an internally threaded heat dissipation copper pipe and an externally threaded heat dissipation copper pipe, the laser diode is fixed inside the heat dissipation copper pipe assembly, and the heat dissipation copper pipe assembly is fixed inside a groove opened on the heat sink.

[0010] Furthermore, thermally conductive silicone grease is applied between the laser diode and the heat dissipation copper pipe assembly, and thermally conductive silicone grease is applied between the heat dissipation copper pipe assembly and the heat sink.

[0011] Furthermore, the angle between the incident surface and the reflecting surface of the reflecting prism is 45°, and the angle between the exit surface and the reflecting surface is 45°.

[0012] Furthermore, the laser emitted by the laser diode is collimated by the collimating lens and then incident perpendicularly on the incident surface of the reflecting prism, while the outgoing light is perpendicular to the exiting surface of the reflecting prism.

[0013] Furthermore, the inner surface of the reflective cup is coated with a reflective film to reduce the divergence angle of the white light emitted from the phosphor sheet.

[0014] Furthermore, the angle between the side edges and the bottom surface of the pyramidal microstructure is 40~60°, and the pyramidal microstructure array is arranged on the lower surface of the phosphor sheet.

[0015] Furthermore, the reflector cup is fixed above the reflector, and a square groove is formed in the middle of the bottom surface of the reflector cup, into which the phosphor sheet is embedded.

[0016] Furthermore, the microlens array and the focusing lens are fixed in a groove inside the reflector.

[0017] Furthermore, the laser emitted by the laser diode is collimated by a collimating lens and then incident on the lower surface of the microlens array through a reflecting prism. The collimated laser beam generates several sub-laser beams after passing through the microlens array. The sub-beams are then uniformly irradiated onto the lower surface of the phosphor sheet after passing through the focusing lens, thereby exciting the phosphor to produce uniform white light.

[0018] The advantages of this invention compared to the prior art are: This invention employs a microlens array and a focusing lens to achieve uniform laser beam illumination of the phosphor surface, improving the luminous flux and color consistency of the light source, and effectively preventing phosphor thermal quenching caused by excessive local energy. Compared with the traditional method of combining multiple lasers with reflective phosphor excitation, this invention eliminates the need for extra space for optical path folding and the assembly requirements of reflective elements, thereby reducing the packaging size of the light source module and improving light energy utilization. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of a laser white light source module for improving light color consistency in an embodiment of the present invention.

[0020] Figure 2 is a schematic diagram of the heat dissipation structure of the laser diode in an embodiment of the present invention.

[0021] Figure 3 is a schematic diagram of the heat dissipation copper pipe assembly in an embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the internal structure of a laser white light source module for improving light color consistency in an embodiment of the present invention.

[0023] Figure 5 is a schematic diagram of the cross-section of the phosphor sheet in an embodiment of the present invention.

[0024] Figure 6 This is a schematic diagram of the external structure of a laser white light source module for improving light color consistency in an embodiment of the present invention.

[0025] Explanation of reference numerals in the attached drawings: 10-Laser diode, 20-Collimating lens, 21-Reflecting prism, 22-Microlens array, 23-Focusing lens, 30-Phosphor sheet, 40-Heat sink, 50-Internal threaded heat sink copper tube, 51-External threaded heat sink copper tube, 60-Housing shell, 70-Reflector, 71-Reflecting cup. Detailed Implementation To further understand the present invention, the present invention will be further described below with reference to specific embodiments. However, the implementation of the present invention is not limited thereto. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0026] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein for convenience of description to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms are intended to also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, then the element or feature described as “below” or “under” the other element or feature will be oriented “above” the other element or feature. Therefore, the exemplary terms “below” and “under” can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or otherwise) and the spatial descriptive terms used herein will be interpreted accordingly.

[0027] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising” and / or “including,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0028] Example 1 like Figure 1-6 As shown, this embodiment provides a laser white light source module for improving light color uniformity, including a laser diode 10, a heat sink 40, a heat dissipation copper pipe assembly, a collimating lens 20, a reflecting prism 21, a microlens array 22, a focusing lens 23, a reflector structure, and a phosphor sheet 30. The laser diode 10 is fixedly installed inside the heat dissipation copper pipe assembly, and the heat dissipation copper pipe assembly is fixedly installed inside the heat sink 40. The collimating lens 20 and the reflecting prism 21 are located above the laser diode 10 in sequence; The reflector structure is located above the encapsulation housing 60. The reflector structure includes a reflector 70 and a reflector cup 71. A microlens array 22 and a focusing lens 23 are disposed opposite each other in the reflector 70, and the microlens array 22 is opposite to the reflecting prism 21. A phosphor sheet 30 is disposed in the reflector cup 71. The surface of the phosphor sheet 30 is provided with microstructures for diffusing laser light. The inner surface of the reflector 70 and the lower surface of the reflector cup 71 are coated with a reflective film for reflecting the backlight scattered by the phosphor sheet 30 back to the phosphor sheet 30.

[0029] Please see Figure 2 , Figure 3 In this embodiment, the heat dissipation copper pipe assembly is fixed in the groove of the heat sink 40 with thermally conductive silicone grease. The heat dissipation copper pipe assembly includes an internally threaded heat dissipation copper pipe 50 and an externally threaded heat dissipation copper pipe 51. The bottom of the laser diode 10 is fixed in the groove of the internally threaded heat dissipation copper pipe 50 with thermally conductive silicone grease. The internally threaded heat dissipation copper pipe 50 and the externally threaded heat dissipation copper pipe 51 are connected by threads. When the laser diode 10 is working, heat can be transferred out through the heat dissipation copper pipe assembly, the heat sink 40, and the thermally conductive silicone grease, and then dissipated through forced convection, which can ensure the stable output of the laser diode 10.

[0030] Example 2 like Figure 1-6 As shown, this embodiment provides a laser white light source module for improving light color uniformity, including a laser diode 10, a heat sink 40, a heat dissipation copper pipe assembly, a collimating lens 20, a reflecting prism 21, a microlens array 22, a focusing lens 23, a reflector structure, and a phosphor sheet 30. The laser diode 10 is fixedly installed inside the heat dissipation copper pipe assembly, and the heat dissipation copper pipe assembly is fixedly installed inside the heat sink 40. The collimating lens 20 and the reflecting prism 21 are located above the laser diode 10 in sequence; The reflector structure is located above the encapsulation housing 60. The reflector structure includes a reflector 70 and a reflector cup 71. A microlens array 22 and a focusing lens 23 are disposed opposite each other in the reflector 70, and the microlens array 22 is opposite to the reflecting prism 21. A phosphor sheet 30 is disposed in the reflector cup 71. The surface of the phosphor sheet 30 is provided with microstructures for diffusing laser light. The inner surface of the reflector 70 and the lower surface of the reflector cup 71 are coated with a reflective film for reflecting the backlight scattered by the phosphor sheet 30 back to the phosphor sheet 30.

[0031] In this embodiment, please refer to Figure 1 , Figure 4The collimating lens 20 is fixed inside the heat sink 40 and located above the laser diode 10. The package shell 60 is disposed on the heat sink 40. The reflecting prism 21 is fixed inside the package shell 60. One laser diode 10 corresponds to one collimating lens 20. Except for the laser diode 10 located at the center position, the other laser diodes 10 correspond to one reflecting prism 21. The microlens array 22 and the focusing lens 23 are fixed in the groove inside the reflector 70. The microlens array 22 and the focusing lens 23 are arranged opposite to each other, and the center sub-lens of the microlens array 22 corresponds to the center of the focusing lens 23. After collimation, the laser beam is collimated and incident on the lower surface of the microlens array 22 and splits into several sub-divergent beams. After passing through the focusing lens 23, a uniform illumination is formed on the lower surface of the phosphor sheet 30.

[0032] The collimating lens 20 and the reflecting prism 21 are used to collimate the laser and reduce the beam spacing. After passing through the microlens array 22 and the focusing lens 23, the collimated beam is uniformly irradiated on the lower surface of the phosphor sheet 30.

[0033] Example 3 like Figure 1-6 As shown, this embodiment provides a laser white light source module for improving light color uniformity, including a laser diode 10, a heat sink 40, a heat dissipation copper pipe assembly, a collimating lens 20, a reflecting prism 21, a microlens array 22, a focusing lens 23, a reflector structure, and a phosphor sheet 30. The laser diode 10 is fixedly installed inside the heat dissipation copper pipe assembly, and the heat dissipation copper pipe assembly is fixedly installed inside the heat sink 40. The collimating lens 20 and the reflecting prism 21 are located above the laser diode 10 in sequence; The reflector structure is located above the encapsulation housing 60. The reflector structure includes a reflector 70 and a reflector cup 71. A microlens array 22 and a focusing lens 23 are disposed opposite each other in the reflector 70, and the microlens array 22 is opposite to the reflecting prism 21. A phosphor sheet 30 is disposed in the reflector cup 71. The surface of the phosphor sheet 30 is provided with microstructures for diffusing laser light. The inner surface of the reflector 70 and the lower surface of the reflector cup 71 are coated with a reflective film for reflecting the backlight scattered by the phosphor sheet 30 back to the phosphor sheet 30.

[0034] In this embodiment, three laser diodes 10, three collimating lenses 20, and two reflecting prisms 21 are provided. The specific number can be determined according to the actual application requirements.

[0035] In this embodiment, the outer casing 60 is made of metal, such as an aluminum alloy casing.

[0036] Example 4 like Figure 1-6As shown in the figure, an embodiment of the present invention provides a laser white light source module for improving light color uniformity, including a laser diode 10, a collimating lens 20, a reflecting prism 21, a microlens array 22, a focusing lens 23, a phosphor sheet 30, a heat dissipation structure, a packaging shell 60, and a reflector structure.

[0037] Please see Figure 1 , Figure 4 The collimating lens 20 is fixed inside the heat sink 40 and located above the laser diode 10. The package shell 60 is disposed on the heat sink 40. The reflecting prism 21 is fixed inside the package shell 60. One laser diode 10 corresponds to one collimating lens 20. Except for the laser diode 10 located at the center position, the other laser diodes 10 correspond to one reflecting prism 21. The microlens array 22 and the focusing lens 23 are fixed in the groove inside the reflector 70. The microlens array 22 and the focusing lens 23 are arranged opposite to each other, and the center sub-lens of the microlens array 22 corresponds to the center of the focusing lens 23. After collimation, the laser beam is collimated and incident on the lower surface of the microlens array 22 and splits into several sub-divergent beams. After passing through the focusing lens 23, a uniform illumination is formed on the lower surface of the phosphor sheet 30.

[0038] In this embodiment, the incident aperture of the sub-lens of the microlens array 22 is a rectangular aperture, and the aperture size can be determined according to the required phosphor sheet size.

[0039] In this embodiment, please refer to Figure 1 , Figure 5 , Figure 6 The reflector structure is mounted on the encapsulation housing 60. The reflector structure includes a reflector 70 and a reflector cup 71 positioned above the reflector 70. A phosphor sheet 30 is positioned opposite the focusing lens 23, and the phosphor sheet 30 is embedded in a square groove at the center of the bottom surface of the reflector cup 71 to ensure symmetrical light emission angles and uniform light intensity distribution. The lower surface of the phosphor sheet 30 is arranged with pyramidal microstructures; the size and number of these microstructures can be determined according to actual application requirements.

[0040] In this embodiment, the inner surface of the reflector 70 and the area below the reflector cup 71 are both coated with a reflective film.

[0041] During operation, the blue light output from the laser diode 10 passes sequentially through the collimating lens 20, the reflecting prism 21, the microlens array 22, and the focusing lens 23. After being diffused by the pyramidal microstructure on the lower surface of the phosphor 30, it enters the phosphor 30. Part of the blue light is excited by the yellow phosphor to produce yellow light, while the rest is scattered away from the phosphor 30. The portion of the light that exits above the phosphor 30 is called the forward light, and the other portion that exits below the phosphor 30 is called the backlight. The reflective film can reflect the backlight scattered by the phosphor 30 back to the phosphor 30, improving energy utilization and increasing the luminous flux of the laser white light module. The blue light is uniformly irradiated onto the lower surface of the phosphor 30. The pyramidal microstructure increases the divergence angle of the incident blue light, and the blue light and the yellow light generated by the excited phosphor are emitted approximately uniformly above the phosphor 30, mixing to produce white light, thus improving the color consistency of the laser white light source module.

[0042] This laser white light source module can be used in automotive headlights, motorcycle lights, streetlights, etc. By adopting this laser white light source module, it is possible to reduce the size of vehicle lights while providing sufficient luminous flux for high-power lighting, reducing energy loss and improving lighting quality.

[0043] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A laser white light source module for improving light color uniformity, characterized in that, It includes a laser diode (10), a heat sink (40), a heat dissipation copper tube assembly, a collimating lens (20), a reflecting prism (21), a microlens array (22), a focusing lens (23), a reflector structure, and a phosphor sheet (30). The laser diode (10) is fixedly installed inside the heat dissipation copper pipe assembly, and the heat dissipation copper pipe assembly is fixedly installed inside the heat sink (40); The collimating lens (20) and the reflecting prism (21) are located above the laser diode (10) in sequence; The reflector structure is located above the encapsulation shell (60). The reflector structure includes a reflector (70) and a reflector cup (71). A microlens array (22) and a focusing lens (23) are arranged opposite to each other inside the reflector (70), and the microlens array (22) is opposite to the reflecting prism (21). A phosphor sheet (30) is arranged inside the reflector cup (71). The surface of the phosphor sheet (30) is provided with microstructures for diffusing laser light. The inner surface of the reflector (70) and the lower surface of the reflector cup (71) are coated with a reflective film for reflecting the backlight scattered by the phosphor sheet (30) back to the phosphor sheet (30).

2. The laser white light source module for improving light color uniformity according to claim 1, characterized in that: The heat dissipation copper pipe assembly includes an internally threaded heat dissipation copper pipe (50) and an externally threaded heat dissipation copper pipe (51). The internally threaded heat dissipation copper pipe (50) and the externally threaded heat dissipation copper pipe (51) are connected by a threaded connection. The laser diode (10) is fixed inside the heat dissipation copper pipe assembly.

3. A laser white light source module for improving light color uniformity according to claim 2, characterized in that: Thermal grease is applied between the laser diode (10) and the heat dissipation copper pipe assembly, and thermal grease is applied between the heat dissipation copper pipe assembly and the heat sink (40).

4. A laser white light source module for improving light color uniformity according to claim 1, characterized in that: The angle between the incident surface and the reflecting surface of the reflecting prism (21) is 45°, and the angle between the exit surface and the reflecting surface is 45°.

5. A laser white light source module for improving light color uniformity according to claim 4, characterized in that: The laser emitted by the laser diode (10) is collimated by the collimating lens (20) and then incident perpendicularly on the incident surface of the reflecting prism (21), while the outgoing light is perpendicular to the outgoing surface of the reflecting prism (21).

6. A laser white light source module for improving light color uniformity according to claim 1, characterized in that: The inner surface of the reflector cup (71) is coated with a reflective film to reduce the divergence angle of the light beam emitted from the phosphor sheet.

7. A laser white light source module for improving light color uniformity according to claim 6, characterized in that: The bottom surface of the reflective cup (71) has a groove in the middle, and the phosphor sheet (30) is embedded in the groove.

8. A laser white light source module for improving light color uniformity according to claim 1, characterized in that: The microstructure is a pyramidal microstructure, and the angle between the side edges and the base of the pyramidal microstructure is 40~60°.

9. A laser white light source module for improving light color uniformity according to claim 1, characterized in that: The microlens array (22) and the focusing lens (23) are fixed in a groove inside the reflector (70).

10. A laser white light source module for improving light color uniformity according to claims 1-9, characterized in that: The laser emitted by the laser diode (10) is collimated by the collimating lens (20) and then incident on the lower surface of the microlens array (22) through the reflecting prism (21). After the collimated laser beam passes through the microlens array (22), it generates several sub-laser beams. After the sub-beams pass through the focusing lens (23), they are uniformly irradiated onto the lower surface of the phosphor sheet (30), exciting the phosphor to produce uniform white light.

Images