Laser lighting modules and projection equipment
By adopting a specific optical architecture of a laser illumination module in the micro-projection device, diffuse first and then combine light, and using the phase delay sheet to change the polarization state of some light, the problems of brightness and color gamut limitation of the micro-projection device are solved, and better speckle dissipation effect and projection image quality are achieved.
Patent Information
- Application Number
- CN202411974702.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-30
- Publication Date
- 2025-09-02
- Estimated Expiration
- 2044-12-30
AI Technical Summary
In traditional micro-projection equipment, LED light sources have upper limits in terms of brightness and color gamut, which limits the further development of micro-projection technology. There is room for improvement in the effect of the speckle dissipation system of existing laser projection equipment.
A laser illumination module is adopted, including a light source, a static diffusion sheet, a light composite assembly, a first uniform assembly, a second uniform assembly, a phase retardation sheet and a relay part. Through an optical architecture that first diffuses and then combines the light, the phase retardation sheet is used to change the polarization state of part of the light to reduce speckle phenomenon.
It improves the brightness and color gamut performance of micro-projection equipment, significantly improves the speckle dissipation effect, and provides clearer and more delicate projection image quality.
Smart Images

Figure CN119620522B_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present application relate to the field of optical display technology. More specifically, the embodiments of the present application relate to a laser lighting module and a projection device. Background Art
[0002] Micro-projection technology has been widely developed and applied in recent years. Its miniaturization and portability make it highly competitive in the market. However, traditional micro-projection devices mostly use LED light sources, which have upper limits in terms of brightness and color gamut, limiting the further development of micro-projection technology. Laser light sources, due to their small divergence angle and high light purity, are an ideal choice for improving micro-projection performance. Although current laser projection architectures on the market include speckle reduction systems, their speckle reduction effect still needs to be improved. Therefore, developing a new laser illumination architecture to enhance speckle reduction and optimize overall lighting performance has become an urgent problem to be solved in this field. Summary of the Invention
[0003] The purpose of this application is to provide a new technical solution for laser lighting modules and projection equipment.
[0004] In a first aspect, the present application provides a laser lighting module. The laser lighting module comprises:
[0005] a light source for providing a laser beam;
[0006] A static diffuser, used to diffuse and eliminate speckles of the laser beam;
[0007] a light combining component, configured to receive and combine the light emitted from the static diffuser;
[0008] The first light homogenization component is used to receive the combined light and perform initial light homogenization processing;
[0009] A second light homogenizing component, used to further homogenize the light;
[0010] a phase retarder, disposed on the light-emitting side of the first light-homogenizing component or within the second light-homogenizing component, wherein the size of the phase retarder is smaller than the size of the laser spot, so that only a portion of the laser beam can pass through the phase retarder to change the polarization state of the light, while the other portion of the laser beam maintains the original polarization state, thereby eliminating the spot;
[0011] The relay part is used to shape the light after secondary homogenization and reflect it to the imaging light path.
[0012] Optionally, the light illumination module includes a turning mirror assembly;
[0013] The turning mirror assembly includes a first reflecting mirror and a second reflecting mirror;
[0014] The first reflector is located between the first light homogenizing component and the second light homogenizing component, and is used to change the propagation direction of the light after the initial homogenization;
[0015] The second reflector is located between the second light homogenizing component and the relay part, and is used to change the direction of light to adapt to the light input requirement of the relay part.
[0016] Optionally, the first light homogenization component includes a dynamic diffuser, a first fly-eye lens, and a first lens sequentially arranged along the first optical axis;
[0017] The phase retarder is disposed along the first optical axis on a side of the first lens away from the first fly-eye lens.
[0018] Optionally, the second light homogenization assembly includes a lens group consisting of a second lens, a second fly-eye lens, at least one third lens, and a fourth lens, which are sequentially arranged along the second optical axis;
[0019] The phase retarder is disposed along the second optical axis on a surface of the second fly-eye lens that is away from the second lens.
[0020] Optionally, the light combining component includes a reflective element and a filter element;
[0021] The filter element is located on the reflection path of the reflective element, and is used to transmit light of a specific wavelength and reflect light of other wavelengths to achieve light combining processing.
[0022] Optionally, the light source includes a first light-emitting unit and a second light-emitting unit;
[0023] The first light-emitting unit is capable of emitting a blue laser beam and a green laser beam, and the reflective element is located on the light-emitting path of the first light-emitting unit and can be used to guide the laser beam emitted by the first light-emitting unit to the filter element;
[0024] The second light-emitting unit is capable of emitting a red laser beam, and the filter element is located on the light output path of the second light-emitting unit. The filter element is used to transmit the red laser beam and combine it with the blue laser beam and the green laser beam to project it onto the first light homogenization component.
[0025] Optionally, the lens group further includes at least one lens glued to or spaced apart from the third lens.
[0026] Optionally, the relay part includes a total reflection prism, a fifth lens and a sixth lens are sequentially provided on the light incident side of the total reflection prism, and a DMD chip is provided on the reflection side of the total reflection prism;
[0027] The relay part is used to shape the light to match the DMD chip and project it to the imaging light path of the external device through the total reflection prism.
[0028] Optionally, the effective display area of the DMD chip is provided with protective glass.
[0029] In a second aspect, the present application provides a projection device. The projection device includes:
[0030] The laser lighting module as described in the first aspect.
[0031] The beneficial effects of this application are:
[0032] The embodiments of the present application provide a laser illumination module that can be applied to projection equipment such as micro-projection equipment. By adopting a specific laser illumination module architecture, including a light source, a static diffuser, a light combining component, a first light homogenizing component, a second light component, a phase delay plate and a relay part, the optical architecture is not only conducive to improving the brightness and color gamut performance of the micro-projection equipment, but also has a significant improvement in eliminating speckle. In particular, the design in the present application uses a static diffuser for diffusion and speckle elimination before light combining, and uses a specially designed phase delay plate for speckle elimination. The phase delay plate is also designed to be located after the light combining component. This design increases the polarization diversity of light by changing the polarization state of part of the light, effectively reduces the coherence of the light and significantly reduces the laser speckle phenomenon, which is conducive to optimizing the projection image quality and bringing users clearer and more delicate visual effects.
[0033] Other features and advantages of the present specification will become apparent from the following detailed description of exemplary embodiments of the present specification with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the specification and, together with the description, serve to explain the principles of the specification.
[0035] Figure 1 This is one of the structural schematic diagrams of the laser lighting module provided in an embodiment of the present application;
[0036] Figure 2 This is the second structural schematic diagram of the laser lighting module provided in an embodiment of the present application.
[0037] Description of reference numerals:
[0038] 100, light source; 101, first light-emitting unit; 102, second light-emitting unit;
[0039] 200, static diffuser;
[0040] 300, light combining component; 301, reflective element; 302, filter element;
[0041] 400, first light homogenizing component; 401, dynamic diffuser; 402, first fly-eye lens; 403, first lens;
[0042] 500, first reflector;
[0043] 600, second light homogenizing assembly; 601, second lens; 602, second fly-eye lens; 603, third lens; 604, fourth lens;
[0044] 700, second reflector;
[0045] 800, relay unit; 801, fifth lens; 802, sixth lens; 803, total reflection prism; 804, DMD chip;
[0046] 900. Phase retarder. DETAILED DESCRIPTION
[0047] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present application.
[0048] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present disclosure, its application, or uses.
[0049] Techniques and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the techniques and equipment should be considered part of the specification.
[0050] In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.
[0051] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.
[0052] The laser illumination module and projection device provided in the embodiments of the present application are described in detail below with reference to the accompanying drawings.
[0053] According to one embodiment of the present application, a laser lighting module is provided. Figure 1 The laser lighting module can be applied to laser projection equipment such as micro-projection equipment, and of course can also be applied to other types of projection equipment.
[0054] The laser lighting module provided in the embodiment of the present application is shown in FIG. Figure 1 and Figure 2 The laser lighting module includes: a light source 100, a static diffuser 200, a light combining component 300, a first light homogenizing component 400, a second light homogenizing component 600, a phase delay plate 900, and a relay part 800 along the light transmission path; the light source 100 is used to provide a laser beam; the static diffuser 200 is used to diffuse and eliminate speckles of the laser beam emitted by the light source 100; the light combining component 300 is used to receive the light emitted by the static diffuser 200 and combine the light; the first light homogenizing component 400 is used to receive the light after the light is combined The light is uniformly distributed on the first and second light homogenizing components 600, and the second light homogenizing component 600 is used to further homogenize the light. The phase delay plate 900 is arranged on the light-emitting side of the first light homogenizing component 400 or in the second light homogenizing component 600. The size of the phase delay plate 900 is smaller than the size of the laser spot, so that only a part of the laser beam can pass through the phase delay plate 900 to change the polarization state of the light, and the other part of the laser beam maintains the original polarization state to eliminate the spot. The relay part 800 is used to shape the light after the secondary homogenization and reflect it to the imaging optical path.
[0055] The optical architecture of the laser illumination module provided in the embodiment of the present application is shown in FIG. Figure 1 , which includes multiple optical components along the light transmission path. The functions and technical effects of each optical component are analyzed as follows.
[0056] The laser illumination module of the present application includes a light source 100 , which serves as the basis of the entire laser illumination module and is used to provide a laser beam, which is a prerequisite for subsequent optical processing.
[0057] The light source 100 provided in this application is a laser light source, which can emit laser beams of different colors. The laser light source has the characteristics of small divergence angle and high light purity, and is suitable for projection applications with high requirements on brightness and color gamut.
[0058] The laser illumination module of the present application includes a static diffuser 200, which is used to diffuse the laser beam emitted by the light source 100. This helps increase the range of incident angles of the light, thereby enabling subsequent optical components to better receive and process the light, improving the uniformity and utilization of the light (e.g., the laser beam). Furthermore, the static diffuser 200 helps eliminate speckle.
[0059] The laser lighting module of the present application includes a light combining component 300 , which is located behind the static diffuser 200 . The light combining component 300 is used to receive light beams of multiple colors emitted from the static diffuser 200 and perform light combining processing.
[0060] For example, the light combining component 300 can combine laser beams of different colors, such as a red laser beam (R), a green laser beam (G), and a blue laser beam (B), into one path, providing a basis for subsequent speckle elimination and light uniformity processing.
[0061] In the present application, the laser beam emitted by the light source 100 is first diffused by the static diffuser 200 and then enters the light combining assembly 300 for light combining. This has the following advantages:
[0062] (1) By first processing the laser beam with a static diffuser, the incident angle range of the beam can be increased, making the light spot more uniform. This uniformity provides a better foundation for subsequent optical processing and helps to improve the light uniformity of the entire laser lighting module.
[0063] (2) Light combining is the process of combining laser beams of different colors or directions into one beam. If the laser beams have uneven spot or uneven intensity distribution before light combining, the light after light combining may also have these problems. Diffusion of the laser beams first can make the light before light combining more uniform, thereby optimizing the light combining effect and reducing light loss and distortion during the light combining process.
[0064] (3) The energy density of a laser beam is high, but if the spot is too concentrated, it may cause some areas to be too bright while others to be insufficiently bright. By first diffusing the laser beam, the laser spot can be made more uniform, thereby improving the utilization rate of the light. In this way, more light can be evenly irradiated to the target area, improving the overall efficiency of the laser lighting module of this application.
[0065] (4) For laser projection products, the uniformity and quality of the laser beam directly affect the projection image quality. By first diffusing the laser beam and then combining it, the light projected onto the imaging surface can be made more uniform, thereby improving the projection image quality. This design helps provide users with a clearer visual experience.
[0066] To sum up, in the optical solution provided in the embodiment of the present application, the laser beam is first diffused and then combined. This design shows significant advantages in improving light uniformity, optimizing light combining effects, improving light utilization, and improving projection image quality.
[0067] The laser illumination module of the present application includes a first light homogenization component 400 and a second light homogenization component 600 .
[0068] The first light homogenization component 400 is used to receive the combined light and perform initial light homogenization. This step can preliminarily adjust the distribution of light, reduce speckle in the light, and improve the uniformity of the light, which is crucial for subsequent optical processing and imaging quality. The second light homogenization component 600 is used to perform a secondary homogenization on the light homogenized by the first light homogenization component 400, which can further eliminate the unevenness in the light and make the final output light more uniform and stable. Through two homogenizations, it is ensured that the light has a high degree of uniformity and consistency before reaching the imaging optical path.
[0069] The laser illumination module of the present application further includes a phase delay plate 900 .
[0070] The phase retarder 900 is, for example, a half-wave plate, an optical element that can change the polarization state of light. In the illumination module of the present application, a half-wave plate is used to change the polarization direction of a portion of the laser beam while maintaining the original polarization state of the other portion. This design helps increase the polarization diversity of the light, thereby reducing the coherence of the light and minimizing speckle.
[0071] Regarding the increase in polarization diversity, the explanation is as follows:
[0072] The phase retarder 900 (e.g., a half-wave plate) is designed to be smaller than the laser spot size. This means that when the combined laser beam passes through the phase retarder 900, only a portion of the beam passes through the phase retarder 900, thereby changing its polarization state; the other portion of the beam does not pass through the phase retarder 900 and thus maintains its original polarization state. This design increases the diversity of polarization states in the light, that is, the presence of light with multiple polarization directions.
[0073] The reduction in coherence is explained as follows:
[0074] The generation of laser speckle phenomenon is closely related to the coherent interference of light waves. When two or more coherent light waves meet at a certain point in space, they interfere with each other to form a randomly distributed brightness pattern, i.e., speckle. However, in the optical architecture provided in the present application, due to the presence of two beams of light with different polarization directions (one part has its polarization state changed by the phase delay plate 900, while the other part has not changed), the coherence between the two beams of light will be reduced. This is because: based on the phase change, the polarization direction (polarization state) of the light is changed, and the two beams of light with different polarization directions do not interfere, thereby weakening the polarization effect. Therefore, the interference light intensity of the entire laser illumination module will be reduced, thereby reducing the formation of speckle.
[0075] Thus, by increasing the polarization diversity of light and reducing coherence, the laser illumination module provided by the embodiments of the present application can effectively improve the laser speckle phenomenon. This design not only improves the uniformity of light but also provides better lighting effects for micro-projection devices based on laser light sources.
[0076] It should be noted that the laser light in this application is linearly polarized light LP.
[0077] In the design of the laser illumination module of this application, the position and size of the phase retarder 900 (half-wave plate) are carefully designed to effectively improve laser speckle. First, the phase retarder 900 is placed after the light combining assembly 300. This design ensures that the polarization state of the laser beam is adjusted after it passes through the light combining assembly to form a single optical path.
[0078] Secondly, regarding the size design of the phase delay plate 900 (half-wave plate), it is deliberately set to be smaller than the size of the laser spot. The purpose of this is to ensure that when the laser beam (the laser beam after combining) passes through the phase delay plate 900 (half-wave plate), only a part of the beam can pass through and change its polarization state, while the other part of the beam will not pass through, thus maintaining its original polarization state. Such a design increases the polarization diversity of the light, that is, two beams of light with different polarization states exist in the module at the same time. For example, in the interference intensity formula I=I1+I2+2(√I1*I2*cos△φ), due to the existence of the phase difference, the polarization state of the light will be changed, so that the interference effect between the two beams of light will be weakened. Specifically, interference will only occur within the beam of the same polarization state, and there will be no interference between beams of different polarization states. Therefore, such a design reduces I1 and I2 in the interference intensity formula, that is, reduces the interference light intensity, thereby improving the laser speckle phenomenon.
[0079] In this application, see Figure 1 The first light homogenizing component 400 includes a dynamic diffuser 401, which works in conjunction with the static diffuser 200 to adjust the incident angle of the laser beam. This design allows the dynamic diffuser 401 to better utilize its function, further improving the laser speckle phenomenon. By adjusting the incident angle of the laser beam, the size of the laser speckle can be influenced.
[0080] According to the laser speckle size formula d=(1.22λ*L) / πω0 2 ω0 = λ / πθ. Based on this, we can conclude that the speckle diameter d is related to the observation distance L and the minimum beam waist radius ω0 of the laser beam (the minimum cross-sectional area of the beam). By adjusting the incident angle of the laser beam, the divergence angle θ of the laser beam can be changed, thereby affecting the speckle diameter. Therefore, this design can reduce the speckle diameter and make it less noticeable.
[0081] In summary, the placement of the half-wave plate after the combined beams and its smaller size than the laser spot size are designed to increase polarization diversity and reduce coherence, thereby effectively improving laser speckle. Furthermore, the combination of the static diffuser 200 and the dynamic diffuser 401 further adjusts the incident angle of light, reducing the speckle diameter and making it less noticeable.
[0082] The laser lighting module of the present application includes a relay part 800, which is mainly used to shape the light after being homogenized by the second homogenizing component 600 and reflect it to the imaging light path of the external device, ensuring that the projection light can be accurately projected to the target area to form a high-quality image.
[0083] The laser illumination module provided in the embodiments of the present application utilizes the specifically designed phase retarder 900 (e.g., a half-wave plate) to ensure that only a portion of the light changes polarization, thereby increasing polarization diversity, reducing coherence, and effectively improving laser speckle. Due to the significant speckle reduction effect and high light uniformity, the laser illumination module provided in the embodiments of the present application can provide users with clearer and more detailed projection images.
[0084] In summary, the laser illumination module provided in the embodiments of the present application exhibits significant advantages in terms of speckle elimination, light uniformity, and projection image quality, and has broad application prospects.
[0085] In some examples of this application, see Figure 1 , the laser illumination module includes a turning mirror assembly;
[0086] The turning mirror assembly includes a first reflecting mirror 500 and a second reflecting mirror 700;
[0087] The first reflector 500 is located between the first light homogenizing component 400 and the second light homogenizing component 600, and is used to change the propagation direction of the light after the initial homogenization;
[0088] The second reflector 700 is located between the second light homogenizing component 600 and the relay part 800 and is used to change the direction of light to adapt to the light input requirement of the relay part 800.
[0089] In this example of the present application, the laser illumination module is further optimized by introducing a deflection mirror assembly to achieve flexible adjustment of the light direction. Specifically, the deflection mirror assembly includes a first reflector 500 and a second reflector 700. These two reflectors play a crucial role in the optical path, making the entire laser illumination module more compact.
[0090] In the laser illumination module provided in the embodiment of the present application, the first reflector 500 is located between the first light homogenizing component 400 and the second light homogenizing component 600. The first reflector 500 can be used to change the propagation direction of light after the initial homogenization.
[0091] The first reflector 500 is used to change the direction of light after initial homogenization. The first homogenization component 400 can be used to reduce or eliminate the speckle effect produced by the laser light source, making the light more uniform. The addition of the first reflector 500 ensures that the processed light enters the second homogenization component 600 in a predetermined direction for further homogenization.
[0092] Through the reflection effect of the first reflector 500, the light processed by the first light homogenizing component 400 can be effectively guided to the second light homogenizing component 600 without directly extending the light path or changing the position of other components. This helps save space while ensuring the compactness of the light path.
[0093] The second reflector 700 redirects the light to match the input requirements of the relay unit 800. The second light homogenization component 600 further processes the light to achieve the required uniformity and other optical properties. The second reflector 700 then ensures that this high-quality light accurately enters the relay unit 800 for subsequent optical transmission or processing.
[0094] The introduction of the second reflector 700 allows light to be adjusted and directed according to the specific light input requirements of the relay unit 800. This ensures that light can smoothly enter the relay unit 800 for further spot shaping and reflection into the imaging optical path. This also provides greater design flexibility and adaptability for the entire laser illumination module.
[0095] In this example of the present application, the introduction of the deflection mirror assembly ensures efficient transmission and utilization of light within the module, reducing light loss and waste. The arrangement of the first reflector 500 and the second reflector 700, in conjunction with the first and second light homogenization components 400 and 600, can significantly improve the uniformity of the laser beam, providing a high-quality light source for subsequent optical processing or applications.
[0096] The design of the turning mirror group makes the design of the laser illumination module provided in this application more flexible, and can adapt to different optical path layouts and light input requirements by adjusting the angle and position of the reflector.
[0097] The introduction of the turning mirror group helps to optimize the structural layout of the entire laser illumination module, making the connection between the various components more compact and efficient, and helping to reduce the volume and weight of the module.
[0098] In summary, the turning mirror design in this example of the present application improves the utilization and uniformity of light by precisely controlling the direction and path of light, enhances the flexibility and structural optimization of the laser illumination module, and provides high-quality light source support for subsequent optical applications.
[0099] In some examples of this application, see Figure 1 The first light homogenizing component 400 includes a dynamic diffuser 401, a first fly-eye lens 402 and a first lens 403 arranged in sequence along the first optical axis; the phase delay plate 900 is arranged along the first optical axis on the side of the first lens 403 away from the first fly-eye lens 402.
[0100] The laser illumination module of the present application includes a first light homogenizing assembly 400, which can include a dynamic diffuser 401, a first fly-eye lens 402, and a first lens 403 arranged in sequence. Furthermore, the phase retarder 900 can be arranged on the light-emitting side of the first lens 403. In this case, the phase retarder 900 can be equivalent to a part of the first light homogenizing assembly 400. Based on this, the first light homogenizing assembly 400 can effectively improve the speckle problem generated by the laser light source during the projection or illumination process, thereby improving the uniformity and clarity of the projected image.
[0101] Optionally, the phase retarder 900 is located on the light-emitting side of the first lens 403 and is spaced apart from the first lens 403 along the first optical axis.
[0102] The dynamic diffuser 401 is an optical element that can change the angle of incidence of light. In the laser illumination module of this application, the dynamic diffuser 401, through its unique diffusion properties, spreads the laser beam across a wider angle range, thereby increasing the diversity and uniformity of the light. This diffusion effect helps reduce the formation of speckle, as speckle is often related to the coherence and uniformity of light. The diffusion effect of the dynamic diffuser reduces the coherence of the light and reduces the speckle phenomenon.
[0103] The first fly-eye lens 402 is an optical element composed of multiple small lenses, designed to further even out light distribution. In the laser illumination module of this application, the first fly-eye lens 402 receives light from the dynamic diffuser 401, disperses it onto the various small lenses, and then re-converges it into a more uniform light beam. This design helps further reduce speckle and improve brightness uniformity across the entire illuminated area.
[0104] The first lens 403 is used to focus or diverge the laser beam to adjust the direction and intensity of the beam. In the speckle reduction and light homogenization assembly, the first lens 403 can further homogenize the light or adjust the focal length of the light to ensure that the light can be evenly irradiated on the target area.
[0105] The coordinated use of the static diffuser 200 and the dynamic diffuser 401 , and the light homogenization effect of the first fly-eye lens 402 and the first lens 403 , together ensure that the light has a high degree of uniformity and consistency before reaching the imaging optical path.
[0106] In some examples of this application, see Figure 2 The second light homogenizing component 600 includes a lens group consisting of a second lens 601, a second fly-eye lens 602, at least one third lens 603 and a fourth lens 604 arranged in sequence along the second optical axis; the phase delay plate 900 is arranged on the side surface of the second fly-eye lens 602 away from the second lens 601 along the second optical axis.
[0107] The phase retarder 900 is a key optical element for eliminating speckles, and its location is flexible. It can also be located at Figure 2 On one surface of the second fly-eye lens 602. This position is also located after the light combining assembly 300, and is used to perform speckle removal processing on the light beam after light combining.
[0108] Specifically, the phase retarder 900 is glued onto the surface of the second fly-eye lens 602 facing away from the second lens 601 .
[0109] That is, the phase retarder 900 can be arranged after the first light homogenizing component 400 or in the second light homogenizing component 600. In practical applications, since the phase retarder 900 itself has low transmittance but high absorptivity, placing it after the light homogenizing component helps reduce light energy loss.
[0110] The structural design of the second light homogenization component 600 is described in this example of the present application. Figure 2 , which includes a lens group consisting of a second lens 601, a second fly-eye lens 602, at least one third lens 603, and a fourth lens 604, which are arranged in sequence along the second optical axis. This arrangement and design is intended to further improve and homogenize the distribution of the laser beam to ensure the quality and consistency of the projected image.
[0111] It should be noted that, based on the arrangement of the first reflector 500, the first light homogenizing component 400 and the second light homogenizing component 600 are not on the same optical axis. The first light homogenizing component 400 can be arranged along the first optical axis, and the second light homogenizing component 600 can be arranged along the second optical axis.
[0112] Through the preliminary focusing and calibration of the second lens 601 , the light is preliminarily adjusted.
[0113] The introduction of the second fly-eye lens 602 helps to eliminate the unevenness in the light due to its special optical properties, thereby achieving more uniform light distribution.
[0114] A third lens 603 may be provided after the second fly-eye lens 602 . The third lens 603 may further fine-tune and optimize the light processed by the second fly-eye lens 602 , thereby further enhancing the uniformity of the light.
[0115] Optionally, the third lens 603 following the second fly-eye lens 602 can be replaced with a lens assembly, which can further improve imaging quality. It should be noted that the lens assembly can include different numbers and types of lenses to suit different application requirements and scenarios. This design provides the system with a certain degree of flexibility and scalability, allowing for adjustment and optimization as needed.
[0116] The third lens 603 and the fourth lens 604 serve as the final focusing and adjustment elements, and can ensure that the light has the best uniformity and focusing when reaching the DMD chip 804 or other imaging elements.
[0117] The arrangement and design of the lenses and fly-eye lens in the second light homogenization assembly 600 of the present application have been carefully considered to ensure that the propagation path of light in the system is as efficient and stable as possible. By reducing unnecessary light loss and interference, this design can improve light utilization, thereby enhancing the efficiency and performance of the entire projection system.
[0118] Because the second light-diffusion component 600 effectively improves light uniformity, problems such as uneven brightness and color aberration in the projected image are effectively reduced. This results in a clearer, more detailed projected image with richer, more realistic colors. Furthermore, the uniform light distribution reduces glare and ghosting in the projected image, further improving the visual quality of the image.
[0119] In summary, in this application, the second light homogenization component 600, by introducing a lens group consisting of a second lens 601, a second fly-eye lens 602, at least one third lens 603, and a fourth lens 604, achieves significant improvements in light uniformity, optimizes the optical path design, improves projected image quality, and enhances system flexibility and scalability. These technical effects make this example of significant application value in laser projection architectures.
[0120] In some examples of this application, see Figure 1The light combining component 300 includes a reflective element 301 and a filter element 302; the filter element 302 is located on the reflection path of the reflective element 301, and is used to transmit light of a specific wavelength and reflect light of other wavelengths to achieve light combining processing.
[0121] In this example of the present application, see Figure 1 The light combining assembly 300 includes a reflective element 301 and a filter element 302. The filter element 302 is located in the reflection path of the reflective element 301. Its function is to transmit light of a specific wavelength (e.g., the red laser beam R) and reflect light of other wavelengths (e.g., the blue laser beam B and the green laser beam G). In this way, light combining of laser beams of different colors is achieved.
[0122] The design of the filter element 302 allows it to selectively transmit and reflect light based on its wavelength. This means that in a laser projection architecture, the three primary colors of laser light, red, blue, and green, can be effectively combined by the filter element 302, providing a uniform mixed light for subsequent optical processing.
[0123] The design of the light combining assembly 300 becomes more flexible by introducing the filter element 302. The combination of the reflective element 301 and the filter element 302 can precisely control the path and angle of light, so that light can propagate in the system in a predetermined manner.
[0124] In traditional laser projection architectures, multiple complex components may be required to combine light. However, in this example of the present application, the combination of the reflective element 301 and the filter element 302 simplifies the structure of the light combining assembly 300 and reduces the number of required components. This not only reduces the cost of the entire laser illumination module, but also improves its reliability and stability.
[0125] The efficiency and flexibility of the light-combining assembly 300 help improve the quality of projected images. Because different colored laser beams can be precisely combined, the colors of the projected image appear more realistic and vivid. Furthermore, precise control of the optical path helps reduce light loss and interference within the system, thereby improving image clarity and contrast.
[0126] In some examples of this application, see Figure 1 , the light source 100 includes a first light emitting unit 101 and a second light emitting unit 102;
[0127] The first light-emitting unit 101 is capable of emitting a blue laser beam and a green laser beam. The reflective element 301 is located on the light-emitting path of the first light-emitting unit 101 and can be used to guide the laser beam emitted by the first light-emitting unit 101 to the filter element 302.
[0128] The second light-emitting unit 102 is capable of emitting a red laser beam, and the filter element 302 is located on the light output path of the second light-emitting unit 102. The filter element 302 is used to transmit the red laser beam and combine it with the blue laser beam and the green laser beam to project it onto the first light homogenization component 400.
[0129] In this example of the application, see Figure 1 The reflective element 301 is located on the light-emitting path of the first light-emitting unit 101 and can be used to reflect the blue and green laser beams emitted by the first light-emitting unit 101 to the filter element 302. The second light-emitting unit 102 can emit a red laser beam. The filter element 302 is located on the light-emitting path of the second light-emitting unit 102 and is used to transmit the red laser beam and combine it with the blue and green laser beams emitted by the first light-emitting unit 101.
[0130] By dividing the light source 100 into a first light-emitting unit 101 and a second light-emitting unit 102, the light source 100 is modularized and integrated. This design allows each light-emitting unit to independently emit a laser beam of a specific color, thereby improving the flexibility and controllability of the light source. Furthermore, the modular design facilitates maintenance and replacement of the light source.
[0131] The combination of the reflective element 301 and the filter element 302 optimizes the optical path. The reflective element 301 precisely directs the laser beam emitted by the first light-emitting unit 101 to the filter element 302, while the filter element 302 simultaneously processes the laser beams from the first light-emitting unit 101 (after reflection) and the second light-emitting unit 102, combining them. This design not only simplifies the optical path but also improves light utilization and overall system performance.
[0132] Because each light-emitting unit independently emits a laser beam of a specific color, and these beams are combined at the filter element 302, the accuracy of color synthesis is guaranteed. This precise color synthesis helps improve the color reproduction and saturation of the projected image, making the image more realistic and vivid.
[0133] By modularizing the light source and optimizing the optical path design, the examples of this application improve the module's efficiency and reliability. The modular light source design enables each light-emitting unit to operate independently, reducing the module's overall power consumption and heat generation. Furthermore, the optimized optical path design reduces light loss and interference, improving light utilization and system stability.
[0134] In some examples of the present application, the lens group further includes at least one lens glued to or spaced apart from the third lens 603 .
[0135] In the second light homogenization assembly 600 of the present application, a lens group can be provided after the second fly-eye lens 602. This lens group includes not only the third lens 603 but also at least one lens glued to or spaced apart from the third lens 603. This design provides greater flexibility to accommodate different optical performance and imaging requirements.
[0136] The optical performance of the entire lens assembly can be further adjusted and optimized by gluing or spacing additional lenses with the third lens 603. This adjustment can include optimizing focal length, aberration correction, light deflection angle, and other aspects, thereby ensuring higher clarity of the projected image.
[0137] The focal length of the entire lens assembly can be flexibly adjusted by adding a lens glued to or spaced apart from the third lens 603. This enables the laser illumination module of the present application to adapt to different projection distances and screen sizes, providing a wider range of applicability.
[0138] In this example of the present application, the additional lenses in the lens assembly can be used to correct various aberrations. Correcting these aberrations is crucial to improving the quality and clarity of the projected image. By correcting aberrations, the projected image can be ensured to have greater detail and fewer visual artifacts.
[0139] When the lenses in the lens assembly are glued together, the complexity of the assembly process can be reduced. For example, multiple optical elements can be assembled at one time.
[0140] In some examples of this application, see Figure 1 The relay part 800 includes a total reflection prism 803, and the light incident side of the total reflection prism 803 is sequentially provided with a fifth lens 801 and a sixth lens 802, and the reflection side of the total reflection prism 803 is provided with a DMD chip 804; the relay part 800 is used to shape the light to match the DMD chip 804, and project it to the imaging light path of the external device through the total reflection prism 803.
[0141] In this example of the present application, the combination of the fifth lens 801 and the sixth lens 802 plays a key role in light shaping, adjusting the light's diffusion angle, focal point, and spot size to ensure that the light is well matched to the effective display surface of the DMD chip 804. This matching is crucial to the clarity and image quality of the projected image, as it reduces light scattering and loss on the DMD chip 804, thereby improving image contrast and brightness.
[0142] The total internal reflection prism 803 (TIR prism) has efficient light reflection performance. It can reflect nearly all incident light to the DMD chip 804, thereby maximizing the use of light resources. This efficient reflection helps reduce light waste and improve the light efficiency and energy utilization of the entire projection system.
[0143] In the optical architecture provided herein, by compactly arranging the fifth lens 801, the sixth lens 802, and the total reflection prism 803, the relay unit 800 achieves a compact optical path design. This design helps reduce the overall size and weight of the projection system, making it more portable and easier to install. Furthermore, the compact optical path design helps reduce interference and loss during light transmission, thereby improving the stability of the projected image.
[0144] Since the relay unit 800 can effectively shape the light and reflect it to the DMD chip 804, the clarity of the projected image is significantly improved. This improvement in clarity is very important to users because it can provide a better visual experience and viewing effect.
[0145] In some examples of this application, see Figure 1 and Figure 2 The effective display area of the DMD chip 804 is provided with a protective glass.
[0146] The protective glass effectively prevents dust, dirt, moisture, and other possible impurities from directly contacting and damaging the DMD chip 804. This extends the life of the DMD chip 804 and reduces performance degradation or malfunctions caused by contamination. The DMD protective glass is highly hard and wear-resistant, and can withstand physical damage such as scratches and impacts.
[0147] See also Figure 1 and Figure 2 The sixth lens 802 and the light incident surface of the total reflection prism 803 are adjacently arranged, and the light incident surface of the sixth lens 802 and the total reflection prism 803 are designed to be approximately parallel. Of course, the two are not completely parallel, and there is an angle of about 3.5° between the two.
[0148] The optical path design in the laser illumination module in this application has been carefully optimized to ensure that the laser beam can be efficiently and accurately projected onto the DMD chip 804, and modulated by the micromirror array of the DMD chip 804, ultimately forming a high-quality projection image.
[0149] In the laser illumination module provided in the embodiment of the present application, the phase retarder 900 is, for example, a half-wave plate, and the half-wave plate is located in the optical path after the combined light. The use and position of the half-wave plate in the present application is conducive to improving the speckle effect.
[0150] Of course, in practical applications, the phase retarder 900 can be replaced with a quarter-wave plate or the like as needed, and this application does not make any specific limitation on the phase retarder.
[0151] In the laser lighting module provided in this application, by placing a half-wave plate in the light path after the light is combined, the polarization direction of a portion of the laser light beam can be adjusted, so that there are two beams of light with the same light intensity but different polarization directions in the laser lighting module. This polarization diversity helps to reduce the coherence between the laser beams, thereby effectively reducing the speckle phenomenon. It should be noted that speckle is a common problem in laser projection, which will cause random brightness changes in the projected image, affecting the image quality. The introduction of the half-wave plate significantly improves this problem, making the projected image clearer and more uniform.
[0152] In the present application, the phase delay plate 900 can be set in two positions, one of which is located on the side of the first lens 403 away from the first fly-eye lens 402. At this time, the phase delay plate 900 is located between the two fly-eye lenses (i.e., the first fly-eye lens 402 and the second fly-eye lens 602). This design plays an important role in enhancing the stability and reliability of the projection system. It can not only offset the changes in the optical path caused by external environmental factors through physical compensation and phase adjustment, but also improve the performance and stability of the entire projection system.
[0153] Of course, the phase delay plate 900 may also be arranged behind the second fly-eye lens 602. In this case, the phase delay plate 900 and the second fly-eye lens 602 may be glued together to achieve a good speckle elimination effect.
[0154] According to another embodiment of the present application, a projection device is provided, which includes the laser illumination module as described above.
[0155] The projection device provided in the embodiment of the present application is, for example, a projection device based on DLP (digital light processing) technology.
[0156] The projection device provided in the embodiments of the present application utilizes the laser illumination module of the aforementioned embodiments. Laser light sources are characterized by a small divergence angle and high light purity. Compared to traditional LED light sources, laser light sources can provide higher brightness and a wider color gamut. This means that the projection device can display more vivid and lively images, especially with superior dark details and color saturation.
[0157] Speckle, a common phenomenon in laser projection, can affect image clarity and uniformity. The laser illumination module used in this application effectively reduces speckle by employing a special first light-homogenizing component 400. This design makes the projected image smoother and more uniform, improving the visual quality of the image.
[0158] Using the laser illumination module provided in the embodiments of this application in projection equipment can achieve technical benefits such as significantly improved brightness and color gamut, improved speckle, optimized optical path design, enhanced system stability and reliability, and reduced costs and energy consumption. These technical benefits enable projection equipment to excel in image quality, performance stability, and cost-effectiveness, making it suitable for a variety of application scenarios.
[0159] The specific implementation of the projection device of the embodiment of the present application can refer to the various embodiments of the above-mentioned laser illumination module, and therefore at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.
[0160] The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.
[0161] Although some specific embodiments of the present application have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present application. It should be understood by those skilled in the art that the above examples may be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.
Claims
1. A laser lighting module, characterized in that: include: a light source (100) for providing a laser beam; A static diffuser (200) for diffusing the laser beam and eliminating speckles; A light combining component (300) is used to receive the light emitted from the static diffuser (200) and combine the light; A first light homogenization component (400) is used to receive the combined light and perform initial light homogenization processing; A second light homogenizing component (600) is used to further homogenize the light; A phase retarder (900) is arranged on the light-emitting side of the first light homogenizing component (400) or in the second light homogenizing component (600), wherein the size of the phase retarder (900) is smaller than the size of the laser spot, so that only a portion of the laser beam can pass through the phase retarder (900) to change the polarization state of the light, while the other portion of the laser beam maintains the original polarization state to eliminate the spot; The relay part (800) is used to shape the light after the secondary homogenization and reflect it to the imaging light path.
2. The laser lighting module according to claim 1, characterized in that: The laser illumination module includes a turning mirror assembly; The turning mirror assembly includes a first reflecting mirror (500) and a second reflecting mirror (700); The first reflector (500) is located between the first light homogenizing component (400) and the second light homogenizing component (600), and is used to change the propagation direction of light after initial homogenization; The second reflector (700) is located between the second light homogenizing component (600) and the relay part (800), and is used to change the direction of light to adapt to the light input requirement of the relay part (800).
3. The laser lighting module according to claim 2, characterized in that: The first light homogenizing component (400) comprises a dynamic diffuser (401), a first fly-eye lens (402), and a first lens (403) sequentially arranged along a first optical axis; The phase delay plate (900) is arranged along the first optical axis on a side of the first lens (403) away from the first fly-eye lens (402).
4. The laser lighting module according to claim 2, characterized in that: The second light homogenizing component (600) comprises a lens group consisting of a second lens (601), a second fly-eye lens (602), at least one third lens (603), and a fourth lens (604) arranged in sequence along the second optical axis; The phase delay plate (900) is arranged along the second optical axis on a surface of the second fly-eye lens (602) on a side facing away from the second lens (601).
5. The laser lighting module according to claim 1, characterized in that: The light combining component (300) comprises a reflective element (301) and a filter element (302); The filter element (302) is located on the reflection path of the reflection element (301) and is used to transmit light of a specific wavelength and reflect light of other wavelengths to achieve light combining processing.
6. The laser lighting module according to claim 5, characterized in that: The light source (100) comprises a first light-emitting unit (101) and a second light-emitting unit (102); The first light-emitting unit (101) is capable of emitting a blue laser beam and a green laser beam, and the reflective element (301) is located on a light-emitting path of the first light-emitting unit (101) and is capable of directing the laser beam emitted by the first light-emitting unit (101) to the filter element (302); The second light-emitting unit (102) is capable of emitting a red laser beam, and the filter element (302) is located on a light-emitting path of the second light-emitting unit (102). The filter element (302) is used to transmit the red laser beam, combine it with the blue laser beam and the green laser beam, and then project it onto the first light homogenization component (400).
7. The laser lighting module according to claim 4, characterized in that: The lens group also includes at least one lens glued to or spaced apart from the third lens (603).
8. The laser lighting module according to claim 1, characterized in that: The relay part (800) includes a total reflection prism (803), a fifth lens (801) and a sixth lens (802) are sequentially arranged on the light incident side of the total reflection prism (803), and a DMD chip (804) is arranged on the reflection side of the total reflection prism (803); The relay part (800) is used to shape the light to match the DMD chip (804), and project the light to the imaging light path of the peripheral device through the total reflection prism (803).
9. The laser lighting module according to claim 8, characterized in that: The effective display area of the DMD chip (804) is provided with protective glass.
10. A projection device, characterized in that: include: The laser lighting module according to any one of claims 1 to 9.
Citation Information
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