Laser illumination module and projection device

Abstract

A laser illumination module and a projection device. The laser illumination module comprises a light source (100), a static diffuser (200), a light combining assembly (300), a first light homogenizing assembly (400), a second light homogenizing assembly (600), a phase retarder (900) and a relay part (800). The light source (100) is used for providing a laser beam; the static diffuser (200) is used for diffusing the laser beam and eliminating speckles; the light combining assembly (300) is used for receiving light rays emitted from the static diffuser (200) and combining same; the first light homogenizing assembly (400) is used for receiving the combined light rays and performing primary light homogenization processing; the second light homogenizing assembly (600) is used for further homogenizing the light rays; the phase retarder (900) is arranged on the light exit side of the first light homogenizing assembly (400) or is arranged in the second light homogenizing assembly (600), and the size of the phase retarder (900) is smaller than the size of a laser spot, such that only part of the laser beam can pass through the phase retarder (900) to change the polarization state of light, while the other part of the laser beam remains in the original polarization state, so as to eliminate speckles; and the relay part (800) is used for shaping and reflecting the light rays after secondary homogenization to an imaging optical path.

Description

Laser lighting modules and projection equipment

[0001] This application claims priority to Chinese Patent Application No. 202411974702.X, filed on December 30, 2024, entitled "Laser Lighting Module and Projection Device", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of optical display technology, and more specifically, to a laser lighting module and a projection device. Background Technology

[0003] Micro-projection technology has seen widespread development and application in recent years, with its miniaturization and portability making it highly competitive in the market. However, traditional micro-projection devices mostly use LED light sources, which have limitations in brightness and color gamut, restricting further development of micro-projection technology. Laser light sources, due to their small divergence angle and high light purity, have become an ideal choice for improving micro-projection performance. Although current laser projection architectures include speckle reduction systems, there is still room for improvement in speckle reduction effectiveness. Therefore, developing a novel laser illumination architecture to improve speckle reduction and optimize overall illumination performance has become an urgent problem to be solved in this field. Summary of the Invention

[0004] The purpose of this application is to provide a new technical solution for laser lighting modules and projection equipment.

[0005] In a first aspect, this application provides a laser lighting module. The laser lighting module includes:

[0006] A light source used to provide a laser beam;

[0007] A static diffuser is used to diffuse and reduce speckle on the laser beam.

[0008] A light combining component is used to receive and combine the light emitted through the static diffuser.

[0009] The first light homogenizing component is used to receive the combined light and perform the initial light homogenizing process.

[0010] The second light homogenizing component is used to further homogenize the light;

[0011] A phase retarder is disposed on the light-emitting side of the first homogenizing component or in the second homogenizing component. 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 retains its original polarization state, thereby eliminating the spot.

[0012] The relay section is used to reshape the light rays after secondary homogenization and reflect them to the imaging optical path.

[0013] Optionally, the light illumination module includes a concave mirror assembly;

[0014] The conversion mirror assembly includes a first reflecting mirror and a second reflecting mirror;

[0015] The first reflector is located between the first light-diffusing component and the second light-diffusing component, and is used to change the direction of light propagation after the initial light-diffusing.

[0016] The second reflector is located between the second light-diffusing component and the relay section, and is used to change the direction of light to adapt to the light input requirements of the relay section.

[0017] Optionally, the first light-diffusing component includes a dynamic diffuser, a first compound eye lens, and a first lens arranged sequentially along the first optical axis;

[0018] The phase delay film is disposed along the first optical axis on the side of the first lens opposite to the first compound eye lens.

[0019] Optionally, the second light-diffusing component includes a lens group consisting of a second lens, a second compound eye lens, at least one third lens, and a fourth lens arranged sequentially along the second optical axis;

[0020] The phase delay film is disposed along the second optical axis on the surface of the second compound eye lens on the side opposite to the second lens.

[0021] Optionally, the light combining component includes a reflective element and a filter element;

[0022] 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.

[0023] Optionally, the light source includes a first light-emitting unit and a second light-emitting unit;

[0024] The first light-emitting unit is capable of emitting blue laser beams and green laser beams, 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;

[0025] The second light-emitting unit is capable of emitting a red laser beam. The filter element is located on the light-emitting 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 before projecting it onto the first light-uniforming component.

[0026] Optionally, the lens group further includes at least one lens that is cemented together with or spaced apart from the third lens.

[0027] Optionally, the relay section includes a total internal reflection prism, with a fifth lens and a sixth lens sequentially disposed on the incident side of the total internal reflection prism, and a DMD chip disposed on the reflecting side of the total internal reflection prism.

[0028] The relay section is used to shape the light to match the DMD chip and project it onto the imaging optical path of the peripheral device through the total reflection prism.

[0029] Optionally, the effective display area of ​​the DMD chip is provided with protective glass.

[0030] Secondly, this application provides a projection device. The projection device includes:

[0031] The laser lighting module as described in the first aspect.

[0032] The beneficial effects of this application are as follows:

[0033] This application provides a laser illumination module applicable to projection devices such as micro-projection devices. By employing 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 retardation plate, and a relay section, this optical architecture not only improves the brightness and color gamut performance of the micro-projection device but also significantly enhances speckle reduction. In particular, this application utilizes a static diffuser for diffusion and speckle reduction before light combining, and employs a specially designed phase retardation plate for speckle reduction. Furthermore, the phase retardation plate is positioned after the light combining component. This design, by altering the polarization state of some light, increases the polarization diversity of light, effectively reduces light coherence, and significantly reduces laser speckle phenomena. This optimizes projection image quality, providing users with a clearer and more detailed visual experience.

[0034] Other features and advantages of this specification will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0035] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of this specification and, together with their description, serve to explain the principles of this specification.

[0036] Figure 1 is one of the structural schematic diagrams of the laser lighting module provided in the embodiment of this application;

[0037] Figure 2 is a second schematic diagram of the structure of the laser lighting module provided in the embodiment of this application.

[0038] Explanation of reference numerals in the attached drawings: 100, Light source; 101, First light-emitting unit; 102, Second light-emitting unit; 200, Static diffuser; 300, Light combining assembly; 301, Reflective element; 302, Filter element; 400, First light-uniforming assembly; 401, Dynamic diffuser; 402, First compound eye lens; 403, First lens; 500, First reflector; 600, Second light-uniforming assembly; 601, Second lens; 602, Second compound eye lens; 603, Third lens; 604, Fourth lens; 700, Second reflector; 800, Relay section; 801, Fifth lens; 802, Sixth lens; 803, Total internal reflection prism; 804, DMD chip; 900, Phase retardation film. Detailed Implementation

[0039] 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 arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0040] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0041] Technologies and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies and equipment should be considered part of the specification.

[0042] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0043] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0044] The laser lighting module and projection device provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0045] According to one embodiment of this application, a laser illumination module is provided. Referring to Figure 1, the laser illumination module can be applied to laser projection devices such as micro-projection devices, and of course, it can also be applied to other types of projection devices.

[0046] The laser illumination module provided in this application embodiment, as shown in Figures 1 and 2, includes, along the light transmission path, a light source 100, a static diffuser 200, a beam combiner 300, a first beam homogenizing component 400, a second beam homogenizing component 600, a phase delay film 900, and a relay section 800. The light source 100 provides a laser beam; the static diffuser 200 diffuses and reduces speckle on the laser beam emitted from the light source 100; the beam combiner 300 receives and combines the light emitted from the static diffuser 200; the first beam homogenizing component 400... Component 400 is used to receive the combined light and perform initial homogenization. The second homogenization component 600 is used to further homogenize the light. The phase retardation plate 900 is disposed on the light-emitting side of the first homogenization component 400 or inside the second homogenization component 600. The size of the phase retardation plate 900 is smaller than the size of the laser spot, so that only a portion of the laser beam can pass through the phase retardation plate 900 to change the polarization state of the light, while the other portion of the laser beam retains its original polarization state to eliminate the spot. The relay part 800 is used to shape the light after secondary homogenization and reflect it to the imaging optical path.

[0047] The optical architecture of the laser illumination module provided in this application embodiment is shown in Figure 1. It includes multiple optical components along the light transmission path. The function and technical effect of each optical component are analyzed as follows.

[0048] The laser illumination module of this application includes a light source 100, which serves as the foundation of the entire laser illumination module and is used to provide a laser beam, which is a prerequisite for subsequent optical processing.

[0049] 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 for brightness and color gamut.

[0050] The laser illumination module of this application includes a static diffuser 200, which can be used to diffuse the laser beam emitted from the light source 100. This helps to increase the incident angle range of the light, thereby enabling subsequent optical components to better receive and process the light, and improve the uniformity and utilization of the light (such as the laser beam). At the same time, the static diffuser 200 also helps to reduce speckle.

[0051] The laser lighting module of this application includes a beam combining component 300, which is located after the static diffuser 200. The beam combining component 300 is used to receive beams of various colors emitted from the static diffuser 200 and perform beam combining processing.

[0052] For example, the light combining component 300 can combine laser beams of different colors, such as red laser beam (R), green laser beam (G), and blue laser beam (B), into a single beam, providing a basis for subsequent speckle removal and homogenization processing.

[0053] In this application, the laser beam emitted from the light source 100 is first diffused by the static diffuser 200, and then enters the beam combining assembly 300 for beam combining. The advantages of this method are:

[0054] (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 illumination module.

[0055] (2) Beam combining is the process of merging laser beams of different colors or directions into a single beam. If the laser beam spot is uneven or the intensity distribution is uneven before beam combining, the combined beam may also have these problems. Diffusion processing of the laser beam first can make the beam more uniform before beam combining, thereby optimizing the beam combining effect and reducing light loss and distortion during the beam combining process.

[0056] (3) The laser beam has a high energy density, but if the beam spot is too concentrated, it may cause some areas to be too bright while other areas are not bright enough. By first diffusing the laser beam, the laser spot can be made more uniform, thereby improving the utilization rate of light. In this way, more light can be evenly irradiated to the target area, improving the overall efficiency of the laser illumination module of this application.

[0057] (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 to provide users with a clearer visual experience.

[0058] In summary, the optical solution provided in this application first diffuses the laser beam and then combines it. This design has significant advantages in improving light uniformity, optimizing the light combining effect, improving light utilization, and enhancing the projection image quality.

[0059] The laser lighting module of this application includes a first light-diffusing component 400 and a second light-diffusing component 600.

[0060] The first homogenizing component 400 receives the combined light and performs initial homogenization. This step preliminarily adjusts the light distribution, reduces speckle patterns, and improves light uniformity, which is crucial for subsequent optical processing and imaging quality. The second homogenizing component 600 performs secondary homogenization on the light after homogenization by the first homogenizing component 400, further eliminating non-uniformity and resulting in a more uniform and stable final output light. Through these two homogenization processes, a high degree of uniformity and consistency is ensured that the light has these characteristics before reaching the imaging optical path.

[0061] The laser illumination module of this application also includes a phase delay plate 900.

[0062] The phase retardation plate 900, for example, is a half-wave plate, an optical element capable of altering the polarization state of light. In the illumination module of this application, the half-wave plate is used to change the polarization direction of a portion of the laser beam, while the other portion retains its original polarization state. This design helps increase the polarization diversity of light, thereby reducing light coherence and speckle phenomena.

[0063] The increase in polarization diversity can be explained as follows:

[0064] The phase retarder 900 (such as a half-wave plate) is designed to be smaller than the size of the laser spot. This means that when the combined laser beam passes through the phase retarder 900, only a portion of the beam will pass through it, thus changing the polarization state of that portion; while the other portion will not pass through it, thus maintaining its original polarization state. This design leads to an increase in the diversity of polarization states in the light, meaning that there are multiple beams with different polarization directions.

[0065] The decrease in coherence is explained as follows:

[0066] The generation of laser speckle is closely related to the coherent interference of light waves. When two or more coherent light waves meet at a point in space, they interfere with each other, forming randomly distributed brightness patterns, i.e., speckle. However, in the optical architecture provided in this application, the coherence between two beams of light with different polarization directions is reduced because one part has its polarization state changed by the phase retardation plate 90°, while the other part remains unchanged. This is because: based on the phase change, the polarization direction (polarization state) of the light changes, and the two beams with different polarization directions do not interfere, thereby weakening the polarization effect. Therefore, the interference light intensity of the entire laser illumination module is reduced, thus reducing the formation of speckle.

[0067] Therefore, by increasing the polarization diversity of light and reducing coherence, the laser illumination module provided in this application embodiment can effectively improve laser speckle phenomenon. This design not only improves the uniformity of light but also provides better illumination for laser-based micro-projection devices.

[0068] It should be noted that the laser light in this application is linearly polarized light (LP).

[0069] In the design of the laser illumination module of this application, the position and size of the phase retardation plate 900 (half-wave plate) were carefully designed to effectively improve the laser speckle phenomenon. First, the phase retardation plate 900 is placed after the beam combining component 300. This design ensures that the polarization state is adjusted only after the laser beam has passed through the beam combining component and formed a single optical path.

[0070] Secondly, regarding the size design of the phase retardation plate 900 (half-wave plate), it was intentionally set to be smaller than the size of the laser spot. The purpose of this is to ensure that when the laser beam (the combined laser beam) passes through the phase retardation plate 900 (half-wave plate), only a portion of the beam can pass through and change its polarization state, while the other portion of the beam will not pass through, thus maintaining its original polarization state. This design increases the polarization diversity of the light, meaning that two beams of light with different polarization states can coexist in the module. For example, in the interference intensity formula I=I1+I2+2 In this process, the phase difference alters the polarization state of the light, thus weakening the interference effect between the two beams. Specifically, interference only occurs within beams with the same polarization state; beams with different polarization states do not interfere. Therefore, this design reduces I1 and I2 in the interference intensity formula, thereby decreasing the intensity of the interfering light and improving laser speckle phenomena.

[0071] In this application, referring to Figure 1, the first beam homogenizing component 400 includes a dynamic diffuser 401, which cooperates with the static diffuser 200 to adjust the incident angle of the laser beam. This design allows the dynamic diffuser 401 to better function and further improve the laser speckle phenomenon. By adjusting the incident angle of the laser beam, the size of the laser speckle can be affected.

[0072] According to the laser speckle size formula d=(1.22λ*L) / πω02, ω0=λ / πθ, it can be seen that the speckle diameter d is related to the observation distance L and the minimum beam waist radius ω0 (the minimum cross-sectional area of ​​the laser beam). By adjusting the incident angle of the laser beam, the divergence angle θ can be changed, thus affecting the speckle diameter. Therefore, this design can reduce the speckle diameter, making the speckle less noticeable.

[0073] In summary, positioning the half-wave plate after beam combining and making its size smaller than the laser spot size increases the polarization diversity of the light rays and reduces coherence, thereby effectively improving laser speckle phenomena. Simultaneously, the combination of the static diffuser 200 and the dynamic diffuser 401 further adjusts the incident angle of the light, reducing the speckle diameter and making the speckle less noticeable.

[0074] The laser illumination module of this application includes a relay section 800, which is mainly used to shape the light after it has been homogenized by the second homogenizing component 600 and reflect it to the imaging optical path of the peripheral device, so as to ensure that the projected light can be accurately projected onto the target area to form a high-quality image.

[0075] The laser illumination module provided in this application embodiment, through the specific design of the phase delay plate 900 (such as a half-wave plate), allows only a portion of the light to change its polarization state, thereby increasing the polarization diversity of light, reducing coherence, and effectively improving laser speckle phenomena. Due to the significant speckle reduction effect and high light uniformity, the laser illumination module provided in this application embodiment can provide users with clearer and more detailed projection image quality.

[0076] In summary, the laser illumination module provided in this application embodiment exhibits significant advantages in terms of speckle reduction, light uniformity, and projection image quality, and has broad application prospects.

[0077] In some examples of this application, referring to Figure 1, the laser illumination module includes a concave mirror group;

[0078] The conversion mirror assembly includes a first reflecting mirror 500 and a second reflecting mirror 700;

[0079] The first reflector 500 is located between the first light-diffusing component 400 and the second light-diffusing component 600, and is used to change the direction of light propagation after the initial light-diffusing.

[0080] The second reflector 700 is located between the second light-diffusing component 600 and the relay part 800, and is used to change the direction of light to adapt to the light input requirements of the relay part 800.

[0081] In this example of the application, the laser illumination module is further optimized by introducing the deflection mirror group to achieve flexible adjustment of the light direction. Specifically, the deflection mirror group may include a first reflector 500 and a second reflector 700. These two reflectors play a crucial role in the optical path, which helps to make the entire laser illumination module more compact.

[0082] In the laser lighting module provided in this application embodiment, the first reflector 500 is located between the first light homogenizing component 400 and the second light homogenizing component 600, and the first reflector 500 can be used to change the light propagation direction after the initial light homogenization.

[0083] The first reflector 500 primarily functions to change the direction of light propagation after initial homogenization. The first homogenizing component 400 can reduce or eliminate the speckle effect generated by the laser source, making the light more uniform. The addition of the first reflector 500 ensures that this processed light can enter the second homogenizing component 600 in a predetermined direction for further homogenization.

[0084] Through the reflection of the first reflector 500, the light processed by the first light-diffusing component 400 can be effectively guided to the second light-diffusing component 600 without directly extending the optical path or changing the position of other components. This helps save space while ensuring the compactness of the optical path.

[0085] The second reflector 700 functions to change the direction of light to suit the light input requirements of the relay section 800. The second homogenizing component 600 further processes the light to achieve the required uniformity and other optical properties. Then, the second reflector 700 ensures that this high-quality light can accurately enter the relay section 800 for subsequent optical path transmission or processing.

[0086] The introduction of the second reflector 700 allows light to be adjusted and guided according to the specific incident light requirements of the relay section 800. This ensures that the light can smoothly enter the relay section 800 for further spot shaping and reflection to the imaging optical path. At the same time, this also provides greater design flexibility and adaptability for the entire laser illumination module.

[0087] In this example of the application, the introduction of the deflection mirror group 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 homogenizing component 400 and the second homogenizing component 600, can significantly improve the uniformity of the laser beam, providing a high-quality light source for subsequent optical processing or applications.

[0088] The design of the aforementioned convection mirror group makes the laser illumination module design 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.

[0089] The introduction of the concave 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 size and weight of the module.

[0090] In summary, the convection mirror group design in this example 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.

[0091] In some examples of this application, referring to FIG1, the first light-diffusing component 400 includes a dynamic diffuser 401, a first compound eye lens 402 and a first lens 403 arranged sequentially along the first optical axis; the phase delay film 900 is arranged along the first optical axis on the side of the first lens 403 opposite to the first compound eye lens 402.

[0092] The laser illumination module of this application includes a first light-diffusing component 400, which may include a dynamic diffuser 401, a first compound eye lens 402, and a first lens 403 arranged sequentially. Furthermore, a phase retardation plate 900 can be disposed on the light-emitting side of the first lens 403, in which case the phase retardation plate 900 can be considered a part of the first light-diffusing component 400. Based on this, the first light-diffusing component 400 can effectively improve the speckle problem generated by the laser light source during projection or illumination, thereby improving the uniformity and clarity of the projected image.

[0093] Optionally, the phase delay film 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.

[0094] The dynamic diffuser 401 is an optical element capable of changing the incident angle of light. In the laser illumination module of this application, the dynamic diffuser 401, through its special diffusion characteristics, diffuses the laser beam into a wider angular range, thereby increasing the diversity and uniformity of the light. This diffusion effect helps reduce speckle formation, as speckle phenomena are often related to the coherence and uniformity of light. Through the diffusion effect of the dynamic diffuser, the coherence of light is reduced, and speckle phenomena are thus minimized.

[0095] The first compound eye lens 402 is an optical element composed of multiple small lenses, designed to further homogenize light distribution. In the laser illumination module of this application, the first compound eye lens 402 can receive light from the dynamic diffuser 401, disperse it onto the individual small lenses, and then reconverge it into a more uniform light beam. This design helps to further reduce speckle and improve the brightness uniformity of the entire illumination area.

[0096] 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-reducing and homogenizing assembly, the first lens 403 can further homogenize the light or adjust the focal length of the light beam to ensure that the light can be uniformly irradiated onto the target area.

[0097] The combined use of the static diffuser 200 and the dynamic diffuser 401, along with the light-uniforming effect of the first compound eye lens 402 and the first lens 403, ensures that the light has a high degree of uniformity and consistency before reaching the imaging optical path.

[0098] In some examples of this application, referring to FIG2, the second light-diffusing component 600 includes a lens group consisting of a second lens 601, a second compound eye lens 602, at least one third lens 603 and a fourth lens 604 arranged sequentially along the second optical axis; the phase delay plate 900 is disposed along the second optical axis on the side surface of the second compound eye lens 602 opposite to the second lens 601.

[0099] The phase retardation plate 900, as a key optical element for speckle reduction, has a flexible placement; it can also be placed on a surface of the second compound eye lens 602, as shown in Figure 2. This position is also located after the beam combining assembly 300, and it is used to reduce speckle on the combined beam.

[0100] Specifically, the phase delay film 900 is bonded to the surface of the second compound eye lens 602 opposite to the second lens 601.

[0101] In other words, the phase retardation film 900 can be disposed after the first homogenizing component 400 or within the second homogenizing component 600. In practical applications, since the phase retardation film 900 itself has low transmittance but high absorptivity, placing it after homogenization helps to reduce light energy loss.

[0102] This example of the application describes the structural design of the second homogenizing component 600, as shown in Figure 2. It includes a lens group consisting of a second lens 601, a second compound eye lens 602, at least one third lens 603, and a fourth lens 604, arranged sequentially along the second optical axis. This arrangement and design aim to further improve and homogenize the distribution of the laser beam to ensure the quality and consistency of the projected image.

[0103] It should be noted that, based on the configuration of the first reflector 500, the first light-diffusing component 400 and the second light-diffusing component 600 are not on the same optical axis. The first light-diffusing component 400 can be configured along the first optical axis, and the second light-diffusing component 600 can be configured along the second optical axis.

[0104] The light is initially adjusted through the preliminary focusing and calibration of the second lens 601.

[0105] The introduction of the second compound eye lens 602, due to its special optical properties, helps to eliminate non-uniformity in light, thereby achieving a more uniform light distribution.

[0106] A third lens 603 can be provided after the second compound eye lens 602. The third lens 603 can further finely adjust and optimize the light after it has been processed by the second compound eye lens 602, thereby further enhancing the uniformity of the light.

[0107] Optionally, the third lens 603 following the second compound eye lens 602 can also be replaced with a lens group, which can further improve image quality. It should be noted that this lens group can contain different numbers and types of lenses to adapt to different application needs and scenarios. This design gives the system a certain degree of flexibility and scalability, allowing for adjustment and optimization as needed.

[0108] The third lens 603 and the fourth lens 604 serve as the final focusing and adjustment elements, ensuring that light has optimal uniformity and focus when it reaches the DMD chip 804 or other imaging elements.

[0109] The arrangement and design of the lenses and compound eye lenses in the second light-diffusing assembly 600 of this application have been carefully considered to ensure that the light propagation path 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.

[0110] Because the second light-uniforming component 600 effectively improves the uniformity of light, problems such as uneven brightness and color difference in the projected image can be effectively reduced. This results in a clearer, more detailed, and more vibrant and realistic projected image. Furthermore, the uniform light distribution can reduce glare and ghosting in the projected image, further improving the visual quality.

[0111] In summary, the example of the second light-uniforming component 600 in this application achieves a significant improvement in light uniformity, optimization of optical path design, improvement in projected image quality, and enhancement of system flexibility and scalability by introducing a lens group consisting of a second lens 601, a second compound eye lens 602, at least one third lens 603, and a fourth lens 604. These technical effects make this example of significant application value in laser projection architectures.

[0112] In some examples of this application, referring to FIG1, the 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.

[0113] In this example of the application, referring to Figure 1, the light combining component 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, and its function is to transmit light of a specific wavelength (e.g., a red laser beam R) and reflect light of other wavelengths (e.g., a blue laser beam B and a green laser beam G). In this way, the light combining process of laser beams of different colors is achieved.

[0114] The filter element 302 is designed to selectively transmit and reflect light based on its wavelength. This means that in a laser projection architecture, laser beams of the three primary colors—red, blue, and green—can be effectively combined together by the filter element 302, providing uniform mixed light for subsequent optical processing.

[0115] By introducing the filter element 302, the design of the light combining assembly 300 becomes more flexible. The combination of the reflective element 301 and the filter element 302 can precisely control the path and angle of light, allowing light to propagate in the system in a predetermined manner.

[0116] In traditional laser projection architectures, multiple complex components may be required to combine the light rays. However, in this example, the combination of the reflective element 301 and the filter element 302 simplifies the structure of the light combining component 300 and reduces the number of required components. This not only lowers the overall cost of the laser illumination module but also improves its reliability and stability.

[0117] The high efficiency and flexibility of the light combining component 300 help improve the quality of the projected image. Because laser beams of different colors can be precisely combined, the colors in the projected image will be more realistic and vibrant. Furthermore, precise control of the optical path helps reduce light loss and interference within the system, thereby improving image clarity and contrast.

[0118] In some examples of this application, referring to FIG1, the light source 100 includes a first light-emitting unit 101 and a second light-emitting unit 102;

[0119] The first light-emitting unit 101 is capable of emitting blue laser beams and green laser beams. 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.

[0120] The second light-emitting unit 102 is capable of emitting a red laser beam. The filter element 302 is located on the light-emitting 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 before projecting it onto the first light-uniforming component 400.

[0121] In this example of the application, as shown in Figure 1, the reflective element 301 is located in 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 is capable of emitting a red laser beam, and the filter element 302 is located in the light-emitting path of the second light-emitting unit 102 to transmit the red laser beam and combine it with the blue and green laser beams emitted by the first light-emitting unit 101.

[0122] 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. Simultaneously, the modular design also facilitates the maintenance and replacement of the light source.

[0123] The combination of the reflective element 301 and the filter element 302 optimizes the optical path. The reflective element 301 can precisely guide the laser beam emitted by the first light-emitting unit 101 to the filter element 302, while the filter element 302 can simultaneously process the laser beams from the first light-emitting unit 101 (after reflection) and the second light-emitting unit 102, achieving their beam combining. This design not only simplifies the optical path but also improves the utilization rate of light and the overall performance of the system.

[0124] 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.

[0125] By modularizing the light source and optimizing the optical path design, the examples in this application improve the efficiency and reliability of the module. The modular light source design allows each light-emitting unit to operate independently, thereby reducing the overall power consumption and heat generation of the module. At the same time, the optimized optical path design reduces light loss and interference, improving light utilization and system stability.

[0126] In some examples of this application, the lens group further includes at least one lens that is cemented together or spaced apart from the third lens 603.

[0127] In the second light-diffusing assembly 600 of this application, a lens group can be disposed after the second compound eye lens 602. This lens group not only includes the third lens 603, but may further include at least one lens cemented together or spaced apart from the third lens 603. This design provides greater flexibility to adapt to different optical performance and imaging requirements.

[0128] By bonding additional lenses to or spacing them with the third lens 603, the optical performance of the entire lens group can be further adjusted and optimized. This adjustment can include optimization of focal length, aberration correction, light deflection angle, etc., thereby ensuring higher sharpness of the projected image.

[0129] By adding lenses that are cemented together or spaced apart from the third lens 603, the focal length of the entire lens group can be flexibly adjusted. This allows the laser illumination module of this application to adapt to different projection distances and screen sizes, providing wider applicability.

[0130] In this example of the application, the additional lenses in the lens group can be used to correct various aberrations. Correction of these aberrations is crucial for improving the quality and sharpness of the projected image. Aberration correction ensures that the projected image has higher detail and fewer visual defects.

[0131] When the lenses in the lens group are cemented together, the complexity of the assembly process can be reduced. For example, multiple optical elements can be assembled in one go.

[0132] In some examples of this application, referring to Figure 1, the relay section 800 includes a total internal reflection prism 803. A fifth lens 801 and a sixth lens 802 are sequentially arranged on the light incident side of the total internal reflection prism 803, and a DMD chip 804 is arranged on the reflection side of the total internal reflection prism 803. The relay section 800 is used to shape the light to match the DMD chip 804 and project it to the imaging optical path of the peripheral device through the total internal reflection prism 803.

[0133] In this example of the application, the combination of the fifth lens 801 and the sixth lens 802 plays a crucial role in light shaping. They can adjust the diffusion angle, focal point, and spot size of the light to ensure that the light can be well matched with the effective display surface of the DMD chip 804. This matching is essential for the sharpness and image quality of the projected image because it reduces light scattering and loss on the DMD chip 804, thereby improving the image contrast and brightness.

[0134] The total internal reflection prism 803 (TIR prism) has highly efficient light reflection performance. It can reflect almost all incident light to the DMD chip 804, thereby maximizing the utilization of light resources. This efficient reflection helps reduce light waste and improve the light efficiency and energy utilization of the entire projection system.

[0135] In the optical architecture provided in this application, the relay section 800 achieves a compact optical path design by compactly arranging the fifth lens 801, the sixth lens 802, and the total internal reflection prism 803 together. This design helps reduce the overall size and weight of the projection system, making it easier to carry and install. Simultaneously, the compact optical path design also helps reduce interference and loss of light during transmission, thereby improving the stability of the projected image.

[0136] Because the relay section 800 effectively shapes the light and reflects it to the DMD chip 804, the clarity of the projected image is significantly improved. This improvement in clarity is very important for users, as it provides a better visual experience and viewing effect.

[0137] In some examples of this application, see Figures 1 and 2, the effective display area of ​​the DMD chip 804 is provided with protective glass.

[0138] The protective glass effectively prevents dust, dirt, moisture, and other potential impurities from directly contacting and damaging the DMD chip 804. This extends the lifespan of the DMD chip 804 and reduces performance degradation or malfunctions caused by contamination. The DMD protective glass has high hardness and abrasion resistance, resisting physical damage such as scratches and impacts.

[0139] Referring to Figures 1 and 2, the light-incident surfaces of the sixth lens 802 and the total internal reflection prism 803 are arranged adjacent to each other, and the light-incident surfaces of the sixth lens 802 and the total internal reflection prism 803 are designed to be approximately parallel. Of course, they are not completely parallel, and there is an angle of about 3.5° between them.

[0140] The optical path design in the laser illumination module of this application has been carefully optimized to ensure that the laser beam can be projected onto the DMD chip 804 efficiently and accurately, and modulated by the micromirror array of the DMD chip 804 to finally form a high-quality projected image.

[0141] In the laser illumination module provided in this application embodiment, the phase retardation plate 900 is, for example, a half-wave plate, and the half-wave plate is located in the optical path after light combining. The use and position of the half-wave plate in this application is beneficial to improving the speckle effect.

[0142] Of course, in practical applications, the phase delay plate 900 can be replaced with a quarter-wave plate or the like as needed. This application does not make any specific restrictions on the phase delay plate.

[0143] In the laser illumination module provided in this application, by placing a half-wave plate in the optical path after beam combining, the polarization direction of a portion of the laser beam can be adjusted, resulting in two beams with the same intensity but different polarization directions within the laser illumination module. This polarization diversity helps reduce the coherence between laser beams, thereby effectively reducing speckle phenomena. It should be noted that speckle is a common problem in laser projection, causing random brightness variations in the projected image and affecting image quality. The introduction of the half-wave plate significantly improves this problem, making the projected image clearer and more uniform.

[0144] In this application, the phase delay film 900 can be positioned in two locations. One location is on the side of the first lens 403 away from the first compound eye lens 402. In this case, the phase delay film 900 is located between the two compound eye lenses (i.e., the first compound eye lens 402 and the second compound eye lens 602). This design plays an important role in enhancing the stability and reliability of the projection system. It can not only compensate for 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.

[0145] Of course, the phase delay film 900 can also be placed after the second compound eye lens 602. In this case, the phase delay film 900 can be bonded to the second compound eye lens 602, which can also achieve a good spot-reducing effect.

[0146] According to yet another embodiment of this application, a projection device is provided, the projection device including the laser illumination module as described above.

[0147] The projection device provided in this application embodiment is, for example, a projection device based on DLP (Digital Light Processing) technology.

[0148] The projection device provided in this application embodiment employs the laser illumination module described in the above embodiment. 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 vibrant and vivid images, especially excelling in dark detail and color saturation.

[0149] Speckle, a common phenomenon in laser projection, can affect image sharpness and uniformity. The laser illumination module used in this application effectively reduces speckle by employing a special first homogenizing component 400. This design results in a smoother, more uniform projected image, improving the visual effect.

[0150] Using the laser illumination module provided in this application embodiment in projection equipment can bring about significant improvements in brightness and color gamut, reduced speckle, optimized optical path design, enhanced system stability and reliability, and reduced cost and energy consumption. These technical effects enable projection equipment to perform excellently in terms of image quality, performance stability, and cost-effectiveness, making it suitable for various application scenarios.

[0151] The specific implementation of the projection device in this application can refer to the various embodiments of the laser lighting module described above. Therefore, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be described in detail here.

[0152] The above embodiments mainly describe 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. For the sake of brevity, they will not be elaborated here.

[0153] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. A laser illumination module, characterized in that, include: A light source (100) is used to provide a laser beam; A static diffuser (200) is used to diffuse and diffuse the laser beam; A light combining component (300) is used to receive light emitted through the static diffuser (200) and combine it; The first light homogenizing component (400) is used to receive the combined light and perform the initial light homogenization process; The second light homogenizing component (600) is used to further homogenize the light; A phase retarder (900) is disposed on the light-emitting side of the first homogenizing component (400) or in the second homogenizing component (600). The size of the phase retarder (900) is smaller than the size of the laser spot, so that only a part of the laser beam can pass through the phase retarder (900) to change the polarization state of the light, while the other part of the laser beam maintains the original polarization state to dissipate the spot. The relay section (800) is used to shape and reflect the light after secondary homogenization to the imaging optical path.

2. The laser illumination module according to claim 1, characterized in that, The laser illumination module includes a convection mirror group; The conversion mirror assembly includes a first reflecting mirror (500) and a second reflecting mirror (700); The first reflector (500) is located between the first light-diffusing component (400) and the second light-diffusing component (600) and is used to change the direction of light propagation after the initial light-diffusing. The second reflector (700) is located between the second light-diffusing component (600) and the relay part (800) and is used to change the direction of light to adapt to the light input requirements of the relay part (800).

3. The laser illumination module according to claim 2, characterized in that, The first light-diffusing component (400) includes a dynamic diffuser (401), a first compound eye lens (402), and a first lens (403) arranged sequentially along the first optical axis; The phase delay film (900) is disposed along the first optical axis on the side of the first lens (403) opposite to the first compound eye lens (402).

4. The laser illumination module according to claim 2, characterized in that, The second light-diffusing component (600) includes a lens group consisting of a second lens (601), a second compound eye lens (602), at least one third lens (603), and a fourth lens (604) arranged sequentially along the second optical axis; The phase delay film (900) is disposed along the second optical axis on the side surface of the second compound eye lens (602) facing away from the second lens (601).

5. The laser illumination module according to claim 1, characterized in that, The 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.

6. The laser illumination module according to claim 5, characterized in that, The light source (100) includes a first light-emitting unit (101) and a second light-emitting unit (102); The first light-emitting unit (101) is capable of emitting blue laser beams and green laser beams. 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). The second light-emitting unit (102) is capable of emitting a red laser beam. The filter element (302) is located on the light-emitting 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 before projecting it onto the first light-uniforming component (400).

7. The laser illumination module according to claim 4, characterized in that, The lens group also includes at least one lens that is cemented together or spaced apart from the third lens (603).

8. The laser illumination module according to claim 1, characterized in that, The relay section (800) includes a total internal reflection prism (803), and a fifth lens (801) and a sixth lens (802) are sequentially arranged on the light incident side of the total internal reflection prism (803), and a DMD chip (804) is arranged on the reflection side of the total internal reflection prism (803). The relay section (800) is used to shape the light to match the DMD chip (804) and project it onto the imaging optical path of the peripheral device through the total reflection prism (803).

9. The laser illumination 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 illumination module as described in any one of claims 1-9.

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