Light source and lighting device
By introducing a light guiding element into the light source to change the direction of the excitation light, the wavelength conversion element is brought closer to the light collecting lens, which solves the problem of low collection efficiency in existing light sources and achieves more efficient light collection and brightness improvement.
Patent Information
- Application Number
- CN202423098347.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-13
- Publication Date
- 2026-01-09
- Estimated Expiration
- 2034-12-13
AI Technical Summary
The laser emitted by the wavelength conversion element in existing light sources is of the Lambertian type with a divergence angle of 180 degrees, which results in a long distance for the receiving optical element and low collection efficiency.
By introducing first and second light guiding elements into the light source, the direction of the excitation light is changed so that it points towards the cover plate. The wavelength conversion element is set on the outside of the housing, and the light collecting lens is placed closer, thereby improving the collection efficiency.
By reducing the distance between the wavelength conversion element and the receiving optical element, the light collection efficiency is improved, and the brightness and brightness uniformity of the light source are enhanced.
Smart Images
Figure CN223782711U_ABST
Abstract
Description
[Technical Field]
[0001] This utility model relates to the field of lighting, and in particular to a light source and a lighting device. [Background Technology]
[0002] A known light source integrates its laser chip and wavelength conversion element into a hermetically sealed housing, which is small in size and easy to use. However, the laser emitted by the wavelength conversion element is of the Lambertian type with a divergence angle of 180 degrees. The sealing cover of the device is a flat window light-transmitting area, which makes the optical elements such as lenses placed behind it far away from the wavelength conversion element, resulting in a smaller angle of reception and low collection efficiency. [Utility Model Content]
[0003] The purpose of this invention is to provide a light source that can reduce the distance between the wavelength conversion element and the optical element receiving light.
[0004] To achieve the above objectives, this utility model provides a light source, comprising:
[0005] The housing includes a base plate, a cover plate opposite to the base plate, and a retaining wall located between the base plate and the cover plate, wherein the base plate, the cover plate, and the retaining wall enclose an installation space.
[0006] A first light-emitting element is disposed on the upper surface of the substrate, and the first light-emitting element is used to emit a first excitation light;
[0007] A first light guiding element is disposed on the upper surface of the substrate. The first light guiding element is used to change the travel direction of the first excitation light so that the travel direction of the first excitation light points towards the cover plate; and
[0008] A wavelength conversion element for converting at least a portion of the first excitation light into a first laser beam with a different wavelength range, the wavelength conversion element being disposed on the outer side of the cover plate.
[0009] In some possible implementations, the first excitation beam has a fast axis and a slow axis, and the divergence angle of the first excitation beam on the fast axis is greater than the divergence angle of the first excitation beam on the slow axis.
[0010] The first light guiding element includes:
[0011] A first incident surface is used to receive the first excitation light. The first incident surface is set as a curved surface along the fast axis direction of the first excitation light to converge the divergence angle on the fast axis of the first excitation light.
[0012] A first reflecting surface is used to reflect the first excitation light incident via the first incident surface and change the direction of travel of the first excitation light to point towards the cover plate; and
[0013] A first exit surface is used to emit the first excitation light. The first exit surface is set as a curved surface along the fast axis direction of the first excitation light to converge the divergence angle on the fast axis of the first excitation light.
[0014] In some possible implementations, the first incident surface is configured as a cylindrical surface with its axis parallel to the slow axis of the first excitation light, and the first exit surface is configured as a cylindrical surface with its axis parallel to the slow axis of the first excitation light.
[0015] In some possible implementations, the first reflective surface is arranged at an angle relative to the upper surface of the substrate.
[0016] In some possible implementations, the angle between the first reflective surface and the upper surface of the substrate is less than 45 degrees.
[0017] In some possible implementations, the wavelength conversion element is spaced apart from the cover plate.
[0018] In some possible implementations, it also includes:
[0019] A diffusion element is disposed between the cover plate and the wavelength conversion element.
[0020] In some possible implementations, it also includes:
[0021] A second light-emitting element is disposed on the upper surface of the substrate. The second light-emitting element is used to emit a second excitation light. The divergence angle of the second excitation light on the fast axis is greater than the divergence angle of the second excitation light on the slow axis.
[0022] A second light guiding element is disposed on the upper surface of the substrate. The second light guiding element is used to change the direction of travel of the second excitation light so that the direction of travel of the second excitation light points to the cover plate.
[0023] The wavelength conversion element is also used to convert at least a portion of the second excitation light into a second laser with a different wavelength range.
[0024] In some possible implementations, the second excitation light has a fast axis and a slow axis;
[0025] The second light guiding element includes:
[0026] The second incident surface is used to receive the second excitation light. The second incident surface is set as a curved surface along the fast axis of the second excitation light to converge the divergence angle on the fast axis of the second excitation light.
[0027] A second reflecting surface is used to reflect the second excitation light incident via the second incident surface and change the direction of travel of the second excitation light to point towards the cover plate; and
[0028] The second exit surface is used to emit the second excitation light. The second exit surface is set as a curved surface along the fast axis of the second excitation light to converge the divergence angle on the fast axis of the second excitation light.
[0029] In some possible implementations, the second incident surface is configured as a cylindrical surface with its axis parallel to the slow axis of the second excitation light, and the second exit surface is configured as a cylindrical surface with its axis parallel to the slow axis of the second excitation light.
[0030] In some possible implementations, the second reflective surface is arranged at an angle relative to the upper surface of the substrate.
[0031] In some possible implementations, the angle between the second reflective surface and the upper surface of the substrate is less than 45 degrees.
[0032] In some possible implementations, the first excitation light is incident on a first region of the wavelength conversion element, and the second excitation light is incident on a second region of the wavelength conversion element, wherein the first region overlaps, partially overlaps, or is side by side with the second region.
[0033] This utility model also provides a lighting device, including the light source described above.
[0034] The beneficial effects of this utility model are:
[0035] This utility model discloses a light source in which a first light-emitting element is installed inside a housing, and a first light-guiding element guides the first excitation light emitted by the first light-emitting element to a wavelength conversion element outside the housing. The collecting optical element for collecting the first laser light generated by the wavelength conversion element can be installed closer to the wavelength conversion element, thereby improving the light collection efficiency. [Attached Image Description]
[0036] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:
[0037] Figure 1 This is a schematic diagram of the structure of the light source according to an embodiment of the present invention;
[0038] Figure 2 This is a schematic diagram of the internal structure of the light source in an embodiment of the present invention.
Detailed Implementation Methods
[0039] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.
[0040] Please refer to Figure 1 and Figure 2 This application provides a light source, including a housing 1, a first light-emitting element 2, a first light-guiding element 3, and a wavelength conversion element 4. The housing 1 has an airtight internal space, and the first light-emitting element 2 and the first light-guiding element 3 are disposed within this airtight space. The first light-emitting element 2 emits a first excitation light, and the first light-guiding element 3 changes the direction of the first excitation light to point towards the top cover of the housing 1, allowing the first excitation light to pass through the top cover and exit. The wavelength conversion element 4 is disposed on the outside of the housing 1, located in the optical path of the first excitation light, to convert at least a portion of the first excitation light into a first laser beam with a different wavelength range. On the light-emitting side of the wavelength conversion element 4, an optical element for collecting light, such as a light-collecting lens, can be disposed to collect the emitted light from the wavelength conversion element 4 for illumination, projection, etc. Because the wavelength conversion element 4 is arranged on the outside of the housing 1, the position of the light-collecting lens can be closer to the wavelength conversion element 4, thus shortening the distance the emitted light from the wavelength conversion element 4 travels in space, thereby improving the light-collecting efficiency of the light-collecting lens.
[0041] In some embodiments of this application, the housing 1 may include a substrate 10, a cover plate 11, and a dam 12. The substrate 10 and the cover plate 11 are arranged opposite to each other, and the dam 12 is disposed between the substrate 10 and the cover plate 11, extending from the substrate 10 to the cover plate 11 at the edges of the substrate 10 and the cover plate 11 to connect the substrate 10 and the cover plate 11. The substrate 10, the cover plate 11, and the dam 12 enclose a mounting space 13. A first light-emitting element 2 and a first light-guiding element 3 are disposed within the mounting space 13. The mounting space 13 may be configured as an airtight space, for example.
[0042] In some embodiments, the cover plate 11 may be selected to be transmissive to light, so that the first excitation light can be transmitted through the cover plate 11 to the outside of the housing 1 and incident on the wavelength conversion element 4. Optionally, the cover plate 11 may be made of a light-transmitting material such as glass or ceramic, and the cover plate 11 may also be configured to have a light-transmitting area, for example, a light-transmitting window is provided at the position where the first excitation light is incident.
[0043] The substrate 10 has an upper surface 100 on the side facing the cover plate 11. The first light-emitting element 2 is disposed on the upper surface 100 of the substrate 10. For example, the first light-emitting element 2 can be mounted on the upper surface 100 of the substrate 10 using a surface mount process, thus increasing the heat-conducting area and improving the heat dissipation capacity of the first light-emitting element 2. Figure 1 As shown, in some embodiments, a first heat sink 5 is disposed between the first light-emitting element 2 and the substrate 10. The first heat sink 5 has a thermally conductive medium and an upper surface and a lower surface located on the upper and lower sides of the thermally conductive medium, wherein the lower surface of the first heat sink 5 is in contact with the upper surface 100 of the substrate 10, and the upper surface of the first heat sink 5 is in contact with the lower surface of the first light-emitting element 2. The heat generated by the first light-emitting element 2 can be quickly conducted to the substrate 10 through the first heat sink 5, and then conducted and dissipated through the substrate 10.
[0044] The first light guiding element 3 can be disposed on the light emission axis of the first excitation light. For example... Figure 1 As shown, the light emission axis of the first excitation light is, for example, parallel to the upper surface 100 of the substrate 10, and the first light guiding element 3 is disposed on the upper surface 100 of the substrate 10 and located on the light axis of the first excitation light. The first light guiding element 3 can be directly disposed on the upper surface 100 of the substrate 10, or it can be indirectly disposed on the upper surface 100 of the substrate 10. Figure 1 There may be a gap between the first light guiding element 3 and the upper surface 100 of the substrate 10. For this purpose, a bracket (not shown) can be arranged below the first light guiding element 3 to fix the first light guiding element 3.
[0045] In this embodiment, the first light-emitting element 2 can be configured as a laser diode chip, and the first excitation light is, for example, a laser. Figure 1 and Figure 2 As shown, the first excitation light has a fast axis ( Figure 1 (middle X direction) and slow axis ( Figure 2In the Y-direction, the divergence angle of the first excitation light in the fast axis direction is greater than that in the slow axis direction. Therefore, as the distance the first excitation light travels in space increases, the spot size of the first excitation light in the fast axis direction will be significantly larger than that in the slow axis direction. To address this, the first light guiding element 3 can be configured to change the travel direction of the first excitation light and shape it to reduce the difference in spot size between the fast and slow axes.
[0046] like Figure 1 As shown, the first light guiding element 3 includes a first incident surface 30, a reflecting surface 31, and a first exiting surface 32. The first incident surface 30 is used to receive the first excitation light, wherein the first incident surface 30 is configured as a curved surface along the fast axis direction X of the first excitation light to converge the divergence angle of the first excitation light along the fast axis; the first reflecting surface 31 is used to reflect the first excitation light incident through the first incident surface and change the travel direction of the first excitation light to point towards the cover plate 11; the first exiting surface 32 is used to emit the first excitation light, and the first exiting surface 32 is configured as a curved surface along the fast axis direction of the first excitation light to converge the divergence angle of the first excitation light. Optionally, the first incident surface 30 and the first exiting surface 32 can be configured as curved surfaces convex outward relative to the first reflecting surface 31, and the first incident surface 30 and the first exiting surface 32 can be disposed on the same curved surface.
[0047] like Figure 2 As shown, the first incident surface 30 is a cylindrical surface with its axis parallel to the slow axis Y of the first excitation light, and the first exit surface 32 is a cylindrical surface with its axis parallel to the slow axis Y of the first excitation light. Therefore, the first light guiding element 3 does not change the divergence angle of the first excitation light in the slow axis direction.
[0048] Continue to refer to Figure 1 The first reflective surface 31 is arranged at an angle relative to the upper surface 100 of the substrate 10, so that the first excitation light is reflected and travels toward the cover plate 11. In some embodiments of this application, the angle between the first reflective surface 31 and the upper surface 100 of the substrate 10 is, for example, less than 45 degrees, so that the first excitation light is reflected and travels in a direction with a certain angle relative to the upward vertical line, so that the first excitation light is obliquely incident on the cover plate 11 and the wavelength conversion element 4.
[0049] In this embodiment, the wavelength conversion element 4 is configured as a transmissive wavelength conversion element, meaning that the surface of the wavelength conversion element 4 that receives the first excitation light and the surface that emits the first laser beam are two opposing surfaces. Optionally, the wavelength conversion element 4 includes a substrate and a wavelength conversion layer (not shown) disposed on the side of the substrate facing away from the housing 1. The substrate is transparent, for example, a sapphire substrate. The incident first excitation light first enters the substrate and is transmitted through the substrate before entering the wavelength conversion layer. For example, an antireflection film is disposed on the surface of the substrate facing the housing 1 to improve the transmittance of the first excitation light. The wavelength conversion layer is selected, for example, as a fluorescent material layer. The fluorescent material layer has fluorescent material and can be excited by the first excitation light, converting at least a portion of the first excitation light into the first laser beam with a different wavelength range. A dichroic film can be disposed on the surface of the substrate facing away from the housing 1. The dichroic film can transmit the first excitation light and reflect the first laser beam, thus ensuring that the first excitation light enters the fluorescent material layer and can reflect the first laser beam generated in the fluorescent material layer, thereby improving the utilization rate of the first laser beam.
[0050] In some embodiments, the wavelength conversion element 4 can be mounted on a bracket, which can be connected to or separated from the housing 1. Optionally, a light-collecting lens can be arranged on the light-emitting side of the wavelength conversion element 4 to collect the emitted first laser beam. Since the wavelength conversion element 4 is arranged on the outside of the housing 1, the light-collecting lens can be arranged at a distance relatively close to the wavelength conversion element 4, thereby improving the collection efficiency of the first laser beam.
[0051] In some embodiments, the light source further includes a diffusion element 6, which is disposed between the cover plate 11 of the housing 1 and the wavelength conversion element 4. The diffusion element 6 is located in the optical path of the first excitation light and is used to diffuse the first excitation light. The diffusion element 6 can be selected, for example, as a Gaussian diffuser, an elliptical Gaussian diffuser, or a flat-top diffuser.
[0052] Continue to refer to Figure 1 and Figure 2 In some embodiments of this application, the light source further includes: a second light-emitting element 7 and a second light-guiding element 8. The second light-emitting element 7 is disposed on the upper surface 100 of the substrate 10 and is used to emit a second excitation light; the second light-guiding element 8 is disposed on the upper surface 100 of the substrate 10 and is used to change the direction of travel of the second excitation light so that the direction of travel of the second excitation light points to the cover plate 11, so that the second excitation light is transmitted through the cover plate 11 and incident on the wavelength conversion element 4. The wavelength conversion element 4 is also used to convert at least a portion of the second excitation light into a second laser with a different wavelength range.
[0053] The second light-emitting element 7 can be surface-mounted on the upper surface 100 of the substrate 10. To improve heat dissipation, a second heat sink 9 can be disposed between the second light-emitting element 7 and the substrate 10. The second heat sink 9 is, for example, composed of a thermally conductive medium and has light transmittance. The lower surface of the second heat sink 9 is in contact with the upper surface 100 of the substrate 10, and the upper surface of the second heat sink 9 is in contact with the lower surface of the second light-emitting element 7. The second heat sink 9 is used to conduct the heat generated by the second light-emitting element 7 to the substrate 10. The second light-emitting element 7 can be, for example, a laser diode, and the second excitation light can be, for example, a laser. The second excitation light has a fast axis and a slow axis, wherein the divergence angle of the second excitation light in the fast axis direction is greater than the divergence angle of the second excitation light in the slow axis direction. Optionally, the first excitation light and the second excitation light can be configured to have the same wavelength range, for example, the first excitation light and the second excitation light can be configured to be blue excitation light.
[0054] The second light guiding element 8 may be configured to include a second incident surface 80, a second reflecting surface 81, and a second exiting surface 82. The second incident surface 80 is used to receive the second excitation light, and the second incident surface is configured as a curved surface along the fast axis of the second excitation light to converge the divergence angle of the second excitation light in the fast axis direction; the second reflecting surface 81 is used to reflect the second excitation light incident through the second incident surface 80 and change the travel direction of the second excitation light to point towards the cover plate 11; the second exiting surface 82 is used to emit the second excitation light, and the second exiting surface is configured as a curved surface along the fast axis of the second excitation light to converge the divergence angle of the second excitation light in the fast axis direction.
[0055] In some embodiments, the second incident surface 80 is configured as a cylindrical surface with its axis parallel to the slow axis of the second excitation light, and the second exit surface 82 is configured as a cylindrical surface with its axis parallel to the slow axis of the second excitation light. Therefore, while guiding the second excitation light toward the cover plate 11 and incident on the wavelength conversion element 4, the second light guiding element 8 shapes the second excitation light, converges the divergence angle of the fast axis direction of the second excitation light, and maintains the slow axis direction of the second excitation light, so that the spot size of the second excitation light in the fast axis direction is closer to the spot size in the slow axis direction of the second excitation light.
[0056] In some embodiments, the second reflective surface 81 is arranged at an angle relative to the upper surface of the substrate 10. Optionally, the angle between the second reflective surface 81 and the upper surface of the substrate 10 is less than 45 degrees, thereby causing the second excitation light to be obliquely incident on the cover plate 11 and the wavelength conversion element 4.
[0057] In some embodiments, the first light-emitting element 2 and the second light-emitting element 7 can be disposed on the circumference of a first predetermined circle defined by the central axis of the substrate 10. The first light-emitting element 2 and the second light-emitting element 7 can be configured to emit a first excitation light and a second excitation light respectively toward the central axis of the substrate 10. The first light-guiding element 3 and the second light-guiding element 8 can be disposed on the circumference of a second predetermined circle defined by the central axis of the substrate 10, wherein the radius of the second predetermined circle is smaller than the radius of the first predetermined circle. It is understood that the first light-guiding element 3 and the second light-guiding element 8 respectively change the first excitation light and the second excitation light to the inclined incident cover plate 11 and the wavelength conversion element 4, allowing the first excitation light and the second excitation light to gradually approach each other during their spatial propagation, thus reducing the need for deflecting optical elements in the optical paths of the first excitation light and the second excitation light. Figure 1 and Figure 2 In one example of this application, the first light-emitting element 2 and the second light-emitting element 7 can be arranged symmetrically about the central axis of the substrate 10; the first light-guiding element 3 and the second light-guiding element 8 can also be arranged symmetrically about the central axis of the substrate 10, and both the first light-guiding element 3 and the second light-guiding element 8 have a certain distance relative to the central axis of the substrate 10. Optionally, the first excitation light emitted by the first light-emitting element 2 and the second excitation light emitted by the second light-emitting element 7 can have the same fast axis direction and slow axis direction, i.e., as shown in the example. Figure 1 and Figure 2 As shown, the fast axis of the second excitation light emitted by the second light-emitting element 7 can be parallel to the X direction, and the slow axis of the second excitation light can be parallel to the Y direction. It is understood that in different embodiments, the first light-emitting element 2 and the second light-emitting element 7, as well as the first light guiding element 3 and the second light guiding element 8, can be mounted with reference to other axes of the substrate 10, and are not necessarily limited to the central axis of the substrate 10.
[0058] In some embodiments, the first excitation light and the second excitation light are respectively guided to the wavelength conversion element 4 by the first light guiding element 3 and the second light guiding element 8, so as to be converted into the first and second received lasers and emitted, thereby increasing the optical power density of the incident light and the brightness of the emitted light from the wavelength conversion element 4. The first excitation light and the second excitation light can be selected to have the same wavelength range, such as blue excitation light. The wavelength conversion layer of the wavelength conversion element 4 includes, for example, a wavelength conversion material layer, which includes, for example, yellow phosphor, red phosphor, etc., so as to convert the blue excitation light into received lasers of different wavelengths such as yellow or red, and the brightness of the output received laser is increased due to the increased optical power density of the incident excitation light. The first excitation light and the second excitation light can also be selected to be excitation light with different wavelength ranges, for example, the first excitation light is blue excitation light and the second excitation light is green excitation light, which can improve the brightness of the emitted light and supplement the spectral range to a certain extent, thereby improving the color rendering.
[0059] In some embodiments, a first excitation light is incident on a first region of the wavelength conversion element 4, and a second excitation light is incident on a second region of the wavelength conversion element 4, wherein the first region and the second region are configured to overlap, partially overlap, or be side-by-side. When the first region and the second region overlap, the optical power density of the incident excitation light is maximized, resulting in a maximum increase in brightness. When the first region and the second region partially overlap, the optical power density is relatively reduced. Since the center of the spot of the first excitation light incident on the wavelength conversion element 4 is offset from the center of the spot of the second excitation light incident on the wavelength conversion element 4, the maximum optical power density received by the wavelength conversion element 4 can be reduced, avoiding excessive heat accumulation. However, in this case, the brightness of the central region of the emitted light is also significantly increased. When the first region and the second region are side-by-side, the overall brightness of the emitted light is improved, and the brightness distribution is more uniform.
[0060] In some embodiments, the diffusion element 6 is disposed in the optical path of the first excitation light and the second excitation light, so the diffusion element 6 can diffuse the first excitation light and the second excitation light simultaneously.
[0061] It is understood that the tilt angle of the first light guiding element 3 and the second light guiding element 8 relative to the upper surface of the substrate 10 can be set to change the position of the first region and the second region. Alternatively, the distance between the wavelength conversion element and the first light guiding element 3 and the second light guiding element 8 can be changed to change the position of the first region and the second region. Or, the distance between the first light guiding element 3 and the second light guiding element 8 relative to the central axis of the substrate 10 can be changed to change the position of the first region and the second region. Of course, these can be adjusted separately or in combination.
[0062] This application also provides a lighting device, including the light source described above. The lighting device includes, but is not limited to, stage lights, vehicle lights, flashlights, and searchlights.
[0063] The above description is merely an embodiment of this utility model. It should be noted that those skilled in the art can make improvements without departing from the inventive concept of this utility model, but these improvements all fall within the protection scope of this utility model.
Claims
1. A light source, characterized in that, include: The housing includes a base plate, a cover plate opposite to the base plate, and a retaining wall located between the base plate and the cover plate, wherein the base plate, the cover plate, and the retaining wall enclose an installation space. A first light-emitting element is disposed on the upper surface of the substrate, and the first light-emitting element is used to emit a first excitation light; A first light guiding element is disposed on the upper surface of the substrate. The first light guiding element is used to change the direction of travel of the first excitation light so that the direction of travel of the first excitation light points to the cover plate. as well as A wavelength conversion element for converting at least a portion of the first excitation light into a first laser beam with a different wavelength range, the wavelength conversion element being disposed on the outer side of the cover plate.
2. The light source according to claim 1, characterized in that, The first excitation beam has a fast axis and a slow axis, and the divergence angle of the first excitation beam on the fast axis is greater than the divergence angle of the first excitation beam on the slow axis; The first light guiding element includes: A first incident surface is used to receive the first excitation light. The first incident surface is set as a curved surface along the fast axis direction of the first excitation light to converge the divergence angle on the fast axis of the first excitation light. A first reflecting surface is used to reflect the first excitation light incident via the first incident surface and change the direction of travel of the first excitation light to point towards the cover plate; and A first exit surface is used to emit the first excitation light. The first exit surface is set as a curved surface along the fast axis direction of the first excitation light to converge the divergence angle on the fast axis of the first excitation light.
3. The light source according to claim 2, characterized in that, The first incident surface is a cylindrical surface with its axis parallel to the slow axis of the first excitation light, and the first exit surface is a cylindrical surface with its axis parallel to the slow axis of the first excitation light.
4. The light source according to claim 2, characterized in that, The first reflective surface is arranged at an angle relative to the upper surface of the substrate.
5. The light source according to claim 4, characterized in that, The angle between the first reflective surface and the upper surface of the substrate is less than 45 degrees.
6. The light source according to claim 1, characterized in that, The wavelength conversion element is spaced apart from the cover plate.
7. The light source according to claim 6, characterized in that, Also includes: A diffusion element is disposed between the cover plate and the wavelength conversion element.
8. The light source according to claim 1, characterized in that, Also includes: A second light-emitting element is disposed on the upper surface of the substrate, and the second light-emitting element is used to emit a second excitation light; A second light guiding element is disposed on the upper surface of the substrate. The second light guiding element is used to change the direction of travel of the second excitation light so that the direction of travel of the second excitation light points to the cover plate. The wavelength conversion element is also used to convert at least a portion of the second excitation light into a second laser with a different wavelength range.
9. The light source according to claim 8, characterized in that, The second excitation beam has a fast axis and a slow axis, and the divergence angle of the second excitation beam on the fast axis is greater than the divergence angle of the second excitation beam on the slow axis; The second light guiding element includes: The second incident surface is used to receive the second excitation light. The second incident surface is set as a curved surface along the fast axis of the second excitation light to converge the divergence angle on the fast axis of the second excitation light. A second reflecting surface is used to reflect the second excitation light incident via the second incident surface and change the direction of travel of the second excitation light to point towards the cover plate; and The second exit surface is used to emit the second excitation light. The second exit surface is set as a curved surface along the fast axis of the second excitation light to converge the divergence angle on the fast axis of the second excitation light.
10. The light source according to claim 9, characterized in that, The second incident surface is set as a cylindrical surface with its axis parallel to the slow axis of the second excitation light, and the second exit surface is set as a cylindrical surface with its axis parallel to the slow axis of the second excitation light.
11. The light source according to claim 9, characterized in that, The second reflective surface is arranged at an angle relative to the upper surface of the substrate.
12. The light source according to claim 11, characterized in that, The angle between the second reflective surface and the upper surface of the substrate is less than 45 degrees.
13. The light source according to claim 8, characterized in that, The first excitation light is incident on a first region of the wavelength conversion element, and the second excitation light is incident on a second region of the wavelength conversion element. The first region and the second region overlap, partially overlap, or are side by side.
14. A lighting device, characterized in that, Includes the light source as described in any one of claims 1-13.