Optical machine module and optical projection equipment

Abstract

The embodiment of the invention provides an optical machine module and optical projection equipment. Wherein the ray machine module comprises a front diaphragm, a projection lens, an Xcube color combination prism and an image source which are arranged in sequence; the projection lens comprises four aspherical lenses, a first lens, a second lens, a third lens and a fourth lens are sequentially arranged in the direction from the front diaphragm to the Xcube color combination prism, and the projection lens has positive focal power; the image source comprises a red muLED panel, a green muLED panel and a blue muLED panel which are used for emitting red light, green light and blue light respectively. The Xcube color combination prism is configured to perform color combination processing on red, green and blue light rays from the image source so as to form a full-color image; the pixel size Pixel Size, the angular resolution PPD and the diagonal field of view DFOV of the image source meet the condition that Pixel Size * PPD * DFOV is larger than or equal to 2.0 and smaller than or equal to 8.0.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of projection optical display, and more specifically, to a light engine module and an optical projection device. Background Art

[0002] With the rapid development of AR technology, high resolution, high image quality imaging, and miniaturization have become important trends in AR light engine design. μLED (MicroLED) light engine technology is considered the ultimate choice for the AR light engine industry due to its advantages such as high brightness, high contrast, and low power consumption.

[0003] However, most of the existing μLED light engines are based on low-resolution designs and are difficult to meet the requirements of high-resolution imaging. At the same time, traditional designs also have limitations in terms of miniaturization. Therefore, it is of great significance to develop a high-resolution and extremely miniaturized μLED AR light engine module. Summary of the Invention

[0004] The purpose of the present application is to provide a new technical solution for a light engine module and an optical projection device.

[0005] In a first aspect, the embodiments of the present application provide a light engine module, which includes, in sequence: a front aperture stop, a projection lens, an Xcube dichroic prism, and an image source; Among them, the projection lens includes four aspherical lenses, which are, in sequence from the front aperture stop to the Xcube dichroic prism, a first lens, a second lens, a third lens, and a fourth lens, and the projection lens has a positive optical power; The image source includes red, green, and blue μLED panels, which are used to emit red, green, and blue light respectively; The Xcube dichroic prism is configured to perform color mixing on the red, green, and blue light from the image source to form a full-color image; The pixel size Pixel Size, angular resolution PPD, and diagonal field of view DFOV of the image source satisfy: 2.0 ≤ Pixel Size × PPD × DFOV ≤ 8.0.

[0006] Optionally, the total focal length f of the light engine module, the length L of the Xcube dichroic prism along the optical axis direction, and the air gap G between the Xcube dichroic prism and the image source satisfy the following relationship: 0.2 mm < f - L - G < 2 mm.

[0007] Optionally, the light engine module satisfies the following relationship: 2 ≤ Panel Size + G * tan(arcsin1 / 2F #) + L * tan{arcsin[sin(arcsin1 / 2F # )] / n dcube} ≤ 5; Where: Panel Size is the diagonal size of the image source, and 0.1 inch ≤ Panel Size ≤ 0.3 inch; G is the air gap between the Xcube dichroic prism and the image source; L is the length of the Xcube dichroic prism along the optical axis direction; F # is the f-number of the optical engine module, and 1 ≤ F # ≤ 3; n dcube is the refractive index of the Xcube dichroic prism.

[0008] Optionally, the f-number F of the optical engine module # satisfies: 1 ≤ F # ≤ 3, and the ratio of the f-number F # to the total focal length f of the optical engine module satisfies the relationship: 0.5 ≤ F# / f ≤ 5.

[0009] Optionally, the pixel size Pixel Size of the image source is 1.5 μm ≤ Pixel Size ≤ 8 μm.

[0010] Optionally, the effective focal lengths of the four aspherical lenses in the projection lens satisfy the relationship: 0.1 < (f1 + f4) / (f2 + f3) < 0.3, where: f1 is the effective focal length of the first lens; f2 is the effective focal length of the second lens; f3 is the effective focal length of the third lens; f4 is the effective focal length of the fourth lens; The first lens and the fourth lens are biconvex lenses; The second lens and the third lens are meniscus lenses.

[0011] Optionally, the first lens and the second lens have positive optical power, the third lens has negative optical power, and the fourth lens has positive optical power; The effective focal length f1 of the first lens, the effective focal length f2 of the second lens, the effective focal length f3 of the third lens, and the effective focal length f4 of the fourth lens and the total focal length f of the optical engine module satisfy the following relationship: 0.7 < f1 / f < 1; 5.9 < f2 / f < 10.3; -0.5 < f3 / f < -0.3; 0.5 < f4 / f < 0.6.

[0012] Optionally, the effective focal length f1 of the first lens is: 4 mm < f1 < 6 mm; The effective focal length f2 of the second lens is: 33 mm < f2 < 58 mm; The effective focal length f3 of the third lens is: -3 mm < f3 < -2 mm; The effective focal length f4 of the fourth lens is: 3 mm < f4 < 4 mm.

[0013] Optionally, the total optical length of the optical engine module is L', satisfying the following conditions: 0.7 < (f1 + f4) / L' < 1.1, and 3.7 < (f2 + f3) / L' < 6.8.

[0014] Optionally, the air gap between the first lens and the second lens is A1, the air gap between the second lens and the third lens is A2, the air gap between the third lens and the fourth lens is A3, and the air gap between the fourth lens and the Xcube color-combining prism is A4. The air gaps A1, A2, A3, and A4 satisfy the relationship: 0.7 < (A1 + A4) / (A2 + A3) < 0.9.

[0015] Optionally, the total optical length of the optical engine module is L', satisfying the following conditions: 0.1 < (A1 + A4) / L' < 0.2, and 0.1 < (A2 + A3) / L' < 0.2.

[0016] Optionally, the total optical length L' of the optical engine module and the image height H of the image source satisfy the following relationship: 0.4 < H / L' < 0.5.

[0017] Optionally, the imaging distance of the optical engine module is infinity, the exit pupil distance of the front aperture is 0 ≤ exit pupil distance < 150 mm, and the exit pupil distance is the distance from the surface of the front aperture close to the image source to the surface of the first lens far from the image source along the optical axis direction.

[0018] Optionally, the fourth lens is made of optical glass material.

[0019] In a second aspect, an embodiment of the present application provides an optical projection device, which includes: The optical engine module as described in the first aspect; and A waveguide device, where the diameter of the front aperture of the optical engine module matches the entrance pupil diameter of the waveguide device.

[0020] The beneficial effects of the present application are: The optical engine module provided by the embodiment of the present application uses a positive focal length projection lens composed of four aspherical lenses, combined with the configuration of red, green, and blue μLED panels and an Xcube color combining prism, to achieve a design of high-resolution imaging and extreme miniaturization. Specifically, the pixel size Pixel Size, angular resolution PPD, and diagonal field of view FOV of the image source are controlled within a specific relationship of 2.0≤2.0≤Pixel Size×PPD×DFOV≤8.0. This design ensures that while maintaining high resolution, the optical engine module can also provide a large field of view (for example, the field of view FOV can reach 40°), thus meeting the high requirements of AR devices for visual experience.

[0021] In addition, the projection lens composed of four aspherical lenses cooperates with the Xcube color combining prism, effectively reducing aberration, color distortion, and light loss, and significantly improving the optical efficiency and imaging quality. The application of aspherical lenses not only corrects the aberration that is difficult to eliminate by traditional spherical lenses, but also further promotes the miniaturization of the optical engine module by reducing the number and thickness requirements of the lenses. The precise configuration of the Xcube color combining prism ensures the accurate color combination of red, green, and blue light rays, avoids color distortion, and improves the color reproducibility of imaging.

[0022] In summary, the optical engine module of the embodiment of the present application realizes an extreme miniaturization design while maintaining high resolution and a large field of view, provides strong technical support for the development of AR devices, and promotes the development of AR technology towards higher performance and more portability.

[0023] Through the following detailed description of the exemplary embodiments of this specification with reference to the accompanying drawings, other features and advantages of this specification will become clear. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings incorporated in and constituting a part of this specification illustrate embodiments of this specification and, together with the description, are used to explain the principles of this specification.

[0025] Figure 1 One of the structural schematic diagrams of the optical engine module provided by the embodiment of the present application; Figure 2 is Figure 1 the distortion diagram of the optical engine module provided; Figure 3 is Figure 1 the MTF diagram of the optical engine module provided; Figure 4 is Figure 1 the relative illumination diagram of the optical engine module provided; Figure 5The second structural schematic diagram of the optical engine module provided by the embodiment of the present application; Figure 6 For Figure 5 The distortion diagram of the optical engine module provided; Figure 7 For Figure 5 The MTF diagram of the optical engine module provided; Figure 8 For Figure 5 The relative illumination diagram of the optical engine module provided; Figure 9 The third structural schematic diagram of the optical engine module provided by the embodiment of the present application; Figure 10 For Figure 9 The distortion diagram of the optical engine module provided; Figure 11 For Figure 9 The MTF diagram of the optical engine module provided; Figure 12 For Figure 9 The relative illumination diagram of the optical engine module provided.

[0026] Explanation of reference numerals: 1. Image source; 2. Xcube dichroic prism; 3. Projection lens; 301. First lens; 302. Second lens; 303. Third lens; 304. Fourth lens; 4. Front diaphragm. Detailed implementation manners

[0027] Now, various exemplary embodiments of the present application will 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 values set forth in these embodiments do not limit the scope of the present application.

[0028] The following description of at least one exemplary embodiment is merely illustrative in nature and in no way serves as a limitation to the present application or its application or use.

[0029] Technologies and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies and devices should be regarded as part of the specification.

[0030] In all the examples shown and discussed here, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values.

[0031] It should be noted that: like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0032] The following will describe in detail the optical engine module and the optical projection device provided by the embodiments of the present application in conjunction with the accompanying drawings.

[0033] According to an embodiment of the present application, an optical engine module is provided. Refer to Figure 1 , Figure 5 and Figure 9 . The optical engine module includes, arranged in sequence: a front aperture 4, a projection lens 3, an Xcube dichroic prism 2, and an image source 1. The projection lens 3 includes four aspherical lenses. From the direction of the front aperture 4 to the Xcube dichroic prism 2, they are the first lens 301, the second lens 302, the third lens 303, and the fourth lens 304 in sequence. The projection lens has a positive optical power. The image source 1 includes red, green, and blue μLED panels for emitting red, green, and blue light respectively. The Xcube dichroic prism 2 is configured to perform color combination processing on the red, green, and blue light from the image source 1 to form a full-color image. The pixel size Pixel Size, angular resolution PPD, and diagonal field of view DFOV of the image source 1 satisfy: 2.0 ≤ Pixel Size × PPD × DFOV ≤ 8.0.

[0034] The optical engine module provided by the embodiments of the present application has a compact structure. Each main part works together to achieve high-resolution and high-image-quality full-color imaging and meet the design requirements of miniaturization of the entire optical engine module. The following is a detailed analysis of the structural composition of the optical engine module provided by the embodiments of the present application and the functions of its main components.

[0035] The optical engine module provided by the embodiments of the present application includes a front aperture 4. Refer to Figure 3 . The front aperture 4 is arranged on the side of the entire optical engine module far from the image source 1, that is, at the forefront position of the entire optical engine module. The core function of the front aperture 4 is to limit the beam aperture range entering the projection lens 3. This design plays an important role in controlling the aberration of the optical engine module and improving the resolution.

[0036] By adjusting the diameter parameter of the front aperture 4, it can be ensured that only light within a specific angle and range can smoothly enter the projection lens 3, thereby effectively optimizing the imaging quality and reducing unnecessary stray light interference.

[0037] In addition, the diameter design of the front aperture 4 needs to match the entrance pupil diameter of the external optical waveguide device. This matching design not only enhances the overall compatibility of the optical projection system but also significantly improves the optical coupling efficiency, providing a strong guarantee for the efficient and stable operation of the optical engine module.

[0038] The optical engine module of the embodiments of the present application includes a projection lens 3. Refer to Figure 1 , Figure 5and Figure 9 The projection lens 3 mainly consists of four aspherical lenses arranged along the same optical axis. Specifically, starting from the side where the front diaphragm 4 is located and along the propagation path of light towards the Xcube dichroic prism 2, a first lens 301, a second lens 302, a third lens 303, and a fourth lens 304 are arranged in sequence. The projection lens 3 is used to focus the divergent light from the image source 1 and finally form a clear and color-accurate image on the projection plane, providing an excellent visual experience for the AR device.

[0039] In the embodiment of this application, the projection lens 3 adopts a design scheme of four aspherical lenses. This design effectively reduces aberration and greatly improves the clarity and resolution of imaging by precisely controlling the light propagation path, thus achieving excellent performance in high-resolution imaging. Notably, in this application, the effect of reducing aberration is achieved by using only four lenses, which is a breakthrough in traditional designs. At the same time, this streamlined lens configuration also greatly promotes the miniaturization process of the optical engine module as a whole, providing strong technical support for the compact design of AR devices.

[0040] The aspherical lens design adopted in this application can more precisely regulate the light propagation path. Compared with traditional spherical lenses, it significantly reduces the number of required lenses while ensuring the same imaging quality. This improvement not only simplifies the overall structure but also effectively reduces the volume of the optical engine module, meeting the requirements of AR devices for compact design.

[0041] In addition, the production and processing process of aspherical lenses relies on die-casting production technology, which greatly improves production efficiency and ensures product consistency. Die-casting production is not only conducive to achieving mass production but also effectively reduces production costs, thus significantly enhancing the market competitiveness of products and laying a foundation for the popularization and commercial application of AR devices.

[0042] In the optical engine module provided in the embodiment of this application, the projection lens 3 has a positive focal power. This configuration with positive focal power effectively converges the light within the projection lens 3, further enhancing the imaging effect, such as improving the clarity and contrast of imaging.

[0043] One of the core components of the optical engine module provided in the embodiment of this application is the Xcube dichroic prism 2. For its specific position and structure, please refer to Figure 1 、 Figure 5 and Figure 9。In the optical design of this application, the Xcube dichroic prism 2 is arranged between the projection lens 3 and the image source 1, undertaking the key task of efficiently combining the red (R), green (G), and blue (B) light rays from the image source 1 to form a high-quality full-color image.

[0044] With its unique optical properties, the Xcube dichroic prism 2 can ensure the uniform mixing of the red (R), green (G), and blue (B) light rays during the color combination process, effectively avoiding the occurrence of chromatic aberration or color cast phenomena. This property plays an important role in ensuring the color accuracy and clarity of the final output image, enabling users to immerse themselves in a more realistic visual experience. Through the color combination process of the Xcube dichroic prism 2, the optical engine module provided by the embodiments of this application has achieved a significant improvement in color performance, precisely meeting the user's requirements for high-quality full-color images.

[0045] The optical engine module provided by the embodiments of this application further includes an image source 1, see Figure 1 、 Figure 5 and Figure 9 。The image source 1 includes, for example, red, green, and blue μLED panels, which are used to emit red, green, and blue light rays respectively. The image source 1 is the imaging basis of the optical engine module provided by the embodiments of this application. After the three-color light rays emitted by it are combined by the Xcube dichroic prism 2, a full-color image can be formed.

[0046] It is worth mentioning that the three-color μLED panels used in the image source 1 have many remarkable advantages, such as high brightness output, high contrast performance, and low power consumption characteristics, etc. Under the combined action of these advantages, the image source 1 can provide high-quality and high-stability image output, laying a foundation for the improvement of the overall performance of the optical engine module.

[0047] In the design of the optical engine module provided by the embodiments of this application, the pixel size (Pixel Size), angular resolution (PPD), and diagonal field of view (DFOV) of the image source 1 satisfy a specific relational expression: 2.0 ≤ Pixel Size × PPD × DFOV ≤ 8.0. This parameter design ensures the balance of high resolution, small volume, and large field of view (up to 40° field of view) of the optical engine module. The following is a detailed analysis of this design.

[0048] Regarding the pixel size (Pixel Size) of the image source 1: The pixel size is a basic parameter of the image source 1, which determines the physical size of each pixel. A smaller pixel size usually means a higher pixel density, thus potentially enabling a higher resolution. However, an overly small pixel size may increase the manufacturing difficulty and cost.

[0049] Regarding the angular resolution PPD of the image source 1: The angular resolution is an important indicator to measure the imaging clarity of the opto-mechanical module. It represents the number of pixels corresponding to the minimum angle that the human eye or the opto-mechanical module can distinguish. A higher PPD means that more details can be presented within the same field of view, thereby improving the imaging quality.

[0050] Regarding the diagonal field of view DFOV of the image source 1: The diagonal field of view is the maximum angle in the diagonal direction of the scene range that the opto-mechanical module can cover. A larger DFOV means that the user can see a wider scene, thereby enhancing the user experience. However, increasing the field of view usually leads to a decrease in resolution because the light needs to be distributed over a larger range.

[0051] In the optical design provided by this application, by setting the relationship of Pixel Size × PPD × DFOV, this application ensures the performance of the opto-mechanical module in terms of high resolution. A smaller pixel size and a higher PPD help to improve the imaging clarity, enabling the user to see finer image details. This relationship also takes into account the miniaturization requirements of the opto-mechanical module. By optimizing the balance between the pixel size, PPD, and DFOV, the volume of the opto-mechanical module can be reduced without sacrificing resolution. This is of great significance for application scenarios with extremely strict space requirements such as AR devices.

[0052] Although increasing the field of view usually leads to a decrease in resolution, this application achieves the balance between a large field of view and high resolution by carefully designing the relationship between Pixel Size, PPD, and DFOV. A larger DFOV enables the user to see a wider scene, while high resolution ensures the clarity and detail presentation of the scene.

[0053] In addition, this parameter design in this application not only improves the individual performance of the opto-mechanical module in terms of resolution, volume, and field of view, but also realizes the improvement of the comprehensive performance through their synergistic effects. The user can enjoy the wide field of view brought by the large field of view while also experiencing the delicate image effect brought by high resolution.

[0054] In summary, in the opto-mechanical module design provided by the embodiments of this application, by setting a specific relationship between the pixel size, angular resolution, and diagonal field of view of the image source, the balance among high resolution, small volume, and large field of view is achieved. This design not only improves the overall performance of the opto-mechanical module, but also brings a more high-quality and immersive visual experience to the user.

[0055] The opto-mechanical module provided by the embodiments of this application achieves remarkable technical effects through a carefully designed optical structure and optical parameter configuration, which are specifically described as follows: (1)High resolution and clear imaging: The projection lens 3 adopts a design of four aspherical lenses. Compared with traditional spherical lenses, it can more effectively correct aberrations such as spherical aberration and coma, thus significantly improving the clarity and resolution of imaging.

[0056] (2)Positive optical power configuration: The projection lens 3 is set to have a positive optical power. This design helps the effective focusing of light within the projection lens 3, further improving the imaging quality.

[0057] (3)Relationship among Pixel Size, PPD, and DFOV: The pixel size Pixel Size, angular resolution PPD, and diagonal field of view DFOV of the image source 1 satisfy the relational expression of 2.0 ≤ Pixel Size × PPD × DFOV ≤ 8.0. This design ensures that while maintaining high resolution, a large field of view and small volume can also be achieved, meeting the user's requirements for a large field of view, high-definition visual experience, etc.

[0058] (4)Optimization of the number of lenses: By adopting a four-lens design, compared with traditional multi-lens systems, the number of lenses is effectively reduced, thereby reducing the volume and weight of the optical engine module. The use of aspherical lenses not only improves the imaging quality but also, due to its unique curved surface design, helps to achieve more efficient light control within a limited space, further promoting the miniaturization of the optical engine module. This application realizes reducing aberrations with the fewest lenses, achieving high-resolution imaging, and miniaturizing the module volume.

[0059] (5)Xcube color-combining prism 2: The Xcube color-combining prism 2 is configured to perform color-combining processing on the red R, green G, and blue B light rays from the image source 1 to form a high-quality full-color image. This color-combining method effectively reduces color distortion and improves the accuracy of color reproduction.

[0060] The design of the optical engine module provided by the embodiments of this application is not only applicable to portable devices such as AR smart glasses but can also be extended according to requirements and applied to a wider range of AR display fields.

[0061] In summary, through the new optical structure design and optical parameter configuration, the optical engine module of the embodiments of this application achieves various technical effects such as high-resolution imaging, module miniaturization, efficient color-combining and color reproduction, and optical performance optimization, providing strong technical support for the development of AR devices.

[0062] In some examples of this application, the total focal length f of the optical engine module, the length L of the Xcube color-combining prism 2 along the optical axis direction, and the air gap G between the Xcube color-combining prism 2 and the image source 1 satisfy the following relationship: 0.2mm < f - L - G < 2mm.

[0063] In some examples provided in this application, a specific relationship is satisfied among the total focal length f of the optical engine module, the length L of the Xcube dichroic prism 2 along the optical axis direction, and the air gap G between the Xcube dichroic prism 2 and the image source 1: 0.2 mm < f - L - G < 2 mm. By precisely controlling the range of f - L - G, it is ensured that a balance is achieved among the total focal length f of the optical engine module, the length L of the Xcube dichroic prism 2, and the air gap G between the Xcube dichroic prism 2 and the image source 1. This balance is crucial for achieving the ultimate miniaturization of the optical engine module while maintaining high-resolution imaging. The following is a detailed explanation of the parameters and a detailed analysis of this specific relationship.

[0064] Some parameter definitions in this example of this application are as follows: f represents the total focal length of the optical engine module, which determines the ability of light rays to converge, that is, the clarity and focusing effect of imaging.

[0065] L represents the length of the Xcube dichroic prism 2 along the optical axis direction, which reflects the physical size of the Xcube dichroic prism 2 and has a direct impact on the color combination and propagation path of light rays.

[0066] G represents the air gap in the optical axis direction between the Xcube dichroic prism 2 and the image source 1, which affects the propagation path of light rays between the Xcube dichroic prism 2 and the image source 1 and thus affects the imaging quality.

[0067] By optimizing the relationship among f, L, and G, the overall length of the optical engine module can be effectively reduced, thereby achieving the miniaturized design of the optical engine module. This miniaturized design not only helps improve the portability of the AR device but also significantly enhances the user experience, enabling users to use the device more easily.

[0068] The specific relationship provided in the example of this application ensures that after passing through the Xcube dichroic prism 2 and the air gap G, the light rays can be precisely converged on the projection plane and maintain a high-resolution imaging effect. For AR devices, high-resolution imaging is crucial because it can provide a clearer and more realistic visual experience, enhancing the user's sense of immersion and reality.

[0069] It should be noted that if the value of f - L - G is not within the range of 0.2 mm to 2 mm, a series of problems may occur. Specifically: If f - L - G ≤ 0.2 mm: The total focal length f of the optical engine module may be too short, resulting in the inability of light rays to effectively converge at a point during propagation, thereby affecting the clarity and resolution of imaging.

[0070] If the length L of the Xcube dichroic prism 2 and the air gap G are too large due to improper parameter adjustment, the light will deviate from the expected path during propagation, increasing aberration and affecting the accuracy and stability of imaging.

[0071] In addition, an overly compact structural design may pose great challenges to the manufacturing and assembly of the optical engine module, increasing production costs and difficulties.

[0072] If f - L - G ≥ 2 mm: the total focal length f of the optical engine module may be too long, resulting in a significant increase in the overall length of the optical engine module, which is contrary to the development trend of miniaturization of AR devices.

[0073] If the length L of the Xcube dichroic prism 2 and the air gap G are too small due to improper parameter adjustment, it may cause unnecessary interference or scattering of light during propagation, further reducing the imaging quality.

[0074] An overly long optical engine module may not only increase the overall weight and volume of the AR device, but also affect the user's wearing comfort and usage experience.

[0075] In summary, the relational expression 0.2 mm < f - L - G < 2 mm provided in this example of the present application is of crucial significance for ensuring the miniaturization and high-resolution imaging of the optical engine module. By precisely controlling the relationship between these parameters, it is possible to ensure that the entire optical engine module reaches the best balance between optical performance and physical size, thereby providing users with a better-quality and more convenient visual experience.

[0076] In some examples of the present application, the optical engine module satisfies the following relationship: 2 ≤ Panel Size + G * tan(arcsin1 / 2F # ) + L * tan{arcsin[sin(arcsin1 / 2F # )] / n dcube} ≤ 5; where: Panel Size is the diagonal size of the image source 1, and 0.1 inch ≤ Panel Size ≤ 0.3 inch; G is the air gap between the Xcube dichroic prism 2 and the image source 1; L is the length of the Xcube dichroic prism 2 along the optical axis direction; F # is the aperture number of the optical engine module, and 1 ≤ F # ≤ 3; n dcube is the refractive index of the Xcube dichroic prism 2.

[0077] According to the example provided in the present application, a specific relationship is obtained by comprehensively considering the diagonal size Panel Size of the image source 1, the air gap G in the optical axis direction between the Xcube dichroic prism 2 and the image source 1, the length L of the Xcube dichroic prism 2 in the optical axis direction, the f-number F of the optical engine module # and the refractive index n of the Xcube dichroic prism 2 dcube and other factors, which constrains the overall optical design of the optical engine module. This design can ensure that the optical engine module has an extremely short overall optical length, thereby achieving miniaturization of the volume of the optical engine module. That is to say, through this relationship, it can be ensured that the overall length of the optical engine module is controlled within the minimum range while meeting the imaging quality requirements. This miniaturization design helps to improve the user experience of the AR device.

[0078] The parameter settings in the specific relationship provided by this example of the present application fully consider the requirements of imaging quality. For example, the range of the diagonal size Panel Size of the image source 1 ensures that the image source 1 has sufficient pixel density to support high-resolution imaging. The range limitation of the f-number F# ensures that the optical engine module has sufficient light flux output to meet the brightness requirements of the AR optical engine, and at the same time helps to control aberration and improve imaging clarity. By controlling the relationship between these parameters, it can be ensured that the light rays can accurately converge on the projection imaging surface, thereby maintaining a high-resolution imaging effect.

[0079] The specific relationship in this example of the present application is of great significance for ensuring the miniaturization and high-resolution imaging of the optical engine module. By controlling the relationship between these parameters, it can be ensured that the optical engine module achieves the best balance between performance and size, providing users with a better quality and more convenient visual experience.

[0080] If Panel Size + G * tan(arcsin1 / 2F # ) + L * tan{arcsin[sin(arcsin1 / 2F # )] / n dcube} < 2, it may occur that, for example, the size Panel Size of the image source 1 is too small. If the size PanelSize of the image source 1 is less than the minimum value allowed by the specific relationship, although the miniaturization of the entire optical engine module may be achieved to a certain extent, it will lead to insufficient pixel density, thereby reducing the resolution and clarity of the imaging. For an AR device, a low-resolution image will seriously affect the user experience and cannot provide a clear visual effect.

[0081] Another possibility is that the air gap G between the Xcube dichroic prism 2 and the image source 1 or the length L of the Xcube dichroic prism 2 along the optical axis is too small, which may cause unnecessary interference or scattering of light during propagation. If the air gap G is too small, light may not be effectively propagated, increasing crosstalk between optical elements and reducing the imaging quality. And if the length L of the Xcube dichroic prism 2 along the optical axis is too small, it will affect the color combination effect of light, resulting in color distortion or reduced uniformity.

[0082] When Panel Size + G * tan(arcsin 1 / 2F # ) + L * tan{arcsin[sin(arcsin 1 / 2F # )] / n dcube} < 2, the optical engine module may not meet the requirements of high-resolution imaging, and at the same time, the miniaturization of the module may be difficult to achieve due to overly compact structure, increasing the difficulty and cost of manufacturing and assembly.

[0083] If Panel Size + G * tan(arcsin 1 / 2F # ) + L * tan{arcsin[sin(arcsin 1 / 2F # )] / n dcube} > 5, one possible situation is that the size Panel Size of the image source 1 is too large. If the size Panel Size of the image source 1 is too large, although it can provide a higher pixel density, it will increase the overall size of the optical engine module, which is not conducive to miniaturization design. A larger image source size may increase the overall weight and volume of the AR device.

[0084] Another possibility is that the air gap G between the Xcube dichroic prism 2 and the image source 1 or the length L of the Xcube dichroic prism 2 along the optical axis is too large, which will cause the light to deviate from the expected path during propagation, increasing aberration and chromatic aberration, and reducing the accuracy and stability of imaging. For example, a larger air gap G and prism length L may increase the overall length of the optical engine module, which is not conducive to miniaturization design.

[0085] When Panel Size + G * tan(arcsin 1 / 2F # ) + L * tan{arcsin[sin(arcsin 1 / 2F # )] / n dcube} > 5, the optical engine module may be too large to meet the requirements of portability and miniaturization of the AR device.

[0086] Generally speaking, the parameter range designed in this example of the present application (i.e., 2 to 5) ensures the miniaturization design of the optical engine module while maintaining high-resolution imaging. If the parameters are not within this range, it will have an adverse impact on the performance and size of the optical engine module, and thus affect the overall performance and user experience of the AR device. Therefore, when designing the optical engine module, this mathematical relationship in this example of the present application must be observed to ensure the best balance between the performance and size of the optical engine module.

[0087] In some examples of the present application, the aperture number F of the optical engine module # satisfies: 1 ≤ F # ≤ 3, and the ratio of the aperture number F # to the total focal length f of the optical engine module satisfies: 0.5 ≤ F# / f ≤ 5.

[0088] In some examples of the present application, the aperture number F of the optical engine module # and its ratio to the total focal length f are controlled within a specific range, that is: 1 ≤ F # ≤ 3, 0.5 ≤ F # / f ≤ 5. This optical design aims to optimize the contrast, stray light performance, optical efficiency, and light flux output of the optical engine module.

[0089] The aperture number F # is an important parameter of the optical engine module, which determines the amount of light passing through, that is, the light flux. In the examples provided by the present application, the aperture number F of the optical engine module # is controlled between 1 and 3, which means that the optical engine module has a moderate aperture size. A moderate aperture size helps to balance the light input and depth of field of the optical engine module, ensuring clear imaging at different distances.

[0090] And the ratio of F # / f further refines the selection of the aperture number F # . Specifically, the ratio of F # / f is between 0.5 and 5. This design means that a certain proportional relationship needs to be maintained between the aperture number F # of the optical engine module and the total focal length f of the optical engine module. This proportional relationship helps to optimize the optical performance of the optical engine, such as contrast, stray light suppression, etc. In the present application, by adjusting the ratio of the aperture number F # of the optical engine module to the total focal length f of the optical engine module, it can be ensured that the optical engine module can maintain stable performance under different working conditions.

[0091] By restricting the range of the aperture number F # and F #The ratio of F / f can ensure that the optical engine module provided by the embodiments of the present application has sufficient contrast. Contrast is one of the important indicators for measuring imaging quality, which determines the difference between the bright and dark parts in an image. High contrast helps to improve the clarity and layering of the image, enabling the AR device to present a more realistic visual effect.

[0092] An appropriate aperture number and a reasonable F # / f ratio helps to suppress the generation of stray light. Stray light refers to the interfering light formed after non-imaging light enters the optical engine module, which will reduce the clarity and contrast of the image. In the present application, by optimizing the aperture number F of the optical engine module # and the aperture number F # and the ratio of the total focal length f of the module, the interference of stray light can be reduced, and the imaging quality of the optical engine module can be improved.

[0093] The selection of the aperture number F of the optical engine module # directly affects the efficiency of the optical engine module. For the optical engine module provided by the embodiments of the present application, an appropriate aperture size can ensure that the optical engine module has a high optical efficiency when receiving light and reduce the loss of light. At the same time, a reasonable F # / f ratio also helps to optimize the optical performance of the optical engine module and further improve the optical efficiency of the optical engine module.

[0094] By ensuring the efficiency and light flux output of the optical engine module, it can be ensured that the AR optical engine has sufficient brightness. Brightness is one of the important performance indicators of the AR device, which directly affects the visual experience of users during use.

[0095] In summary, in the present application, by restricting the aperture number F of the optical engine module # and its ratio to the total focal length f, the optimization of the contrast, stray light performance, optical efficiency and light flux output of the optical engine module is achieved. This design helps to improve the overall performance of the AR device and provide a better visual experience for users.

[0096] In some examples of the present application, the pixel size Pixel Size of the image source 1 is 1.5μm ≤ PixelSize ≤ 8μm.

[0097] In some examples of the present application, the pixel size Pixel Size of the image source 1 is controlled within the range of 1.5μm to 8μm. This design is based on the consideration of the imaging quality requirements of the optical engine module, especially for the key evaluation index of the modulation transfer function (MTF).

[0098] MTF (Modulation Transfer Function) is an important indicator for measuring the imaging clarity of an optical system, which reflects the ability of the optical system to transfer signals of different spatial frequencies.

[0099] In the optical engine module provided in the embodiments of the present application, a high MTF value means that the optical engine module can transfer image details more accurately, thus presenting a clearer and more vivid visual effect.

[0100] The MTF index is evaluated based on the Nyquist frequency, and the Nyquist frequency is inversely proportional to the pixel size (Nyquist frequency = 1 / (2 * Pixel Size)). This means that the smaller the pixel size Pixel Size, the higher the Nyquist frequency, the more image details the optical engine module can transfer, and the higher the MTF value.

[0101] In the examples provided in the present application, restricting the pixel size Pixel Size within the range of 1.5 μm to 8 μm is based on a comprehensive consideration of various factors such as the performance, cost, and manufacturing process of the optical engine module. Specifically, a smaller pixel size helps to improve the MTF value, but may increase the manufacturing difficulty and cost; a larger pixel size may reduce the MTF value, but the manufacturing is relatively easy and the cost is lower. Therefore, choosing the pixel size range of 1.5 μm to 8 μm takes into account the acceptability of the manufacturing process and cost while ensuring the imaging quality.

[0102] By restricting the pixel size Pixel Size, the design of the present application can ensure that the AR optical engine has a high MTF value, thereby improving the imaging clarity. This enables the AR device to transfer details more accurately when presenting images, reducing blur and distortion, and providing a clearer and more vivid visual experience for users. The appropriate selection of the pixel size helps to optimize the overall performance of the optical engine module. It can reduce the complexity and manufacturing cost of the optical engine module while ensuring the imaging quality, and improve the reliability and stability of the optical engine module. The design of the present application provides strong support for the development of AR technology.

[0103] In some examples of the present application, the effective focal lengths of the four aspherical lenses in the projection lens satisfy the relationship: 0.1 < (f1 + f4) / (f2 + f3) < 0.3, where: f1 is the effective focal length of the first lens 301; f2 is the effective focal length of the second lens 302; f3 is the effective focal length of the third lens 303; f4 is the effective focal length of the fourth lens 304; and the first lens 301 and the fourth lens 304 are biconvex lenses; the second lens 302 and the third lens 303 are meniscus lenses.

[0104] In some examples of this application, the effective focal lengths of the four aspherical lenses in the projection lens satisfy the relationship: 0.1 < (f1 + f4) / (f2 + f3) < 0.3. This design is based on the consideration of optimizing the overall performance of the opto-mechanical module, especially for the comprehensive consideration of imaging aberration, resolution, Nyquist frequency, and the volume of the opto-mechanical module.

[0105] For the projection lens 3 in this application, by constraining the relationship between the effective focal lengths of the four lenses, it can be ensured that the positive and negative lenses are evenly matched in the opto-mechanical module. This even matching helps to balance the refraction and deflection of light when passing through each lens, thereby reducing imaging aberration.

[0106] Regarding the surface shapes of the four lenses provided in this example of this application: The first lens 301 and the fourth lens 304 are biconvex lenses, and the second lens 302 and the third lens 303 are meniscus lenses.

[0107] Among them, the first lens 301 and the second lens 302 have positive optical powers, the third lens 303 has a negative optical power, and the fourth lens 304 has a positive optical power. This distribution of optical powers helps the reasonable propagation and focusing of light in the projection lens 3, further reducing aberration and improving imaging quality.

[0108] By satisfying the focal length relationship of 0.1 < (f1 + f4) / (f2 + f3) < 0.3, imaging with high resolution and high Nyquist frequency can be achieved, while reducing the volume of the opto-mechanical module. Among them, high-resolution imaging means that the image details are more abundant, and high Nyquist frequency ensures the clarity of the image in the high-frequency region. And reducing the volume of the opto-mechanical module helps to improve the portability and user experience of the AR device.

[0109] If the relationship between the effective focal lengths of the four aspherical lenses in the projection lens 3 does not satisfy 0.1 < (f1 + f4) / (f2 + f3) < 0.3, it will have an adverse impact on the performance of the opto-mechanical module. Specifically, the uneven matching of the positive and negative lenses will lead to the imbalance of the refraction and deflection of light when passing through each lens, thereby increasing imaging aberration. The increase in aberration will reduce the clarity and contrast of the image, affecting the user's visual experience. The non-satisfaction of the focal length relationship will also affect the reasonable propagation and focusing of light in the projection lens 3, resulting in a decrease in resolution and Nyquist frequency, which will cause the loss of image details and the blurring of the high-frequency region, unable to meet the requirements of the AR device for high-quality imaging. In addition, in order to compensate for the performance degradation caused by the non-satisfaction of the focal length relationship, generally, the number or size of the lenses needs to be increased, resulting in an increase in the volume of the opto-mechanical module.

[0110] In summary, the effective focal length relationship of the four aspherical lenses in the projection lens 3, 0.1 < (f1 + f4) / (f2 + f3) < 0.3, plays an important role in the design of this application. It ensures the performance optimization of the optical engine module, realizes imaging with high resolution and high Nyquist frequency, and reduces the volume of the optical engine module.

[0111] In some examples of this application, the following relationships are satisfied between the effective focal lengths of the lenses in the projection lens and the total focal length f of the optical engine module: 0.7 < f1 / f < 1, 5.9 < f2 / f < 10.3, -0.5 < f3 / f < -0.3, and 0.5 < f4 / f < 0.6; where f1 is the effective focal length of the first lens 301, f2 is the effective focal length of the second lens 302, f3 is the effective focal length of the third lens 303, and f4 is the effective focal length of the fourth lens 304.

[0112] In this example provided by this application, the proportional relationships between the effective focal lengths of the lenses (the first lens 301, the second lens 302, the third lens 303, the fourth lens 304) in the projection lens 3 and the total focal length f of the optical engine module are described. Specifically: The ratio of the effective focal length f1 of the first lens 301 to the total focal length f of the optical engine module should satisfy 0.7 < f1 / f < 1.

[0113] The ratio of the effective focal length f2 of the second lens 302 to the total focal length f of the optical engine module should satisfy 5.9 < f2 / f < 10.3.

[0114] The ratio of the effective focal length f3 of the third lens 303 to the total focal length f of the optical engine module should satisfy -0.5 < f3 / f < -0.3.

[0115] The ratio of the effective focal length f4 of the fourth lens 304 to the total focal length f of the optical engine module should satisfy 0.5 < f4 / f < 0.6.

[0116] The above proportional relationships ensure the uniform distribution of the optical power of each lens in the optical engine module, which is the key to realizing high-resolution imaging and reducing the sensitivity to tolerances.

[0117] Specifically, by precisely controlling the ratio of the effective focal lengths of the lenses in the projection lens 3 to the total focal length f of the optical engine module, it can be ensured that the refraction and deflection of light when passing through each lens reach the best balance, thereby realizing the uniform distribution of optical power. This uniform distribution helps to reduce the loss and distortion of light during propagation, and improves the utilization rate of light and the imaging quality.

[0118] Aberration is one of the important factors affecting imaging quality. By optimizing the distribution of the optical power of each lens in the projection lens 3, aberrations such as spherical aberration, coma, and astigmatism can be effectively controlled. Reducing aberrations means that image details can be captured and presented more accurately, thus achieving high-resolution imaging. This is crucial for AR devices because users require clear and realistic visual experiences.

[0119] Thus, by precisely controlling the ratio of the effective focal length of each lens in the projection lens 3 to the total focal length f of the optical engine module, the overall performance of the optical engine module can be optimized, providing a clear and realistic visual experience for AR devices.

[0120] In some examples of the present application, the first lens 301 and the second lens 302 have positive optical power, the third lens 303 has negative optical power, and the fourth lens 304 has positive optical power; the following relationships are satisfied between the effective focal length f1 of the first lens 301, the effective focal length f2 of the second lens 302, the effective focal length f3 of the third lens 303, the effective focal length f4 of the fourth lens 304, and the total focal length f of the optical engine module: 0.7 < f1 / f < 1, 5.9 < f2 / f < 10.3, -0.5 < f3 / f < -0.3, 0.5 < f4 / f < 0.6.

[0121] In some examples of the present application, the effective focal lengths of the four lenses in the projection lens 3 are set within a specific range: the effective focal length f1 of the first lens 301 is 4mm < f1 < 6mm, the effective focal length f2 of the second lens 302 is 33mm < f2 < 58mm, the effective focal length f3 of the third lens 303 is -3mm < f3 < -2mm, and the effective focal length f4 of the fourth lens 304 is 3mm < f4 < 4mm. The selection of these focal length ranges is based on a comprehensive consideration of optical performance, structural compactness, and mass production feasibility.

[0122] By precisely setting the effective focal lengths of the lenses in the projection lens 3, the present application can optimize the optical performance of the projection lens 3, including aberration correction, chromatic aberration control, and imaging clarity, etc.

[0123] Among them, the first lens 301 and the second lens 302, as positive optical power lenses, are responsible for the initial convergence and correction of light; the third lens 303, as a negative optical power lens, is used to further correct aberrations; the fourth lens 304, as a positive optical power lens, helps with the final convergence and imaging of light. The reasonable distribution of the focal lengths of each lens helps to achieve the structural compactness of the projection lens 3. By avoiding unnecessary lens numbers and complex lens shapes, the present application can reduce the volume and weight of the projection lens 3 while ensuring optical performance, thus meeting the requirements of AR devices for miniaturization and lightweight.

[0124] In this application, the setting of the effective focal lengths of the lenses in the projection lens 3 also takes into account the feasibility of mass production. By selecting a focal length range that is easy to process and mass produce, this application can reduce the production cost of the lenses, improve production efficiency, and ensure product consistency and reliability. This is of great significance for applying the technical solution of this application to large-scale production.

[0125] The optimized projection lens 3 can provide a higher quality imaging effect, including higher resolution, more accurate color reproduction, and lower aberration, etc. This will directly enhance the visual experience of users when using AR devices, enabling them to enjoy clearer and more realistic images.

[0126] In some examples of this application, the total optical length of the optical engine module is L', satisfying the following conditions: 0.7 < (f1 + f4) / L' < 1.1, and 3.7 < (f2 + f3) / L' < 6.8.

[0127] Through these two conditions, this application ensures a uniform distribution of the optical powers of the four lenses in the optical engine module. This uniform distribution helps to reduce aberration and improve imaging quality. Especially when light passes through multiple lenses, a uniform distribution of optical powers can ensure that light propagates in a more stable and accurate manner, thereby reducing distortion and chromatic aberration.

[0128] These two conditions are also conducive to the miniaturization of the AR optical engine. By precisely controlling the ratio of the optical power of the lenses to the total optical length, the size and weight of the lenses can be reduced while ensuring imaging quality. This helps to reduce the volume of the entire optical engine module, making it more suitable for application scenarios with extremely high space requirements such as AR glasses.

[0129] The uniform distribution of optical powers and the compact optical design jointly optimize the imaging performance of the optical engine module. In AR applications, users need to see clear images. This application ensures that the optical engine module can provide high-quality imaging effects by precisely controlling the optical power and total optical length of the lenses.

[0130] In some examples of this application, the air gap between the first lens 301 and the second lens 302 is A1, the air gap between the second lens 302 and the third lens 303 is A2, the air gap between the third lens 303 and the fourth lens 304 is A3, and the air gap between the fourth lens 304 and the Xcube color-combining prism 2 is A4. Then, the air gaps A1, A2, A3, and A4 satisfy the relationship: 0.7 < (A1 + A4) / (A2 + A3) < 0.9.

[0131] In some examples of the present application, the four air gaps in the projection lens 3 - the air gap A1 between the first lens 301 and the second lens 302, the air gap A2 between the second lens 302 and the third lens 303, the air gap A3 between the third lens 303 and the fourth lens 304, and the air gap A4 between the fourth lens 304 and the Xcube color combining prism 2 - are designed to satisfy a specific proportional relationship: 0.7 < (A1 + A4) / (A2 + A3) < 0.9. This design is based on a comprehensive consideration of the performance, structural compactness, and production feasibility of the optical engine module.

[0132] By reasonably setting the proportional relationship of the air gaps A1, A2, A3, and A4, the present application can optimize the overall structural design of the projection lens 3. This setting of the air gaps helps to ensure the relative positions of the lenses are stable and reduces the optical performance fluctuations caused by uneven structures.

[0133] The uniform setting of the air gaps also helps to reduce the sensitivity of the optical engine module to manufacturing tolerances. During the production process, minor dimensional deviations may have a significant impact on the optical performance. However, by following the proportional relationship of the air gaps provided in this example of the present application, these deviations can be offset to a certain extent, ensuring that the optical engine module maintains consistent performance among different production batches.

[0134] By optimizing the spacing between the lenses, it is possible to reduce unnecessary space occupancy while ensuring the optical performance, thereby making the optical engine module more compact and lightweight.

[0135] In addition, the reasonable setting of the air gaps also helps to improve the imaging quality of the optical engine module. By ensuring that the light rays undergo appropriate spatial adjustments during propagation, optical problems such as aberrations and chromatic aberrations can be reduced, thereby improving the clarity and color accuracy of the imaging. This is crucial for providing high-quality and realistic virtual images.

[0136] In some examples of the present application, the optical total length of the optical engine module is L', satisfying the following conditions: 0.1 < (A1 + A4) / L' < 0.2, and 0.1 < (A2 + A3) / L' < 0.2.

[0137] In some examples of the present application, the total optical length of the optical engine module is L'. For the proportional relationships between the air gaps A1 (the air gap between the first lens 301 and the second lens 302), A2 (the air gap between the second lens 302 and the third lens 303), A3 (the air gap between the third lens 303 and the fourth lens 304), A4 (the air gap between the fourth lens 304 and the Xcube color combining prism 2) and the total optical length L', two conditions are proposed: 0.1 < (A1 + A4) / L' < 0.2 and 0.1 < (A2 + A3) / L' < 0.2. These two conditions are aimed at realizing the miniaturized design of the optical engine module by optimizing the proportion of the air gap in the total optical length.

[0138] Specifically, this control enables the compression of the air gap as much as possible while ensuring the optical performance, thereby reducing the volume of the optical engine module. The miniaturized optical engine module not only helps improve the integration of the device, enabling more functions to be realized in a limited space, but also facilitates the carrying and use of the device. Users can wear the AR device more easily and enjoy a more comfortable visual experience.

[0139] In some examples of the present application, the following relationship is satisfied between the total optical length L' of the optical engine module and the image height H of the image source 1: 0.4 < H / L' < 0.5.

[0140] In some examples of the present application, a specific proportional relationship is set between the total optical length L' of the optical engine module and the image height H of the image source 1: 0.4 < H / L' < 0.5. This design constraint is based on the design consideration of the miniaturization requirement of the optical engine module, aiming to achieve the shortest design of the optical engine module by optimizing the proportion between the total optical length L' and the image height H, and further achieving the purpose of miniaturization.

[0141] By setting the proportional relationship of 0.4 < H / L', the present application ensures the best balance between the total optical length L' of the optical engine module and the image height H of the image source 1. This design enables the optical engine module to shorten its overall length as much as possible while maintaining the necessary imaging performance, thereby achieving the shortest optical engine design. The shortest optical engine design directly leads to the miniaturization of the optical engine module. The miniaturized optical engine module is not only convenient for integration into various AR devices, but also improves the wearing comfort of the device.

[0142] By optimizing the proportion between the total optical length L' and the image height H, the loss and distortion of light during propagation can be reduced, and the clarity and accuracy of imaging can be improved. At the same time, the compact structure design also reduces unnecessary space occupation and improves the space utilization rate of the optical engine module.

[0143] In some examples of the present application, the imaging distance of the optical engine module is infinity, the exit pupil distance of the front diaphragm 4 is 0 ≤ exit pupil distance < 150 mm, and the exit pupil distance is the distance along the optical axis from the surface of the front diaphragm 4 close to the image source 1 to the surface of the first lens 301 away from the image source 1.

[0144] In some examples of the present application, the design of the optical engine module takes into account its characteristics as a waveguide image source, specifically reflected in two aspects: imaging distance and the exit pupil distance of the front diaphragm 4.

[0145] The imaging distance of the optical engine module is infinity, which matches the optical characteristics of the waveguide, thus ensuring that the light emitted from the optical engine module can smoothly enter and propagate along the waveguide.

[0146] The exit pupil distance of the front diaphragm 4 is precisely controlled within the range of 0 ≤ exit pupil distance < 150 mm. This distance refers to the distance along the optical axis from the surface of the front diaphragm 4 close to the image source 1 to the surface of the first lens 301 away from the image source 1.

[0147] When the exit pupil distance is 0, the optical engine module can be directly attached to the waveguide device to achieve a compact integrated design. The limitation that the exit pupil distance is less than 150 mm takes into account the actual situation of placing the optical engine module on the temple of the AR glasses, ensuring that the optical engine module can work properly within a limited space.

[0148] A reasonable design of the exit pupil distance helps to improve the wearing comfort and visual experience of the AR glasses. Users can adjust the wearing method of the AR glasses according to their own needs without worrying that the imaging quality will be affected due to improper installation position of the optical engine module.

[0149] By setting the parameter ranges of the imaging distance and the exit pupil distance, the optical engine module design of the present application has stronger versatility and compatibility. It can be matched with different types of waveguides and AR glasses to meet the needs of different users and application scenarios.

[0150] In some examples of the present application, the fourth lens 304 is made of optical glass material.

[0151] In some examples of the present application, the fourth lens 304 is made of optical glass material. This design is based on the consideration of the overall performance and reliability of the optical engine module, especially considering the position of the fourth lens 304 in the optical path and its proximity to the image source 1 (heat source).

[0152] The optical glass material has excellent high-temperature resistance and can maintain stable physical and chemical properties in a high-temperature environment. Since the fourth lens 304 is close to the image source 1 (i.e., close to the heat source), using the optical glass material can effectively resist the heat generated by the heat source, prevent the lens from deforming or its performance from deteriorating due to excessive temperature, and thus improve the overall temperature resistance of the optical engine module.

[0153] The stability and durability of the optical glass material enable the fourth lens 304 to maintain stable imaging performance during long-term use. This helps to reduce the degradation of imaging quality or optical engine failures caused by lens aging or damage, thereby enhancing the overall reliability of the optical engine module.

[0154] The optical glass material has excellent optical properties, such as high transmittance, low dispersion, etc. These characteristics help to optimize the imaging quality of the optical engine module. As an important part of the optical path, the fourth lens 304 made of the optical glass material can ensure the stability and accuracy of light during propagation, reduce aberration and distortion, and improve the clarity and color accuracy of imaging.

[0155] In addition, the optical glass material has a high degree of maturity and reliability in production and processing. Using the optical glass material to manufacture the fourth lens 304 can make full use of existing production processes and equipment, reduce production costs and cycles. At the same time, the stability and consistency of the optical glass material also help to improve production efficiency and product quality.

[0156] The following will illustrate the optical engine module of the present application through Embodiment 1 to Embodiment 3 respectively.

[0157] Embodiment 1 Referring to Figure 1 , the optical engine module provided in this Embodiment 1 includes, arranged in sequence: a front aperture 4, a projection lens 3, an Xcube dichroic prism 2, and an image source 1; wherein, the projection lens 3 includes four aspherical lenses, and in the direction from the front aperture 4 to the Xcube dichroic prism 2 are the first lens 301, the second lens 302, the third lens 303, and the fourth lens 304 in sequence, and the projection lens has a positive optical power; the image source 1 includes red, green, and blue μLED panels, which are used to emit red, green, and blue light respectively; the Xcube dichroic prism 2 is configured to perform color combination processing on the red, green, and blue light from the image source 1 to form a full-color image; Among them, the image source 1 is a 600*800*2.5μm μLED panel, its image height H is 2.5mm, and the FOV is 25°; The optical total length L' of the optical engine module is 8.2mm, its entrance pupil diameter is 3.5mm, and the f-number F of the optical engine module #= 1.6, and the total focal length f of the optical engine module is 5.6 mm; Among them, the wavelength of the light generated by the image source 1 is set to 463:528:650 nm = 1:2:1; Among them, Pixel Size × PPD × DFOV is 2.51 mm.

[0158] Figure 1 The specific parameters of the shown optical engine module are as shown in Table 1 below, which include the radius of curvature, thickness, glass material, and semi-aperture of the lens.

[0159] Table 1

[0160] For the optical engine module provided in the above Embodiment 1, the optical performance is as follows: See Figure 2 , Figure 2 is the distortion map of the optical engine module. The absolute value of the distortion of the optical engine module is less than 1%, which can greatly improve the imaging quality.

[0161] See Figure 3 , Figure 3 is the MTF map of the optical engine module. The average MTF of each field of view > 0.6 @ 200 lp / mm (Nyquist frequency), and the imaging is good.

[0162] See Figure 4 , Figure 4 is the relative illumination map of the optical engine module. The relative illumination at the outermost edge relative to the center is > 85%, which is beneficial to improving the uniformity of the optical engine.

[0163] Embodiment 2 See Figure 5 , the optical engine module provided in this Embodiment 2 includes, in sequence: a front aperture 4, a projection lens 3, an Xcube dichroic prism 2, and an image source 1; among them, the projection lens 3 includes four aspherical lenses, and in the direction from the front aperture 4 to the Xcube dichroic prism 2 are the first lens 301, the second lens 302, the third lens 303, and the fourth lens 304 in sequence. The projection lens has a positive optical power; the image source 1 includes red, green, and blue μLED panels, which are used to emit red, green, and blue light respectively; the Xcube dichroic prism 2 is configured to combine the red, green, and blue light from the image source 1 for color combination to form a full-color image; Among them, the image source 1 is based on a 600*800*2.5 μm μLED panel, its image height H is 2.5 mm, and the FOV is 25°; The overall optical length L' of the optical engine module is 8.2 mm, its entrance pupil diameter is 3.5 mm, and the f-number F of the optical engine module # = 1.59, and the total focal length f of the optical engine module is 5.6 mm; Among them, the wavelength of the light generated by the image source 1 is set to 463:528:650 nm = 1:2:1; Among them, Pixel Size × PPD × DFOV is 2.56 mm.

[0164] Figure 5 The specific parameters of the shown optical engine module are as shown in Table 2 below, which includes the radius of curvature, thickness, glass material, and semi-aperture of the lens.

[0165] Table 2

[0166] For the optical engine module provided in the above Embodiment 2, the optical performance is as follows: See Figure 6 , Figure 6 is the distortion map of the optical engine module. The absolute value of the distortion of the optical engine module is less than 0.8%, which can greatly improve the imaging quality.

[0167] See Figure 7 , Figure 7 is the MTF map of the optical engine module. The average MTF of each field of view > 0.6 @ 200 lp / mm (Nyquist frequency), and the imaging is good.

[0168] See Figure 8 , Figure 8 is the relative illumination map of the optical engine module. The relative illumination at the outermost edge relative to the center is > 86%, which is beneficial to improving the uniformity of the optical engine.

[0169] Embodiment 3 See Figure 9 , the optical engine module provided in this Embodiment 3 includes, in sequence: a front aperture 4, a projection lens 3, an Xcube dichroic prism 2, and an image source 1; among them, the projection lens 3 includes four aspherical lenses, and in the direction from the front aperture 4 to the Xcube dichroic prism 2 are a first lens 301, a second lens 302, a third lens 303, and a fourth lens 304 in sequence. The projection lens has a positive optical power; the image source 1 includes red, green, and blue μLED panels for respectively emitting red, green, and blue light; the Xcube dichroic prism 2 is configured to perform color mixing on the red, green, and blue light from the image source 1 to form a full-color image; Among them, the image source 1 is a 600*800*2.5μm μLED panel, with an image height H of 2.5mm and a FOV of 25°; The total optical length L' of the optical engine module is 8.2mm, its entrance pupil diameter is 3.5mm, and the f-number F # = 1.59 of the optical engine module, and the total focal length f of the optical engine module is 5.7mm; Among them, the wavelength of the light generated by the image source 1 is set to 463:528:650nm = 1:2:1; Among them, Pixel Size×PPD×DFOV is 2.51mm.

[0170] Figure 9 The specific parameters of the shown optical engine module are as shown in Table 3 below, which include the radius of curvature, thickness, glass material, and semi-aperture of the lens.

[0171] Table 3

[0172] For the optical engine module provided in the above Embodiment 3, the optical performance is as follows: See Figure 10 , Figure 10 the distortion map of the optical engine module. The absolute value of the distortion of the optical engine module is less than 0.8%, which can greatly improve the imaging quality.

[0173] See Figure 11 , Figure 11 is the MTF map of the optical engine module. The average MTF of each field of view > 0.6 @ 200lp / mm (Nyquist frequency), and the imaging is good.

[0174] See Figure 12 , Figure 12 is the relative illumination map of the optical engine module. The relative illumination at the outermost edge relative to the center is > 86%, which is beneficial to improving the uniformity of the optical engine.

[0175] According to another embodiment of the present application, an optical projection device is provided. The optical projection device includes: the optical engine module and the optical waveguide device as described above; among them, the diameter of the front aperture 4 of the optical engine module matches the entrance pupil diameter of the optical waveguide device.

[0176] The specific implementation manners of the optical projection device in the embodiments of the present application can refer to the respective embodiments of the above optical engine module. Therefore, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, and will not be elaborated here one by one.

[0177] In the above embodiments, the differences between the various embodiments are mainly described. 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.

[0178] Although some specific embodiments of the present 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 not for limiting the scope of the present application. Those skilled in the art should understand that the above embodiments can 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. An optical-mechanical module, characterized in that, Including, successively arranged: a front aperture (4), a projection lens (3), an Xcube dichroic prism (2), and an image source (1); Among them, the projection lens (3) includes four aspherical lenses. From the direction of the front aperture (4) to the Xcube dichroic prism (2), they are successively the first lens (301), the second lens (302), the third lens (303), and the fourth lens (304). The projection lens has a positive optical power; The image source (1) includes red, green, and blue μLED panels, which are used to emit red, green, and blue light respectively; The Xcube dichroic prism (2) is configured to perform color combination processing on the red, green, and blue light from the image source (1) to form a full-color image; Among the pixel size Pixel Size, angular resolution PPD, and diagonal field of view DFOV of the image source (1), the following is satisfied: 2.0 ≤ Pixel Size × PPD × DFOV ≤ 8.

0.

2. The optical engine module according to claim 1, wherein Among the total focal length f of the optical engine module, the length L of the Xcube dichroic prism (2) along the optical axis direction, and the air gap G between the Xcube dichroic prism (2) and the image source (1), the following relationship is satisfied: 0.2 mm < f - L - G < 2 mm.

3. The optical engine module according to claim 2, wherein, The optical engine module satisfies the following relationship: 2 ≤ Panel Size + G * tan(arcsin(1 / 2F # )) + L * tan{arcsin[sin(arcsin(1 / 2F # ))] / n dcube} ≤ 5; Among them: Panel Size is the diagonal size of the image source (1), and 0.1 inch ≤ Panel Size ≤ 0.3 inch; G is the air gap between the Xcube dichroic prism (2) and the image source (1); L is the length of the Xcube dichroic prism (2) along the optical axis direction; F # is the aperture number of the optical engine module, and 1 ≤ F # ≤ 3; n dcube is the refractive index of the Xcube dichroic prism (2).

4. The optical engine module according to claim 3, wherein The aperture number F of the optical engine module # satisfies: 1 ≤ F # ≤ 3, and the ratio of the aperture number F # to the total focal length f of the optical engine module satisfies the relationship: 0.5 ≤ F# / f ≤ 5.

5. The optical engine module according to claim 1, wherein The pixel size PixelSize of the image source (1) is 1.5 μm ≤ Pixel Size ≤ 8 μm.

6. The optical machine module according to claim 1, wherein Among the effective focal lengths of the four aspherical lenses in the projection lens, the following relationship is satisfied: 0.1 < (f1 + f4) / (f2 + f3) < 0.3, where: f1 is the effective focal length of the first lens (301); f2 is the effective focal length of the second lens (302); f3 is the effective focal length of the third lens (303); f4 is the effective focal length of the fourth lens (304); The first lens (301) and the fourth lens (304) are biconvex lenses; The second lens (302) and the third lens (303) are meniscus lenses.

7. The optical engine module according to claim 6, wherein The first lens (301) and the second lens (302) have positive optical power, the third lens (303) has negative optical power, and the fourth lens (304) has positive optical power; Among the effective focal length f1 of the first lens (301), the effective focal length f2 of the second lens (302), the effective focal length f3 of the third lens (303), and the effective focal length f4 of the fourth lens (304) and the total focal length f of the optical engine module, the following relationship is satisfied: 0.7 < f1 / f < 1; 5.9 < f2 / f < 10.3; -0.5 < f3 / f < -0.3; 0.5 < f4 / f < 0.

6.

8. The optical engine module according to claim 6 or 7, characterized in that, The effective focal length f1 of the first lens (301) is: 4 mm < f1 < 6 mm; The effective focal length f2 of the second lens (302) is: 33 mm < f2 < 58 mm; The effective focal length f3 of the third lens (303) is: -3 mm < f3 < -2 mm; The effective focal length f4 of the fourth lens (304) is: 3 mm < f4 < 4 mm.

9. The optical engine module according to claim 6, wherein The total optical length of the optical engine module is L', satisfying the following conditions: 0.7 < (f1 + f4) / L' < 1.1, and 3.7 < (f2 + f3) / L' < 6.

8.

10. The optical machine module according to claim 1 or 6, characterized in that, The air gap between the first lens (301) and the second lens (302) is A1, the air gap between the second lens (302) and the third lens (303) is A2, the air gap between the third lens (303) and the fourth lens (304) is A3, and the air gap between the fourth lens (304) and the Xcube dichroic prism (2) is A4. The air gaps A1, A2, A3, and A4 satisfy the relationship: 0.7 < (A1 + A4) / (A2 + A3) < 0.

9.

11. The optical engine module according to claim 10, wherein The total optical length of the optical engine module is L', satisfying the following conditions: 0.1 < (A1 + A4) / L' < 0.2, and 0.1 < (A2 + A3) / L' < 0.

2.

12. The optical engine module according to claim 1, wherein The total optical length L' of the optical engine module and the image height H of the image source (1) satisfy the following relationship: 0.4 < H / L' < 0.

5.

13. The optical engine module according to claim 1, wherein, The imaging distance of the optical engine module is infinity, and the exit pupil distance of the front aperture (4) is 0 ≤ exit pupil distance < 150 mm. The exit pupil distance is the distance along the optical axis from the surface of the front aperture (4) close to the image source (1) to the surface of the first lens (301) far from the image source (1).

14. The optical engine module according to claim 1, characterized in that, The fourth lens (304) is made of optical glass material.

15. An optical projection device, characterized in that, Comprising: The optical engine module according to any one of claims 1-14; And An optical waveguide device, wherein the diameter of the front aperture (4) of the optical engine module matches the entrance pupil diameter of the optical waveguide device.

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