AR optical module and smart head-mounted device

Abstract

The embodiment of the application provides an AR optical module and a smart head-mounted device; the AR optical module comprises a display, a lens group, a light splitting element, a phase retarder and a polarization reflection element; the lens group comprises a first prism, a first lens, a second prism and a third prism; the light splitting element is arranged on a first surface of the first lens; the phase retarder is arranged on a second surface of the first lens; the polarization reflection element is arranged on a surface of the second prism adjacent to the first prism, and the phase retarder is located between the light splitting element and the polarization reflection element; the first side of the first prism is provided with the display, the first lens and the third side of the first prism are arranged in an air interval retaining mode and are glued, the second side of the first prism and the second prism are arranged in an air interval retaining mode and are glued, and the third prism is glued to the side of the second prism away from the first prism.

Description

Technical Field

[0001] This application relates to the field of projection optical display technology, and more specifically, to an AR optical module and a smart head-mounted device. Background Technology

[0002] With the development of AR technology, large field of view and small size have become important development trends for AR optical display devices. However, as the field of view increases, the size of the optical system increases dramatically, which limits the portability and user experience of AR optical display devices. Therefore, how to further reduce the size of the optical system while maintaining a large field of view has become an urgent problem to be solved in the current AR technology field. Summary of the Invention

[0003] The purpose of this application is to provide a new technology solution for AR optical modules and smart head-mounted devices.

[0004] In a first aspect, embodiments of this application provide an AR optical module including:

[0005] monitor;

[0006] The lens assembly includes a first prism, a first lens, a second prism, and a third prism;

[0007] A beam-splitting element is disposed on the first surface of the first lens;

[0008] A phase delayer is disposed on the second surface of the first lens;

[0009] A polarizing reflective element is disposed on the surface of the second prism adjacent to the first prism, and the phase delayer is located in the optical path between the beam splitter and the polarizing reflective element;

[0010] The first prism has the display mounted on its first side, the first lens is bonded to the third side of the first prism with an air gap, the second prism is bonded to the second side of the first prism with an air gap, and the third prism is bonded to the side of the second prism opposite to the first prism.

[0011] Optionally, the air gap between the first lens 3 and the third side of the first prism 2 is L1, and the air gap between the second prism 4 and the second side of the first prism 2 is L2. Both L1 and L2 satisfy: 0.05mm≤L1, L2≤0.15mm.

[0012] Optionally, the AR optical module further includes a second lens, which is disposed on the side of the first lens facing outward. The optical power of the second lens and the optical power of the first lens can cancel each other out, so that the first lens and the second lens are combined to form a light-transmitting plate with zero optical power.

[0013] Optionally, the second lens and the first lens are cemented together to form a cemented lens.

[0014] Optionally, the first prism includes a first effective surface, a second effective surface, and a third effective surface;

[0015] The second prism includes a fourth effective surface and a fifth effective surface;

[0016] Wherein, the display is adjacent to and spaced apart from the first effective surface; the third effective surface is bonded to the edge of the second surface of the first lens, and an air gap is maintained between them; the edges of the second effective surface and the fifth effective surface are bonded together, and an air gap is maintained between them; the second effective surface and the third effective surface are formed as total reflective surfaces.

[0017] Optionally, the aperture of the cemented area between the third effective surface of the first prism and the second surface of the first lens is D1, the un-cemented area on the third effective surface forms the total reflection surface, the aperture of the total reflection surface is D2, and 0.75≤D1 / D2≤1;

[0018] The aperture of the bonded area between the second effective surface of the first prism and the fifth effective surface of the second prism is D3. The unbonded area on the second effective surface forms the total reflection surface, and the aperture of the total reflection surface is D4, and 0.75≤D3 / D4≤1.

[0019] Optionally, the angle A1 between the second effective surface of the first prism and the vertical direction satisfies 20°≤A1≤25°.

[0020] Optionally, the angle A2 between the fourth effective surface of the second prism and the vertical direction satisfies 10°≤A2≤15°.

[0021] Optionally, the beam splitter is disposed on the first surface, the phase delayer is disposed on the second surface, and the polarization reflection element is disposed on the fourth effective surface.

[0022] Optionally, the AR optical module further includes a first polarization element;

[0023] The sixth effective surface of the third prism is positioned close to the human eye, and the first polarizing element is located on the sixth effective surface.

[0024] Optionally, the AR optical module further includes a second polarization element, which is stacked on the side of the phase retarder away from the second surface.

[0025] Optionally, the first lens is an aspherical lens.

[0026] Optionally, at least one lens is disposed between the display and the first side of the first prism.

[0027] Secondly, embodiments of this application provide a micro-projection device, the micro-projection device comprising:

[0028] The outer casing; and

[0029] As described in the second aspect, the AR optical module.

[0030] The beneficial effects of this application are as follows:

[0031] The AR optical module provided in this application embodiment, through its unique optical design and layout, significantly improves imaging quality while achieving a small size and a large field of view, specifically manifested in:

[0032] The AR optical module provided in this application embodiment effectively reduces the physical contact area between lenses by optimizing the specific layout and configuration of the lens group, especially by using a bonding method that retains air gaps. Specifically, the first lens and the first prism, as well as the second prism and the first prism, are bonded together with air gaps. This design not only reduces interference between lenses but also makes the entire optical module more compact.

[0033] The AR optical module provided in this application uses a combination of beam splitters, phase delayers, and polarization reflectors to control the polarization state of light. The addition of air gaps increases the number of light reflections, ensuring sufficient optical path and achieving a wide field of view. Specifically, the light emitted from the display undergoes transmission and total internal reflection through a first prism, then beam splitting and phase delay through a first lens, and finally reflection through the polarization reflector before entering the human eye. This process involves multiple reflections and transmissions, effectively expanding the field of view.

[0034] The AR optical module provided in this application achieves a large field of view without sacrificing module size. Through special optical design and layout, the AR optical module achieves a small size while ensuring a large field of view. This balance makes the AR optical module more suitable for various AR optical display devices that require portability and a large field of view, such as smart head-mounted devices.

[0035] Other features and advantages of this specification will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0036] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of this specification and, together with their description, serve to explain the principles of this specification.

[0037] Figure 1 This is one of the optical architecture diagrams of the AR optical module provided in Embodiment 1 of this application;

[0038] Figure 2 This is the second optical architecture diagram of the AR optical module provided in Embodiment 1 of this application;

[0039] Figure 3 for Figure 2 The provided dot array diagram of the AR optical module;

[0040] Figure 4 for Figure 2 The provided MTF diagram of the AR optical module;

[0041] Figure 5 for Figure 2 Field curvature and distortion diagrams of the provided AR optical module;

[0042] Figure 6 for Figure 2 The provided chromatic aberration diagram of the AR optical module;

[0043] Figure 7 This is one of the optical architecture diagrams of the AR optical module provided in Embodiment 2 of this application;

[0044] Figure 8 This is the second optical architecture diagram of the AR optical module provided in Embodiment 2 of this application;

[0045] Figure 9 for Figure 8 The provided dot array diagram of the AR optical module;

[0046] Figure 10 for Figure 8 The provided MTF diagram of the AR optical module;

[0047] Figure 11 for Figure 8 Field curvature and distortion diagrams of the provided AR optical module;

[0048] Figure 12 for Figure 8 The provided chromatic aberration diagram of the AR optical module;

[0049] Figure 13This is an optical architecture diagram of the AR optical module provided in Embodiment 3 of this application.

[0050] Explanation of reference numerals in the attached figures:

[0051] 1. Display; 2. First prism; 21. First effective surface; 22. Second effective surface; 23. Third effective surface; 3. First lens; 31. First surface; 311. Beam splitter; 32. Second surface; 321. Phase retarder; 322. Second polarizing element; 4. Second prism; 41. Fourth effective surface; 411. Polarizing reflective element; 42. Fifth effective surface; 5. Third prism; 51. Sixth effective surface; 511. First polarizing element; 52. Seventh effective surface; 6. Second lens; 01. Human eye. Detailed Implementation

[0052] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0053] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0054] Technologies and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies and equipment should be considered part of the specification.

[0055] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0056] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0057] The AR optical module and smart head-mounted device provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0058] According to one embodiment of this application, an AR optical module is provided, see [link to relevant documentation]. Figure 1The AR optical module includes a display 1, a lens group, a beam splitter 311, a phase retarder 321, and a polarizing reflector 411. The display 1 provides virtual imaging light. The lens group includes a first prism 2, a first lens 3, a second prism 4, and a third prism 5. The beam splitter 311 is disposed on the first surface 31 of the first lens 3; the phase retarder 321 is disposed on the second surface 32 of the first lens 3. The polarizing reflector 411 is disposed on the surface of the second prism 4 adjacent to the first prism 2, and the phase retarder 321 is located in the optical path between the beam splitter 311 and the polarizing reflector 411. The display 1 is disposed on the first side of the first prism 2; the first lens 3 is cemented to the third side of the first prism 2 with an air gap; the second prism 4 is cemented to the second side of the first prism 2 with an air gap; and the third prism 5 is cemented to the side of the second prism 4 opposite to the first prism 2.

[0059] The AR optical module provided in this application can be applied to AR optical display devices, such as AR smart head-mounted devices. Of course, this AR optical module can also be applied to other types of optical display devices according to actual needs, and this application does not impose specific limitations on this. The AR optical module provided in this application will be further described below.

[0060] The AR optical module provided in this application embodiment includes a display 1, see [link]. Figure 1 and Figure 2 The display 1, as the source of virtual imaging light, is mainly responsible for generating and emitting the image light that needs to be displayed.

[0061] The AR optical module provided in this application includes a specially designed lens group, which comprises three prisms and one optical lens. Specifically, the lens group includes a first lens 3, a first prism 2, a second prism 4, and a third prism 5 arranged in sequence. These lenses work together to transmit, reflect, and totally internally reflect the virtual imaging light emitted by the display 1, thereby achieving image projection and magnification.

[0062] In the lens assembly, see Figure 1The first prism 2 has at least three effective optical surfaces: a first effective surface 21, a second effective surface 22, and a third effective surface 23. These three effective surfaces form the first side, the second side, and the third side of the first prism 2, respectively. Through a special design of the air gap, two effective surfaces of the first prism 2, namely the second effective surface 22 and the third effective surface 23, form a total internal reflection surface, which can be used to guide light to undergo multiple reflections inside the AR optical module, thereby increasing the optical path and reducing the thickness of the AR optical module (i.e., realizing a small-size design for the AR optical module).

[0063] In the lens assembly, see Figure 1 The first lens 3 has two optical surfaces: a first surface 31 facing the outside (or world side) and a second surface 32 bonded to the first prism 2. A beam splitting element 311 and a phase delayer 321 are respectively disposed on these two optical surfaces to control the polarization state and beam splitting ratio of the light (mainly the virtual image imaging light emitted by the display 1).

[0064] In the lens assembly, see Figure 1 The second prism 4 has at least two optically effective surfaces, namely a fourth effective surface 41 and a fifth effective surface 42; wherein a polarization reflection element 411 is provided on the fourth effective surface 41 for reflecting light with a specific polarization direction.

[0065] It should be noted that the phase delayer 321 must be located between the beam splitter 311 and the polarization reflection element 411 in order to ensure the formation of the folded optical path.

[0066] In the lens group described above, please continue to refer to Figure 1 The third prism 5 and the second prism 4 are bonded together on the side opposite to the first prism 2, which is used to further guide light into the human eye O1 for imaging.

[0067] Preferably, the second prism 4 and the third prism 5 are glued together, and no air gap is required between them.

[0068] Of course, the second prism 4 and the third prism 5 may not be glued together, but may be placed close to each other or have a very small air gap.

[0069] In the AR optical module provided in this application embodiment, optical films such as beam splitter 311, phase delayer 321 and polarization reflection element 411 are introduced. These optical films, together with specially designed lenses, such as first lens 3 and second prism 4, can form a folded optical path.

[0070] The beam splitter 311 can transmit a portion of the light while reflecting a portion of the light, thus splitting the light into different paths or changing the direction of light propagation.

[0071] In the embodiments provided in this application, the beam splitter 311 is, for example, a semi-transparent and semi-reflective film.

[0072] The phase delayer 321 is disposed on the second surface 32 (the surface facing away from the outside) of the first lens 3. It can be used to change the polarization state of light so that it matches the subsequent optical elements (such as the polarizing reflective element 411).

[0073] The phase delayer 321 can be used to delay the phase of light, thereby changing the polarization state of the light. This is a key component for realizing specific optical functions (such as circular polarization conversion). For example, the phase delayer 321 is used to convert linearly polarized light into circularly polarized light or vice versa.

[0074] In this embodiment, the phase delayer 321 is, for example, a quarter-wave plate.

[0075] The polarization reflection element 411 is disposed on the surface of the second prism 4 adjacent to the first prism 2, and is used to reflect light with a specific polarization direction to achieve selective reflection and transmission of light.

[0076] The polarization reflective element 411 can reflect or transmit light according to the polarization state of the light.

[0077] In this embodiment, the polarization reflective element 411 is a polarization reflective film.

[0078] In the AR optical module provided in this application embodiment, the first lens 3 and the first prism 2, and the second prism 4 and the first prism 2 are both bonded together with air gaps. This ensures the relative position stability between the lenses while retaining the necessary air gaps to achieve total internal reflection and transmission of light.

[0079] See Figure 1 In the AR optical module provided in this application embodiment, the optical path transmission path of the virtual imaging light emitted by the display 1 is, for example, as follows: the virtual imaging light emitted by the display 1 passes sequentially through the first prism 2 (total internal reflection) → the beam splitter 311 (reflection) → the phase delayer 321 (polarization conversion) → the polarization reflection element 411 (secondary reflection), and finally enters the human eye O1. In this process, by increasing the number of reflections of the virtual imaging light to ensure the optical path, the thickness of the AR optical module can be greatly reduced (i.e., the size of the AR optical module is reduced).

[0080] In this embodiment, through specific optical design and optical element layout, especially by utilizing the principle of total internal reflection and the bonding method that retains air gaps, the AR optical module of this application significantly reduces the overall thickness of the module while ensuring a large field of view, thus achieving the design goal of small size.

[0081] It is worth emphasizing that the AR optical module provided in this application has achieved a significant breakthrough in optical structure design, with its overall thickness controlled within the range of ≤10mm. Compared to AR optical modules currently prevalent in the market (whose overall thickness is at least 15mm), the AR optical module of this application achieves a reduction of at least 30% in overall thickness. This design not only significantly improves the portability of the product but also provides users with a lighter and more comfortable wearing experience, while also helping to promote the development of AR technology towards a thinner and more efficient direction.

[0082] Furthermore, the AR optical module in this embodiment employs a novel air-gap bonding design, which effectively avoids stress deformation problems that may be caused by traditional bonding structures. Simultaneously, it eliminates the need for additional support structures, making the AR optical module structurally simpler and more efficient. This improvement not only optimizes the optical performance of the AR optical module but also significantly promotes its lightweight design, reducing the overall weight of the module by 15% to 20%, further enhancing product portability and user experience.

[0083] In the AR optical module provided in this application embodiment, the combined use of the beam splitter 311, the phase delayer 321 and the polarization reflection element 411 effectively controls the polarization state and beam splitting ratio of the light, reduces the influence of stray light and chromatic aberration, and improves the clarity and contrast of the image.

[0084] The AR optical module provided in this application embodiment can significantly expand the field of view by increasing the number of reflections and transmission paths of light (especially virtual imaging light), enabling users to observe a wider virtual image area.

[0085] The AR optical module provided in this application embodiment achieves a balance between a large field of view and a small module size, making it more suitable for various AR optical display devices that require portability and a large field of view, such as smart head-mounted devices, and providing users with a more comfortable and immersive experience.

[0086] In some examples of this application, the air gap between the first lens 3 and the third side of the first prism 2 is L1, and the air gap between the second prism 4 and the second side of the first prism 2 is L2. Both L1 and L2 satisfy: 0.05mm≤L1, L2≤0.15mm.

[0087] The air gap L1 between the first lens 3 and the first prism 2, and the air gap L2 between the second prism 4 and the first prism 2, should not be too large or too small.

[0088] Larger air gaps would increase the overall size of the AR optical module, which contradicts the goal of miniaturization in this application. By limiting the air gaps L1 and L2 to a reasonable range as described in this example, a compact layout of the AR optical module can be achieved, making it more suitable for applications in size-sensitive scenarios such as smart head-mounted devices.

[0089] Excessive air gaps can cause light to deviate from its intended path during propagation, increasing the risk of light scattering and loss. In the AR optical module provided in this application embodiment, precise control of the light propagation path is crucial for achieving high-quality imaging.

[0090] Larger air gaps can introduce additional aberrations, such as spherical aberration and coma, which reduce image sharpness and contrast. By limiting the air gap, the effects of these aberrations can be reduced, thus improving image quality.

[0091] Insufficient air gaps increase assembly difficulty, requiring higher machining and assembly precision. Too small an air gap can lead to stress concentration between lenses, increasing the risk of lens deformation. Especially under conditions of temperature changes or mechanical vibration, insufficient air gaps may exacerbate lens deformation, affecting the stability and reliability of the AR optical module.

[0092] In summary, limiting the air gap L1 between the first lens 3 and the first prism 2, and the air gap L2 between the second prism 4 and the first prism 2, to a range of 0.05 mm to 0.15 mm is the result of comprehensively considering factors such as module compactness, light propagation control, imaging quality, assembly processability, stress deformation, and optical performance stability. This design ensures both the performance requirements of the AR optical module and the feasibility and cost-effectiveness of actual production.

[0093] See some examples in this application. Figure 2 The AR optical module also includes a second lens 6, which is disposed on the side of the first lens 3 facing outward. The optical power of the second lens 6 and the optical power of the first lens 3 can cancel each other out, so that the first lens 3 and the second lens 6 are combined to form a light-transmitting plate with zero optical power.

[0094] Optical power is a physical quantity that measures the ability of a lens to deflect light. When two lenses have equal optical powers but opposite signs, their combined optical power is zero, meaning they have no deflecting effect on light; for example, they can be equivalent to a flat piece of glass.

[0095] See the examples provided in this application. Figure 2 A second lens 6 is introduced on the outer side of the first lens 3. The optical power of the first lens 3 and the second lens 6 are designed to cancel each other out. The combined structure is optically represented as a light-transmitting plate.

[0096] The examples in this application involve optical power compensation design. The principle of dual-lens extinction is as follows: the optical power of the second lens 6... Optical power of the first lens 3 satisfy The combination of the two is equivalent to a light-transmitting plate, which has no focusing or diverging effect on ambient light (external light), thus avoiding the introduction of additional aberrations.

[0097] From the position and layout of the second lens 6, the second lens 6 is set on the outer side of the first lens 3 (that is, the opposite side of the human eye's observation direction). It is in contact with the ambient light, ensuring that the ambient light passes through the module with basically no distortion.

[0098] By introducing the second lens 6 and combining it with the first lens 3 to form a combination with zero optical power, aberrations caused by the lens's own optical power, such as spherical aberration and coma, can be effectively reduced or eliminated, thereby improving the clarity and accuracy of the image. This light-transmitting flat panel design makes the AR optical module more stable under different ambient lighting conditions. Since it does not produce additional refraction of light, it can reduce image quality fluctuations caused by changes in ambient light. In addition, the dual-lens combination can cancel out aberrations such as spherical aberration and field curvature of a single lens, and in particular, it can compensate for edge astigmatism caused by the large field of view of the first lens 3.

[0099] See some examples in this application. Figure 2 The second lens 6 and the first lens 3 are cemented together to form a cemented lens.

[0100] In the example provided in this application, the second lens 6 can be glued to the first lens 3 to form a glued lens on the outer side, which simplifies the assembly process.

[0101] In this cemented surface design, the curvature of the surface (cemented surface) of the second lens 6 can be complementary to that of the first lens 3 (cemented surface). For example, if the cemented surface of the first lens 3 is convex, the cemented surface of the second lens 6 can be concave. The specific curvature of the cemented surface is designed according to the aberration correction requirements.

[0102] In the example of this application, the cemented design of the first lens 3 and the second lens 6 effectively reduces the air gap between the two lenses, thereby reducing the reflection and scattering loss of ambient light between them. This helps to improve the transmittance of ambient light, allowing more ambient light to be accurately focused on the human eye O1, thus improving the clarity and contrast of the image. At the same time, this cemented lens design can also reduce aberrations caused by air gaps between lenses, such as chromatic aberration and astigmatism, further optimizing image quality.

[0103] Gluing the second lens 6 to the first lens 3 together simplifies the assembly process of the AR optical module. This reduces the number of positioning and fixing steps between lenses, improves production efficiency, and reduces performance fluctuations caused by improper assembly.

[0104] In this example of the application, bonding the first lens 3 with the second lens 6 can reduce the air gap between the two lenses and the additional fixing structure, making the entire AR optical module more compact and lightweight, which is beneficial for achieving a lightweight design of AR devices.

[0105] Optimized image quality and enhanced module stability contribute to a better user experience. When using AR optical display devices, users can enjoy clearer and more stable images, reducing visual fatigue or discomfort caused by poor optical module performance.

[0106] Optionally, an anti-reflective coating may be provided on the surface of the second lens 6.

[0107] In the AR optical module design of this application, there are two feasible solutions for the combination of the first lens 3 and the second lens 6, and each solution has its specific advantages and application scenarios.

[0108] On the one hand, the first lens 3 and the second lens 6 can be bonded together using the aforementioned bonding method to form a single cemented lens. This design significantly reduces the air gap between the lenses, thereby reducing light reflection and scattering between them and improving light transmittance and image quality. Simultaneously, as a whole, the cemented lens has a more stable internal structure, contributing to the long-term stability and reliability of the AR optical module.

[0109] On the other hand, the first lens 3 and the second lens 6 can also be left unbonded, maintaining a certain air gap, as long as the sum of their optical powers is zero. This unbonded design gives designers greater flexibility, as the surface shapes of two adjacent lenses can be designed differently. This flexibility allows AR optical modules to better adapt to different application scenarios and performance requirements. For example, the transmission of light at a specific wavelength can be optimized by adjusting the lens surface shape, or an asymmetrical lens structure can be designed to achieve specific optical effects.

[0110] Regardless of whether a glued or non-glued design is chosen, the key is to ensure that the sum of the optical powers of the first lens 3 and the second lens 6 is zero, in order to meet the requirements of the AR optical module for imaging quality and module stability. The specific choice of method should be based on a comprehensive consideration of factors such as the actual application scenario, performance requirements, and manufacturing costs.

[0111] See some examples in this application. Figure 1 and Figure 2 The first prism 2 includes a first effective surface 21, a second effective surface 22, and a third effective surface 23. The second prism 4 includes a fourth effective surface 41 and a fifth effective surface 42. The display 1 is adjacent to and spaced apart from the first effective surface 21; the third effective surface 23 is bonded to the edge of the second surface 32 of the first lens 3, with an air gap between them; the edges of the second effective surface 22 and the fifth effective surface 42 are bonded together, with an air gap between them; the second effective surface 22 and the third effective surface 23 are formed as total reflection surfaces.

[0112] In the example provided in this application, the first prism 2 includes three effective surfaces: a first effective surface 21, a second effective surface 22, and a third effective surface 23.

[0113] Optionally, an antireflection membrane is provided on all three effective surfaces.

[0114] The display 1 is adjacent to and spaced apart from the first effective surface 21 (located on the first side) of the first prism 2, so that the light emitted by the display 1 (such as virtual imaging light) first enters the first prism 2 and enters the interior of the first prism 2 from its first effective surface 21.

[0115] Regarding the connection between the first prism 2 and the first lens 3:

[0116] See Figure 1 and Figure 2The third effective surface 23 of the first prism 2 is glued to the edge of the second surface 32 of the first lens 3, with an air gap maintained between them. This design allows light (the virtual imaging light emitted by the display 1) to undergo total internal reflection on the third effective surface 23, while maintaining the relative positional stability between the first prism 2 and the first lens 3.

[0117] Regarding the connection between the first prism 2 and the second prism 4:

[0118] See Figure 1 and Figure 2 The second effective surface 22 of the first prism 2 is glued to the edge of the fifth effective surface 42 of the second prism 4, while also maintaining an air gap. This method also allows light (the virtual imaging light emitted by the display 1) to undergo total internal reflection on the second effective surface 22 and helps to achieve precise alignment between the two prisms.

[0119] In the embodiments of this application, both the second effective surface 22 and the third effective surface 23 of the first prism 2 are designed as total internal reflection surfaces, which is one of the key factors for miniaturizing the AR optical module. By utilizing the principle of total internal reflection, light can be reflected multiple times inside the first prism 2, thereby increasing the optical path. With this design, the thickness of the AR optical module can be reduced.

[0120] In summary, by utilizing total reflection surfaces (the second effective surface 22 and the third effective surface 23) and a bonding method that retains air gaps, the AR optical module of this application significantly reduces the overall thickness (small size) of the module while maintaining a large field of view. This design makes the AR optical display device more portable and suitable for various application scenarios. Furthermore, the edge bonding method between the first prism 2 and the first lens 3 maintains the relative positional stability between the optical elements, reducing performance fluctuations caused by mechanical vibration or temperature changes. This stability is crucial for ensuring the reliable operation of the AR optical module in various environments.

[0121] In some examples of this application, the aperture of the cemented area between the third effective surface 23 of the first prism 2 and the second surface 32 of the first lens 3 is D1, and the uncemented area on the third effective surface 23 forms the total internal reflection surface, the aperture of which is D2, and 0.75≤D1 / D2≤1. The aperture of the cemented area between the second effective surface 22 of the first prism 2 and the fifth effective surface 42 of the second prism 4 is D3, and the uncemented area on the second effective surface 22 forms the total internal reflection surface, the aperture of which is D4, and 0.75≤D3 / D4≤1.

[0122] By appropriately setting the ratio of the cemented area aperture (D1, D3) to the total internal reflection surface aperture (D2, D4) (0.75≤D1 / D2≤1 and 0.75≤D1 / D2≤1), effective propagation and total internal reflection of light between the first prism 2 and the first lens 3, and between the first prism 2 and the second prism 4, are ensured. This guarantees the integrity of the optical path. When the ratio of the cemented area aperture to the total internal reflection surface aperture is close to but does not exceed 1, it means that the size of the cemented area is minimized as much as possible while ensuring unobstructed light paths. This design helps to reduce the overall size of the optical module, making it more compact.

[0123] In some examples of this application, the angle A1 between the second effective surface 22 of the first prism 2 and the vertical direction satisfies 20°≤A1≤25°.

[0124] In the example provided in this application, the design of the second effective surface 22 of the first prism 2 specifically points out that its angle A1 with the vertical direction satisfies the condition 20°≤A1≤25°. This optical parameter design is closely related to the goal of miniaturizing AR optical modules.

[0125] In this example of the application, the angle between the second effective surface 22 of the first prism 2 and the vertical direction is limited to between 20° and 25°. This range is chosen based on optical design considerations to ensure that total internal reflection can be generated on the second effective surface 22.

[0126] Total internal reflection is an optical phenomenon where light rays travel from an optically denser medium to an optically less dense medium at an angle of incidence greater than or equal to a critical angle, resulting in complete reflection back into the original medium without refraction. In the optical design of this application, by rationally designing the angle between the second effective surface 22 and the vertical direction, light rays (such as virtual imaging rays) satisfy the conditions for total internal reflection on the second effective surface 22, thereby achieving multiple reflections of light rays inside the first prism 2.

[0127] Reducing the overall thickness of the AR optical module while ensuring total internal reflection on the second effective surface 22 is a key design objective of this application. By controlling the included angle A1 between 20° and 25°, this application effectively utilizes the principle of total internal reflection to increase the optical path of light (such as virtual imaging light) while avoiding increasing the physical thickness of the AR optical module. This design allows the AR optical module to maintain a large field of view while achieving a smaller size, improving product portability and user experience.

[0128] In other words, the optical parameter design of 20°≤A1≤25° provided in this example of the application achieves miniaturization of the AR optical module. This design makes AR optical display devices lighter, easier to carry and use.

[0129] It is worth noting that in this application, the application of total internal reflection reduces the loss of light (especially virtual imaging light) during transmission, thereby improving the utilization rate of light. At the same time, by optimizing the design of the included angle A1, this application can also reduce aberrations caused by light refraction or scattering, thereby improving the sharpness and contrast of the image.

[0130] For example, see Figure 1 and Figure 7 The angle A1 between the second effective surface 22 of the first prism 2 and the vertical direction is 23°.

[0131] In some examples of this application, the angle A2 between the fourth effective surface 41 of the second prism 4 and the vertical direction satisfies 10°≤A2≤15°.

[0132] In the example provided in this application, the angle A2 between the fourth effective surface 41 of the second prism 4 and the vertical direction is set within the range of 10° to 15°. This optical parameter design is based on a comprehensive consideration of the overall design and performance optimization of the AR optical module, aiming to ensure that the virtual imaging light emitted by the display 1 can be incident on the polarization reflection element 411 in the optical path at the optimal angle, thereby significantly improving the reflectivity and transmittance of the light.

[0133] Specifically, the polarization reflection element 411, as one of the optical elements in the AR optical module of this application, directly determines the light utilization efficiency. In the AR optical module, by controlling the angle A2 between the fourth effective surface 41 of the second prism 4 and the vertical direction, it can be ensured that the virtual imaging light is incident on the rear polarization reflection element 411 at a near-ideal angle, thereby maximizing the selective reflection and transmission characteristics of the polarization reflection element 411 and effectively improving the light utilization rate.

[0134] Further analysis reveals that the angle at which light is incident on the polarizing reflective element 411 has a decisive impact on its reflectivity and transmittance. If the incident angle deviates from the optimal range, the reflection or transmission efficiency of light on the polarizing reflective element 411 will be significantly reduced, thus affecting the performance of the entire AR optical module. Therefore, by controlling the included angle A2 between 10° and 15°, it can be ensured that light always incident at the optimal angle, thereby optimizing the overall performance of the AR optical module.

[0135] From a technical perspective, controlling the included angle A2 within the aforementioned range has the following significant advantages:

[0136] (1) Improve light utilization: Ensure that more virtual imaging light can be effectively reflected and transmitted, thereby improving the overall efficiency of AR optical modules.

[0137] (2) Optimize imaging quality: reduce the loss of virtual imaging light during the imaging process, improve the brightness and clarity of the image, and bring users a more realistic visual experience.

[0138] (3) Enhance module stability: By controlling the incident angle of light to the polarization reflection element 411, the performance fluctuation caused by improper incident angle is reduced, ensuring that the AR optical module can maintain stable performance in different environments.

[0139] (4) Promote lightweight design: Without increasing the size or weight of the module, the light utilization rate can be significantly improved by optimizing the included angle A2, which provides strong support for realizing a lighter and more portable AR device.

[0140] In summary, this example of the present application maximizes the utilization efficiency of light (especially virtual imaging light) within a range of 10° to 15° by controlling the angle A2 between the fourth effective surface 41 of the second prism 4 and the vertical direction, significantly improving the overall performance of the AR optical module and providing a new approach for the lightweight design of AR optical display devices.

[0141] For example, see Figure 1 and Figure 7 The angle A2 between the fourth effective surface 41 of the second prism 4 and the vertical direction is 14°.

[0142] See some examples in this application. Figure 1 The beam splitter 311 is disposed on the first surface 31, the phase delayer 321 is disposed on the second surface 32, and the polarization reflection element 411 is disposed on the fourth effective surface 41.

[0143] In the example provided in this application, a folded optical path is formed through careful design of the layout and configuration of optical elements. Specifically, see [link to relevant documentation]. Figure 1 The beam splitter 311 (a semi-transparent, semi-reflective film) is disposed on the first surface 31 of the first lens 3, the phase retarder 321 (a quarter-wave plate) is disposed on the second surface 32 of the first lens 3, and the polarizing reflective element 411 (a polarizing reflective film) is disposed on the fourth effective surface 41 (the surface closest to the human eye O1) of the second prism 4. This arrangement fully utilizes the characteristics of each optical element, which work together on the light propagation path to form a compact and efficient folded optical path.

[0144] In the AR optical module provided in this application embodiment, through the synergistic effect of the beam splitter 311, the phase delayer 321, and the polarization reflection element 411, light forms a folded light path of multiple reflections and transmissions within the module, especially between the first lens 3 and the second prism 4. This design greatly reduces the overall thickness of the AR optical module, achieving the design goal of miniaturization.

[0145] The folded optical path design allows light (especially the virtual imaging light emitted by the display 1) to be used multiple times within a limited space, thereby improving light utilization. More light is effectively guided to the human eye, enhancing the imaging and display effects of the AR optical module.

[0146] See some examples in this application. Figure 1 The AR optical module further includes a first polarizing element 511; the sixth effective surface 51 of the third prism 5 is disposed close to the human eye 01, and the first polarizing element 511 is disposed on the sixth effective surface 51.

[0147] See Figure 1 The AR optical module provided in this application embodiment also incorporates a first polarizing element 511, which is disposed on the surface of the third prism 5 near the human eye 01, i.e. Figure 1 and Figure 2 The sixth effective surface 51 is shown in the figure. This sixth effective surface 51 is the last optical interface through which light enters the human eye.

[0148] The primary function of the first polarizing element 511 proposed in this example is to reduce stray light and improve image clarity and contrast. Specifically, in AR optical modules, stray light may originate from reflections of ambient light, scattering by optical elements, etc., and this stray light can interfere with the user's viewing experience of the image display. The first polarizing element 511 is configured to selectively allow light of a specific polarization direction to pass through while blocking light of other polarization directions, thereby effectively reducing the impact of stray light.

[0149] The first polarizing element 511 is, for example, composed of a polarizing film, which has specific polarization selectivity characteristics. When light is incident on the first polarizing element 511, only light rays with the same polarization direction as the first polarizing element 511 can be transmitted, while light rays in other directions are absorbed or reflected. In this way, the first polarizing element 511 can filter out most stray light, allowing only image-related light rays to enter the human eye 01.

[0150] Therefore, by reducing stray light, the first polarizing element 511 improves the imaging quality of the AR optical module. Users can see the displayed image more clearly, reducing visual fatigue caused by stray light interference. The clear imaging quality provides users with a better AR experience. Users can more naturally immerse themselves in the environment composed of virtual and reality, enjoying a more immersive visual experience.

[0151] The addition of the first polarization element 511 also helps improve the stability of the AR optical module. By reducing the influence of stray light, the module performs more consistently in different environments, reducing performance fluctuations caused by changes in ambient light. The first polarization element 511, together with other optical elements in the AR optical module, such as the beam splitter 311, phase retarder 321, polarization reflector 411, and lens group, works together to form a highly efficient and compact optical system. The cooperation between the various optical elements ensures that light can propagate along a predetermined path and achieve the best imaging effect before entering the viewer's eyes.

[0152] See some examples in this application. Figure 1 The AR optical module further includes a second polarization element 322, which is stacked on the side of the phase delayer 321 away from the second surface 32.

[0153] See the examples provided in this application. Figure 1 The AR optical module may further include a second polarizing element 322, which is stacked on the side of the phase retarder 321 away from the second surface 32 of the first lens 3. The following is a detailed description of the second polarizing element 322.

[0154] Optionally, an antireflection film may be introduced into the stacked structure formed by the second polarization element 322 and the phase retarder 321, with the antireflection film located on the side of the second polarization element 322 away from the phase retarder 321.

[0155] From the position and function of the second polarizing element 322:

[0156] The second polarization element 322 is located on the side of the phase delayer 321 away from the second surface 32. This arrangement ensures that light (such as virtual imaging light emitted by the display 1) can adjust its polarization state as needed before or after passing through the phase delayer 321.

[0157] The main function of the second polarizing element 322 is to change the polarization state of light. In particular, when the display 1 emits natural light, the second polarizing element 322 can convert it into linearly polarized light to meet the specific polarization requirements of subsequent optical elements (such as the phase retarder 321 and the polarization reflection element 411).

[0158] In the example provided in this application, the second polarizing element 322 is, for example, composed of a polarizing film. This film can selectively transmit light with a specific polarization direction while blocking light with other polarization directions. When natural light (containing light with all polarization directions) is incident on the second polarizing element 322, only light with the same polarization direction as the second polarizing element 322 can pass through, thereby realizing the conversion from natural light to linearly polarized light.

[0159] By adding a second polarizing element 322, the AR optical module of this application can adapt to different types of light sources, including display lights that emit natural light. This enhances the versatility and flexibility of the module.

[0160] By converting natural light into linearly polarized light, the propagation and reflection / transmission behavior of light in subsequent optical elements (such as phase delayer 321 and polarization reflection element 411) becomes more controllable and predictable, thereby optimizing the performance of the entire AR optical module.

[0161] By controlling the polarization state of light, the second polarization element 322 helps reduce light loss and distortion during propagation, thereby improving the clarity and contrast of the image.

[0162] In some examples of this application, the first lens 3 is an aspherical lens.

[0163] In the example provided in this application, the first lens 3 is designed as an aspherical lens, a design that has a significant effect on improving the performance of the AR optical module.

[0164] Firstly, regarding the optical module design resulting from the increased field of view, spherical lenses are prone to spherical aberration in the edge areas, leading to image blurring. Aspherical lenses, on the other hand, can effectively correct this aberration due to their unique surface shape, ensuring a clear and sharp image throughout the entire field of view.

[0165] Secondly, the aspherical design of the first lens 3 in this application not only improves the imaging quality, but also makes it possible to achieve miniaturization and a large field of view for AR optical modules. By optimizing the surface shape of the aspherical lens, light (such as ambient light) can be utilized more effectively, thereby expanding the field of view without increasing the thickness of the AR optical module.

[0166] Furthermore, the AR optical module in this embodiment also achieves a synergistic expansion of the horizontal field of view, reaching over 50°, by strategically positioning the beam-splitting element 311 (combined with the aspherical design of the first lens 3) and carefully setting the tilt angle (A2 within the range of 10° to 15°) of the fourth effective surface 41 of the second prism 4. This design considers both the propagation path of light and fully utilizes the advantages of aspherical lenses, enabling the module to provide a wider field of view while maintaining a compact structure.

[0167] Finally, aspherical lenses, while increasing the field of view, can also effectively correct advanced aberrations such as coma and astigmatism, further improving image quality. This means that users can enjoy a clearer and more realistic visual experience when using AR optical modules, and have a more immersive experience whether watching videos, playing games, or performing other interactive operations.

[0168] See some examples in this application. Figure 13 At least one lens is disposed between the display 1 and the first side of the first prism 2.

[0169] In the AR optical module provided in this application embodiment, a lens can be added between the display 1 and the first prism 2. This design can bring the following advantages, which are analyzed in detail below.

[0170] By adding a lens between the display 1 and the first prism 2, the light emitted from the display 1 (virtual imaging light) can be modulated, effectively reducing excessive light divergence. This design ensures better light propagation in subsequent optical elements and reduces light loss.

[0171] The addition of a lens also provides a focusing function, allowing light to be more concentrated when it reaches the first prism 2. This focusing effect can improve the utilization rate of light, thereby enhancing the clarity of the image.

[0172] By adding a lens between the display 1 and the first prism 2, aberrations generated during light propagation, such as spherical aberration and coma, can be corrected or reduced. This aberration correction significantly improves the imaging quality of the entire AR optical module.

[0173] By placing a lens between the display 1 and the first prism 2, greater flexibility can be provided in the layout of the AR optical module. The position, focal length, and other parameters of the lens can be adjusted according to actual needs to optimize the performance of the entire AR optical module.

[0174] It should be noted that different displays may have different light-emitting characteristics and beam divergence angles. By adding a lens between the display 1 and the first prism 2, these characteristics can be better accommodated, ensuring that light can enter subsequent optical components efficiently.

[0175] By adding one or more lenses between the display 1 and the first prism 2, the influence of ambient light on the AR optical module can be reduced to a certain extent, thereby improving the stability and anti-interference ability of the AR optical module.

[0176] While directly expanding the field of view primarily relies on the overall design of the module, the addition of lenses can assist in achieving this expansion to some extent. This auxiliary effect is particularly pronounced when working in conjunction with other optical elements such as the first prism 2.

[0177] The lens design in this example allows for adjustment of light distribution, resulting in more uniform light delivery to the human eye (O1). This adjustment of light distribution improves viewing comfort and provides a better visual experience for the user.

[0178] In one example, see Figure 13 Two lenses are disposed between the display 1 and the first effective surface 21 of the first prism 2.

[0179] According to the AR optical module provided in the embodiments of this application, see [link to relevant documentation]. Figure 1 The propagation path of the virtual optical path is described in detail below:

[0180] First, the linearly polarized light emitted by the display 1 is incident on the first effective surface 21 of the first prism 2 and is transmitted through this surface, continuing to propagate forward.

[0181] Subsequently, the light rays pass sequentially through the second effective surface 22 and the third effective surface 23 of the first prism 2, and undergo total internal reflection at both surfaces. The conditions for total internal reflection are determined by the surface design of the first prism 2 and the incident angle of the light rays, ensuring that the light rays can propagate efficiently inside the first prism 2.

[0182] Next, the light reaches the fourth effective surface 41 of the second prism 4, where a polarizing reflective element 411 (polarizing reflective film) is provided. The light is reflected on this surface, changing its propagation direction. The reflected light then passes through the second effective surface 22 of the first prism 2 and enters the first lens 3. On the first surface 31 of the first lens 3, the light first passes through the phase retarder 321 (quarter-wave plate), changing its polarization state from linearly polarized to circularly polarized. Subsequently, the circularly polarized light continues to transmit through the first surface 31 of the first lens 3, reaching the beam splitter 311 (semi-transparent and semi-reflective film) provided thereon.

[0183] Upon encountering the beam splitter 311 (semi-transparent and semi-reflective film), part of the light is reflected back into the first lens 3, while the other part continues to transmit. The reflected light then passes through the phase delayer 321 (quarter-wave plate), where its polarization state changes from circularly polarized to linearly polarized, and it is transmitted through the first surface 31 of the first lens 3.

[0184] Subsequently, this linearly polarized light is transmitted again through the second effective surface 22 of the first prism 2 and the fourth effective surface 41 of the second prism 4, and enters the third prism 5. Inside the third prism 5, the light is transmitted through its effective surfaces and finally leaves the third prism 5, entering the human eye 01 to form the virtual image seen by the user.

[0185] According to the AR optical module provided in this application embodiment, light from the real world first passes through the second lens 6, and then sequentially passes through the first lens 3, the first prism 2, the second prism 4, and the third prism 5. These lenses, according to a specific design and layout, ensure that light from the real world can pass through and ultimately accurately enter the human eye 01, allowing the user to simultaneously see the real world and virtual images, achieving an augmented reality effect.

[0186] The AR optical module provided in the embodiments of this application has a large field of view while maintaining a small size. The contribution of the optical design in this application to the field of view is analyzed in detail below.

[0187] The beam splitter 311 is disposed on the first surface 31 (facing the outside) of the first lens 3, and its tilt angle directly determines the incident light receiving range. Combined with the tilt angle of the fourth effective surface 41 of the second prism 4 (A2 = 10°~15°), the lower limit of the effective field of view can be obtained as 50° (horizontal direction).

[0188] The second effective surface 22 (angle A1 = 20°~25°) and the third effective surface 23 of the first prism 2 serve as total reflection surfaces, ensuring that large-angle light rays (such as ±25° incident light rays) are not leaked and reflected within the first prism 2, which can extend the field of view to 60°, or even larger.

[0189] The first lens 3 adopts an aspherical design to correct edge distortion and astigmatism caused by a large field of view.

[0190] The coordinated arrangement of the polarization reflection element 411 with the phase delayer 321 and the beam splitter 311 and other film materials reduces polarization-related light energy loss, ensures uniformity of edge field of view brightness, and avoids the field of view angle from decreasing due to reduced light efficiency.

[0191] The AR optical module of this application will be described below through Examples 1 to 3.

[0192] Example 1

[0193] See Figure 1 and Figure 2 The AR optical module provided in Embodiment 1 includes a display 1, a lens group, a beam splitter 311, a phase delayer 321, and a polarization reflection element 411.

[0194] The lens assembly includes a first prism 2, a first lens 3, a second prism 4, and a third prism 5; the beam splitter 311 is disposed on the first surface 31 of the first lens 3; the phase retarder 321 is disposed on the second surface 32 of the first lens 3; the polarizing reflection element 411 is disposed on the surface of the second prism 4 adjacent to the first prism 2, and the phase retarder 321 is located in the optical path between the beam splitter 311 and the polarizing reflection element 411.

[0195] The first prism 2 has the display 1 disposed on its first side, the first lens 3 is bonded to the third side of the first prism 2 with an air gap, the second prism 4 is bonded to the second side of the first prism 2 with an air gap, and the third prism 5 is bonded to the side of the second prism 4 opposite to the first prism 2.

[0196] The AR optical module further includes a second lens 6, which is disposed on the side of the first lens 3 facing outwards. The optical power of the second lens 6 cancels out the optical power of the first lens 3, so that the first lens 3 and the second lens 6 combine to form a light-transmitting flat plate with zero optical power; see also Figure 2 The second lens 6 and the first lens 3 are cemented together to form a cemented lens;

[0197] Further, the first prism 2 includes a first effective surface 21, a second effective surface 22, and a third effective surface 23; the second prism 4 includes a fourth effective surface 41 and a fifth effective surface 42; wherein, the display 1 is adjacent to and spaced apart from the first effective surface 21; the edge of the third effective surface 23 is bonded to the edge of the second surface 32 of the first lens 3, and an air gap is maintained between them; the edges of the second effective surface 22 and the fifth effective surface 42 are bonded together, and an air gap is maintained between them; the second effective surface 22 and the third effective surface 23 are formed as total reflection surfaces;

[0198] The beam splitter 311 is disposed on the first surface 31, the phase delayer 321 is disposed on the second surface 32, and the polarization reflection element 411 is disposed on the fourth effective surface 41;

[0199] The AR optical module also includes a first polarizing element 511; the sixth effective surface 51 of the third prism 5 is disposed close to the human eye 01, and the first polarizing element 511 is disposed on the sixth effective surface 51.

[0200] The AR optical module also includes a second polarization element 322, which is stacked on the side of the phase delayer 321 away from the second surface 32.

[0201] The first lens 3 is an aspherical lens.

[0202] Please refer to Table 1 below for the main optical parameters of the AR optical module provided in this embodiment 1.

[0203] Table 1

[0204]

[0205] Please refer to Table 2 for the surface tilt angles of each lens in the AR optical module provided in this embodiment 1.

[0206] Table 2

[0207] 52 14 51 0 42 23 41 14 32 0 31 0 23 0 22 23 21 68

[0208] The AR optical module provided in Example 1 has the following optical performance: Figures 3 to 6 As shown: Figure 3 This is a schematic diagram of a dot-matrix diagram. Figure 4 It is an MTF curve. Figure 5 This is a diagram of the curvature and distortion. Figure 6 This is a vertical axis chromatic aberration diagram. The following is about... Figure 3 and Figure 6 Analysis:

[0209] See Figure 3The AR optical module provided in this embodiment 1 has a maximum image size of less than 65μm in the dot matrix diagram.

[0210] See Figure 4 The AR optical module provided in this embodiment 1 has an MTF of >0.1 at 12lp / mm.

[0211] See Figure 5 In the AR optical module provided in this embodiment 1, the maximum distortion occurs in 1 field of view, and the absolute value is less than 12%.

[0212] See Figure 6 The AR optical module provided in this embodiment 1 has a maximum color difference value of less than 55μm.

[0213] Example 2

[0214] See Figure 7 and Figure 8 The AR optical module provided in Embodiment 2 has a basically the same optical architecture as that provided in Embodiment 1. The difference between the two embodiments lies in the design of the optical parameters of the lenses in the AR optical module, which can be found in Tables 3 and 4 below.

[0215] Please refer to Table 3 below for the main optical parameters of the AR optical module provided in this embodiment 2.

[0216] Table 3

[0217]

[0218] Please refer to Table 4 for the surface tilt angles of each lens in the AR optical module provided in this embodiment 2.

[0219] Table 4

[0220]

[0221]

[0222] The AR optical module provided in this embodiment 2 has the following optical performance: Figures 9 to 12 As shown: Figure 9 This is a schematic diagram of a dot-matrix diagram. Figure 10 It is an MTF curve. Figure 11 This is a diagram of the curvature and distortion. Figure 12 It is a vertical axis color difference diagram.

[0223] See Figure 9 The AR optical module provided in this embodiment 2 has a maximum image size of less than 62μm in the dot matrix diagram.

[0224] See Figure 10 The AR optical module provided in this embodiment 2 has an MTF of >0.3 at 12lp / mm.

[0225] See Figure 11 The AR optical module provided in this embodiment 2 has the maximum distortion occurring in the field of view, with an absolute value of less than 12%.

[0226] See Figure 12 The AR optical module provided in this embodiment 3 has a maximum color difference value of less than 55μm.

[0227] Example 3

[0228] See Figure 13 The AR optical module provided in Embodiment 3 differs from the optical architecture provided in Embodiments 1 and 2 above in that two additional lenses are introduced between the display 1 and the first effective surface 21 of the first prism 2.

[0229] It should be noted that the optical parameter table in Example 3 (excluding the two introduced lenses) can be found in Tables 1 and 2 of Example 1, or Tables 3 and 4 of Example 2.

[0230] The optical performance of the AR optical module in this embodiment 3 is as follows:

[0231] The AR optical module provided in this embodiment 3 has a maximum image value of less than 65μm in the dot matrix diagram, an MTF of >0.1 at 12lp / mm, maximum distortion occurring in the field of view with an absolute value of less than 12%, and a maximum chromatic difference of less than 55μm.

[0232] According to another embodiment of this application, a smart head-mounted device is provided, the smart head-mounted device including a housing and an AR optical module as described above.

[0233] The smart head-mounted device provided in this application embodiment is, for example, AR glasses or an AR helmet.

[0234] The specific implementation of the smart head-mounted device in this application can refer to the various embodiments of the AR optical module described above. Therefore, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be described in detail here.

[0235] The above embodiments mainly describe the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be elaborated here.

[0236] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. An AR optical module, characterized in that, include: Display (1); The lens group includes a first prism (2), a first lens (3), a second prism (4), and a third prism (5); A beam splitter (311) is disposed on the first surface (31) of the first lens (3); A phase delayer (321) is disposed on the second surface (32) of the first lens (3); A polarizing reflective element (411) is disposed on the surface adjacent to the second prism (4) and the third prism (5), and the phase delayer (321) is located in the optical path between the beam splitter (311) and the polarizing reflective element (411); The first prism (2) has a display (1) on its first side, the first lens (3) is glued to the third side of the first prism (2) with an air gap, the second prism (4) is glued to the second side of the first prism (2) with an air gap, and the third prism (5) is glued to the side of the second prism (4) away from the first prism (2).

2. The AR optical module according to claim 1, characterized in that, The air gap between the first lens (3) and the third side of the first prism (2) is L1, and the air gap between the second prism (4) and the second side of the first prism (2) is L2. Both L1 and L2 satisfy: 0.05mm≤L1, L2≤0.15mm.

3. The AR optical module according to claim 1 or 2, characterized in that, The AR optical module also includes a second lens (6), which is disposed on the side of the first lens (3) facing outward. The optical power of the second lens (6) and the optical power of the first lens (3) can cancel each other out, so that the first lens (3) and the second lens (6) are combined to form a light-transmitting plate with zero optical power.

4. The AR optical module according to claim 3, characterized in that, The second lens (6) and the first lens (3) are glued together to form a glued lens.

5. The AR optical module according to claim 3, characterized in that, The first prism (2) includes a first effective surface (21), a second effective surface (22) and a third effective surface (23); The second prism (4) includes a fourth effective surface (41) and a fifth effective surface (42); Wherein: the display (1) is adjacent to and spaced apart from the first effective surface (21); The third effective surface (23) is glued to the edge of the second surface (32) of the first lens (3), and an air gap is maintained between them; The edges of the second effective surface (22) and the fifth effective surface (42) are glued together, with an air gap between them; The second effective surface (22) and the third effective surface (23) are formed as total reflective surfaces.

6. The AR optical module according to claim 5, characterized in that, The aperture of the cemented area between the third effective surface (23) of the first prism (2) and the second surface (32) of the first lens (3) is D1, and the un-cemented area on the third effective surface (23) forms the total reflection surface, the aperture of the total reflection surface is D2, and 0.75≤D1 / D2≤1; The diameter of the glued area between the second effective surface (22) of the first prism (2) and the fifth effective surface (42) of the second prism (4) is D3. The un-glued area on the second effective surface (22) forms the total reflection surface, and the diameter of the total reflection surface is D4, and 0.75≤D3 / D4≤1.

7. The AR optical module according to claim 5, characterized in that, The angle A1 between the second effective surface (22) of the first prism (2) and the vertical direction satisfies 20°≤A1≤25°.

8. The AR optical module according to claim 5, characterized in that, The angle A2 between the fourth effective surface (41) of the second prism (4) and the vertical direction satisfies 10°≤A2≤15°.

9. The AR optical module according to claim 8, characterized in that, The beam splitter (311) is disposed on the first surface (31), the phase delayer (321) is disposed on the second surface (32), and the polarization reflection element (411) is disposed on the fourth effective surface (41).

10. The AR optical module according to claim 1 or 9, characterized in that, The AR optical module also includes a first polarization element (511). The sixth effective surface (51) of the third prism (5) is located close to the human eye (01), and the first polarizing element (511) is located on the sixth effective surface (51).

11. The AR optical module according to claim 10, characterized in that, The AR optical module also includes a second polarization element (322), which is stacked on the side of the phase delayer (321) away from the second surface (32).

12. The AR optical module according to claim 1, characterized in that, The first lens (3) is an aspherical lens.

13. The AR optical module according to claim 1, characterized in that, At least one lens is disposed between the display (1) and the first side of the first prism (2).

14. A smart head-mounted device, characterized in that, include: shell; and The AR optical module as described in any one of claims 1-13.

Images