Ar optical lens and ar device

Abstract

This invention relates to the field of AR device technology, providing an AR optical lens and an AR device. The lens includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged sequentially along the optical axis from the object side to the image side. The first lens has positive optical power, with a convex surface on the object side and a concave surface on the image side; the second lens has positive optical power, with a convex surface on the object side and a concave surface on the image side; the third lens has negative optical power, with both the object side and the image side being concave; the fourth lens has positive optical power, with a concave surface on the object side and a convex surface on the image side; and the fifth lens has negative optical power, with a concave surface on the object side and a convex surface on the image side. All lenses are aspherical lenses. This invention, through a positive-positive-negative-positive-negative optical power arrangement of lenses, can simultaneously correct various aberrations such as spherical aberration, field curvature, and distortion, effectively achieving a large field of view, low distortion, and high resolution imaging effect, enhancing the immersiveness and clarity of AR displays.

Description

Technical Field

[0001] This invention relates to the field of AR device technology, and more particularly to AR optical lenses and AR devices. Background Technology

[0002] Augmented Reality (AR) technology, as a crucial carrier of next-generation human-computer interaction, has been widely applied in numerous fields such as industrial maintenance, healthcare, education and training, and consumer electronics, possessing broad market prospects and application potential. As the core optical component connecting virtual imaging and real-world scenes in AR devices, the optical performance, structural dimensions, and imaging quality directly determine the immersive experience, wearing comfort, and overall design of the AR device. Currently, mainstream AR optical solutions struggle to achieve an effective balance between thinness, wide field of view, high imaging quality, and mass production costs, and many technical bottlenecks remain.

[0003] To achieve a wide field of view and high resolution, existing AR optical systems often employ multiple glass lenses or complex prism combinations, resulting in excessively long overall optical length, bulky lenses, and high weight, failing to meet the lightweight requirements of head-mounted AR devices. While some thinner and lighter solutions simplify the structure, they lack sufficient aberration correction capabilities, easily leading to issues such as field curvature, distortion, and edge blurring, affecting image uniformity and viewing experience. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides an AR optical lens and an AR device.

[0005] This invention provides an AR optical lens, comprising a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged sequentially along the optical axis from the object side to the image side, wherein: The first lens has positive optical power, with a convex surface on the object side and a concave surface on the image side; The second lens has positive optical power, with a convex surface on the object side and a concave surface on the image side; The third lens has negative optical power, and both the object plane side and the image plane side are concave. The fourth lens has positive optical power, with a concave surface on the object side and a convex surface on the image side; The fifth lens has negative optical power, with a concave surface on the object side and a convex surface on the image side; The first lens, the second lens, the third lens, the fourth lens, and the fifth lens are all aspherical lenses.

[0006] According to an AR optical lens provided by the present invention, an aperture stop is provided on the object plane side of the first lens.

[0007] According to an AR optical lens provided by the present invention, the first lens is a glass aspherical lens, and the second lens, the third lens, the fourth lens, and the fifth lens are all plastic aspherical lenses.

[0008] According to an AR optical lens provided by the present invention, the second lens is a meniscus aspherical lens bent toward the image plane side; the fourth lens and the fifth lens are meniscus aspherical lenses bent toward the object plane side.

[0009] According to the present invention, an AR optical lens satisfies at least one of the following conditions: 1.2 <f1 / f<1.8; -3.5 <f3 / f<-1.5; Where f is the overall focal length of the AR optical lens, f1 is the focal length of the first lens, and f3 is the focal length of the third lens.

[0010] According to the present invention, an AR optical lens satisfies the following condition: TTL / IH < 2.5; Where TTL is the total optical length, which is the distance from the object plane of the first lens to the imaging plane on the optical axis of the AR optical lens, and IH is the image height, which is the maximum distance from the image point to the optical axis on the imaging plane.

[0011] According to an AR optical lens provided by the present invention, the first lens is a meniscus aspherical lens that bends toward the image plane.

[0012] According to the present invention, an AR optical lens has an optical distortion of less than 0.55% and a maximum field curvature of 0.1.

[0013] The present invention also provides an AR device, including the AR optical lens described above.

[0014] This invention provides an AR optical lens and AR device. By arranging lenses with positive-positive-negative-positive-negative optical power, it can simultaneously correct various aberrations such as spherical aberration, field curvature, and distortion. This effectively achieves a large field of view, low distortion, and high resolution imaging effect, improving the immersion and clarity of AR displays. It balances imaging quality, size, and cost, and can be adapted to AR devices in various fields such as industrial maintenance, medical health, and education and training. It provides a high-performance and cost-effective optical solution for the next generation of human-computer interaction. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a structural layout diagram of the AR optical lens provided by the present invention.

[0017] Figure 2 This is an image showing the effect of the AR optical lens provided by this invention on the optimization and correction of field curvature distortion.

[0018] Figure 3 This is the MTF defocus curve of the AR optical lens provided by the present invention.

[0019] Figure 4 This is the axial chromatic aberration diagram of the AR optical lens provided by the present invention.

[0020] Figure 5 This is a high-temperature defocusing effect diagram of the AR optical lens provided by the present invention.

[0021] Figure label: 11: First lens; 12: Second lens; 13: Third lens; 14: Fourth lens; 15: Fifth lens. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0023] Figure 1 A schematic diagram of the structure of an AR optical lens provided by the present invention is shown below. Figure 1 The AR lens includes a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, and a fifth lens 15 arranged sequentially along the optical axis from the object side to the image side, wherein: The first lens 11 has positive optical power, with a convex surface on the object side and a concave surface on the image side; The second lens 12 has positive optical power, with a convex surface on the object side and a concave surface on the image side; The third lens 13 has negative optical power, and both the object plane side and the image plane side are concave. The fourth lens 14 has positive optical power, with a concave surface on the object side and a convex surface on the image side; The fifth lens 15 has negative optical power, with a concave surface on the object side and a convex surface on the image side; The first lens 11, the second lens 12, the third lens 13, the fourth lens 14, and the fifth lens 15 are all aspherical lenses.

[0024] It should be noted that AR (Augmented Reality) technology, as an important carrier of the next generation of human-computer interaction, has been widely used in many fields such as industrial maintenance, healthcare, education and training, and consumer electronics, possessing broad market prospects and application potential. As the core optical component connecting virtual imaging and real-world scenes in AR devices, the optical performance, structural dimensions, and imaging quality directly determine the immersive experience, wearing comfort, and overall design of the AR device. Currently, mainstream AR optical solutions struggle to achieve an effective balance between thinness, wide field of view, high imaging quality, and mass production costs, and many technical bottlenecks remain.

[0025] To achieve a wide field of view and high resolution, existing AR optical systems often employ multiple glass lenses or complex prism combinations, resulting in excessively long optical length, bulky lenses, and high weight, failing to meet the lightweight requirements of head-mounted AR devices. While some thinner and lighter solutions simplify the structure, they lack sufficient aberration correction capabilities, easily leading to issues such as field curvature, distortion, and edge blurring, affecting image uniformity and viewing experience. Furthermore, traditional solutions rely on glass lenses or glass-plastic hybrid structures, which involve complex manufacturing processes, low yields, and high production costs, and are prone to stray light and ghosting phenomena, reducing image contrast and clarity. These shortcomings severely restrict the widespread adoption and promotion of AR devices towards miniaturization, lightweight design, high performance, and low cost.

[0026] Therefore, this invention adopts a five-element positive and negative optical power alternating optimization structure. Through the lens combination method of "positive-positive-negative-positive-negative", the overall optical power of the system is reasonably distributed and balanced. It can simultaneously and efficiently correct various optical aberrations such as spherical aberration, coma, field curvature, and distortion, and significantly improve imaging uniformity and image clarity.

[0027] Through the coordinated operation and surface optimization of five aspherical lenses, a comprehensive imaging performance of large field of view, low distortion, and high resolution can be achieved within a compact optical structure. This effectively shortens the overall optical length, reduces the size and weight of the lens, and perfectly matches the design requirements of head-mounted AR devices for miniaturization, lightweighting, and ultra-thin form, while also taking into account imaging quality and mass production feasibility.

[0028] In this invention, along the optical axis from the object plane side to the image plane side, the AR optical lens is sequentially provided with a first lens 11, a second lens 12, a third lens 13, a fourth lens 14 and a fifth lens 15. Each lens adopts an aspherical lens structure, which facilitates the correction of higher-order aberrations, optimizes imaging quality and reduces system size.

[0029] The first lens 11 has positive optical power. Its surface facing the object plane is convex, and its surface facing the image plane is concave. It is used to collect incident light rays and initially converge the beam. It undertakes the main positive optical power distribution of the system and lays the foundation for subsequent aberration correction.

[0030] The second lens 12 has positive optical power. Its surface facing the object plane is convex, and its surface facing the image plane is concave. Together with the first lens 11, it forms a double positive lens combination, which further enhances the system's converging ability. At the same time, it works together to correct spherical aberration and chromatic aberration, and optimizes the symmetry of light propagation.

[0031] The third lens 13 has negative optical power, and both its object side and image side are concave. It is used to balance the field curvature and distortion caused by the positive optical power of the previous group, to cancel the positive magnification chromatic aberration generated by the preceding lens, and to improve the imaging quality of the edge field of view.

[0032] The fourth lens 14 has positive optical power, with a concave object plane and a convex image plane. It is used for secondary convergence and calibration of light, to compensate for residual aberrations in the system, and to improve the uniformity of resolution in the central and peripheral fields of view.

[0033] The fifth lens 15 has negative optical power, with a concave object plane and a convex image plane. It is used to finally correct residual field curvature, distortion and axial chromatic aberration of the system, so that light is accurately focused on the imaging plane and ensures high-definition and low-distortion imaging effect in the entire field of view.

[0034] An aperture stop is provided on the side of the first lens 11 facing the object plane. The aperture stop is located at the very front of the entire optical system and is used to limit, regulate, and filter stray light from the incident light, effectively controlling the aperture and incident angle of the beam entering the lens and optimizing the symmetry of light incidence. By placing the aperture stop at the front, the on-axis and off-axis aberration distribution of the system can be significantly improved, enhancing the uniformity of the center and edges of the image. At the same time, it suppresses stray light reflection and ghosting phenomena within the optical system, improving image contrast and image purity, and further enhancing the imaging stability and environmental adaptability of the AR optical lens in large field-of-view and high-resolution application scenarios.

[0035] Furthermore, the AR optical lens of this invention adopts a glass-plastic hybrid aspherical lens structure to balance imaging performance, structural miniaturization, and mass production economy.

[0036] When a glass-plastic hybrid structure is adopted, the first lens 11 is a glass aspherical lens, utilizing the high refractive index and low coefficient of thermal expansion of glass to improve the system's high-temperature stability and optical accuracy; the second lens 12 to the fifth lens 15 are plastic aspherical lenses, optimizing manufacturing costs and processing efficiency while ensuring imaging performance. Through the reasonable combination of glass and plastic materials, a heatless design of the optical system is achieved, enabling the lens to maintain stable imaging performance in high and low temperature environments, thus broadening the range of applicable environments for the equipment.

[0037] Furthermore, to further optimize the light propagation path, improve aberration correction, and achieve a compact system design, the AR optical lens of this invention features a finely configured meniscus orientation for each lens: The first lens 11 is a meniscus aspherical lens that bends toward the image plane. Combined with positive optical power, it achieves preliminary and efficient convergence of light, while reducing the volume and thickness of the front lens group, laying the foundation for overall lightweight design.

[0038] The second lens 12 is a meniscus aspherical lens that bends toward the image plane. It is bent in the same direction as the first lens 11 to form a double positive meniscus lens combination. This combination can synergistically improve beam converging efficiency, optimize the incident angle of on-axis light rays, efficiently correct spherical aberration and axial chromatic aberration, and improve the imaging quality of the central field of view.

[0039] The fourth lens 14 and the fifth lens 15 are meniscus aspherical lenses that bend toward the object surface. Through the reverse bending surface structure, they balance the field curvature and distortion generated by the front lens group, accurately calibrate the light and compensate for residual aberrations, and ensure clear imaging and low distortion at the edge field of view.

[0040] The bending direction and surface shape of each lens work together to form an optimized optical path structure with the front group converging in the same direction and the rear group correcting in the opposite direction. This achieves a large field of view and high resolution while further compressing the overall optical length, improving the miniaturization of the whole machine and the imaging stability.

[0041] Furthermore, to ensure that the AR optical lens achieves lightweight design, a wide field of view, and high resolution while also maintaining good image quality and mass production feasibility, the optical parameters are optimized and limited using the following conditional formula: 1) Conditional expression: 1.2 <f1 / f<1.8。

[0042] Where f is the overall focal length of the AR optical lens, and f1 is the focal length of the first lens 11. This conditional expression limits the optical power ratio of the first lens 11, so that while the first lens 11 bears the main positive optical power of the system, it avoids the difficulty in correcting spherical aberration and chromatic aberration due to excessive optical power. At the same time, it ensures the light-gathering ability of the front lens group, provides reasonable light incident conditions for subsequent aberration correction, and helps to achieve uniform imaging under a large field of view.

[0043] 2) Conditional expression-3.5 <f3 / f<-1.5。

[0044] Where f3 is the focal length of the third lens 13. This conditional expression limits the negative optical power of the third lens 13, enabling it to effectively balance the field curvature and distortion generated by the front positive lens, while suppressing axial chromatic aberration. It avoids the system size increase and edge field aberration deterioration caused by excessively large negative optical power, or the aberrations that cannot be effectively corrected by excessively small negative optical power, ensuring that the imaging quality of both the central and edge fields of view can meet the high-definition requirements of AR display.

[0045] 3) Conditional TTL / IH < 2.5.

[0046] Where TTL is the total optical length, which is the distance from the object plane side of the first lens 11 to the imaging plane on the optical axis of the AR optical lens, and IH is the image height, which is the maximum distance from the image point to the optical axis on the imaging plane. This conditional expression limits the compactness of the optical system. By controlling the ratio of the total optical length to the image height, a short total optical length design is achieved, significantly reducing the size and weight of the lens, adapting to the requirements of head-mounted AR devices for a thinner and smaller form factor, while ensuring that the system can still achieve a large image height and a large field of view within a limited space, taking into account both the device appearance and the user's wearing experience.

[0047] Through the synergistic constraints of the above-mentioned conditional formulas, the AR optical lens of the present invention achieves comprehensive performance of large field of view, low distortion, high resolution and lightweight within a limited structural size, while ensuring the optical aberration correction effect and the feasibility of mass production, providing a reliable optical solution for the widespread application of AR devices.

[0048] See Figure 2 This invention can optimize and correct field curvature distortion through reasonable optical power allocation, with a maximum field area of ​​0.1 and optical distortion of less than 0.55%; thus, virtual information is accurately aligned with physical world coordinates, improving the accuracy of AR applications and enhancing visual realism.

[0049] See Figure 3 This invention achieves an MTF value greater than 0.8 at the center and greater than 0.7 at the periphery at a spatial frequency of 120 lp / mm. The defocus curves of the center and periphery fields of view are relatively concentrated, ensuring uniformity from the center to the edge of the image and accurate recognition. The MTF value is the Modulation Transfer Function, which can be commonly referred to as a score of the lens's "detail resolution ability." It measures how much contrast between bright and dark areas the lens can retain when shooting black and white stripes.

[0050] See Figure 4The combination of different materials reduces color difference issues. Smaller color differences allow for a natural transition from the center to the edge, enhancing the realism of the virtual and real world fusion and reducing eye fatigue and headaches.

[0051] See Figure 5 Using a glass-plastic hybrid material, through a specific combination, the center field of view defocusing change is less than 3μm when tested in a 60℃ environment, demonstrating good temperature compensation capabilities and giving the lens excellent environmental adaptability.

[0052] The present invention also provides an AR device, including the AR optical lens described above.

[0053] The AR optical lens and AR device provided by this invention, through the arrangement of lenses with positive-positive-negative-positive-negative optical power, can simultaneously correct various aberrations such as spherical aberration, field curvature, and distortion, effectively achieving a large field of view, low distortion, and high resolution imaging effect, improving the immersion and clarity of AR display, and balancing imaging quality, size, and cost. It can be adapted to AR devices in multiple fields such as industrial maintenance, medical health, and education and training, providing a high-performance and cost-effective optical solution for the next generation of human-computer interaction.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An AR optical lens, characterized in that, It includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged sequentially along the optical axis from the object side to the image side, wherein: The first lens has positive optical power, with a convex surface on the object side and a concave surface on the image side; The second lens has positive optical power, with a convex surface on the object side and a concave surface on the image side; The third lens has negative optical power, and both the object plane side and the image plane side are concave. The fourth lens has positive optical power, with a concave surface on the object side and a convex surface on the image side; The fifth lens has negative optical power, with a concave surface on the object side and a convex surface on the image side; The first lens, the second lens, the third lens, the fourth lens, and the fifth lens are all aspherical lenses.

2. The AR optical lens according to claim 1, characterized in that, An aperture is provided on the object plane side of the first lens.

3. The AR optical lens according to claim 1 or 2, characterized in that, The first lens is a glass aspherical lens, and the second, third, fourth, and fifth lenses are all plastic aspherical lenses.

4. The AR optical lens according to claim 3, characterized in that, The second lens is a meniscus aspherical lens that bends toward the image plane; the fourth and fifth lenses are meniscus aspherical lenses that bend toward the object plane.

5. The AR optical lens according to claim 3, characterized in that, The AR optical lens satisfies at least one of the following conditions: 1.2 < f1 / f < 1.8; -3.5 < f3 / f < -1.5; Where f is the overall focal length of the AR optical lens, f1 is the focal length of the first lens, and f3 is the focal length of the third lens.

6. The AR optical lens according to claim 5, characterized in that, The AR optical lens satisfies the following condition: TTL / IH < 2.5; Where TTL is the total optical length, which is the distance from the object plane of the first lens to the imaging plane on the optical axis of the AR optical lens, and IH is the image height, which is the maximum distance from the image point to the optical axis on the imaging plane.

7. The AR optical lens according to claim 4, characterized in that, The first lens is a meniscus aspherical lens that bends toward the image plane.

8. The AR optical lens according to claim 4, characterized in that, The optical distortion of the AR optical lens is less than 0.55%, and the maximum field curvature is 0.

1.

9. An AR device, characterized in that, The AR optical lens includes any one of claims 1-8 above.

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