Laser illumination light source and laser projection device
Patent Information
- Application Number
- CN202522215661.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-20
- Publication Date
- 2026-10-30
- Estimated Expiration
- 2035-10-20
AI Technical Summary
[0002]在以激光作为光源的激光照明光源中，光源合光后通常需借助一组望远透镜组对光斑进行缩束，再经复眼透镜匀化后进入成像系统，其中，望远透镜组通常由多片透镜构成（如正负透镜组合），显著增加了激光照明光源中光学元件的数量和激光照明光源的物理长度，装配工差较大，影响了激光照明光源的输出稳定性
[0026]上述激光照明光源和激光投影设备，激光照明光源包括光源组件、偏振合光组件和透镜组件，光源组件用于输出目标激光，目标激光中的P偏振态的激光通过第一偏振合光元件，且目标激光中的S偏振态的激光通过第二偏振合光元件，其中，偏振合光组件中的第一偏振合光元件和第二偏振合光元件用于对目标激光进行偏振合光，完成偏振合光后的目标激光经透镜组件进行匀化处理和像差校正后输出；本申请通过采用偏振合光组件替代传统激光照明光源的望远透镜组，摒弃传统的几何光学缩束思路，创新性地采用全波长偏振合光技术，即，在合光阶段，通过配置偏振控制组件，直接对目标激光进行高效的偏振态管理与合成，显著简化光路，省去由多片透镜构成的望远透镜组，减少了激光照明光源中光学元件的数量和激光照明光源的物理长度，消除透镜间距与倾斜角的装配公差，提升了激光照明光源的输出稳定性。
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Figure CN224922164U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of laser display technology, and in particular to a laser illumination source and a laser projection device. Background Technology
[0002] In laser illumination sources that use lasers as light sources, after the light from the source is combined, it is usually necessary to use a set of telescopic lenses to reduce the beam of light, and then use compound eye lenses to homogenize it before it enters the imaging system. The telescopic lens set is usually composed of multiple lenses (such as a combination of positive and negative lenses), which significantly increases the number of optical elements and the physical length of the laser illumination source. The assembly tolerance is large, which affects the output stability of the laser illumination source. Utility Model Content
[0003] Therefore, it is necessary to provide a laser lighting source and laser projection device that can reduce assembly tolerances and improve output stability.
[0004] In a first aspect, this application provides a laser lighting source, comprising:
[0005] The light source assembly includes a light-emitting component and a beam combiner assembly. The light-emitting component is used to emit lasers of at least three different colors, and the beam combiner assembly is used to combine the lasers and output the target laser. The polarization state of the target laser includes a P-polarization state and an S-polarization state.
[0006] A polarization combining component includes a first polarization combining element and a second polarization combining element. The first and second polarization combining elements are respectively disposed in different parts of the light output path of the light source component, and the second polarization combining element is disposed on the light output path of the first polarization combining element, such that the P-polarized laser in the target laser passes through the first polarization combining element, and the S-polarized laser in the target laser passes through the second polarization combining element; the first polarization combining element is configured to reflect P-polarized light, and the second polarization combining element is configured to transmit P-polarized light and reflect S-polarized light;
[0007] Lens assembly: The lens assembly is used to homogenize and correct aberrations in the laser beam emitted from the polarization combining assembly.
[0008] In one embodiment, the first polarization combining element is tilted at a 45° angle to the propagation direction of the target laser, the first polarization combining element and the second polarization combining element are arranged in parallel, and there is a gap between the first polarization combining element and the second polarization combining element.
[0009] In one embodiment, aberration correction includes correcting the spherical aberration, field curvature, and chromatic aberration of the laser beam, respectively; the lens assembly includes a homogenizing component and a spherical lens group, and the laser beam emitted from the polarization combining component passes sequentially through the homogenizing component and the spherical lens group;
[0010] The homogenization component is used to homogenize the received laser beam; the spherical lens group includes at least two spherical lenses, which are used to correct the spherical aberration, field curvature and chromatic aberration of the received laser beam.
[0011] In one embodiment, aberration correction includes correcting spherical aberration, field curvature, and chromatic aberration of the laser beam, respectively; the lens assembly includes:
[0012] The laser beam emitted from the homogenizing component and aspherical lens, and the polarization beam combining component, pass sequentially through the homogenizing component and aspherical lens;
[0013] The homogenization component is used to homogenize the received laser beam; the aspherical lens is used to correct the spherical aberration, field curvature and chromatic aberration of the received laser beam.
[0014] In one embodiment, the aspherical lens satisfies:
[0015] ;
[0016] Where z is the surface curvature of the aspherical lens; c is the reciprocal of the vertex radius of curvature; r is the radial coordinate of the aspherical lens; and k is the conic coefficient.
[0017] In one embodiment, at least three different colors of laser light include a red laser, a blue laser, and a green laser; the beam combining mirror assembly includes:
[0018] The first waveplate is disposed in the optical path between the light-emitting component and the first polarization combining element. The first waveplate is used to convert the blue laser in the received laser from the S polarization state to the P polarization state, and to convert the green laser in the received laser from the S polarization state to the P polarization state.
[0019] The second waveplate is positioned in the optical path between the light-emitting component and the second polarization combining element. The second waveplate is used to convert the red laser in the received laser from the P polarization state to the S polarization state.
[0020] In one embodiment, both the first waveplate and the second waveplate are half-wave plates.
[0021] In one embodiment, the light-emitting component includes at least three types of light-emitting chips, each of which emits laser light of a different color.
[0022] In one embodiment, the laser illumination source further includes:
[0023] A diffuser is placed in the optical path between the light source assembly and the polarization combining assembly. The diffuser is used to diffuse the target laser; the diffusion angle of the diffuser ranges from 1 degree to 2 degrees.
[0024] Secondly, this application also provides a laser projection device, including a projection lens and a laser illumination source as described above;
[0025] The projection lens is positioned on the light path of the laser illumination source.
[0026] The aforementioned laser illumination source and laser projection device include a laser illumination source component, a polarization combining component, and a lens component. The light source component outputs the target laser. The P-polarized laser in the target laser passes through a first polarization combining element, and the S-polarized laser in the target laser passes through a second polarization combining element. The first and second polarization combining elements in the polarization combining component are used to polarize and combine the target laser. After polarization and combining, the target laser is homogenized and aberration corrected by the lens component before being output. This application replaces the telescope lens group of the traditional laser illumination source with a polarization combining component, abandoning the traditional geometric optical beam-shrinking approach and innovatively adopting full-wavelength polarization combining technology. That is, in the combining stage, by configuring a polarization control component, the polarization state of the target laser is directly and efficiently managed and combined, significantly simplifying the optical path, eliminating the telescope lens group composed of multiple lenses, reducing the number of optical elements and the physical length of the laser illumination source, eliminating the assembly tolerance of lens spacing and tilt angle, and improving the output stability of the laser illumination source. Attached Figure Description
[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0028] Figure 1 This is a schematic diagram of the structure of a conventional laser illumination source in one embodiment;
[0029] Figure 2 This is a structural block diagram of a laser illumination source in one embodiment;
[0030] Figure 3 This is a schematic diagram of the optical path of a polarization combining component in one embodiment;
[0031] Figure 4 This is a schematic diagram of the structure of the light combining mirror assembly in one embodiment;
[0032] Figure 5 This is a schematic diagram of the structure of a laser illumination source in one embodiment;
[0033] Figure 6This is a schematic diagram of the structure of the laser illumination source in another embodiment;
[0034] Figure 7 This is a structural block diagram of a laser illumination source in another embodiment;
[0035] Figure 8 This is a structural block diagram of a laser projection device in one embodiment. Detailed Implementation
[0036] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.
[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.
[0038] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first polarizing optical combiner element may be referred to as a second polarizing optical combiner element, and similarly, a second polarizing optical combiner element may be referred to as a first polarizing optical combiner element. Both the first polarizing optical combiner element and the second polarizing optical combiner element are polarizing optical combiner elements, but they are not the same polarizing optical combiner element.
[0039] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.
[0040] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.
[0041] In recent years, laser light sources have rapidly risen in the projection display field due to their small optical extension, ultra-high brightness output, and excellent color reproduction capabilities. They have not only completely replaced traditional mercury lamp light sources but also demonstrated significant advantages in competition with LED light sources, especially in professional and high-end consumer projection equipment that pursues high brightness and high image quality. Among them, the MCL (three-color laser) light source solution has become the core light source technology path for achieving top-quality projection systems due to its superior high brightness performance.
[0042] In the optical path design of laser projection systems using the MCL light source scheme, the current mainstream homogenization scheme usually adopts the following process: After the three-color laser completes spatial beam combining, the size and divergence angle of the combined beam often do not meet the requirements of the subsequent laser illumination source. Therefore, a set of telescopic lens groups must be introduced to perform beam contraction processing on the beam after beam combining in order to adjust the beam size. The beam after beam contraction then passes through a diffuser and a vibrating diffuser to change the divergence angle, and then passes through a compound eye lens array for homogenization. Finally, it can be efficiently coupled into the illumination optical path and the subsequent imaging system (projection lens).
[0043] For example, a traditional laser lighting source can be as follows: Figure 1 As shown, the three-color lasers include a red laser 101, a blue laser 102, and a green laser 103. The red laser 101 is first reflected to the beam combining path by a dichroic mirror 203 (characteristics: reflects red light and transmits blue and green light). Then, the blue laser 102 is reflected to the beam combining path by a dichroic mirror 202 (characteristics: reflects blue light and transmits green light). The green laser 103 is directly transmitted. Finally, the three-color lasers are reflected by a high-reflectivity mirror 201 to complete the spatial beam combining. After beam combining, the laser beam passes through waveplate 503 (used to change the polarization state of red laser 101), telescope lens group 502 (used for beam shrinking), reflector 601, diffuser 401 (used for beam homogenization), vibrating diffuser 501 (used for beam homogenization), compound eye lens group 601, spherical lens group (including spherical lens 602 and spherical lens 604, used to correct spherical aberration, field curvature and chromatic aberration of the received laser beam) and reflector 603 before entering the projection lens.
[0044] It should be noted that the telephoto lens group 502 and the spherical lens group can be implemented using other numbers and other structures of lenses, which are not limited in the embodiments of this application.
[0045] However, this traditional approach has at least the following drawbacks: the laser illumination source is highly complex and bulky, and the telescope lens group is usually composed of multiple lenses (such as a combination of positive and negative lenses), which significantly increases the number of optical components and the physical length of the system; the assembly tolerance is sensitive, and the precise alignment and spacing control of multiple lenses require extremely high assembly precision. Even small deviations can easily lead to optical path offset and increased aberrations, affecting the uniformity of the final light spot and the system efficiency; the increased number of components directly leads to higher material costs and more complex assembly and adjustment processes, and may also affect the output stability and reliability of the laser illumination source.
[0046] The laser illumination source and laser projection device provided in this application embodiment include a laser illumination source component, a polarization combining component, and a lens component. The laser illumination source component is used to output a target laser. The P-polarized laser in the target laser passes through a first polarization combining element, and the S-polarized laser in the target laser passes through a second polarization combining element. The first and second polarization combining elements in the polarization combining component are used to polarize and combine the target laser. After polarization and combining, the target laser is corrected by the lens component and then output. This achieves efficient polarization state management and synthesis of the target laser, significantly simplifies the optical path, eliminates the need for a telescope lens group composed of multiple lenses, reduces the number of optical elements and the physical length of the laser illumination source, eliminates assembly tolerances for lens spacing and tilt angle, and improves the output stability of the laser illumination source.
[0047] In one exemplary embodiment, such as Figure 2 As shown, a laser illumination source is provided, comprising:
[0048] The light source assembly 10 includes a light-emitting component 12 and a beam combiner assembly 14. The light-emitting component 12 is used to emit lasers of at least three different colors, and the beam combiner assembly 14 is used to combine the lasers and output the target laser. The polarization state of the target laser includes a P-polarization state and an S-polarization state.
[0049] The polarization combining component 30 includes a first polarization combining element 32 and a second polarization combining element 34. The first polarization combining element 32 and the second polarization combining element 34 are respectively disposed on the light output path of the light source component 10, and the second polarization combining element 34 is disposed in different parts of the light output path of the first polarization combining element 32, so that the P-polarized laser in the target laser passes through the first polarization combining element 32, and the S-polarized laser in the target laser passes through the second polarization combining element 34; the first polarization combining element 32 is configured to reflect P-polarized light, and the second polarization combining element 34 is configured to transmit P-polarized light and reflect S-polarized light;
[0050] Lens assembly 40 is used to homogenize and correct aberrations of the laser beam emitted from polarization beam combining assembly 30.
[0051] Specifically, such as Figure 2 As shown, the beam combining mirror group 14 is used to combine the laser emitted from the light-emitting component 12 and output the target laser to the polarization beam combining component 30. The P-polarized light in the target laser is reflected by the first polarization beam combining element 32 to the second polarization beam combining element 34. The second polarization beam combining element performs polarization beam combining on the transmitted P-polarized light and the reflected S-polarized light. The laser beam after polarization beam combining passes through the lens assembly 40. The lens assembly 40 is used to homogenize and correct aberrations of the laser beam after polarization beam combining. The laser beam after homogenization and aberration correction enters the projection lens to form a projection image.
[0052] In the aforementioned laser illumination source, by replacing the telescope lens group of the traditional laser illumination source with a polarization beam combining component, the traditional geometric optical beam contraction approach is abandoned. Instead, a full-wavelength polarization beam combining technology is innovatively adopted. That is, in the beam combining stage, by configuring a polarization control component, the polarization state of the target laser is directly and efficiently managed and combined, which significantly simplifies the optical path, eliminates the complex beam contraction system (telescope lens group) composed of multiple lenses, reduces the number of optical components, and significantly shortens the optical path, making the structure of the laser illumination source more compact. This avoids the stringent assembly and alignment requirements of multiple lens groups, reduces assembly tolerances, and improves the output stability of the laser illumination source.
[0053] In one embodiment, such as Figure 3 As shown, the first polarization combining element is tilted at a 45° angle to the propagation direction of the target laser, the first polarization combining element and the second polarization combining element are arranged in parallel, and there is a gap between the first polarization combining element and the second polarization combining element.
[0054] Specifically, such as Figure 3 As shown, the first polarization combining element is tilted at a 45° angle to the propagation direction of the diffused target laser. The first polarization combining element and the second polarization combining element are arranged in parallel. The P-polarized light in the target laser is reflected by the first polarization combining element, and the S-polarized light in the target laser is reflected by the second polarization combining element, and the two polarizations are orthogonally combined with the projected P-polarized light. There is a gap between the first polarization combining element and the second polarization combining element to allow the P-polarized light to pass through.
[0055] It should be noted that the specific types of the first polarizing optical combiner and the second polarizing optical combiner can be set according to the actual situation. In this embodiment, the first polarizing optical combiner is a total reflection mirror and the second polarizing optical combiner is a polarizing optical combiner sheet as an example.
[0056] In this embodiment, with the above-described configuration, when the target laser is incident on the first polarization combining element, it reflects P-polarized light; when the target laser is incident on the second polarization combining element, it reflects S-polarized light and transmits the P-polarized light reflected by the first polarization combining element. This achieves orthogonal polarization combining of the P-polarized light transmitted through the second polarization combining element and the S-polarized light reflected by the second polarization combining element, significantly simplifying the optical path while improving the output stability of the laser illumination source.
[0057] In one embodiment, at least three different colors of laser light include a red laser, a blue laser, and a green laser; the beam combining mirror assembly includes:
[0058] The first waveplate is disposed in the optical path between the light-emitting component and the first polarization combining element. The first waveplate is used to convert the blue laser in the received laser from the S polarization state to the P polarization state, and to convert the green laser in the received laser from the S polarization state to the P polarization state.
[0059] The second waveplate is positioned in the optical path between the light-emitting component and the second polarization combining element. The second waveplate is used to convert the red laser in the received laser from the P polarization state to the S polarization state.
[0060] Specifically, the beam combining mirror assembly includes a first waveplate and a second waveplate. The first waveplate is used to convert the blue and green laser light in the received laser light from the S-polarization state to the P-polarization state. This is because the first waveplate is placed in the optical path between the light-emitting component and the first polarization beam combining element. At this time, the laser beam output to the first polarization beam combining element is in the P-polarization state, and the first polarization beam combining element performs total internal reflection on it. Similarly, the second waveplate is used to convert the red laser light in the received laser light from the P-polarization state to the S-polarization state. This is because the second waveplate is placed in the optical path between the light-emitting component and the second polarization beam combining element. At this time, the laser beam output to the second polarization beam combining element is in the S-polarization state, along with the P-polarized light reflected by the first polarization beam combining element, thus completing the orthogonal polarization beam combining.
[0061] For example, the positions of the first waveplate and the second waveplate in the beam combiner assembly can be as follows: Figure 4 As shown, it should be noted that the specific positions of the first waveplate 301 and the second waveplate 302 are related to the laser wavelengths they are designed for, and are not limited in this embodiment.
[0062] In this embodiment, by providing a first waveplate and a second waveplate in the beam combining mirror group, it is convenient for the subsequent polarization beam combining component to polarize and combine the laser beam.
[0063] In one embodiment, both the first waveplate and the second waveplate are half-wave plates.
[0064] Specifically, the first waveplate can convert 50% of the light intensity of blue and green lasers from the S-polarization state to the P-polarization state, and the second waveplate can convert 50% of the light intensity of red lasers from the P-polarization state to the S-polarization state.
[0065] In this embodiment, a half-wave plate design is adopted to facilitate the polarization and combining of the laser beam by the subsequent polarization combining component.
[0066] In one embodiment, aberration correction includes correcting the spherical aberration, field curvature, and chromatic aberration of the laser beam, respectively; the lens assembly includes a homogenizing component and a spherical lens group, and the laser beam emitted from the polarization combining component passes sequentially through the homogenizing component and the spherical lens group;
[0067] The homogenization component is used to homogenize the received laser beam; the spherical lens group includes at least two spherical lenses, which are used to correct the spherical aberration, field curvature and chromatic aberration of the received laser beam.
[0068] The following explanation uses a two-piece spherical lens group as an example. The curvature combination of the two spherical lenses can compensate for spherical aberration and field curvature, and perform the following functions: beam collimation (controlling the divergence angle) and chromatic aberration correction (suppressing focus shift caused by the difference in wavelengths of the three-color lasers).
[0069] The homogenization component includes at least one device for homogenizing the light beam. In this embodiment, the homogenization component includes a speckle elimination component and a beam homogenization component as an example.
[0070] Specifically, the laser beam emitted from the polarization combining component passes sequentially through the speckle elimination component, the homogenizing component, and the spherical lens group to achieve phase coherence elimination, homogenization, and correction of spherical aberration, field curvature, and chromatic aberration of the laser beam.
[0071] To facilitate understanding by those skilled in the art, a specific example is provided below to illustrate a laser illumination source, such as... Figure 5 As shown, the light-emitting component emits red laser 101, blue laser 102, and green laser 103. Green laser 103 has an emission center wavelength of 525 nm and an initial polarization state of S-polarization. Blue laser 102 has an emission center wavelength of 465 nm and an initial polarization state of S-polarization. Red laser 101 has emission center wavelengths of 639 nm, 643 nm, and 647 nm and an initial polarization state of P-polarization.
[0072] Half the light intensity of blue laser 102 and half the light intensity of green laser 103 are converted from S-polarization to P-polarization by the first waveplate 301. Half the light intensity of red laser 101 is converted from P-polarization to S-polarization by the second waveplate 302. The three-color lasers are then reflected by dichroic mirror 203 (characteristics: reflects red light, transmits blue and green light) to the combining path. Subsequently, blue laser 102 is reflected by dichroic mirror 202 (characteristics: reflects blue light, transmits green light) to the combining path, while green laser 103 is directly transmitted. Finally, the light is reflected by high-reflection mirror 201. After spatial beam combining of the three-color lasers via mirror reflection, the divergence angle is changed by diffuser 401. The P-polarized laser is completely reflected by mirror 402 (first polarization combining element), and polarization combining element 403 (second polarization combining element) reflects S-polarized light from the transmitted P-polarized light. Red laser 101, blue laser 102, and green laser 103 (P-polarized light) are directly transmitted through. The converted red laser 101, blue laser 102, and green laser 103 (S-polarized light) are reflected by polarization combining element 403, achieving orthogonal polarization combining with the transmitted P-polarized light, thus replacing the previous polarization. Figure 1 The telescope lens group 502 in the middle.
[0073] After polarization and beam combining, the laser beam passes sequentially through the antispeckle assembly 501, the homogenizing assembly 601, the spherical lens group (spherical lens 602 and spherical lens 604), and the reflector 603 to achieve phase coherence elimination, homogenization, and correction of spherical aberration, field curvature, and chromatic aberration before entering the projection lens.
[0074] It is understandable that by employing polarization combining components (first polarization combining element 402 and second polarization combining element 403), the telescope lens group 502 in the traditional scheme can be directly replaced (see...). Figure 1 (In comparison), it significantly simplifies the optical path, eliminates the complex beam-shrinking system composed of multiple lenses, eliminates the sensitive tolerances of lens spacing and tilt angle, improves the robustness of the laser illumination source, and the more compact structure meets the needs of miniaturized projection equipment.
[0075] In one embodiment, aberration correction includes correcting spherical aberration, field curvature, and chromatic aberration of the laser beam, respectively; the lens assembly includes:
[0076] The laser beam emitted from the homogenizing component and aspherical lens, and the polarization combining component, pass sequentially through the homogenizing component and aspherical lens;
[0077] The homogenization component is used to homogenize the received laser beam; the aspherical lens is used to correct the spherical aberration, field curvature and chromatic aberration of the received laser beam.
[0078] The homogenization component includes at least one device for homogenizing the light beam. In this embodiment, the homogenization component includes a speckle elimination component and a beam homogenization component as an example.
[0079] Specifically, the laser beam emitted from the polarization combining component passes sequentially through the speckle elimination component, the beam homogenization component, and the aspherical lens to achieve phase coherence elimination, beam homogenization, and correction of spherical aberration, field curvature, and chromatic aberration of the laser beam.
[0080] It should be noted that a single aspherical lens can achieve the following functions: ① Spherical aberration elimination: The aspherical curvature gradient accurately cancels the focus deviation of peripheral rays and paraxial rays; ② Field curvature correction: Optimizes the focusing position of off-axis image points so that the image plane coincides with the target plane; ③ Chromatic aberration suppression: Balances the focus shift of red / green / blue light through surface shape optimization.
[0081] In this embodiment, by using aspherical lenses instead of spherical lens groups, the number of optical elements in the laser illumination source is reduced, significantly reducing the sensitivity to assembly tolerances. The single-lens design eliminates the cumulative effect of tolerances in inter-lens spacing and tilt, greatly reducing the dependence on assembly accuracy. At the same time, aberration correction is optimized. Aspherical lenses themselves have stronger aberration correction capabilities, which helps to improve illumination uniformity and light energy utilization.
[0082] In one embodiment, the aspherical lens satisfies:
[0083] ;
[0084] Where z is the surface curvature of the aspherical lens; c is the reciprocal of the vertex radius of curvature; r is the radial coordinate of the aspherical lens; and k is the conic coefficient.
[0085] To facilitate understanding by those skilled in the art, another laser illumination source will be described below with reference to a specific example, such as... Figure 6 As shown, the light-emitting component emits red laser 101, blue laser 102, and green laser 103. Green laser 103 has an emission center wavelength of 525 nm and an initial polarization state of S-polarization. Blue laser 102 has an emission center wavelength of 465 nm and an initial polarization state of S-polarization. Red laser 101 has emission center wavelengths of 639 nm, 643 nm, and 647 nm and an initial polarization state of P-polarization.
[0086] Half the light intensity of blue laser 102 and half the light intensity of green laser 103 are converted from S-polarization to P-polarization by the first waveplate 301. Half the light intensity of red laser 101 is converted from P-polarization to S-polarization by the second waveplate 302. The three-color lasers are then reflected by dichroic mirror 203 (characteristics: reflects red light, transmits blue and green light) to the combining path. Subsequently, blue laser 102 is reflected by dichroic mirror 202 (characteristics: reflects blue light, transmits green light) to the combining path, while green laser 103 is directly transmitted. Finally, the light is reflected by high-reflection mirror 201. After spatial beam combining of the three-color lasers via mirror reflection, the divergence angle is changed by diffuser 401. The P-polarized laser is completely reflected by mirror 402 (first polarization combining element), and polarization combining element 403 (second polarization combining element) reflects S-polarized light from the transmitted P-polarized light. Red laser 101, blue laser 102, and green laser 103 (P-polarized light) are directly transmitted through. The converted red laser 101, blue laser 102, and green laser 103 (S-polarized light) are reflected by polarization combining element 403, achieving orthogonal polarization combining with the transmitted P-polarized light, thus replacing the previous polarization. Figure 1 The telescope lens group 502 in the middle.
[0087] After polarization and beam combining, the laser beam sequentially passes through the speckle-reducing component 501, the beam homogenizing component 601, the reflector 603, and the aspherical lens 701 to achieve phase coherence elimination, beam homogenization, and correction of spherical aberration, field curvature, and chromatic aberration before entering the projection lens. It should be noted that by employing two key technologies—polarization and beam combining and the aspherical single lens—a total of three optical elements are reduced (two are eliminated from the polarization and beam combining component, and one from the spherical lens group), achieving a double simplification of the optical path. Specifically, the polarization and beam combining component eliminates the tolerance of the beam-shrinking lens, and the aspherical lens eliminates the aberration correction tolerance. The overall tolerance sensitivity of the laser illumination source is significantly reduced. This application lays the foundation for high-brightness miniaturization and provides underlying technical support for laser televisions and micro-projectors.
[0088] It is understandable that by employing two key technologies—polarized light combining and aspherical single lenses—a deep simplification and integration of the laser illumination source has been achieved from the source and optical path design. The advantages include: firstly, the significant reduction in the total number of optical components directly lowers material costs; secondly, the laser illumination source's sensitivity to assembly tolerances is significantly reduced, simplifying the manufacturing process and improving production yield. These advantages make this application particularly aligned with the current strong trend of miniaturization, portability, and cost-effectiveness in projection equipment. It possesses extremely broad application potential and competitive advantages in miniaturized projection applications with extremely stringent requirements for space, cost, and reliability, such as embedded projection (e.g., smart projectors, AR / VR), automotive HUDs (head-up displays), and micro-projection modules.
[0089] In one embodiment, the light-emitting component includes at least three types of light-emitting chips, each of which emits laser light of a different color.
[0090] Specifically, the light-emitting component can be an MCL laser, which includes three types of light-emitting chips for emitting red, blue, and green lasers.
[0091] In one embodiment, such as Figure 7 As shown, the laser illumination source also includes:
[0092] A diffuser 20 is disposed in the optical path between the light source assembly 10 and the polarization beam combining assembly 30. The diffuser 20 is used to diffuse the target laser; wherein, the diffusion angle of the diffuser 20 is in the range of 1 degree to 2 degrees.
[0093] Specifically, since the laser spot (target laser) is Gaussian distributed, the spot is homogenized by setting a diffuser 20. However, if the diffusion angle of the diffuser 20 is too large, it will affect the efficiency of the subsequent coating of the second polarization combining element 34. Therefore, the diffusion angle is set to 1 degree to 2 degrees.
[0094] For example, this application also provides a laser illumination source that uses a single aspherical lens instead of a spherical lens group, that is, based on a traditional laser illumination source (such as...). Figure 1 As shown, by replacing the spherical lens group with an aspherical lens while keeping the other components unchanged, the optical path can still be simplified, reducing the number of optical components and the physical length of the laser illumination source, eliminating the assembly tolerances of lens spacing and tilt angle, and improving the output stability of the laser illumination source. Its specific structure is similar to that described above and will not be repeated here.
[0095] In one exemplary embodiment, such as Figure 8 As shown, a laser projection device is provided, including a projection lens and a laser illumination source as described above;
[0096] The projection lens is positioned on the light path of the laser illumination source.
[0097] Specifically, by adopting the aforementioned laser illumination source, the optical path is significantly simplified, eliminating the need for a telescope lens group composed of multiple lenses, reducing the number of optical elements and the physical length of the laser illumination source, eliminating assembly tolerances for lens spacing and tilt angle, improving the output stability of the laser illumination source, and further enhancing the display effect of the projected image output by the projection lens.
[0098] In the description of this specification, the references to terms such as "some embodiments," "other embodiments," "ideal embodiments," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example that are included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.
[0099] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0100] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.
Claims
1. A laser illumination source, characterized in that, include: A light source assembly includes a light-emitting component and a beam combiner assembly. The light-emitting component is used to emit lasers of at least three different colors, and the beam combiner assembly is used to combine the lasers into a beam and output a target laser. The polarization state of the target laser includes a P-polarization state and an S-polarization state. A polarization combining component includes a first polarization combining element and a second polarization combining element. The first and second polarization combining elements are respectively disposed in different portions of the light output path of the light source component, and the second polarization combining element is disposed on the light output path of the first polarization combining element, such that the P-polarized laser in the target laser passes through the first polarization combining element, and the S-polarized laser in the target laser passes through the second polarization combining element; the first polarization combining element is configured to reflect P-polarized light, and the second polarization combining element is configured to transmit P-polarized light and reflect S-polarized light; A lens assembly is used to homogenize and correct aberrations in the laser beam emitted from the polarization combining assembly.
2. The laser illumination source according to claim 1, characterized in that, The first polarization combining element is tilted at a 45° angle to the propagation direction of the target laser. The first polarization combining element and the second polarization combining element are arranged in parallel and are spaced apart.
3. The laser illumination source according to claim 1, characterized in that, The aberration correction includes correcting the spherical aberration, field curvature, and chromatic aberration of the laser beam respectively; the lens assembly includes a homogenizing component and a spherical lens group, and the laser beam emitted from the polarization combining component passes through the homogenizing component and the spherical lens group in sequence; The homogenization component is used to homogenize the received laser beam; the spherical lens group includes at least two spherical lenses, and the spherical lens group is used to correct the spherical aberration, field curvature and chromatic aberration of the received laser beam.
4. The laser illumination source according to claim 1, characterized in that, The aberration correction includes correcting the spherical aberration, field curvature, and chromatic aberration of the laser beam, respectively; the lens assembly includes: The homogenizing component and the aspherical lens are used to combine the laser beam emitted from the polarization combining component, which in turn passes through the homogenizing component and the aspherical lens in sequence. The homogenization component is used to homogenize the received laser beam; the aspherical lens is used to correct the spherical aberration, field curvature and chromatic aberration of the received laser beam.
5. The laser illumination source according to claim 4, characterized in that, The aspherical lens satisfies: ； Wherein, z is the surface curvature of the aspherical lens; c is the reciprocal of the vertex radius of curvature; r is the radial coordinate of the aspherical lens; and k is the conic coefficient.
6. The laser illumination source according to claim 1, characterized in that, The laser light comprises at least three different colors, including red, blue, and green laser light; the beam combining mirror assembly includes: A first waveplate is disposed in the optical path between the light-emitting component and the first polarization combining element. The first waveplate is used to convert the blue laser in the received laser from the S polarization state to the P polarization state, and to convert the green laser in the received laser from the S polarization state to the P polarization state. A second waveplate is disposed in the optical path between the light-emitting component and the second polarization combining element. The second waveplate is used to convert the red laser in the received laser from the P polarization state to the S polarization state.
7. The laser illumination source according to claim 6, characterized in that, Both the first waveplate and the second waveplate are half-wave plates.
8. The laser illumination source according to claim 1, characterized in that, The light-emitting component includes at least three types of light-emitting chips, each of which emits laser light of a different color.
9. The laser illumination source according to claim 1, characterized in that, The laser illumination source also includes: A diffuser is disposed in the optical path between the light source assembly and the polarization combining assembly, and the diffuser is used to diffuse the target laser; wherein the diffusion angle of the diffuser is in the range of 1 degree to 2 degrees.
10. A laser projection device, characterized in that, Includes a projection lens and a laser illumination source as described in any one of claims 1 to 9; The projection lens is positioned on the light output path of the laser illumination source.