AR optical module and intelligent head-mounted device

Abstract

The embodiment of the invention provides an AR optical module and intelligent head-mounted equipment. 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 the first surface of the first lens; the phase retarder is arranged on the second surface of the first lens; the polarization reflection element is arranged on the surface, adjacent to the first prism, of the second prism, and the phase delayer is located between the light splitting element and the polarization reflection element; the display is arranged on the first side of the first prism, the first lens and the third side of the first prism are glued in a manner of reserving an air gap, and the second prism and the second side of the first prism are glued in a manner of reserving an air gap. And the third prism is glued with one side, deviating from the first prism, of the second prism.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of projection optical display technology. More specifically, the embodiments of the present application relate to an AR optical module and an intelligent head-mounted device. Background Art

[0002] With the development of AR technology, large field of view and small size have become important development trends in 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 a pressing issue in the current AR technology field. Summary of the Invention

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

[0004] In a first aspect, an embodiment of the present application provides an AR optical module comprising:

[0005] monitor;

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

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

[0008] a phase retarder, disposed on the second surface of the first lens;

[0009] a polarizing reflective element disposed on a surface of the second prism adjacent to the first prism, and the phase retarder located on an optical path between the beam splitting element and the polarizing reflective element;

[0010] The display is provided on the first side of the first prism, the first lens is glued to the third side of the first prism in a manner of retaining an air gap, the second prism is glued to the second side of the first prism in a manner of retaining an air gap, and the third prism is glued to the side of the second prism facing away from the first prism.

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

[0012] Optionally, the AR optical module also includes a second lens, which is arranged on the side of the first lens facing the outside world. The optical focal length of the second lens and the optical focal length of the first lens can offset each other, so that the first lens and the second lens are combined to form a light-transmitting flat plate with zero optical focal length.

[0013] Optionally, the second lens and the first lens are glued together to form a glued 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] The display is adjacent to the first effective surface and spaced apart; the third effective surface is glued to the edge of the second surface of the first lens, and an air gap is retained between the two; the second effective surface is glued to the edge of the fifth effective surface, and an air gap is retained between the two; the second effective surface and the third effective surface are formed as total reflection surfaces.

[0017] Optionally, the aperture of the bonding area between the third effective surface of the first prism and the second surface of the first lens is D1, the unbonded 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 bonding 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, the aperture of the total reflection surface is D4, and 0.75≤D3 / D4≤1.

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

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

[0021] Optionally, the beam splitter element is disposed on the first surface, the phase retarder is disposed on the second surface, and the polarized reflective 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 arranged close to the human eye, and the first polarizing element is arranged on the sixth effective surface.

[0024] Optionally, the AR optical module further includes a second polarization element, which is stacked on a 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 provided between the display and the first side of the first prism.

[0027] In a second aspect, an embodiment of the present application provides a micro-projection device, the micro-projection device comprising:

[0028] casing; and

[0029] The AR optical module as described in the second aspect.

[0030] The beneficial effects of this application are:

[0031] The AR optical module provided in the embodiments of the present application, through its unique optical design and layout, achieves a small size and a large field of view while significantly improving imaging quality, as embodied in the following aspects:

[0032] The AR optical module provided in the embodiment of the present application effectively reduces the physical contact area between the lenses by optimizing the specific layout and configuration of the lens group, especially by retaining the air gap between the gluing setting; wherein, the first lens and the first prism, and the second prism and the first prism are glued in a manner of retaining the air gap. This design not only reduces the interference between the lenses, but also makes the entire optical module more compact.

[0033] The AR optical module provided in the embodiments of the present application achieves control over the polarization state of light through the combined use of a spectrometer, a phase retarder, and a polarized reflective element. The module also increases the number of light reflections by using an air gap, thereby ensuring a sufficient optical path and achieving a wide field of view display. Specifically, the light emitted by the display is transmitted and totally reflected by the first prism, then split and phase-delayed by the first lens, and finally reflected by the polarized reflective element before entering the human eye. During this process, the light undergoes multiple reflections and transmissions, effectively expanding the field of view.

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

[0035] Other features and advantages of the present specification will become apparent from the following detailed description of exemplary embodiments of the present specification with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

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

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

[0042] Figure 6 for Figure 2 Provided vertical axis chromatic aberration diagram of AR optical module;

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

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

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

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

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

[0048] Figure 12 for Figure 8 Provided vertical axis chromatic aberration diagram of AR optical module;

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

[0050] Description of reference numerals:

[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. Polarized 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 DESCRIPTION

[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 arrangements of components and steps, numerical expressions and numerical values ​​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 in nature and is in no way intended to limit the present disclosure, its application, or uses.

[0054] Techniques and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the techniques and equipment should be considered part of the specification.

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

[0056] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

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

[0058] According to one embodiment of the present application, an AR optical module is provided. Figure 1The AR optical module includes a display 1, a lens group, a beam splitter 311, a phase retarder 321 and a polarizing reflective element 411. The display 1 is used to provide 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 arranged on the first surface 31 of the first lens 3; the phase retarder 321 is arranged on the second surface 32 of the first lens 3. The polarizing reflective element 411 is arranged on the surface of the second prism 4 adjacent to the first prism 2, and the phase retarder 321 is located on the optical path between the beam splitter 311 and the polarizing reflective element 411. The display 1 is provided on the first side of the first prism 2, the first lens 3 is glued to the third side of the first prism 2 in a manner that retains an air gap, the second prism 4 is glued to the second side of the first prism 2 in a manner that retains an air gap, and the third prism 5 is glued to the side of the second prism 4 facing away from the first prism 2.

[0059] The AR optical module provided in the embodiments of this application can be applied to AR optical display devices, such as AR smart head-mounted devices. Of course, the 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 the embodiments of this application is further described below.

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

[0061] The AR optical module provided in the embodiments of the present application includes a specially designed lens assembly comprising three prisms and an optical lens. Specifically, the lens assembly comprises 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 reflect the virtual imaging light emitted by the display 1 to achieve image projection and magnification.

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

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

[0064] In the lens set, 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 polarizing reflection element 411 is provided on the fourth effective surface 41 for reflecting light of a specific polarization direction.

[0065] It should be noted that the phase retarder 321 should be located between the light splitting element 311 and the polarization reflection element 411 to ensure that a folded optical path is formed.

[0066] In the lens set, please continue to see Figure 1 The third prism 5 and the second prism 4 are glued together on the side facing away from the first prism 2 to further guide the light into the human eye 01 for imaging.

[0067] Preferably, the second prism 4 and the third prism 5 are glued together without reserving an air gap between them.

[0068] Of course, the second prism 4 and the third prism 5 may not be glued together, but may be arranged closely together, or with a small air gap between them.

[0069] In the AR optical module provided in the embodiment of the present application, optical film materials such as a spectrometer 311, a phase retarder 321 and a polarization reflection element 411 are introduced. These optical film materials are combined with specially designed lenses, such as a first lens 3 and a second prism 4, to form a folded optical path.

[0070] The light splitting element 311 can transmit a portion of the light and reflect a portion of the light, thereby splitting the light into different paths or changing the propagation direction of the light.

[0071] In the embodiment provided in this application, the light splitting element 311 is, for example, a semi-transparent and semi-reflective film.

[0072] The phase retarder 321 is disposed on the second surface 32 (the surface facing away from the outside world) of the first lens 3 and can be used to change the polarization state of light to match subsequent optical elements (such as the polarized reflective element 411).

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

[0074] In the embodiment of the present application, the phase retarder 321 is, for example, a quarter-wave plate.

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

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

[0077] In the embodiment of the present application, the polarized reflective element 411 is a polarized reflective film.

[0078] In the AR optical module provided in the embodiment of the present application, the first lens 3 and the first prism 2, as well as the second prism 4 and the first prism 2, are glued together to retain an air gap. This ensures the relative position stability between the lenses and retains the necessary air gap to achieve total reflection and transmission of light.

[0079] See also Figure 1 In the AR optical module provided in an embodiment of the present application, the optical 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 through the first prism 2 (total reflection) → the beam splitter 311 (reflection) → the phase retarder 321 (polarization conversion) → the polarized reflective element 411 (secondary reflection), and finally enters the human eye 01. 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 the embodiments of the present application, through specific optical design and optical element layout, especially the use of the total reflection principle and the gluing method of retaining air gaps, the AR optical module of the present application significantly reduces the overall thickness of the module while ensuring a large field of view angle, thereby achieving the design goal of small size.

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

[0082] In addition, the AR optical module in the embodiment of the present application adopts a new design of air-gap bonding, which effectively avoids the stress and deformation problems that may be caused by traditional bonding structures. At the same time, it also eliminates the need for additional support structures, making the AR optical module more simple and efficient in structure. This improvement not only optimizes the optical performance of the AR optical module, but also significantly promotes the lightweight design of the AR optical module, reducing the overall weight of the module by 15% to 20%, further improving the product's portability and user experience.

[0083] In the AR optical module provided in the embodiment of the present application, the combined use of the spectroscopic element 311, the phase retarder 321 and the polarized reflection element 411 effectively controls the polarization state and the splitting ratio of the light, reduces the influence of stray light and chromatic aberration, and improves the clarity and contrast of imaging.

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

[0085] The AR optical module provided in the embodiment of the present application achieves a balance between a large field of view and a small module size, which 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, etc., and can provide users with a more comfortable and immersive experience.

[0086] In some examples of the present 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] A larger air gap increases the size of the entire AR optical module, which contradicts the goal of this application to pursue a small-size design. By limiting the air gaps L1 and L2 to the reasonable range described in this example, it helps to achieve a compact layout of the AR optical module, making it more suitable for use in scenarios with size requirements, such as smart head-mounted devices.

[0089] Excessive air gaps may 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 the embodiments of the present application, precise control of the light propagation path is crucial to achieving high-quality imaging.

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

[0091] Too small an air gap increases assembly difficulty, requiring higher machining and assembly precision. A too small air gap can lead to stress concentration between the lenses, increasing the risk of lens deformation. This can be exacerbated by temperature fluctuations or mechanical vibrations, impacting 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 the range of 0.05mm to 0.15mm is the result of comprehensive consideration of multiple factors, including module compactness, light propagation control, imaging quality, assembly processability, stress deformation, and optical performance stability. This design not only meets the performance requirements of the AR optical module, but also takes into account the feasibility and cost-effectiveness of actual production.

[0093] In some examples of this application, see Figure 2 The AR optical module also includes a second lens 6, which is arranged on the side of the first lens 3 facing the outside world, and the optical focal length of the second lens 6 and the optical focal length of the first lens 3 can offset each other, so that the first lens 3 and the second lens 6 are combined to form a light-transmitting flat plate with zero optical focal length.

[0094] Optical power is a physical quantity that measures a lens's ability to deflect light. When two lenses have equal power but opposite signs, their combined power is zero, meaning they have no light deflection, effectively acting like a flat piece of glass.

[0095] In the examples provided in this application, see Figure 2 A second lens 6 is introduced on the outer side of the first lens 3. The optical powers of the first lens 3 and the second lens 6 are designed to offset each other, so that the combined structure appears optically as a light-transmitting flat plate.

[0096] The example of this application involves the design of optical focal compensation. The principle of double lens extinction is: the optical focal length of the second lens 6 is The optical power of the first lens 3 satisfy The combination of the two is equivalent to a light-transmitting flat plate, which has no focusing or diverging effect on ambient light (external light), thus avoiding the introduction of additional aberrations.

[0097] From the position layout of the second lens 6, the second lens 6 is set on the external 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 external light is basically free of distortion when passing through the module.

[0098] By introducing the second lens 6 and forming a combination with the first lens 3 with zero optical power, aberrations caused by the optical power of the lens itself, such as spherical aberration, coma, etc., can be effectively reduced or eliminated, thereby improving the clarity and accuracy of imaging. The design of this light-transmitting flat plate makes the AR optical module more stable when facing different ambient light conditions. Since it does not produce additional deflection effects on light, it can reduce fluctuations in imaging quality caused by changes in ambient light. In addition, the dual-lens combination can offset aberrations such as spherical aberration and field curvature of a single lens, and in particular can compensate for the edge astigmatism caused by the large field of view of the first lens 3.

[0099] In some examples of this application, see Figure 2 The second lens 6 and the first lens 3 are glued together to form a glued 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 located on the external side. This glued design simplifies the assembly process.

[0101] In this bonding design, the curvature of the surface (bonding surface) of the second lens 6 can be complementary to that of the first lens 3 (bonding surface). For example, if the bonding surface of the first lens 3 is convex, the bonding surface of the second lens 6 is concave. The specific curvature of the bonding 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 losses of ambient light between the two lenses. This helps to improve the transmittance of ambient light, allowing more ambient light to be accurately focused on the human eye 01, thereby improving image clarity and contrast. Furthermore, this cemented lens design can also reduce aberrations caused by the air gap between the lenses, such as chromatic aberration and astigmatism, further optimizing image quality.

[0103] Gluing the second lens 6 to the first lens 3 can simplify the assembly process of the AR optical module, reduce the positioning and fixing steps between the lenses, improve production efficiency, and reduce performance fluctuations caused by improper assembly.

[0104] In this example of the present application, gluing the first lens 3 and the second lens 6 together 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 conducive to the lightweight design of the AR device.

[0105] Optimized image quality and enhanced module stability help improve the user's visual 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 antireflection film may be provided on the surface of the second lens 6 .

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

[0108] On the one hand, the first lens 3 and the second lens 6 can be bonded together to form a single, integrated cemented lens. This design significantly reduces the air gap between the lenses, thereby reducing reflection and scattering of light between the lenses, improving light transmittance and imaging quality. Furthermore, the internal structure of the cemented lens as a whole is more stable, helping to maintain 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 chosen not to be glued together, but to maintain a certain air gap, as long as the sum of their optical powers is zero. This non-glued design gives designers greater flexibility because the surface shapes of two adjacent lenses can be designed to be inconsistent. This flexibility enables AR optical modules to better adapt to different application scenarios and performance requirements. For example, by adjusting the lens surface shape to optimize the transmission of light of a specific wavelength, or designing an asymmetric lens structure to achieve a specific optical effect.

[0110] Whether choosing a glued or non-glueed design, the key is to ensure that the sum of the optical powers of the first lens 3 and the second lens 6 is zero, thereby meeting the imaging quality and module stability requirements of the AR optical module. The specific method to be chosen should be comprehensively considered based on factors such as the actual application scenario, performance requirements, and manufacturing costs.

[0111] In some examples of this application, see 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 the first effective surface 21 and spaced apart from each other; the third effective surface 23 is glued to the edge of the second surface 32 of the first lens 3, with an air gap remaining between the two; the second effective surface 22 is glued to the edge of the fifth effective surface 42, with an air gap remaining between the two; and 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, antireflection films are provided on the 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 also 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 between them. This design allows light (virtual imaging light emitted by the display 1) to be totally reflected off 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 also 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, also retaining an air gap. This approach also allows light (virtual imaging light emitted by the display 1) to be totally reflected at the second effective surface 22 and facilitates precise alignment between the two prisms.

[0119] In the embodiment of the present application, the second effective surface 22 and the third effective surface 23 of the first prism 2 are both designed as total reflection surfaces, which is one of the key factors in achieving a small size of the AR optical module. By utilizing the principle of total reflection, light can be reflected multiple times within 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 the total reflection surface (the second effective surface 22 and the third effective surface 23) and the gluing method that retains the air gap, the AR optical module of the present application significantly reduces the overall thickness of the module (small size) while maintaining a large field of view angle. This design makes the AR optical display device more portable and suitable for various application scenarios. The edge gluing method between the first prism 2 and the first lens 3 maintains the relative position stability between the optical elements and reduces performance fluctuations caused by mechanical vibration or temperature changes. This stability is crucial to ensuring the reliable operation of the AR optical module in various environments.

[0121] In some examples of the present application, the aperture of the bonding 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 unbonded 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 aperture of the bonding 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 unbonded area on the second effective surface 22 forms the total reflection surface. The aperture of the total reflection surface is D4, and 0.75≤D3 / D4≤1.

[0122] By reasonably setting the ratio of the bonding area aperture (D1, D3) to the total reflection surface aperture (D2, D4) (0.75≤D1 / D2≤1 and 0.75≤D1 / D2≤1), the effective propagation and total 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 ensures the integrity of the optical path. When the ratio of the bonding area aperture to the total reflection surface aperture is close to but not more than 1, it means that the size of the bonding area is reduced as much as possible while ensuring a smooth optical path. This design helps to reduce the volume of the entire optical module, making it more compact.

[0123] In some examples of the present application, an included 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 specifies that its angle A1 with the vertical direction satisfies the condition of 20°≤A1≤25°. This optical parameter design is closely related to the goal of achieving a small size of the AR optical module.

[0125] In this example of the present 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 selected 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 a phenomenon in optics. When light travels from a denser medium to a less dense medium, and the angle of incidence is greater than or equal to the critical angle, the light is completely reflected 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 (such as virtual imaging light) satisfies the conditions for total internal reflection on the second effective surface 22, thereby achieving multiple reflections of light within the first prism 2.

[0127] Under the condition of ensuring that the second effective surface 22 produces total reflection, reducing the overall thickness of the AR optical module is an important design goal of this application. By controlling the above-mentioned angle A1 between 20° and 25°, this application can effectively utilize the principle of total 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 enables the AR optical module to achieve a smaller size while maintaining a large field of view angle, thereby improving the portability and user experience of the product.

[0128] In other words, the optical parameter design of 20°≤A1≤25° provided in this example of the present application realizes the miniaturization of the AR optical module. This design can make the AR optical display device 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 the transmission process, thereby improving the utilization rate of light. At the same time, by optimizing the design of angle A1, this application can also reduce aberrations caused by light refraction or scattering, thereby improving the clarity 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 the present application, an included 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 herein, the angle A2 between the fourth effective surface 41 of the second prism 4 and the vertical direction is set within a range of 10° to 15°. This optical parameter design is based on comprehensive considerations of the overall design and performance optimization of the AR optical module, and is intended to ensure that the virtual imaging light emitted by the display 1 can be incident on the polarized reflective element 411 on the optical path at an optimal angle, thereby significantly improving the reflectivity and transmittance of the light.

[0133] Specifically, the performance of the polarized reflective element 411, as one of the optical elements in the AR optical module of this application, directly determines the efficiency of light utilization. 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 is possible to ensure that the virtual imaging light is incident on the rear polarized reflective element 411 at a nearly ideal angle, thereby maximizing the selective reflection and transmission properties of the polarized reflective element 411 and effectively improving the utilization rate of light.

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

[0135] From the technical effect point of view, controlling the angle A2 within the above 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 the AR optical module.

[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 incident on the polarized reflective element 411, performance fluctuations caused by improper incident angles are 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 angle A2, providing strong support for the realization of lighter and more portable AR devices.

[0140] To sum up, this example of the present application maximizes the utilization efficiency of light (especially virtual imaging light) in the 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 new ideas 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] In some examples of this application, see Figure 1 The light splitting element 311 is disposed on the first surface 31 , the phase retarder 321 is disposed on the second surface 32 , and the polarizing reflection element 411 is disposed on the fourth effective surface 41 .

[0143] In the examples provided in this application, the formation of a folded optical path is achieved by carefully designing the layout and configuration of optical elements. Figure 1 The beam splitter 311 (a semi-transmissive, 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 01) of the second prism 4. This layout fully utilizes the characteristics of each optical component, which work together to affect the light propagation path, forming a compact and efficient folded optical path.

[0144] In the AR optical module provided in the embodiment of the present application, the synergistic effect of the beam splitter 311, the phase retarder 321, and the polarized reflective element 411 creates a folded optical path within the module, particularly between the first lens 3 and the second prism 4, with multiple reflections and transmissions. This design significantly reduces the overall thickness of the AR optical module, achieving the goal of a compact design.

[0145] The design of the folded optical path 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 display effect of the AR optical module.

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

[0147] See also Figure 1 The AR optical module provided in the embodiment of the present application further introduces a first polarizing element 511, which is arranged on the surface of the third prism 5 close to the human eye 01, that is, Figure 1 and Figure 2 The sixth effective surface 51 is shown in FIG. The sixth effective surface 51 is the last optical interface before light enters the human eye.

[0148] The main function of the first polarization element 511 proposed in this example of the present application is to reduce stray light and improve the clarity and contrast of imaging. Specifically, in the AR optical module, stray light may come from the reflection of ambient light, scattering of optical elements, etc., which will interfere with the user's viewing experience of the imaging display. The setting of the first polarization element 511 selectively allows light with a specific polarization direction to pass through while blocking light with other polarization directions, thereby effectively reducing the impact of stray light.

[0149] The first polarizing element 511 is, for example, made of a polarizing film with specific polarization-selective properties. When light strikes the first polarizing element 511, only light aligned with the polarization direction of the first polarizing element 511 is transmitted, while light in other directions is absorbed or reflected. In this way, the first polarizing element 511 filters out most stray light, allowing only image-related light to enter the human eye 01.

[0150] Thus, 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 can bring users a better AR experience. Users can more naturally integrate into the environment composed of virtual and real life, enjoying a more immersive visual experience.

[0151] The addition of the first polarizing element 511 also helps to 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 polarizing element 511 works together with other optical elements in the AR optical module, such as the beam splitter 311, the phase retarder 321, the polarized reflective element 411 and the lens group, to form an efficient and compact optical system. The optical elements cooperate with each other to ensure that light can propagate along a predetermined path and achieve the best imaging effect when entering the human eye.

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

[0153] In the examples provided in this application, see Figure 1 The AR optical module may further include a second polarizing element 322, which is stacked on a 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 anti-reflection film may be introduced into the stacked structure formed by the second polarizing element 322 and the phase retarder 321 , and the anti-reflection film is located on a side of the second polarizing element 322 away from the phase retarder 321 .

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

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

[0157] The second polarizing element 322 primarily converts the polarization state of light. Specifically, when the display 1 emits natural light, the second polarizing element 322 converts it into linearly polarized light, thereby satisfying the specific polarization requirements of subsequent optical elements (such as the phase retarder 321 and the polarizing reflective element 411).

[0158] In the example provided herein, the second polarizing element 322 is comprised of, for example, a polarizing film, which selectively transmits light of a specific polarization direction while blocking light of other polarization directions. When natural light (including light of all polarization directions) is incident on the second polarizing element 322, only light aligned with the polarization direction of the second polarizing element 322 is transmitted, thereby achieving a conversion from natural light to linearly polarized light.

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

[0160] After converting natural light into linearly polarized light, the propagation and reflection / transmission behavior of light in subsequent optical elements (such as phase retarder 321 and polarization reflection element 411) will be 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 to reduce the loss and distortion of light during propagation, thereby improving the clarity and contrast of imaging.

[0162] In some examples of the present 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, which has a significant effect on improving the performance of the AR optical module.

[0164] First, with regard to optical module design driven by an increased field of view, spherical lenses are prone to spherical aberration at the edges, resulting in blurred images. However, aspherical lenses, with their unique surface shape, can effectively correct this aberration, ensuring a clear and sharp image across 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 a small size and a large field of view of the AR optical module. By optimizing the surface shape of the aspherical lens, light (such as ambient light) can be used more effectively, thereby expanding the field of view without increasing the thickness of the AR optical module.

[0166] In addition, the AR optical module in the embodiment of the present application also achieves a coordinated expansion of the horizontal field of view angle to over 50° by arranging the beam splitter element 311 (combined with the aspherical design of the first lens 3) and carefully setting the inclination angle of the fourth effective surface 41 of the second prism 4 (A2 is in the range of 10° to 15°). This design not only takes into account the propagation path of light, but also fully utilizes the advantages of aspherical lenses, allowing the module to provide a wider field of view while maintaining a compact structure.

[0167] Finally, aspherical lenses not only increase the field of view but 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 the AR optical module, and gain a more immersive experience whether watching videos, playing games, or performing other interactive operations.

[0168] In some examples of this application, see Figure 13 At least one lens is provided between the display 1 and the first side of the first prism 2 .

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

[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 the transitional divergence of the light. This design ensures better propagation of light in subsequent optical elements and reduces light loss.

[0171] The addition of the lens can also have a focusing function, so that the light can be more concentrated when it reaches the first prism 2. This focusing effect can improve the utilization rate of light and thus improve the clarity of imaging.

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

[0173] The arrangement of a lens between the display 1 and the first prism 2 provides greater flexibility for the layout of the AR optical module. Parameters such as the position and focal length 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 emission characteristics and beam divergence angles. By adding a lens between the display 1 and the first prism 2, these characteristics can be better adapted to ensure that light can efficiently enter subsequent optical elements.

[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] Although directly expanding the field of view mainly depends on the overall design of the module, the addition of lenses can help expand the field of view to a certain extent. This auxiliary effect is more obvious when working in conjunction with other optical elements such as the first prism 2.

[0177] Through the design of the lens in this example of the present application, the distribution of light can be adjusted so that the light is more uniform when it reaches the human eye 01. This adjustment of light distribution improves viewing comfort and provides users with a better visual experience.

[0178] In one example, see Figure 13 Two lenses are arranged 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 embodiment of the present application, see Figure 1 , the propagation path of the virtual light path is described as follows:

[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, and continues to propagate forward.

[0181] The light then passes through the second effective surface 22 and the third effective surface 23 of the first prism 2 in sequence, and is totally reflected on these two surfaces. The conditions for total reflection are determined by the surface design of the first prism 2 and the incident angle of the light, ensuring that the light can propagate efficiently within the first prism 2.

[0182] Next, the light reaches the fourth effective surface 41 of the second prism 4, which is provided with a polarizing reflective element 411 (polarizing reflective film). The light is reflected on this surface, changing its propagation direction. The reflected light is transmitted through the second effective surface 22 of the first prism 2 again, and then 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), and its polarization state is converted from linearly polarized light to circularly polarized light. Subsequently, the circularly polarized light continues to transmit through the first surface 31 of the first lens 3 and reaches the spectroscopic element 311 (semi-transmissive and semi-reflective film) provided thereon.

[0183] After encountering the beam splitter 311 (semi-transmissive, 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 passes through the phase retarder 321 (quarter-wave plate) again, and its polarization state is converted from circularly polarized light to linearly polarized light, which then transmits through the first surface 31 of the first lens 3.

[0184] Subsequently, this linearly polarized light beam 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 beam is transmitted through its effective surface, and finally leaves the third prism 5 and enters the human eye 01, forming the virtual image seen by the user.

[0185] According to the AR optical module provided in the embodiments of the present application, 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 their specific design and layout, ensure that light from the real world can pass through and ultimately accurately enter the human eye 01, ultimately allowing the user to simultaneously see the real world and virtual images, achieving an augmented reality effect.

[0186] The AR optical module provided by the embodiment of the present 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 as follows.

[0187] The beam splitter 311 is disposed on the first surface 31 (facing the outside world) of the first lens 3. Its tilt angle directly determines the range of incident light received. Combined with the tilt angle (A2 = 10° to 15°) of the fourth effective surface 41 of the second prism 4, the lower limit of the effective field of view is 50° (horizontally).

[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 (such as ±25° incident light) has no leakage reflection in the first prism 2, which can expand the field of view angle 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 layout of the polarized reflective element 411, the phase retarder 321, the beam splitter 311 and other film materials reduces polarization-related light energy loss, ensures brightness uniformity at the edge of the viewing field, and avoids a reduction in the viewing angle due to a decrease in light efficiency.

[0191] The AR optical module of the present application is described below through Examples 1 to 3.

[0192] Example 1

[0193] See also Figure 1 and Figure 2 The AR optical module provided in Example 1 includes a display 1, a lens assembly, a beam splitter 311, a phase retarder 321, and a polarized reflective 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 reflective 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 reflective element 411;

[0195] The display 1 is provided on a first side of the first prism 2, the first lens 3 is glued to the third side of the first prism 2 with an air gap therebetween, the second prism 4 is glued to the second side of the first prism 2 with an air gap therebetween, and the third prism 5 is glued to a side of the second prism 4 facing away from 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 the outside world, and the optical power of the second lens 6 offsets the optical power of the first lens 3, so that the first lens 3 and the second lens 6 are combined to form a light-transmitting flat plate with zero optical power; see Figure 2 , the second lens 6 and the first lens 3 are glued together to form a cemented lens;

[0197] Furthermore, 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 the first effective surface 21 and spaced apart; the third effective surface 23 is glued to the edge of the second surface 32 of the first lens 3, with an air gap remaining therebetween; the second effective surface 22 is glued to the edge of the fifth effective surface 42, with an air gap remaining therebetween; 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 retarder 321 is disposed on the second surface 32 , and the polarizing reflective element 411 is disposed on the fourth effective surface 41 ;

[0199] 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 ;

[0200] The AR optical module further includes a second polarizing element 322 , which is stacked on a side of the phase retarder 321 away from the second surface 32 ;

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

[0202] The main optical parameters of the AR optical module provided in this embodiment 1 are shown in Table 1 below.

[0203] Table 1

[0204]

[0205] The surface inclination angles of the lenses of the AR optical module provided in this embodiment 1 are shown in Table 2.

[0206] Table 2

[0207] Surface number Angle with vertical direction (°) 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 this embodiment 1 has optical performance such as Figures 3 to 6 As shown: Figure 3 is a point diagram diagram. Figure 4 is the MTF curve graph, Figure 5 It is the field curvature and distortion diagram, Figure 6 is the vertical axis chromatic aberration diagram. Figure 3 and Figure 6 Perform analysis:

[0209] See also Figure 3In the AR optical module provided in the first embodiment, the maximum value of the image point in the point array diagram is less than 65 μm.

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

[0211] See also 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 also Figure 6 The AR optical module provided in this embodiment 1 has a maximum chromatic aberration value of less than 55 μm.

[0213] Example 2

[0214] See also Figure 7 and Figure 8 The AR optical module provided in Example 2 is substantially the same as the optical architecture provided in Example 1. The difference between the two embodiments is that the optical parameter design of the lenses in the AR optical module can be referred to in Tables 3 and 4 shown below, respectively.

[0215] The main optical parameters of the AR optical module provided in this embodiment 2 are shown in Table 3 below.

[0216] Table 3

[0217]

[0218] The surface tilt angles of the lenses of the AR optical module provided in this embodiment 2 are shown in Table 4.

[0219] Table 4

[0220]

[0221]

[0222] The AR optical module provided in this embodiment 2 has optical performance such as Figures 9 to 12 As shown: Figure 9 is a point diagram diagram. Figure 10 is the MTF curve graph, Figure 11 It is the field curvature and distortion diagram, Figure 12 This is the vertical axis chromatic aberration diagram.

[0223] See also Figure 9 In the AR optical module provided in the second embodiment, the maximum value of the image point in the point array diagram is less than 62 μm.

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

[0225] See also Figure 11 In the AR optical module provided in this embodiment 2, the maximum distortion occurs in 1 field of view, and the absolute value is less than 12%.

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

[0227] Example 3

[0228] See also Figure 13 The AR optical module provided in Example 3 is different from the optical architecture provided in Examples 1 and 2 described 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 refer to Table 1 and Table 2 in Example 1, and can also refer to Table 3 and Table 4 in Example 2.

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

[0231] The AR optical module provided in this embodiment 3 has a maximum value of the image point in the point array diagram less than 65μm, an MTF greater than 0.1 at 12lp / mm, maximum distortion occurring in 1 field of view, with an absolute value less than 12%, and a maximum chromatic aberration value less than 55μm.

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

[0233] The smart head-mounted device provided in the embodiments of the present application is, for example, AR glasses or an AR helmet.

[0234] The specific implementation of the intelligent head-mounted device of the embodiment of the present application can refer to the various embodiments of the above-mentioned AR optical module, and therefore at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here one by one.

[0235] The above embodiments focus on 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. Considering the simplicity of the text, they will not be repeated here.

[0236] Although some specific embodiments of the present application have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present application. It should be understood by those skilled in the art that the above examples may be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. An AR optical module, characterized in that: include: Display (1); A lens assembly comprising a first prism (2), a first lens (3), a second prism (4) and a third prism (5); A light splitting element (311) is disposed on the first surface (31) of the first lens (3); a phase retarder (321) disposed on the second surface (32) of the first lens (3); a polarizing reflection element (411) disposed on a surface of the second prism (4) adjacent to the first prism (2), and the phase retarder (321) located on an optical path between the beam splitting element (311) and the polarizing reflection element (411); The display (1) is provided on the first side of the first prism (2), the first lens (3) is glued to the third side of the first prism (2) in a manner of retaining an air gap, the second prism (4) is glued to the second side of the first prism (2) in a manner of retaining an air gap, and the third prism (5) is glued to the side of the second prism (4) facing away from the first prism (2).

2. The AR optical module according to claim 1, wherein: 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, and both L1 and L2 satisfy: 0.05mm≤L1, L2≤0.15mm.

3. The AR optical module according to claim 1 or 2, wherein: The AR optical module further comprises a second lens (6), which is arranged on the side of the first lens (3) facing the outside world, and the optical focal length of the second lens (6) and the optical focal length of the first lens (3) can offset each other, so that the first lens (3) and the second lens (6) are combined to form a light-transmitting flat plate with zero optical focal length.

4. The AR optical module according to claim 3, wherein: The second lens (6) and the first lens (3) are bonded together to form a bonded lens.

5. The AR optical module according to claim 3, wherein: The first prism (2) comprises 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 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 retained between the two; The second effective surface (22) and the fifth effective surface (42) are glued at their edges, and an air gap is retained between them; The second effective surface (22) and the third effective surface (23) are formed as total reflection surfaces.

6. The AR optical module according to claim 5, wherein: The aperture of the bonding area between the third effective surface (23) of the first prism (2) and the second surface (32) of the first lens (3) is D1, the non-bonded 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 aperture of the bonding 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 non-bonded area on the second effective surface (22) forms the total reflection surface, the aperture of the total reflection surface is D4, and 0.75≤D3 / D4≤1.

7. The AR optical module according to claim 5, wherein: An included 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, wherein: An included 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, wherein: The light splitting element (311) is arranged on the first surface (31), the phase retarder (321) is arranged on the second surface (32), and the polarized reflection element (411) is arranged on the fourth effective surface (41).

10. The AR optical module according to claim 1 or 9, wherein: The AR optical module further includes a first polarization element (511); The sixth effective surface (51) of the third prism (5) is arranged close to the human eye (01), and the first polarizing element (511) is arranged on the sixth effective surface (51).

11. The AR optical module according to claim 10, wherein: The AR optical module further comprises a second polarizing element (322), wherein the second polarizing element (322) is stacked on a side of the phase retarder (321) away from the second surface (32).

12. The AR optical module according to claim 1, wherein: The first lens (3) is an aspherical lens.

13. The AR optical module according to claim 1, wherein: At least one lens is provided 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 according to any one of claims 1 to 13.

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