Laser light source and laser projector
By introducing a combined structure of the reflection region and the wavelength conversion region into the laser light source, the problem of low fluorescence light collection efficiency is solved, and the structure simplification and volume reduction of the laser light source are achieved.
Patent Information
- Application Number
- CN202410030625.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-08
- Publication Date
- 2025-07-08
AI Technical Summary
In the prior art, fluorescence is less efficient in receiving light through a convergence lens, resulting in a complex structure and large volume of the laser light source.
The laser light source structure consisting of a laser, a first convergence lens, a reflective device and a composite parabolic condenser is adopted. The fluorescent device includes a reflection region and a wavelength conversion region. The fluorescent device is arranged around the side wall of the composite parabolic condenser or is located at the bottom. Using the combination of the reflection region and the wavelength conversion region, fluorescence is excited and mixed to form white light to reduce the use of optical devices.
The fluorescence light collection efficiency is improved, the structure of the laser light source is simplified, the number of optical devices is reduced, and the volume of the laser light source is reduced.
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Figure CN120276200A_ABST
Abstract
Description
Technical Field
[0001] Embodiments of the present application relate to optoelectronic technologies. More specifically, the present application relates to a laser light source and a laser projector. Background Art
[0002] With the development of optoelectronic technologies, due to advantages such as high brightness, good directivity, and long lifespan of laser light sources, laser light sources can be used in projection displays and other lighting fields.
[0003] In some related technologies, a laser light source in a laser projector may include devices such as a laser, a fluorescent wheel, a diffuser, and a focusing lens. The laser emits laser light, which irradiates the phosphor on the fluorescent wheel through devices such as a diffuser and a focusing lens. The excited fluorescence is reflected back into the optical path by the substrate, collected and collimated by the focusing lens, and enters the subsequent optical path to achieve projection.
[0004] Since generally the excited fluorescence is a Lambertian body, part of the fluorescence cannot be collected into the optical path by the focusing lens, resulting in low light collection efficiency. Summary of the Invention
[0005] Embodiments of the present application provide a laser light source and a laser projector to solve the problem in related technologies that when collecting light through a focusing lens for fluorescence, the light collection efficiency is low.
[0006] In a first aspect, embodiments of the present application provide a laser light source, including:
[0007] A laser, configured to emit a laser beam;
[0008] A first focusing lens, located on the light-emitting side of the laser, configured to focus the laser beam onto a reflecting device;
[0009] The reflecting device is located on the central axis of a compound parabolic concentrator, and is configured to reflect the laser beam focused by the first focusing lens to a fluorescent device in the compound parabolic concentrator;
[0010] The fluorescent device includes a reflection area and a wavelength conversion area. The reflection area is configured to reflect the laser beam to the light-emitting surface of the compound parabolic concentrator. The wavelength conversion area emits fluorescence based on the laser beam and reflects the fluorescence to the light-emitting surface of the compound parabolic concentrator, so that the fluorescence is mixed with the laser beam reflected by the reflection area to emit white light.
[0011] In some embodiments of the present application, the fluorescent device is disposed around the sidewall of the compound parabolic concentrator or is located at the bottom of the compound parabolic concentrator, and the bottom is disposed opposite to the light-emitting surface of the compound parabolic concentrator.
[0012] In some embodiments of the present application, if the fluorescent device is located at the bottom of the compound parabolic concentrator, the divergence angle of the laser beam converged by the first converging lens is less than or equal to an angle threshold, and the angle threshold is determined based on the upper limit value of the incident angle of the beam received at the bottom of the compound parabolic concentrator.
[0013] In some embodiments of the present application, the reflection area and the wavelength conversion area are coaxially arranged, and the reflection area is a specular reflector or a Lambert reflector.
[0014] In some embodiments of the present application, the positional relationship between the reflection area and the wavelength conversion area is as follows:
[0015] The wavelength conversion area is located in the central area, and the reflection area is located outside the wavelength conversion area;
[0016] Or, the wavelength conversion area includes a first conversion area and a second conversion area, and from the center to the outside are: the first conversion area, the reflection area, and the second conversion area in sequence;
[0017] Or, the reflection area is located in the central area, and the wavelength conversion area is located outside the reflection area.
[0018] In some embodiments of the present application, the first converging lens is integrated on the outer side of the side wall of the compound parabolic concentrator, and an angle-selective transmission film is plated on the inner side of the side wall of the compound parabolic concentrator;
[0019] The angle-selective transmission film is used to transmit the laser beam emitted by the laser, reflect the fluorescence reflected by the wavelength conversion area, and reflect the laser beam reflected by the reflection area.
[0020] In some embodiments of the present application, the first converging lens is located between the compound parabolic concentrator and the laser, and an antireflection film is plated on the surface of the first converging lens and the outer side of the side wall of the compound parabolic concentrator.
[0021] In some embodiments of the present application, the laser light source further includes: a second converging lens;
[0022] The second converging lens is located on the light-emitting side of the compound parabolic concentrator and is used to collect the laser beam and fluorescence emitted from the light-emitting surface of the compound parabolic concentrator.
[0023] In some embodiments of the present application, the laser light source further includes: a collimating lens;
[0024] The collimating lens is located between the first converging lens and the laser and is used to collimate the laser beam emitted by the laser to obtain a parallel beam, so as to emit the obtained parallel beam to the first converging lens.
[0025] In a second aspect, an embodiment of the present application provides a laser projector, including:
[0026] A third converging lens, a color wheel, a light homogenizing element, a total reflection prism, a light valve modulation component, a lens, and the laser light source according to any one of the first aspect.
[0027] This application provides a laser light source and a laser projector. The laser light source includes: a laser, a first converging lens, a reflection device, a compound parabolic concentrator, and a fluorescent device. The laser beam emitted by the laser is converged onto the reflection device by the first converging lens, and after being reflected by the reflection device, the laser beam is reflected onto the fluorescent device in the compound parabolic concentrator. The fluorescent device includes a reflection area and a wavelength conversion area. For the laser beam incident on the wavelength conversion area, fluorescence can be excited and the fluorescence is reflected back to the light exit surface of the compound parabolic concentrator. For the laser beam incident on the reflection area, the reflection area can reflect the laser beam to the light exit surface of the compound parabolic concentrator, and the laser beam is mixed with the fluorescence to obtain white light and then emitted. The laser light source of this application can reflect the large-angle fluorescence through the side wall of the compound parabolic concentrator and emit it at a smaller angle, avoiding the loss of large-angle fluorescence and improving the fluorescence light collection efficiency. At the same time, the number of optical devices used is also reduced, simplifying the structure of the laser light source and facilitating the reduction of the volume of the laser light source. Description of the Drawings
[0028] To more clearly illustrate the embodiments of this application or the implementation manners in the related art, the following will briefly introduce the drawings required for use in the description of the embodiments or the related art. Obviously, the following drawings are some embodiments of this application. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.
[0029] Figure 1 A schematic structural diagram of a laser light source in a related art;
[0030] Figure 2 A schematic structural diagram of a laser projector provided by an embodiment of this application;
[0031] Figure 3 A schematic structural diagram of a laser light source provided by an embodiment of this application Figure 1 ;
[0032] Figure 4 A schematic structural diagram of a laser light source provided by an embodiment of this application Figure 2 ;
[0033] Figure 5 A schematic optical path diagram of laser light and fluorescence being reflected to the light exit surface of the compound parabolic concentrator provided by an embodiment of this application;
[0034] Figure 6 A schematic structural diagram of a reflection area provided by an embodiment of this application;
[0035] Figure 7Schematic diagram of the positional relationship between a wavelength conversion region and a reflection region provided by an embodiment of the present application Figure 1 ;
[0036] Figure 8 Schematic diagram of the positional relationship between a wavelength conversion region and a reflection region provided by an embodiment of the present application Figure 2 ;
[0037] Figure 9 Schematic diagram of the positional relationship between a wavelength conversion region and a reflection region provided by an embodiment of the present application Figure 3 ;
[0038] Figure 10 Schematic diagram of the structure of a laser light source provided by an embodiment of the present application Figure 3 。 Detailed implementation manners
[0039] To make the objectives, implementation manners, and advantages of the present application clearer, the following will clearly and completely describe the exemplary implementation manners of the present application with reference to the accompanying drawings in the exemplary embodiments of the present application. Obviously, the described exemplary embodiments are only a part of the embodiments of the present application, rather than all the embodiments.
[0040] It should be noted that the brief description of the terms in the present application is only for facilitating the understanding of the subsequent described implementation manners, rather than intending to limit the implementation manners of the present application. Unless otherwise specified, these terms should be understood according to their ordinary and common meanings.
[0041] In addition, the terms "comprising" and "having" and any variations thereof are intended to cover but not exclude inclusion. For example, a product or device including a series of components does not necessarily have to be limited to those components clearly listed, but may include other components not clearly listed or inherent to these products or devices.
[0042] Figure 1 In a related technology, the schematic diagram of the structure of a laser light source is as Figure 1 shown. Laser group 1 and laser group 2 emit blue lasers, which are converged into a point through a telescope system, a diffuser, a dichroic mirror, and a first converging lens, i.e., an optical lens, and irradiate onto a phosphor or a phosphor wheel to excite fluorescence. The excited fluorescence is reflected by a substrate, and then collected by the first converging lens and collimated into the dichroic mirror, and then incident into subsequent optical paths such as a second converging lens, a color filter wheel, and a light rod.
[0043] Since the fluorescence generated by excitation is basically a Lambertian body, that is, the emission angle is basically ±90°. Affected by the structure, part of the light at large angles cannot be collected and utilized by the first converging lens, resulting in a low fluorescence utilization rate. At the same time, a blue light circuit also needs to be designed for the blue light to ensure the final synthesis of white light. The number of optical devices used is large and the structure is relatively complex, resulting in a large volume of the laser light source.
[0044] Based on this, the present application provides a laser light source, including: a laser, a first converging lens, an emitting device, a compound parabolic concentrator, and a fluorescence device. The laser beam emitted by the laser is converged by the first converging lens to the reflecting device, and after being reflected by the reflecting device, the laser beam is reflected onto the wavelength conversion area of the fluorescence device to excite fluorescence, and the fluorescence is reflected to the light-emitting surface of the compound parabolic concentrator. Part of the laser beam also irradiates the reflection area of the fluorescence device to reflect the laser beam, and the reflected laser can be mixed with the fluorescence to obtain white light. When the fluorescence of the present application is reflected to the light-emitting surface of the compound parabolic concentrator, the fluorescence at small angles can be directly emitted to the light-emitting surface, and the fluorescence at large angles can be reflected by the side wall of the compound parabolic concentrator and emitted to the light-emitting surface at a smaller angle, realizing the collection and utilization of the large-angle fluorescence, avoiding the loss of the large-angle fluorescence, and improving the fluorescence collection efficiency. At the same time, there is no need to set up a blue light circuit, nor to use optical devices such as a telescope system, reducing the number of optical devices and simplifying the structure of the laser light source, which is beneficial to reducing the volume of the laser light source.
[0045] The laser light source of the present application can be applied to the field of projection technology as the light source of a laser projector. Figure 2 As shown in the structural schematic diagram of a laser projector provided by an embodiment of the present application, Figure 2 As shown, the laser projector includes a laser light source 201, an optical engine 202, and a lens 203. Among them, the laser light source 201 is used to provide a laser beam, which is transmitted to the optical engine 202 and the lens 203 at the rear end. The laser light source 201 can be a single-color laser, a two-color laser, a three-color laser, etc.
[0046] The laser beam provided by the laser light source 201 is incident on the illumination optical path part in the optical engine 202 after being combined and shaped. The illumination optical path includes, but is not limited to, a light homogenizing element, a total reflection prism, a light valve modulation component, etc.
[0047] The lens 203 can be an ultra-short-throw projection lens. The ultra-short-throw projection lens 203 is used to project the image beam onto the projection screen, thereby realizing the display of the projection image.
[0048] In addition to being used as the light source of a laser projector, it can also be used as other lighting devices, such as car lights, flashlights, etc. For example, when the laser light source of the present application is used as a car light, since the car light is only used for lighting, the laser light source of the present application only needs to emit white light, which is small in volume, reduces the occupied space, and there is no need to set up a light valve modulation component for optical modulation to form an image.
[0049] The technical solutions of the present application will be described in detail below in conjunction with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.
[0050] Figure 3 Schematic structure of a laser light source provided by an embodiment of the present application Figure 1 , such as Figure 3 shown, the laser light source may include:
[0051] A laser 31 for emitting a laser beam;
[0052] A first converging lens 32 located on the light-emitting side of the laser 31 for converging the laser beam onto the reflecting device 33;
[0053] The reflecting device 33 is located on the central axis of the compound parabolic concentrator 34 and is used to reflect the laser beam converged by the first converging lens 32 to the fluorescent device 35 in the compound parabolic concentrator 34;
[0054] The fluorescent device 35 includes a reflection area and a wavelength conversion area. The reflection area is used to reflect the laser beam to the light-emitting surface of the compound parabolic concentrator 34. The wavelength conversion area emits fluorescence based on the laser beam and reflects the fluorescence to the light-emitting surface of the compound parabolic concentrator 34, so that the fluorescence is mixed with the laser beam reflected by the reflection area to emit white light.
[0055] The laser 31 can be a monochromatic laser, a two-color laser, a three-color laser, etc. For example, the monochromatic laser can be a blue laser that emits blue laser light, the two-color laser can be a laser that emits blue and red, and the three-color laser is a laser that can emit three colors of red, green, and blue. The present application does not limit the type of the laser.
[0056] The fluorescent device 35 can be fixed on the compound parabolic concentrator 34. In some embodiments, the fluorescent device 35 is disposed around the side wall of the compound parabolic concentrator 34 or is located at the bottom of the compound parabolic concentrator 34, and the bottom is disposed opposite to the light-emitting surface of the compound parabolic concentrator 34.
[0057] In an implementation scenario, a highly reflective film can be deposited on the substrate of the fluorescent device 35, so that the reflection area of the fluorescent device 35 reflects the laser back to the light-emitting surface of the compound parabolic concentrator (CPC) 34, and the wavelength conversion area reflects the fluorescence back to the light-emitting surface of the compound parabolic concentrator 34.
[0058] The reflection area and the wavelength conversion area can be axially arranged along the radial direction. Among them, the reflection area is used to reflect the laser back to the light-emitting surface, and the wavelength conversion area is used to emit fluorescence. The wavelength conversion area is coated with a fluorescent material capable of emitting fluorescence. The fluorescent material can be fluorescent powder, fluorescent ceramic, etc. The present application does not limit the type of fluorescent material.
[0059] Since the laser light source of the present application usually emits white light, that is, the laser beam emitted by the laser 31 and the fluorescence emitted by the fluorescent material can be mixed to obtain white light.
[0060] In an implementation scenario, the color of the fluorescence emitted by the fluorescent material is different from the color of the laser beam emitted by the laser 31, and white light is obtained after mixing. For example, taking the fluorescent material as fluorescent powder for illustration, if the laser emitted by the laser 31 is blue, the fluorescent powder can include red fluorescent powder and green fluorescent powder at this time. Among them, the red fluorescent powder is the fluorescent powder capable of emitting red fluorescence, and the green fluorescent powder is the fluorescent powder emitting green fluorescence.
[0061] In another implementation scenario, the fluorescence emitted by the fluorescent material includes the fluorescence of the color of the laser beam emitted by the laser 31, and also includes the fluorescence of other colors that are mixed with the laser color to obtain white light, which can not only weaken the speckle effect of monochromatic fluorescence, but also increase the color gamut range. Still taking fluorescent powder as an example, if the laser emitted by the laser 31 is blue, in addition to the red fluorescent powder and the green fluorescent powder, the fluorescent powder can also include blue fluorescent powder that emits blue fluorescence.
[0062] Specifically, if the laser 31 is a three-color laser, the fluorescent powder can include one or more of blue fluorescent powder, red fluorescent powder, and green fluorescent powder at this time.
[0063] In an implementation scenario, when the fluorescent material includes a variety of materials that emit different colors, the different materials can be uniformly mixed, can be separately arranged, or can be other distribution methods. The present application does not limit this. At the same time, the proportion of different materials can also be set according to actual needs. For example, if light biased towards green is required, the proportion of the green fluorescent material can be increased at this time.
[0064] In some embodiments, the first converging lens 32 can be integrated on the compound parabolic concentrator 34, that is, formed on the compound parabolic concentrator 34, or can exist independently. Figure 3It shows a situation where the first converging lens 32 is integrated on the compound parabolic concentrator 34. For the situation where the first converging lens 32 exists independently, reference can be made to Figure 4 as shown. Figure 4 This is a schematic structure of a laser light source provided by an embodiment of the present application. Figure 2 .
[0065] In an implementation scenario, when the first converging lens 32 is integrated on the compound parabolic concentrator 34, the first converging lens 32 is integrated on the outer side of the side wall of the compound parabolic concentrator 34, and an angle-selective transmission film is coated on the inner side of the side wall of the compound parabolic concentrator 34; the angle-selective transmission film is used to transmit the laser beam emitted by the laser 31, reflect the fluorescence reflected by the wavelength conversion region, and reflect the laser beam reflected by the reflection region.
[0066] The first converging lens 32 can be integrated on the outer side of the side wall of the compound parabolic concentrator 34 near the light-emitting surface. The angle-selective transmission film allows the incident light, that is, the laser beam emitted by the laser 31, to be transmitted, and reflects the reflected light, that is, the laser beam reflected by the reflection region and the fluorescence reflected by the wavelength conversion region, when the reflected light irradiates the angle-selective transmission film, so that part of the reflected light can be not lost, thereby improving the utilization rate of light.
[0067] In another implementation scenario, when the first converging lens 32 exists independently, the first converging lens 32 is located between the compound parabolic concentrator 34 and the laser 31, and an antireflection film is coated on the surface of the first converging lens 32 and the outer side of the side wall of the compound parabolic concentrator 34.
[0068] The antireflection film can also be called a light-transmitting film. Coating an antireflection film on the surface of the first converging lens 32 and the outer side of the side wall of the compound parabolic concentrator 34 allows most of the laser beam emitted by the laser 31 to pass through the first converging lens 32 and the compound parabolic concentrator 34, thereby improving the utilization rate of light.
[0069] In some embodiments, if the fluorescence device 35 is located at the bottom of the compound parabolic concentrator 34, the divergence angle of the laser beam converged by the first converging lens 32 is less than or equal to an angle threshold, and the angle threshold is determined based on the upper limit value of the incident angle of the light beam received at the bottom of the compound parabolic concentrator 34.
[0070] The divergence angle is the divergence angle of the beam after the laser beam passes through the first converging lens 32 and is converged. Figure 3 or Figure 4 The divergence angle of the shown beam is ±α. Figure 3 or Figure 4Shown is the side view of the compound parabolic concentrator 34, where A, B, C, and D are the four vertices of the compound parabolic concentrator 34 respectively. The bottom size radius of the compound parabolic concentrator 34 is CD / 2 = a', and the output surface size radius of the compound parabolic concentrator 34 is AB / 2 = a, and a' / a = sinα, where α is the angle between AD or BC and the central axis, that is, the upper limit value of the incident beam angle that the bottom of the compound parabolic concentrator 34 can receive. Therefore, the angle threshold can be the upper limit value α of the beam incident angle. Wherein, the central axis is Figure 3 or Figure 4 the line segment l shown in
[0071] The laser beam is converged by the first converging lens 32 into a converging light with a divergence angle of ±θ. When θ is less than or equal to the angle threshold α, the incident laser beam can be fully irradiated onto the bottom of the compound parabolic concentrator 34, that is, the fluorescent device 35.
[0072] In another implementation scenario, for the divergence angle ±θ of the converging light, when θ is greater than the angle threshold α, the beam exits after multiple reflections on the side of the compound parabolic concentrator 34 and cannot be irradiated onto the fluorescent device 35.
[0073] The laser beam passes through the first converging lens 32 and can be converged into a light spot on the central axis of the compound parabolic concentrator 34. At the converged light spot, a reflecting device 33 can be placed, and the reflecting device 33 can be a mirror or other devices that can reflect light.
[0074] In some embodiments, when placing the reflecting device 33, the placement angle of the reflecting device 33 can be such that the principal ray after the laser beam is converged by the first converging lens 32 can be perpendicularly incident onto the fluorescent device 35 after being reflected by the reflecting device 33, irradiating the wavelength conversion region to generate fluorescence, and irradiating the reflection region to reflect the laser beam. Wherein, the principal ray is the central ray in the laser beam emitted by the laser 31.
[0075] In some embodiments, to avoid all the laser beams reflected by the reflecting device 33 directly irradiating onto the bottom of the CPC, the height h of the reflecting device 33 also needs to meet certain requirements, which are specifically as follows:
[0076] h > (a' / 2) / tanα
[0077] Wherein, h is the height of the reflecting device from the bottom of the CPC, a' is the bottom size radius of the CPC, and α is the upper limit value of the incident beam angle that the bottom of the CPC can receive.
[0078] When the height h of the reflection device 33 meets the above requirements, in the laser beam reflected by the reflection device 33, part of the laser beam directly irradiates the bottom of the CPC, and part of the laser beam is reflected by the side wall and then irradiates the bottom of the CPC, thereby ensuring that the laser beam can irradiate the entire bottom of the CPC, that is, the laser beam can irradiate the entire fluorescence device.
[0079] Figure 5 The figure is a schematic optical path diagram for a laser and fluorescence to be reflected to the light-emitting surface of a compound parabolic concentrator provided by an embodiment of the present application. Usually, fluorescence is basically a Lambertian body. In one implementation scenario, when the angle between the fluorescence and the central axis is less than or equal to the upper limit value α of the beam incident angle, it can be directly emitted to the light-emitting surface of the compound parabolic concentrator 34, and reference can be made to Figure 5 the l1 and l2 shown. Figure 5 There are two parts, fluorescence and laser, inside the compound parabolic concentrator 34.
[0080] In another implementation scenario, when the angle between the fluorescence and the central axis is greater than or equal to the upper limit value α of the beam incident angle, the fluorescence can be reflected by the side wall of the compound parabolic concentrator 34 and then emitted to the light-emitting surface of the compound parabolic concentrator 34 at an angle less than or equal to the upper limit value α of the beam incident angle. Refer to Figure 5 the l3 and l4 shown. The fluorescence corresponding to l3 and l4 is emitted after being reflected twice on the side wall of the compound parabolic concentrator 34, so that for the Lambertian fluorescence light source, most of the light will be emitted at an angle less than or equal to the upper limit value α of the beam incident angle.
[0081] Similarly, for the laser beam irradiated to the reflection area, after being reflected by the reflection area to form a Lambertian body, it can also be directly or reflected by the side wall of the compound parabolic concentrator 34 and then emitted to the light-emitting surface of the compound parabolic concentrator 34 at an angle less than or equal to the upper limit value α of the beam incident angle, and mixed with the fluorescence to form a uniformly mixed white light for emission.
[0082] In some embodiments, when the fluorescence device 35 is arranged around the side wall of the compound parabolic concentrator 34, the placement position and placement angle of the reflection device 33 at this time, the divergence angle of the laser beam converged by the first converging lens 32, etc. can be determined according to the specific position of the fluorescence device 35. In another implementation scenario, the fluorescence device 35 can also be located inside the compound parabolic concentrator 34.
[0083] An embodiment of the present application provides a laser light source. The laser beam emitted by the laser 31 is irradiated onto the first converging lens 32. The first converging lens 32 converges the laser beam to a point, and the focal point is located on the central axis of the compound parabolic concentrator 34 and on the reflecting device 33 placed at a certain angle. The laser beam is reflected by the reflecting device 33 to the fluorescent device 35. The laser beam irradiated onto the wavelength conversion area of the fluorescent device 35 can excite fluorescence, and the fluorescence is reflected back into the compound parabolic concentrator 34, and then directly or after being reflected by the side wall of the compound parabolic concentrator 34, it exits at a certain angle of the beam to the light exit surface of the compound parabolic concentrator 34. The laser beam irradiated onto the reflection area of the fluorescent device 35 can directly or after being reflected by the side wall of the compound parabolic concentrator 34, it exits at a certain angle to the light exit surface of the compound parabolic concentrator 34, and is mixed with the fluorescence to form white light for emission. Compared with the lens-type light collection optical path, that is, using a converging lens for light collection, the present application can effectively emit the large-angle fluorescence reflected by the fluorescent device 35 at an angle less than or equal to the upper limit value α of the beam incident angle, improving the fluorescence light collection efficiency. At the same time, there is no need to set an optical path for the laser beam emitted by the laser, reducing the number of optical devices used and simplifying the structure.
[0084] In one or more embodiments of the present application, for the fluorescent device 35 in the laser light source, it includes a reflection area and a wavelength conversion area. In one implementation scenario, the reflection area and the wavelength conversion area are coaxially arranged, and the reflection area is a specular reflector or a Lambert reflector.
[0085] In one implementation scenario, the surface of the reflection area can have various microstructures, such as triangles with random sizes, irregular bodies with random shapes and sizes, etc., so that the reflected laser is a Lambert body, ensuring that the laser is mixed with the fluorescence after emission to obtain mixed white light. The reflection area can also be other shapes, and the present application does not limit this. Figure 6 FIG. is a schematic structural diagram of a reflection area provided by an embodiment of the present application. The reflection area shown in this figure includes multiple triangles.
[0086] In some embodiments, the positional relationship between the reflection area and the wavelength conversion area is:
[0087] The wavelength conversion area is located in the central area, and the reflection area is located outside the wavelength conversion area;
[0088] Or, the wavelength conversion area includes a first conversion area and a second conversion area. From the center to the outside, they are: the first conversion area, the reflection area, and the second conversion area;
[0089] Or, the reflection area is located in the central area, and the wavelength conversion area is located outside the reflection area.
[0090] Figure 7 FIG. is a schematic diagram of the positional relationship between a wavelength conversion area and a reflection area provided by an embodiment of the present application Figure 1 such as Figure 7As shown, the wavelength conversion region is located in the central region, and the reflection region is located at the edge. The laser beam in the middle region can directly irradiate the wavelength conversion region to excite fluorescence, and then be reflected back to the light-emitting surface of the compound parabolic concentrator 34. The laser beam at the edge can be reflected by the side wall of the compound parabolic concentrator 34 and then irradiate the reflection region. After being reflected by the reflection region, the laser beam is reflected back to the light-emitting surface of the compound parabolic concentrator 34 and mixed with the fluorescence to form white light.
[0091] However, since the incident beam in the middle region is a converging beam with a high degree of spot convergence, the excitation efficiency of the fluorescent material will be low. At the same time, since only part of the light is required to excite the fluorescent material, the excess light will be dissipated in the form of heat, resulting in a high temperature and a heat dissipation problem.
[0092] Figure 8 Schematic diagram of the positional relationship between the wavelength conversion region and the reflection region provided by an embodiment of the present application Figure 2 , as Figure 8 shown, from the center to the outside, the first conversion region, the reflection region, and the second conversion region are arranged in sequence. Compared with Figure 7 the wavelength conversion region shown, which is entirely located in the central region, since Figure 8 in this case, only a small area of the first conversion region is arranged in the central region to receive the converging beam incident in the middle region, and a large area of the second conversion region is arranged on the outermost side. The second conversion region receives the beam with a lower degree of convergence at the edge. Therefore, compared with Figure 7 the positional relationship between the wavelength conversion region and the reflection region shown, it is beneficial to improve the excitation efficiency of the fluorescent material. At the same time, it is also beneficial to reduce the heat dissipation problem.
[0093] Figure 9 Schematic diagram of the positional relationship between the wavelength conversion region and the reflection region provided by an embodiment of the present application Figure 3 , as Figure 9 shown, the reflection region is located in the central region, and the wavelength conversion region is located at the edge. Part of the beam incident in the middle region is perpendicularly incident on the reflection region and can be directly reflected back to the light-emitting surface of the compound parabolic concentrator 34, and the heat generated by it can be ignored. The remaining laser beam is reflected by the side wall of the compound parabolic concentrator 34 and then irradiates the wavelength conversion region, and emits light after exciting fluorescence.
[0094] Since the degree of convergence of part of the beam at the edge is low, that is, the degree of convergence of the beam irradiating the wavelength conversion region is low. Among them, most of the beam can be used to excite fluorescence, and only a small excess part of the beam is dissipated in the form of heat. Therefore, compared with Figure 7 and Figure 8 the positional relationship between the reflection region and the wavelength conversion region shown, the excitation efficiency of the fluorescent material is further improved, and at the same time, the heat dissipation problem is effectively reduced.
[0095] In addition to the aboveFigure 7 , Figure 8 and Figure 9 In addition to the positional relationship between the wavelength conversion region and the reflection region shown, the wavelength conversion region and the reflection region may also have other positional relationships, which are not limited in this application.
[0096] Figure 10 The structural schematic diagram of a laser light source provided by an embodiment of this application Figure 3 , as Figure 10 shown, in some embodiments, the laser light source further includes: a second focusing lens 36;
[0097] The second focusing lens 36 is located on the light-emitting side of the compound parabolic concentrator 34, and is used to collect the laser beam and fluorescence emitted from the light-emitting surface of the compound parabolic concentrator 34, and narrow the range of the beam emitted from the light-emitting surface of the compound parabolic concentrator 34, so that most of the light is incident on the subsequent optical path, improving the utilization rate of light.
[0098] In some embodiments, since the laser light source may include multiple laser chips, due to the existence of the fast axis and slow axis of the laser, the light emitted by the laser chips will have a certain angle. Therefore, in order to obtain a parallel beam, the laser light source further includes: a collimating lens 37;
[0099] The collimating lens 37 is located between the first focusing lens 32 and the laser 31, and is used to collimate the laser beam emitted by the laser 31 to obtain a parallel beam, and then emit the obtained parallel beam to the first focusing lens 32.
[0100] In summary, by setting the positions of the wavelength conversion region and the reflection region included in the fluorescence device 35, the excitation efficiency of the fluorescent material is improved, and at the same time, the heat dissipation problem is reduced. At the same time, based on the second focusing lens 36 narrowing the range of the beam emitted from the light-emitting surface of the compound parabolic concentrator 34, the utilization rate of light is improved, and based on the collimating lens 37 collimating the laser beam emitted by the laser 31, a parallel beam is obtained.
[0101] An embodiment of this application provides a laser projector, including: a third focusing lens, a color wheel, a light homogenizing element, a total reflection prism, a light valve modulation component, a lens, and the laser light source according to any one of the above.
[0102] Among them, the light homogenizing element may be a device such as a fly-eye lens or a light bar, and is used to perform light homogenizing processing on the light.
[0103] The light valve modulation component may be a DMD (Digital Micromirror Device), an LCD (Liquid Crystal Display), an LCOS (Liquid Crystal on Silicon), etc.
[0104] In addition to the laser projector, the laser light source of the present application can also be used as other lighting devices, such as automobile lamps, flashlights, etc., and the present application does not limit this.
[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limiting them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.
[0106] For the sake of convenience of explanation, the above description has been made in conjunction with specific embodiments. However, the above exemplary discussions are not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. According to the above teachings, various modifications and variations can be obtained. The selection and description of the above embodiments are for better explaining the principles and practical applications, so that those skilled in the art can better use the embodiments and various different modified embodiments suitable for specific use considerations.
Claims
1. A laser light source, characterized in that, Comprising: A laser for emitting a laser beam; A first converging lens located on the light-emitting side of the laser for converging the laser beam onto a reflecting device; The reflecting device is located on the central axis of the compound parabolic concentrator for reflecting the laser beam converged by the first converging lens to a fluorescent device in the compound parabolic concentrator; The fluorescent device includes a reflection region and a wavelength conversion region. The reflection region is used to reflect the laser beam to the light-emitting surface of the compound parabolic concentrator. The wavelength conversion region emits fluorescence based on the laser beam and reflects the fluorescence to the light-emitting surface of the compound parabolic concentrator, so that the fluorescence is mixed with the laser beam reflected by the reflection region to emit white light.
2. The laser light source according to claim 1, characterized in that, The fluorescent device is arranged around the side wall of the compound parabolic concentrator or located at the bottom of the compound parabolic concentrator, and the bottom is arranged opposite to the light-emitting surface of the compound parabolic concentrator.
3. The laser light source according to claim 2, characterized in that, If the fluorescent device is located at the bottom of the compound parabolic concentrator, the divergence angle of the laser beam converged by the first converging lens is less than or equal to an angle threshold, and the angle threshold is determined based on the upper limit value of the incident angle of the light beam received by the bottom of the compound parabolic concentrator.
4. The laser light source according to any one of claims 1 to 3, characterized in that, The reflection region and the wavelength conversion region are coaxially arranged, and the reflection region is a specular reflector or a Lambert reflector.
5. The laser light source according to claim 4, characterized in that, The positional relationship between the reflection region and the wavelength conversion region is: The wavelength conversion region is located in the central region, and the reflection region is located outside the wavelength conversion region; Or, the wavelength conversion region includes a first conversion region and a second conversion region, and from the center to the outside are: the first conversion region, the reflection region, the second conversion region; Or, the reflection region is located in the central region, and the wavelength conversion region is located outside the reflection region.
6. The laser light source according to claim 1, wherein, The first converging lens is integrated on the outer side of the side wall of the compound parabolic concentrator, and an angle-selective transmission film is plated on the inner side of the side wall of the compound parabolic concentrator; The angle-selective transmission film is used to transmit the laser beam emitted by the laser, and reflect the fluorescence reflected by the wavelength conversion region and the laser beam reflected by the reflection region.
7. The laser light source according to claim 1, characterized in that The first converging lens is located between the compound parabolic concentrator and the laser, and an antireflection film is plated on the surface of the first converging lens and the outer side of the side wall of the compound parabolic concentrator.
8. The laser light source according to claim 1, characterized in that, The laser light source further includes: a second converging lens; The second converging lens is located on the light-emitting side of the compound parabolic concentrator for collecting the laser beam and fluorescence emitted from the light-emitting surface of the compound parabolic concentrator.
9. The laser light source according to claim 1, characterized in that, The laser light source further includes: a collimating lens; The collimating lens is located between the first converging lens and the laser for collimating the laser beam emitted by the laser to obtain a parallel beam, and the obtained parallel beam is emitted to the first converging lens.
10. A laser projector, characterized in that, Comprising: A third converging lens, a color wheel, a light homogenizing element, a total reflection prism, a light valve modulation component, a lens, and the laser light source according to any one of claims 1-9.