Augmented reality optical system with single-screen binocular display and near-to-eye display equipment

Abstract

The invention relates to the technical field of optics, and particularly discloses a single-screen binocular display augmented reality optical system and near-to-eye display device.The system comprises a display image source, a first lens set arranged on the light emitting side of the display image source, and a beam splitter prism set arranged on the light emitting side of the first lens set and used for forming two optical paths; the imaging display modules are arranged on each optical path, each imaging display module comprises a second lens group, a reflective mirror group, a cemented prism group and a curved mirror group which are arranged on the corresponding optical path, each cemented prism group comprises a first wedge prism and a second wedge prism, and a cemented surface is formed at the joint of the first wedge prism and the second wedge prism; after entering from the second wedge prism, imaging light is at least reflected to the curved mirror group through the prism cemented surface, is reflected by the curved mirror group, sequentially penetrates through the second wedge prism and the first wedge prism, is emitted out and reaches human eyes for imaging, and the system has a large field angle and a large exit pupil diameter, and meanwhile, better optical performance in a full field range is ensured.

Description

Technical Field

[0001] This application relates to the field of optical technology, and in particular to an augmented reality optical system and near-eye display device with a single-screen binocular display. Background Technology

[0002] Augmented reality optical systems allow users to directly receive information about their real-world environment and then view virtual scenes or information presented by the system. Currently, AR optical systems are mainly divided into two types: micro-projection optical engines paired with waveguides and Birdbath solutions. The micro-projection optical engine with waveguide solution has difficulty achieving a large field of view, and suffers from poor color uniformity and subpar display quality. The Birdbath solution's field of view is limited by its size, making it difficult to balance a large field of view with a compact design. In contrast, a geometric optical solution using prisms to reflect the light path can achieve a large field of view while maintaining a small system size.

[0003] The geometric optics scheme using prism reflection primarily utilizes the principles of back-and-forth reflection of light paths and total internal reflection to reduce the focal length of the optical system. Specifically, the image emitted from the display system passes through a lens, then is reflected by a prism, reflected by a plano-convex lens, and transmitted through another prism before entering the human eye. Simultaneously, real-world information can directly enter the human eye after being transmitted through plano-convex lenses and prisms. Therefore, the system can overlay and display the required virtual information on top of optical perspective, realizing AR technology functions.

[0004] However, the existing prism-reflecting optical system has not been well optimized and cannot meet the visual requirements for distortion, image clarity and other performance. The system is also difficult to achieve a large exit pupil diameter. At the same time, the module manufactured by the prism-reflecting optical system requires a display system for each eye. However, the display screen in the system is expensive, which increases the production cost of the binocular module. Summary of the Invention

[0005] This application aims to propose an augmented reality optical system and near-eye display device with single-screen binocular display, so as to at least solve the technical problems of poor optimization results of prism reflection optical systems in the prior art, which make it difficult to meet the visual requirements for distortion, image clarity and other performance, and the system is difficult to achieve a large exit pupil diameter, while the corresponding binocular module has high production cost.

[0006] In a first aspect, embodiments of this application provide an augmented reality optical system with a single-screen binocular display, comprising: Display image source, used to provide imaging light; The first lens group is located on the light-emitting side of the display image source and is used to converge and modulate the imaging light. A beam splitter prism group is disposed on the light-emitting side of the first lens group and is used to split the imaging light rays passing through the first lens group into two optical paths. Imaging display modules are respectively disposed on each of the optical paths, and the imaging display modules include: The second lens group is located on the light-emitting side of the beam-splitting prism group; A reflector assembly is located on the light-emitting side of the second lens assembly; A cemented prism assembly is disposed on the light-emitting side of the reflector assembly. The cemented prism assembly includes a first wedge prism and a second wedge prism that are cemented together. An inclined cementing surface is formed at the connection between the first wedge prism and the second wedge prism. The cementing surface is coated with a first special film layer, which is a semi-transparent semi-reflective film or a polarizing reflective film. A curved mirror assembly is disposed on the side of the second wedge prism opposite to the first wedge prism; The imaging light enters from the incident end face of the second wedge prism, is reflected at least by the cemented surface of the prism to the curved mirror group, and after being reflected by the curved mirror group, passes through the second wedge prism and the first wedge prism in sequence to reach the human eye for imaging.

[0007] In some embodiments, the beam-splitting prism group consists of four right-angle prisms, which are bonded together in pairs through their right-angle edges to form a symmetrical beam-splitting structure. A second special film layer is coated at the bonding point, which is a semi-transparent and semi-reflective film. The refractive index of the right-angle prisms ranges from 1.45 to 1.95, the Abbe number ranges from 20 to 70, and the thickness ranges from 6 mm to 10 mm.

[0008] In some embodiments, the first lens group and the second lens group include at least one optical lens, wherein the refractive index of the optical lens ranges from 1.45 to 1.95, the Abbe number ranges from 20 to 70, the radius of curvature ranges from 4 mm to 2000 mm, the thickness ranges from 0.6 mm to 8.6 mm, and the focal length ranges from 10 mm to 105 mm.

[0009] In some embodiments, the second lens group includes a first optical lens, a second optical lens, and a third optical lens, wherein the first optical lens, the second optical lens, and the third optical lens are disposed on the light-emitting side of the beam splitter and arranged sequentially along the optical path.

[0010] In some embodiments, the surface of the reflector group near the cemented prism group is coated with a third special film layer, which is a high-reflection film or a total-reflection film; the surface of the first wedge prism near the exit pupil region and the surface of the second wedge prism near the reflector group are free combinations of spherical, aspherical, and freeform surfaces.

[0011] In some embodiments, the wedge angle of the first wedge prism and the second wedge prism ranges from 15° to 45°, the refractive index ranges from 1.45 to 1.95, the Abbe number ranges from 20 to 70, and the thickness ranges from 6 mm to 15 mm.

[0012] In some embodiments, the thickness of the cemented prism assembly satisfy:

[0013] In the formula, The distance between the light-emitting side of the first wedge prism and the exit pupil of the human eye is [missing information]. The meridional field of view of the optical system. For the angle of refraction, Let be the wedge angle of the first wedge prism, and D be the exit pupil diameter.

[0014] In some embodiments, the meridional field of view of the optical system The calculation expression is:

[0015] The angle of refraction is The calculation expression is:

[0016] In the formula, H:V The aspect ratio of the display module. For the field of view of the optical system, Let be the refractive index of the first wedge prism.

[0017] In some embodiments, the surface of the curved mirror group near the cemented prism group is coated with a fourth special film layer, which is a semi-transparent and semi-reflective film or a combination of a quarter-wave plate and a semi-transparent and semi-reflective film; the refractive index of the curved mirror group ranges from 1.45 to 1.95, the Abbe number ranges from 20 to 70, the thickness ranges from 1 mm to 3 mm, and the focal length ranges from 15 mm to 30 mm.

[0018] Compared with the prior art, the technical solution provided in the first aspect of this application has at least the following beneficial effects or advantages: The single-screen binocular augmented reality optical system provided in this application achieves binocular eye path imaging from a single display image source through the arrangement of a display image source, a first lens group, a beam splitter prism group, and an imaging display module. The beam splitter group forms two optical paths, and the imaging display module positioned along these paths ensures good optical performance across the entire field of view while reducing the manufacturing cost of the binocular imaging optical system. Through the convergence modulation of the imaging light by the first lens group and the secondary optical control by the second lens group, combined with the optical path reflection structure design of the cemented prism group, the reflector group, and the curved mirror group, a large field of view is achieved while reducing the system size. Furthermore, by adjusting the surface shape of the optical elements to optimize the aberration at the exit pupil position, the system ensures optimal binocular optical performance display using a single screen. Moreover, the imaging display module allows for different refractive power adjustments, and combined with a large range of eye movement, it can meet the wearing needs of people with different refractive powers and interpupillary distances, achieving excellent visual effects. It effectively improves the system's imaging clarity, optimizes imaging distortion performance, and increases the exit pupil diameter to meet the imaging performance requirements of the human eye for optical systems.

[0019] Secondly, embodiments of this application provide a near-eye display device, the near-eye display device including the single-screen binocular display augmented reality optical system described in any of the first aspects above.

[0020] It is understandable that the beneficial effects of the second aspect mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here.

[0021] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the optical system provided according to Embodiment 1 of this application; Figure 2 This is a schematic diagram of the glued prism assembly according to Embodiment 1 of this application; Figure 3 This is yet another schematic diagram of the glued prism assembly provided according to Embodiment 1 of this application; Figure 4 This is a schematic diagram of the optical system provided according to Embodiment 2 of this application; Figure 5 It is an MTF curve of the center EB position of -0.5D diopter provided in Embodiment 2 of this application; Figure 6 It is an MTF curve of the vertical edge EB position of -0.5D diopter provided in Embodiment 2 of this application; Figure 7 It is an MTF curve of the EB position in the horizontal direction of -0.5D diopter provided in Embodiment 2 of this application; Figure 8 It is the MTF curve of the center EB position of -2.5D diopter provided in Embodiment 2 of this application; Figure 9 It is the MTF curve of the center EB position of refractive power -6D provided in Embodiment 2 of this application; Figure 10 It is a distortion map of the vertical edge EB position with a refractive power of -0.5D according to Embodiment 2 of this application; Figure 11 It is a distortion map of the EB position in the horizontal direction of -0.5D diopter, according to Embodiment 2 of this application; Figure 12 It is a distortion map of the center EB position with a refractive power of -0.5D according to Embodiment 2 of this application; Figure 13 It is a distortion map of the central EB position of a refractive power of -2.5D provided in Embodiment 2 of this application; Figure 14 It is a distortion map of the central EB position of refractive power -6D provided in Embodiment 2 of this application; Figure 15 This is a schematic diagram of the glued prism assembly according to Embodiment 3 of this application; Figure 16 This is a schematic diagram of the optical system provided according to Embodiment 3 of this application; Figure 17 It is an MTF curve of the center EB position of -0.5D diopter provided in Embodiment 3 of this application; Figure 18 It is an MTF curve of the vertical edge EB position of -0.5D diopter provided in Embodiment 3 of this application; Figure 19 It is an MTF curve of the EB position in the horizontal direction of -0.5D diopter provided in Embodiment 3 of this application; Figure 20 It is the MTF curve of the center EB position of -2.5D diopter provided in Embodiment 3 of this application; Figure 21It is the MTF curve of the center EB position of the refractive power of -6D provided in Embodiment 3 of this application; Figure 22 It is a distortion diagram of the vertical edge EB position with a refractive power of -0.5D according to Embodiment 3 of this application; Figure 23 It is a distortion map of the EB position in the horizontal direction of -0.5D diopter according to Embodiment 3 of this application; Figure 24 It is a distortion map of the center EB position with a refractive power of -0.5D according to Embodiment 3 of this application; Figure 25 It is a distortion map of the central EB position of a refractive power of -2.5D provided in Embodiment 3 of this application; Figure 26 It is a distortion map of the center EB position of diopter-6D provided in Embodiment 3 of this application.

[0024] Figure label: 10. Image source; 20. First lens group; 30. Beam splitter prism group; 40. Second lens group; 41. First optical lens; 42. Second optical lens; 43. Third optical lens; 50. Reflector group; 60. Cemented prism group; 61. First wedge prism; 62. Second wedge prism; 63. Cemented surface; 70. Curved mirror group. Detailed Implementation

[0025] The embodiments of this application are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. It should be understood that the specific embodiments described herein are merely for explaining this application and are not intended to limit this application.

[0026] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0028] With the emergence of virtual reality (VR) and augmented reality (AR), the market for near-eye display devices based on VR or AR modes has developed rapidly. Augmented reality optical systems allow users to directly receive information about the real-world environment while displaying virtual scenes or information presented by the system. Currently, AR optical systems are mainly divided into two types: micro-projection optical engines paired with waveguides and Birdbath solutions. The micro-projection optical engine paired with waveguide solution has difficulty in achieving a large field of view, and the color uniformity of the image is poor, resulting in a lack of display quality. The Birdbath solution's field of view is limited by its size, making it difficult to balance the characteristics of a large field of view and compactness. The geometric optics scheme using prisms for light path reflection can achieve a large field of view while maintaining a small system size. This scheme primarily utilizes the principles of light path reflection and total internal reflection to reduce the focal length of the optical system. Specifically, the image emitted from the display system passes through lenses, then is reflected by prisms, reflected by plano-convex lenses, and transmitted through prisms before entering the viewer's eye. Simultaneously, real-world information can directly enter the viewer's eye after being transmitted through plano-convex lenses and prisms. Therefore, the system can overlay and display the required virtual information on top of optical perspective, realizing AR technology functions.

[0029] However, the inventors discovered that existing prism-reflecting optical systems are difficult to meet the visual requirements for distortion, image clarity, and other performance aspects. The systems are also difficult to achieve a large field of view and exit pupil diameter. In addition, modules manufactured using prism-reflecting optical systems require a display system for each eye, but the display screens in the system are expensive, increasing the production cost of binocular modules.

[0030] Based on this, the inventors propose a single-screen binocular augmented reality optical system and near-eye display device. This optical system features a large field of view and a large exit pupil diameter while ensuring good optical performance across the entire field of view. By adjusting and controlling the spatial distribution of components and the optical elements, the light from the display screen is split, and the surface shape of the optical elements is adjusted to optimize aberrations at the exit pupil position, ensuring that the system achieves optimal binocular optical performance using a single screen. A folded optical path is used at the bottom of the system to achieve a compact overall structure, ensuring a small size and weight, and improving wearing comfort. Furthermore, this optical system utilizes optical component movement for focusing to achieve different refractive power adjustments. Combined with a large range of eye movement, it can meet the wearing needs of people with different refractive powers and interpupillary distances, achieving excellent visual effects. The specific structure and functional principles of this single-screen binocular augmented reality optical system will be further described below with reference to several embodiments.

[0031] Example 1 Please see Figures 1 to 3This embodiment provides an augmented reality optical system with single-screen binocular display. The optical system includes a display image source 10, a first lens group 20, a beam splitter prism group 30, and an imaging display module. The display image source 10 is used to provide imaging light. The display image source 10 can be a self-emissive panel OLED type, an LED type, or a non-self-emissive panel LCD type or LCOS type. The specific selection is based on actual display requirements and is not limited in this embodiment. The display module can selectively attach polarizing elements. Simultaneously, to optimize optical path purity and improve imaging quality, the display module can selectively attach polarizing elements. The first lens group 20 is located on the light-emitting side of the display image source 10. The first lens group 20 is used to converge and modulate the imaging light. The first lens group 20 can be an optical lens located between the display image source 10 and the beam splitter prism group 30. The beam splitter prism group 30 is located on the light-emitting side of the first lens group 20. The light-emitting side can be understood as the side of the first lens group 20 facing away from the display image source 10. The beam splitter prism group 30 can be formed by four right-angle prisms, and its thickness is determined by the beam aperture and manufacturing tolerances. The beam splitter prism group 30 is used to split the imaging light passing through the first lens group 20 into two optical paths. This can be understood as the beam splitter prism group 30 forming two optical paths with balanced energy and symmetrical propagation directions, corresponding to the left and right binocular optical paths respectively.

[0032] Furthermore, the imaging display modules are respectively located on each optical path. Specifically, two sets of imaging display modules are provided, each corresponding to one of the two optical paths. For details on the optical paths, please refer to [link / reference needed]. Figure 1For ease of description, this embodiment only describes the imaging display module set on one of the optical paths. The principle is the same for the other path. The imaging display module includes a second lens group 40, a reflector group 50, a cemented prism group 40, and a curved mirror group 70. The second lens group 40 is located on the light-emitting side of the beam splitter group 30; the reflector group 50 is located on the light-emitting side of the second lens group 40; the reflector group 50 can be a single reflector, and its reflecting surface needs to be flat and smooth. The angle of arrangement can be selected according to actual needs. The cemented prism group 40 is located on the light-emitting side of the reflector group 50; the second lens group 40 can include multiple optical lenses arranged coaxially, such as three, four, or five lenses, specifically selected according to actual needs. The prism assembly 40 can be set up in a separate or glued manner. The glued prism assembly 40 includes a first wedge prism 61 and a first wedge prism 62 glued together. An inclined glued surface 63 is formed at the connection between the first wedge prism 61 and the first wedge prism 62. The glued surface 63 is coated with a first special film layer. The first special film layer can be a semi-transparent and semi-reflective film or a polarizing reflective film. The curved mirror assembly 70 is located on the side of the first wedge prism 62 away from the first wedge prism 61. The curved mirror assembly 70 can be a single curved mirror. When the imaging light enters from the incident end face of the first wedge prism 62, it is reflected at least by the prism glued surface 63 to the curved mirror assembly 70, and after being reflected by the curved mirror assembly 70, it passes through the first wedge prism 62 and the first wedge prism 61 in sequence and exits to reach the human eye for imaging.

[0033] It should be noted that when the wedge angle between the first wedge prism 61 and the first wedge prism 62 is small, the imaging light enters from the top surface of the first wedge prism 62, is reflected from the end face of the first wedge prism 62 near the curved mirror group 70 to the cemented surface 63, and then reflected from the cemented surface 63 to the curved mirror group 70. After being reflected by the curved mirror group 70, it passes through the first wedge prism 62 and the first wedge prism 61 in sequence and exits to reach the human eye for imaging; when the wedge angle between the first wedge prism 61 and the first wedge prism 62 is small, the imaging light enters from the top surface of the first wedge prism 62, is reflected from the end face of the first wedge prism 62 near the curved mirror group 70 to the cemented surface 63, and then reflected from the cemented surface 63 to the curved mirror group 70. After being reflected by the curved mirror group 70, the light passes through the first wedge prism 62 and the first wedge prism 61 in sequence and exits to reach the human eye for imaging. When the wedge angle of prism 62 is large, the imaging light enters from the top surface of the first wedge prism 62 and directly illuminates the cemented surface 63. It is then reflected by the cemented surface 63 to the curved mirror group 70. After being reflected by the curved mirror group 70, it passes through the first wedge prism 62 and the first wedge prism 61 in sequence and exits to reach the human eye for imaging. In both reflection paths, it can be ensured that the light emitted from a single display screen is refracted by the optical path and exits to the pupil, and has good imaging quality throughout the entire exit pupil range.

[0034] It should also be noted that in this embodiment, the components together constitute a single-screen binocular display optical system. The focal length of the entire optical system is 8mm~30mm, and the overall thickness is controlled within 8mm~20mm. Combined with the system's optical path refraction characteristics, a binocular immersive experience can be achieved even with a small screen. Depending on the screen specifications available on the market, the field of view can reach 50°~65° while ensuring good performance of the optical system. The curved mirror group 70, cemented prism group 40, reflecting mirror group, and beam splitter group 30 are used to refract the beam and reuse part of the optical path. The cemented prism group 40, curved mirror group 70, lens group, and beam splitter group 30 jointly share the system aberrations. The cemented prism group 40, with its open surface design, primarily addresses coma, astigmatism, distortion, and chromatic aberration. The curved mirror group 70 reflects light in the optical path, primarily addressing field curvature and astigmatism. The lens group offers greater freedom in surface design and, through mutual compensation, addresses most of spherical aberration, coma, astigmatism, distortion, and field curvature. The beam-splitting prism group 30 primarily functions to deflect light, addressing a smaller amount of coma, astigmatism, and distortion. The optical performance across the entire field of view is evaluated within a 10mm × 6mm area at the exit pupil. By optimizing the surface design of each surface, different types of aberrations compensate for each other, ensuring that light emitted from a single display screen, after being deflected through the optical path, reaches the pupil and maintains good image quality throughout the entire exit pupil range. Adjustments to the focusing components within the system allow for the creation of virtual images at different distances to meet the needs of various myopic individuals, ensuring a good visual experience for users with diverse characteristics across the entire screen.

[0035] The optical system provided in this application, through the arrangement of a display image source 10, a first lens group 20, a beam splitter prism group 30, and an imaging display module, enables a single display image source 10 to provide binocular eye path imaging. The beam splitter prism group 30 splits the beam to form two optical paths, and the imaging display module is positioned along these optical paths. This ensures good optical performance across the entire field of view while reducing the manufacturing cost of the binocular imaging optical system. Through the convergence modulation of the imaging light by the first lens group 20 and the secondary optical control by the second lens group 40, combined with the optical path reflection structure design of the cemented prism group 40, the reflector group 50, and the curved mirror group 70, a large field of view is achieved while reducing the system size. Furthermore, by adjusting the surface shape of the optical elements to optimize the aberration at the exit pupil position, the system ensures optimal binocular optical performance display using a single screen. Moreover, the imaging display module allows for different refractive power adjustments, and combined with a large range of eye movement, it can meet the wearing needs of people with different refractive powers and interpupillary distances, achieving excellent visual effects. It effectively improves the system's imaging clarity, optimizes imaging distortion performance, and increases the exit pupil diameter to meet the imaging performance requirements of the human eye for optical systems.

[0036] Optionally, the materials for the first lens group 20, the beam splitter prism group 30, the second lens group 40, the reflector group 50, the cemented prism group 40, and the curved mirror group 70 can be glass or plastic.

[0037] In some embodiments, continue reading Figure 1 The beam-splitting prism group 30 consists of four right-angle prisms, which are bonded together in pairs through their right-angle edges to form a symmetrical beam-splitting structure. A second special coating layer is deposited at the bonding points. The refractive index of the right-angle prisms ranges from 1.45 to 1.95, the Abbe number ranges from 20 to 70, and the thickness ranges from 6 mm to 10 mm. Specifically, after the first lens group 20 receives the diverging imaging light emitted from the display image source 10, it uses the converging characteristics of optical lenses to initially converge and modulate the light wavefront. The light is then split by the beam-splitting prism group 30. The beam splits into two beams. The four right-angled prisms are glued together by their pairs of right-angled sides to form four intersecting glued joint surfaces that share a common origin. A second special film layer can be deposited on the inner surface of the glued joint. This second special film layer can be a semi-transparent and semi-reflective film. This configuration can split the single beam of imaging light, ensuring that the light energy of the left and right beams is basically the same, avoiding visual discomfort caused by the difference in brightness between the two eyes. The parameters of refractive index, Abbe number and thickness are limited so that the beam splitter prism group 30 has better optical performance (suppressing color distortion).

[0038] It should be noted that the thickness of the four right-angle prisms can be determined according to the beam aperture and manufacturing tolerances. The material of each right-angle prism can be glass or plastic, depending on the actual needs.

[0039] In some embodiments, continue reading Figure 1The first lens group 20 and the second lens group 40 each include at least one optical lens. The refractive index of the optical lens ranges from 1.45 to 1.95, the Abbe number ranges from 20 to 70, the radius of curvature ranges from 4 mm to 2000 mm, the thickness ranges from 0.6 mm to 8.6 mm, and the focal length of a single lens ranges from 10 mm to 105 mm. For example, the refractive index of a single optical lens in the first lens group 20 and the second lens group 40 can be 1. 5. The radius of curvature can be 100mm, the thickness 7mm, and the focal length 50mm, which can be selected according to actual needs. The second lens group 40 is designed with a curvature radius and focal length matching to perform secondary precise modulation on the split beam light, further correcting aberrations (such as spherical aberration, distortion, and chromatic aberration), and guiding the light to the mirror group 50. For example, dispersion compensation is achieved by combining different lens materials (high refractive index low Abbe number materials with low refractive index high Abbe number materials). Through multi-level optical modulation and parameter optimization of the lens group, the collimation and uniformity of the imaging light are effectively improved, system distortion is significantly reduced, and image clarity is guaranteed. The adjustable focal length range of 10mm to 105mm allows the lens group to flexibly match different field of view design requirements. Combined with the parameter combination of refractive index and Abbe number, accurate color reproduction is achieved, meeting the high requirements of human visual perception for optical performance.

[0040] Optional, please continue reading Figure 1 The second lens group 40 includes a first optical lens 41, a second optical lens 42, and a third optical lens 43. The first optical lens 41, the second optical lens 42, and the third optical lens 43 are located on the light-emitting side of the beam splitter and arranged sequentially along the optical path. Specifically, the light beam after being split by the beam splitter group 30 first enters the first optical lens 41, where the curvature design of the lens achieves preliminary collimation of the light. Then, the light enters the second optical lens 42, which corrects the chromatic aberration of the light by matching the refractive index and the Abbe number. Finally, the light passes through the third optical lens 43, which precisely compensates for geometric aberrations such as spherical aberration and coma, thereby achieving hierarchical optimization. The imaging light is directed towards the mirror group 50 in an optimized parallel or precisely converging state. Compared with single-lens or double-lens structures, the sequential arrangement of the three lenses can achieve hierarchical correction of aberrations, improve the accuracy of light modulation, further optimize imaging clarity and image sharpness, and provide a stable optical basis for the symmetrical design of the binocular eye path, ensuring the consistency of imaging between the left and right eyes.

[0041] In some embodiments, please refer to Figure 2The surface of the reflector assembly near the cemented prism assembly 40 is coated with a third special film layer, which can be a high-reflection film or a total-reflection film. The setting of the third special film layer ensures that light rays incident on the surface of the reflector assembly at different angles are reflected to the cemented prism assembly 40 as much as possible. The surface of the first wedge prism 61 near the exit pupil region and the surface of the first wedge prism 62 near the reflector assembly are free combinations of spherical, aspherical, and free-form surfaces. The specific structure of the surface of the first wedge prism 61 near the exit pupil region and the surface of the first wedge prism 62 near the reflector assembly can be selected according to actual needs. With this setting, higher-order aberrations generated during light propagation can be specifically corrected.

[0042] In some embodiments, please continue reading Figure 2 The wedge angles of the first wedge prism 61 and the first wedge prism 62 range from 15° to 45°, the refractive index ranges from 1.45 to 1.95, the Abbe number ranges from 20 to 70, and the thickness ranges from 6 mm to 15 mm. The wedge angle of the wedge prism directly determines the reflection path and deflection angle of the light within the prism. By limiting this angle range, the imaging light reflected by the reflector group 50 can be accurately incident on the cemented surface 63, and after reflection from the cemented surface 63, it can be guided to the curved mirror group 70, and the reflected light can be smoothly transmitted through the prism to the human eye. The refractive index and Abbe number parameters of the prism are combined to reduce the prism volume through the high refractive index characteristics, and to suppress dispersion and avoid color separation through a reasonable Abbe number value. The thickness range ensures the stability of the prism structure and meets the beam aperture requirements, while avoiding optical path redundancy or weight increase due to excessive thickness.

[0043] In some embodiments, please refer to Figure 3 In practical applications, it has been found that the thickness of the cemented prism assembly 40 is not necessarily better the thinner it is. When it is less than a certain critical value, some light rays across the entire field of view will be blocked by the optical components, causing vignetting. This results in uneven brightness distribution in the field of view, leading to problems such as localized brightness attenuation and significant differences in brightness between dark and light areas. Therefore, in this embodiment, based on the optical system parameters, it is assumed that the field of view angle of the optical system is... The aspect ratio of the display module is H:V, and theoretically the system's meridional field of view is... The refractive index of cemented prism 1 is... Then the angle of refraction is Combining the system's exit pupil distance ER, exit pupil diameter D, and the 40mm thickness of the cemented prism assembly... Thus, the beam width can be calculated. The wedge angle of the cemented prism is... Based on lens manufacturing and the condition of unobstructed light, In summary, the cemented prism assembly has a thickness of 40 mm. The following formula should be satisfied:

[0044] In the formula, The distance between the light-emitting side of the first wedge prism 61 and the exit pupil of the human eye is [missing information]. The meridional field of view of the optical system. For the angle of refraction, D is the wedge angle of the first wedge prism 61, and D is the exit pupil diameter.

[0045] Among them, when the cemented prism assembly is 40mm thick When the above formula is satisfied, the brightness uniformity of the entire field of view is high.

[0046] In some embodiments, continue reading Figure 2 and Figure 3 It should be understood that, in addition to participating in the imaging of light emitted from the screen, the curved mirror group 70 also needs to handle the aberrations of the real-world lighting system to achieve the function of interacting with the real world in AR. The inner curved surface of the curved mirror near the prism group adopts an aspherical surface to optimize the optical path. The surface of the curved mirror group 70 near the cemented prism group 40 is coated with a fourth special film layer. The fourth special film layer can be a semi-transparent and semi-reflective film, or a combination of a quarter-wave plate and a semi-transparent and semi-reflective film, which can reflect part of the light reflected by the prism to form a refractive optical path, while transmitting light emitted from the real world. The refractive index of the curved mirror group 70 ranges from 1.45 to 1.95, the Abbe number ranges from 20 to 70, the thickness ranges from 1 mm to 3 mm, and the focal length ranges from 15 mm to 30 mm. The outer surface of the curved mirror group 70 is optimized based on the parameters of the inner curved surface and the surface parameters of the cemented prism to ensure that real-world information, after passing through the curved mirror group 70 and the cemented prism group 40, reaches the exit pupil position and is captured by the human eye without significant aberrations.

[0047] Example 2 Please see Figures 4 to 14 This embodiment provides a single-screen binocular augmented reality optical system. This optical system is a projection optical engine in the AR field, capable of generating virtual images at a certain distance. Based on the reverse engineering of the optical system, it includes an exit pupil position, a cemented prism group 40, a curved mirror group 70, a reflecting mirror group, a second lens group 40, a beam splitter prism group 30, a first lens group 20, and a display image source 10. The optical path multiplexing portion of the system consists of the beam splitter prism group 30, the first lens group 20, and the display image source 10. The remaining optical components are located on both the left and right sides, achieving a single-screen binocular display design architecture.

[0048] The display source 10 is a miniature display screen, which can be selected from self-emissive panels such as OLED and LED, or non-self-emissive panels such as LCD and LCOS. The light emitted by it is focused by a lens and reaches the beam splitter assembly 30. The beam splitter is composed of four right-angled prisms bonded together, and its bonding surface 63 is coated with a special film. After the light passes through the bonding surface of the beam splitter, it is split into left and right beams. The subsequent optical components are symmetrical about the center of the beam splitter. Taking the right beam as an example, after being focused and modulated by multiple lenses, it is refracted again by the reflector assembly and then enters the bonding prism assembly 40. Since the reflector assembly and the bonding prism assembly 40 are tilted at a certain angle, when the light passes through the top of the bonding prism assembly 40 and reaches the plane near the curved mirror assembly 70, the light is reflected to the bonding surface 63 of the bonding prism assembly 40. The bonding surface 63 is coated with a semi-transparent and semi-reflective film or a polarizing composite film. The light is reflected by the bonding surface 63 and passes through the first wedge prism 62 before reaching the curved mirror assembly 70. After being reflected by the curved mirror group 70, the light re-enters the first wedge prism 62. This time, the light is transmitted through the first wedge prism 62 and the first wedge prism 61, reaching the eye position at the exit pupil. Simultaneously, information from the real world is directly transmitted through the curved mirror group 70, the first wedge prism 62, and the first wedge prism 61, reaching the eye position at the exit pupil, thus realizing the augmented reality function of the optical system. Through the joint optimization of various optical components, the system can achieve an exit pupil range of 10mm × 6mm. The distance between the center of the beam splitter and the center of the exit pupil is optimized and adjusted to meet the usage needs of users with different interpupillary distances. The system focal length is 17.34mm, and the overall thickness of the optical module's perspective module is 17.01mm.

[0049] The optimized degrees of freedom of the cemented prism group 40, curved mirror group 70, lens group, and beam splitter group 30 are used to balance various aberrations. Surface 101 of the cemented prism group 40 handles astigmatism, coma, distortion, and chromatic aberration; surface 202 handles distortion, chromatic aberration, and astigmatism; and surface 206 handles distortion, astigmatism, and field curvature. Surface 301 of the curved mirror group 70 handles astigmatism, coma, and field curvature. Surfaces 501, 502, 601, 602, 701, 702, 901, and 902 of the lens group jointly handle spherical aberration, coma, astigmatism, field curvature, and distortion. Surface 801 of the beam splitter group 30 handles chromatic aberration, spherical aberration, coma, and astigmatism, while surface 803 handles chromatic aberration and coma. The aberrations of each surface compensate for each other, achieving good optical performance within a 50° field of view. The beam splitting optical system architecture enables binocular display, collectively ensuring the wearer's visual experience.

[0050] The parameters of each component in the optical system of this embodiment are shown in Table (1) below, where surface number 001 indicates the location of the pupil and 1002 is the image exit surface.

[0051] Table 1 shows the parameters of each component in the optical system.

[0052] The surface parameters of each aspherical surface are shown in Table 2 below.

[0053] Table 2 shows the aspherical surface parameters of each component.

[0054] To achieve the optical path in the technical solution, the eccentricity settings of the components in the system are shown in Table 3 below. Generally, the optical axis direction (parallel to the right of the paper) is the Z direction, the meridional direction (parallel to the top of the paper) is the Y direction, and the sagittal direction (perpendicular to the inwards of the paper) is the X direction. Y-direction eccentricity refers to the translation distance along the Y direction, Z-direction eccentricity refers to the translation distance along the Z direction, Alpha eccentricity refers to the rotation angle around the X-axis, and Beta eccentricity refers to the rotation angle around the Y-axis.

[0055] Table 3 shows the eccentric settings of components in the system.

[0056] To achieve a wide-range exit pupil, the system considers the optical performance at different positions of the evaluation pupil. By adjusting the distance between the first lens group 20 and the beam splitter group 30, as shown in Table 4, the system can form virtual images at different positions to meet the needs of different myopic users.

[0057] Table 4 shows the distance parameters between the first lens group 20 and the beam splitter prism group 30.

[0058] Real-world information enters the human eye after being transmitted through the curved mirror group 70 and the cemented prism group 40. The parameters of the curved mirror group 70 in the perspective light path are shown in Table 5 below. The cemented prism group 40 is located behind the surface 301.

[0059] Table 5 shows the parameters of surfaces 301 and 302.

[0060] The surface parameters of the 302 aspherical surface are shown in Table 6 below.

[0061] Table 6 shows the parameters of the 302 surface profile.

[0062] Among them, see Figures 5 to 14In this embodiment, the diagonal field of view can reach 50.2°, enabling diopter adjustment from -0.5D to -6D. It exhibits excellent optical performance across the entire field of view and at different diopters for eye movement positions within a 10mm × 6mm range. Using a 4mm pupil to evaluate the optical performance at the central eye movement position: at -0.5D diopter, the system's central eye movement position has an MTF above 0.8 at 30lp / mm, with distortion controlled within 1%; at -0.5D diopter, the system's peripheral eye movement positions have an MTF above 0.5 at 30lp / mm, with distortion controlled within 1%; at -2.5D diopter, the system's entire field of view has an MTF above 0.9 at 30lp / mm, with distortion controlled within 1%; and at -6D diopter, the system's entire field of view has an MTF above 0.8 at 30lp / mm, with distortion controlled within 1%.

[0063] Example 3 Please see Figures 15 to 26 This embodiment provides a single-screen binocular augmented reality optical system. Unlike Embodiment 2 described above, this embodiment differs in the position of the first wedge prism 62. When the wedge angle of the cemented prism increases, light is refracted directly to the first wedge prism 61 without being reflected by the plane on the side of the first wedge prism 62. Specifically, the wedge angles of the first wedge prisms 61 and 62 are relatively large, allowing light to directly enter the cemented plane from the top of the first wedge prism 62. After reflection by a special film layer on the cemented plane, the light reaches the curved mirror group 70. After reflection by the curved mirror group 70, the light is transmitted through the first wedge prisms 62 and 61, reaching the exit pupil of the viewer's eye. Information from the real world, after being transmitted through the curved mirror group 70, the first wedge prisms 62 and 61, reaches the exit pupil of the viewer's eye, thus achieving the augmented display function. Through optimization of optical component architecture and surface shape, the system can achieve an exit pupil range of 10mm×6mm, a system focal length of 8.27mm, and an overall thickness of 16.78mm for the optical module.

[0064] In this embodiment, all surface types share the aberrations. Surface 101 of the cemented prism group 40 bears astigmatism, distortion, coma, and chromatic aberration; surface 202 bears chromatic aberration and distortion; and surface 205 bears distortion, chromatic aberration, astigmatism, and field curvature. Surface 301 of the curved mirror group 70 bears field curvature, astigmatism, and distortion. Surfaces 501, 502, 601, 602, 701, 702, 901, and 902 of the lens group jointly bear spherical aberration, coma, astigmatism, distortion, field curvature, and chromatic aberration. Surface 801 of the beam splitter prism group 30 bears astigmatism, coma, distortion, and spherical aberration, while surface 803 bears astigmatism and coma. All surface aberrations compensate for each other, achieving good optical performance within a 50° field of view, and achieving good binocular display effects through a symmetrical architecture.

[0065] The parameters of each component in the optical system are shown in Table 7 below, where surface number 001 indicates the location of the pupil and 1002 is the image exit surface.

[0066] Table 7 shows the parameters of each component in the optical system.

[0067] The surface parameters of each aspherical surface are shown in Table 8 below.

[0068] Table 8 shows the aspherical surface parameters of each component.

[0069] To achieve the optical path in the technical solution, the eccentricity settings of the components in the module are shown in Table 9 below. Generally, the optical axis direction (parallel to the right of the paper) is the Z direction, the meridional direction (parallel to the top of the paper) is the Y direction, and the sagittal direction (perpendicular to the bottom of the paper) is the X direction. Y-direction eccentricity refers to the translation distance along the Y direction, Z-direction eccentricity refers to the translation distance along the Z direction, Alpha eccentricity refers to the rotation angle around the X-axis, and Beta eccentricity refers to the rotation angle around the Y-axis.

[0070] Table 9 shows the eccentric settings of components in the system.

[0071] To achieve a wide-range exit pupil, the system considers the optical performance at different positions of the evaluation pupil. By adjusting the distance between the first lens group 20 and the beam splitter group 30, as shown in Table 10, the system can form virtual images at different positions to meet the needs of different myopic users.

[0072] Table 10 shows the distance parameters between the first lens group 20 and the beam splitter prism group 30.

[0073] Real-world information enters the human eye after being transmitted through the curved mirror group 703 and the cemented prism group 402. The parameters of the curved mirror group 70 in the perspective light path are shown in the table below. Behind the surface of 301 is the cemented prism group 402.

[0074] Table 11 shows the parameters of surfaces 301 and 302.

[0075] The surface parameters of the 302 aspherical surface are shown in Table 12 below.

[0076] Table 12 shows the parameters of the 301 surface profile.

[0077] Please refer to Figure 17-26In this embodiment, the diagonal field of view can reach 50°, enabling diopter adjustment from -0.5D to -6D. It exhibits excellent optical performance across the entire field of view, regardless of the exit pupil diameter or diopter configuration. At -0.5D diopter, the system's central eye movement at 30 lp / mm has a MTF higher than 0.7, with distortion controlled within 1%. At -0.5D diopter, the system's peripheral eye movement at 30 lp / mm has a MTF higher than 0.3, with distortion controlled within 1%. At -2.5D diopter, the system's entire field of view at 30 lp / mm has a MTF higher than 0.8, with distortion controlled within 1%. At -6D diopter, the system's entire field of view at 30 lp / mm has a MTF higher than 0.8, with distortion controlled within 1%.

[0078] Example 4 In some embodiments, a near-eye display device is also provided, the near-eye display device including the single-screen binocular augmented reality optical system described in any of the above embodiments.

[0079] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0080] Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The reference to "embodiment" herein means that a specific feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily indicate the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0081] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A single-screen binocular augmented reality optical system, characterized in that, include: Display image source, used to provide imaging light; The first lens group is located on the light-emitting side of the display image source and is used to converge and modulate the imaging light. A beam splitter prism group is disposed on the light-emitting side of the first lens group and is used to split the imaging light rays passing through the first lens group into two optical paths. Imaging display modules are respectively disposed on each of the optical paths, and the imaging display modules include: The second lens group is located on the light-emitting side of the beam-splitting prism group; A reflector assembly is located on the light-emitting side of the second lens assembly; A cemented prism assembly is disposed on the light-emitting side of the reflector assembly. The cemented prism assembly includes a first wedge prism and a second wedge prism that are cemented together. An inclined cementing surface is formed at the connection between the first wedge prism and the second wedge prism. The cementing surface is coated with a first special film layer, which is a semi-transparent semi-reflective film or a polarizing reflective film. A curved mirror assembly is disposed on the side of the second wedge prism opposite to the first wedge prism; The imaging light enters from the incident end face of the second wedge prism, is reflected at least by the cemented surface of the prism to the curved mirror group, and after being reflected by the curved mirror group, passes through the second wedge prism and the first wedge prism in sequence to reach the human eye for imaging.

2. The augmented reality optical system with single-screen binocular display according to claim 1, characterized in that, The beam-splitting prism assembly consists of four right-angle prisms, which are bonded together in pairs through their right-angle edges to form a symmetrical beam-splitting structure. A second special film layer, which is a semi-transparent and semi-reflective film, is coated at the bonded joints. The refractive index of the right-angle prisms ranges from 1.45 to 1.95, the Abbe number ranges from 20 to 70, and the thickness ranges from 6 mm to 10 mm.

3. The augmented reality optical system with single-screen binocular display according to claim 1, characterized in that, The first lens group and the second lens group include at least one optical lens, wherein the refractive index of the optical lens ranges from 1.45 to 1.95, the Abbe number ranges from 20 to 70, the radius of curvature ranges from 4 mm to 2000 mm, the thickness ranges from 0.6 mm to 8.6 mm, and the focal length ranges from 10 mm to 105 mm.

4. The augmented reality optical system with single-screen binocular display according to claim 3, characterized in that, The second lens group includes a first optical lens, a second optical lens, and a third optical lens. The first optical lens, the second optical lens, and the third optical lens are disposed on the light-emitting side of the beam splitter and arranged sequentially along the optical path.

5. The augmented reality optical system with single-screen binocular display according to claim 1, characterized in that, The surface of the reflector assembly near the cemented prism assembly is coated with a third special film layer, which is a high-reflection film or a total-reflection film; the surface of the first wedge prism near the exit pupil region and the surface of the second wedge prism near the reflector assembly are free combinations of spherical, aspherical, and free-form surfaces.

6. The augmented reality optical system with single-screen binocular display according to claim 5, characterized in that, The wedge angle of the first wedge prism and the second wedge prism ranges from 15° to 45°, the refractive index ranges from 1.45 to 1.95, the Abbe number ranges from 20 to 70, and the thickness ranges from 6 mm to 15 mm.

7. The augmented reality optical system with single-screen binocular display according to claim 6, characterized in that, The thickness of the cemented prism assembly satisfy: In the formula, The distance between the light-emitting side of the first wedge prism and the exit pupil of the human eye is [missing information]. The meridional field of view of the optical system. For the angle of refraction, Let be the wedge angle of the first wedge prism, and D be the exit pupil diameter.

8. The augmented reality optical system with single-screen binocular display according to claim 7, characterized in that, The optical system's meridional field of view The calculation expression is: The angle of refraction is The calculation expression is: In the formula, H:V The aspect ratio of the display module. For the field of view of the optical system, Let be the refractive index of the first wedge prism.

9. The augmented reality optical system with single-screen binocular display according to claim 1, characterized in that, The surface of the curved mirror assembly near the cemented prism assembly is coated with a fourth special film layer, which is a semi-transparent and semi-reflective film or a combination of a quarter-wave plate and a semi-transparent and semi-reflective film; the refractive index of the curved mirror assembly ranges from 1.45 to 1.95, the Abbe number ranges from 20 to 70, the thickness ranges from 1 mm to 3 mm, and the focal length ranges from 15 mm to 30 mm.

10. A near-eye display device, characterized in that, The near-eye display device includes the modulation optical waveguide as described in any one of claims 1-9.

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