AR lens module and optical display device

Abstract

The embodiment of the invention provides an AR lens module and optical display equipment. The AR lens module is used for a full-color AR light machine, and comprises a lens group, an X-cube color combination prism and a display chip which are arranged along the same optical axis, wherein the lens group is composed of a first lens, a second lens, a third lens and a fourth lens which are arranged in sequence, and the fourth lens and the X-cube color combination prism are arranged adjacently; the focal power of the first lens and the third lens is positive, and the focal power of the second lens and the fourth lens is negative; the first lens, the second lens, the third lens and the fourth lens are all aspherical mirrors. The CRA of the AR lens module is 13 degrees, and the CRA is the included angle between the chief light of the edge field of view and the optical axis of the display chip.

Description

Technical Field

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

[0002] With the development of augmented reality technology, the market has put forward higher and higher requirements on the size and weight of wearable AR optical display devices. For wearable AR optical display devices (such as smart glasses), smaller size and lighter weight can significantly improve the wearing comfort of users. However, the size and weight of current wearable AR optical display devices largely depend on the AR lens module inside them. Traditional AR lens modules often cause optical display devices to be bulky and heavy because they contain complex lighting optical paths and large imaging lenses (including many lenses).

[0003] Therefore, developing an AR lens module that can significantly reduce size and weight while ensuring excellent imaging quality has become a key issue that needs to be urgently addressed in the field of augmented reality technology. Summary of the invention

[0004] The purpose of this application is to provide a new technical solution for an AR lens module and an optical display device.

[0005] In a first aspect, the present application provides an AR lens module. The AR lens module is used for a full-color AR optical machine, and includes a lens group, an X-cube color combination prism, and a display chip arranged along the same optical axis;

[0006] The lens group is composed of a first lens, a second lens, a third lens and a fourth lens arranged in sequence, and the fourth lens and the X-cube color combining prism are arranged adjacent to each other;

[0007] The optical power of the first lens and the third lens is positive, and the optical power of the second lens and the fourth lens is negative;

[0008] The first lens to the fourth lens are all aspherical lenses;

[0009] The CRA of the AR lens module is 13°, where CRA is the angle between the main light of the edge field of view and the optical axis of the display chip.

[0010] Optionally, the first lens is a plano-convex lens;

[0011] The fourth lens is a meniscus lens curved toward the third lens;

[0012] The effective focal length F4 of the fourth lens is -80mm to -50mm.

[0013] Optionally, the AR lens module satisfies:

[0014] 1.2 < (F1 + F3) / L < 1.65;

[0015] -12 < (F2 + F4) / L < -6;

[0016] Wherein, F1 is the effective focal length of the first lens, F2 is the effective focal length of the second lens, F3 is the effective focal length of the third lens, F4 is the effective focal length of the fourth lens, and L is the total optical length of the AR lens module.

[0017] Optionally, the AR lens module satisfies: 30 < (F1 + F3)*Q < 44; wherein, Q is the maximum aperture of the lenses from the first lens to the fourth lens.

[0018] Optionally, the AR lens module satisfies: 1.9 < (A1 + A3) / (A2 + A4) < 2.5; wherein, A1 is the air gap between the first lens and the second lens, A2 is the air gap between the second lens and the third lens, A3 is the air gap between the third lens and the fourth lens, A4 is the air gap between the fourth lens and the X-cube dichroic prism, and Q is the maximum aperture of the lenses from the first lens to the fourth lens.

[0019] Optionally, the AR lens module satisfies: 3 < L / (A1 + A2 + A3 + A4) < 3.7; wherein, L is the total optical length of the AR lens module.

[0020] Optionally, the AR lens module satisfies:

[0021] N1 > N2 > N4 > N3;

[0022] 14 < (N1*F1 + N3*F3) < 20;

[0023] Wherein, N1 is the refractive index of the first lens, N2 is the refractive index of the second lens, N3 is the refractive index of the third lens, N4 is the refractive index of the fourth lens, F1 is the effective focal length of the first lens, and F3 is the effective focal length of the third lens.

[0024] Optionally, three of the first lens to the fourth lens are plastic aspherical lenses, and the other lens is a glass aspherical lens.

[0025] Optionally, the first lens is a glass aspherical lens, and the second lens, the third lens, and the fourth lens are all plastic aspherical lenses.

[0026] Optionally, the effective focal length F1 of the first lens is 3.2 mm to 3.8 mm;

[0027] The effective focal length F2 of the second lens is -4.5mm to -3.7mm;

[0028] The effective focal length F3 of the third lens is 6.9 mm to 7.6 mm.

[0029] Optionally, the AR lens module includes an aperture, which is located on a side of the first lens away from the second lens; the air gap between the aperture and the first lens is ≤0.3 mm; and the aperture of the aperture is 3.4 mm to 3.6 mm.

[0030] Optionally, the total optical length L of the AR lens module is 7.53 mm;

[0031] The maximum effective aperture of the AR lens module is 3.5 mm.

[0032] In a second aspect, the present application provides an optical display device. The optical display device comprises:

[0033] The AR lens module as described in the first aspect; and

[0034] Optical waveguide device, the aperture of the diaphragm of the AR lens module matches the entrance pupil diameter of the optical waveguide device.

[0035] The beneficial effects of this application are:

[0036] The AR lens module provided in the embodiment of the present application realizes the miniaturized design of the AR lens module while ensuring high-quality imaging effects; the optimized CRA design not only reduces the volume, but also effectively improves the utilization rate of light energy and enhances the display effect. The design of four aspherical mirrors effectively reduces the spherical aberration caused by the large aperture and significantly improves the imaging quality. The design of using positive, negative, positive and negative optical power further offsets the aberration, which is conducive to reducing the aberration of the entire AR lens module, thereby ensuring high-definition images.

[0037] This application achieves the extreme miniaturization of AR lens modules while maintaining excellent imaging effects, providing strong technical support for the development of augmented reality devices.

[0038] 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

[0039] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the specification and, together with the description, serve to explain the principles of the specification.

[0040] Figure 1This is one of the structural schematic diagrams of the AR lens module provided in the embodiment of the present application;

[0041] Figure 2 The second structural diagram of the AR lens module provided in the embodiment of the present application;

[0042] Figure 3 for Figure 2 Distortion diagram of the provided AR lens module;

[0043] Figure 4 for Figure 2 The modulation transfer function diagram of the AR lens module provided;

[0044] Figure 5 The third structural diagram of the AR lens module provided in the embodiment of the present application;

[0045] Figure 6 for Figure 5 The modulation transfer function diagram of the AR lens module provided;

[0046] Figure 7 The fourth structural diagram of the AR lens module provided in the embodiment of the present application;

[0047] Figure 8 for Figure 7 The modulation transfer function diagram of the AR lens module provided;

[0048] Fig. 9 The fifth structural diagram of the AR lens module provided in the embodiment of the present application;

[0049] Fig.10 for Fig. 9 The modulation transfer function diagram of the AR lens module provided;

[0050] Fig.11 The sixth structural diagram of the AR lens module provided in the embodiment of the present application;

[0051] Fig.12 for Fig.11 Modulation transfer function diagram of the AR lens module provided.

[0052] Description of reference numerals:

[0053] 1. First lens; 2. Second lens; 3. Third lens; 4. Fourth lens; 5. X-cube color combining prism; 6. Display chip. DETAILED DESCRIPTION

[0054] 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 of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application.

[0055] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present application, its application, or uses.

[0056] 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.

[0057] 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.

[0058] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0059] The AR lens module and optical display device provided in the embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0060] According to one embodiment of the present application, an AR lens module is provided for a full-color AR optical machine, wherein the AR lens module comprises a lens group arranged along the same optical axis, an X-cube color combining prism 5 and a display chip 6; wherein the lens group is composed of a first lens 1, a second lens 2, a third lens 3 and a fourth lens 4 arranged in sequence, and the fourth lens 4 and the X-cube color combining prism 5 are arranged adjacent to each other; the optical power of the first lens 1 and the third lens 3 is positive, and the optical power of the second lens 2 and the fourth lens 4 is negative; the first lens 1 to the fourth lens 4 are all aspherical lenses; the CRA of the AR lens module is 13°, and CRA is the angle between the main light of the edge field of view and the optical axis of the display chip 6.

[0061] The AR lens module provided in the embodiment of the present application is a miniaturized AR lens module for full-color AR lenses. The AR lens module in the embodiment of the present application not only achieves significant miniaturization in volume, but also reduces its overall weight while ensuring excellent imaging quality, providing new technical guidance for the application of full-color AR technology.

[0062] Through new optical architecture design and optimization, the AR lens module provided in the embodiment of the present application can provide clear and colorful images while maintaining a compact structure, fully demonstrating its technical advantages in the field of augmented reality.

[0063] The AR lens module provided in the embodiment of the present application is suitable for full-color AR optical machine. Specifically, the AR lens module includes a lens group, an X-cube color-combining prism 5 and a display chip 6; wherein the lens group is composed of four lenses, namely the first lens 1, the second lens 2, the third lens 3 and the fourth lens 4, which are arranged in sequence along the same optical axis. This arrangement is conducive to the orderly transmission of light and the control of imaging quality. Figure 1 The first lens 1 is located on a side close to the aperture, and the fourth lens 4 and the X-cube color combining prism 5 are arranged adjacent to each other.

[0064] In the AR lens module provided in the embodiment of the present application, all lenses are aspherical mirrors. This design can effectively reduce the spherical aberration caused by the large aperture, thereby improving the clarity of the image. Aspherical mirrors can control light more flexibly and achieve higher optical performance.

[0065] The AR lens module provided in the embodiment of the present application adopts a specially designed combination of optical powers: the optical powers of the first lens 1 and the third lens 3 are positive, while the optical powers of the second lens 2 and the fourth lens 4 are negative. In this way, in the order from the first lens 1 to the fourth lens 4, this positive-negative-positive-negative optical power combination can create more high-order aberrations to offset the primary aberrations, significantly reduce the total aberration of the entire AR lens module, and improve the Modulation Transfer Function (MTF), thereby ensuring high definition of the image.

[0066] The AR lens module provided in the embodiment of the present application also includes an X-cube color combining prism 5 and a display chip 6.

[0067] As a component directly adjacent to the lens group, the X-cube color combining prism 5 is used to combine light of different colors to achieve full-color display.

[0068] The display chip 6 is a light emitting source, which is also called a light emitting panel. By precisely controlling the light emitting angle and brightness of the display chip 6 and coordinating with the CRA design, efficient light energy utilization and high-quality display effects are achieved.

[0069] In the embodiment of the present application, the CRA of the AR lens module is set to 13°. CRA is the angle between the main light of the edge field of view and the optical axis of the display chip 6. Setting the CRA to 13° is a key innovation, which helps to maintain a high light energy utilization rate while reducing the volume of the AR lens module. A larger CRA angle enables the lens group to receive more light from the display chip 6, thereby enhancing the display effect, especially in the edge field of view area.

[0070] By appropriately increasing the CRA, the AR lens module of the present application can further reduce the size and weight while maintaining high performance. This is crucial for augmented reality devices because it is directly related to the user's wearing comfort.

[0071] The AR lens module provided in the embodiment of the present application can achieve the following technical effects through the new design of the lens group (including aspherical mirrors and special optical power matching), the efficient X-cube color combination prism and the optimized CRA setting:

[0072] (1) High-quality imaging effect: The combination of aspherical mirrors and positive and negative optical powers significantly reduces aberrations and improves image clarity and contrast.

[0073] (2) Miniaturization of the module: The increased CRA effectively reduces the volume of the AR lens module.

[0074] (3) Efficient light energy utilization: The optimized CRA design ensures sufficient light passes through the AR lens module, enhancing the display effect, especially in the edge field of view area.

[0075] (4) Full-color display: The X-cube color-combining prism 5 is used in conjunction with the lens group to achieve high-quality full-color display and enhance the user's visual experience.

[0076] The AR lens module provided in the embodiment of the present application realizes the miniaturized design of the AR lens module while ensuring high-quality imaging effects; the optimized CRA design not only reduces the volume, but also effectively improves the utilization rate of light energy and enhances the display effect. The design of four aspherical mirrors effectively reduces the spherical aberration caused by the large aperture and significantly improves the imaging quality. The design of using positive, negative, positive and negative optical power further offsets the aberration, which is conducive to reducing the aberration of the entire AR lens module, thereby ensuring high-definition images.

[0077] This application achieves the extreme miniaturization of AR lens modules while maintaining excellent imaging effects, providing strong technical support for the development of augmented reality devices.

[0078] In some examples of this application, see Figure 1 The first lens 1 is a plano-convex lens, the fourth lens 4 is a meniscus lens curved toward the third lens 3, and the effective focal length F4 of the fourth lens 4 is -80 mm to -50 mm.

[0079] In the lens group of the present application, the first lens 1 (close to the aperture) is designed as a plano-convex lens, and the convex surface of the plano-convex lens can effectively converge the light from the display chip 6, so that the light can propagate in the expected direction and be emitted through the aperture to an external light output device such as an optical waveguide device.

[0080] By properly designing the curvature and thickness of the first lens 1, i.e., the plano-convex lens, the effective aperture of the AR lens module can be controlled to avoid aberration problems caused by a large aperture, and it also helps to miniaturize the AR lens module. For example, the maximum effective aperture of the AR lens module of the present application is 3.5 mm.

[0081] In the present application, by designing the first lens 1 as an aspherical plano-convex lens, spherical aberration can be further reduced, which helps to improve imaging quality and ensure image clarity.

[0082] In the lens assembly of the present application, the fourth lens 4 is a meniscus lens that is bent toward the third lens 3, and the effective focal length F4 of the fourth lens 4 is -80 mm to -50 mm. The thickness of the fourth lens 4 can be designed to be relatively thin.

[0083] Specifically, the fourth lens 4 is a meniscus lens that is bent toward the third lens 3, and both sides thereof are curved, with the bending direction facing the third lens 3. The special shape of the meniscus lens can effectively correct field curvature, which is crucial to improving the flatness and consistency of the image.

[0084] Due to the special shape and orientation design of the meniscus lens, more optical performance optimization can be achieved without increasing the overall length of the AR lens module, which helps to achieve the miniaturization and lightweight of the lens module.

[0085] In the present application, the effective focal length F4 of the fourth lens 4 is: -80mm to -50mm. This shows that the fourth lens is a negative lens, and the absolute value of its focal length is relatively large. This design allows the fourth lens 4 to become the main negative lens in the entire AR lens group, which helps to further reduce the module volume and optimize aberrations such as field curvature. At the same time, its curved thin meniscus lens shape is also conducive to reducing field curvature and improving the modulation transfer function (MTF).

[0086] For example, the total optical length of the AR lens module of the present application is 7.52 mm.

[0087] According to the example of the present application, the first lens 1 is designed as a plano-convex lens, and the fourth lens 4 is designed as a meniscus lens curved toward the third lens 3, and the effective focal length F4 of the fourth lens 4 is -80mm to -50mm. This combination design can bring significant technical effects:

[0088] (1) High-quality imaging: Through the light convergence of the plano-convex lens and the field curvature correction of the meniscus lens, the AR lens module can provide high-quality imaging effects and ensure image clarity.

[0089] (2) Miniaturization and lightweight of AR lens module: The surface design of these two lenses helps to achieve miniaturization and lightweight of AR lens module.

[0090] (3) Improve light energy utilization: The combined design of the plano-convex lens and the meniscus lens ensures efficient light energy utilization, allowing more light to reach the user's eyes, which helps to improve the brightness and display effect of AR optical display devices.

[0091] In some examples of the present application, the AR lens module satisfies:

[0092] 1.2<(F1+F3) / L<1.65;

[0093] -12<(F2+F4) / L<-6;

[0094] Among them, F1 is the effective focal length of the first lens 1, F2 is the effective focal length of the second lens 2, F3 is the effective focal length of the third lens 3, F4 is the effective focal length of the fourth lens 4, and L is the total optical length of the AR lens module.

[0095] In the present application, the design of the AR lens module satisfies the relationship between a specific focal length and the total optical length L. These relationships are intended to achieve extreme miniaturization and high performance of the AR lens module through control of optical design parameters.

[0096] When the AR lens module satisfies 1.2<(F1+F3) / L<1.65, this relationship limits the ratio between the sum of the effective focal lengths of the first lens 1 and the third lens 3 and the total optical length L of the entire AR lens module. Since both F1 and F3 are positive focal lengths, their sum (F1+F3) represents the total amount of positive focal power in the AR lens module. By limiting this sum within a certain range, it can be ensured that the AR lens module has an appropriate positive focal power distribution, which is neither too concentrated nor too dispersed, thereby helping to achieve good imaging quality and compact structural design.

[0097] When the AR lens module satisfies -12<(F2+F4) / L<-6, this relationship involves the ratio between the sum of the effective focal lengths of the second lens 2 and the fourth lens 4 and the total optical length of the AR lens module. Since F2 and F4 are both negative focal lengths, their sum (F2+F4) represents the total amount of negative optical power in the AR lens module. Limiting this sum to a specific negative value range can ensure that the entire AR lens module has sufficient negative optical power to balance the positive optical power, achieve effective convergence and divergence of light, and control aberrations to improve imaging quality. In addition, this distribution of negative optical power also helps to reduce the volume of the lens module.

[0098] When the AR lens module meets the two conditions in this example of the present application, the imaging quality can be optimized. By controlling the proportional relationship between the effective focal length of each lens and the total optical length L of the AR lens, a reasonable distribution of optical power can be achieved, thereby effectively correcting aberrations and improving imaging quality. This design enables the AR lens module to provide clear images while maintaining miniaturization.

[0099] For example, the total optical length L of the AR lens module provided in the embodiment of the present application is 7.53 mm.

[0100] The limitation of the relationship in this example of the present application helps to achieve the miniaturization of the AR lens module while maintaining high performance. By reasonably allocating positive and negative optical focal lengths, the thickness of each lens and the number of lenses used can be reduced, thereby reducing the overall volume and weight of the AR lens module.

[0101] In addition, the optimized optical power distribution helps the light to propagate efficiently in the AR lens module, reducing light energy loss and improving light energy utilization. This is especially important for micro LED-based augmented reality optical devices, as it needs to ensure sufficient brightness output to provide a high-quality visual experience.

[0102] In some examples of the present application, the AR lens module satisfies: 30<(F1+F3)*Q<44; wherein Q is the maximum aperture of the lenses from the first lens 1 to the fourth lens 4.

[0103] According to this example of the present application, this relationship relates the sum of the effective focal lengths of the first lens 1 and the third lens 3 (F1+F3) to the product of the largest aperture Q among the four lenses, and limits it to a specific range (i.e., between 30 and 44).

[0104] F1+F3: represents the total amount of positive optical power in the AR lens module. The first lens 1 and the third lens 3 are both positive lenses, and the sum of the two determines the ability of the AR lens module to collect and converge light.

[0105] Q: As the maximum aperture of the lens in the lens group, it directly affects the amount of light that the entire AR lens module can receive and the overall size of the AR lens module. A larger aperture usually means more light can be received, but it may also cause the size of the AR lens module to increase.

[0106] For example, in the embodiment of the present application, the maximum aperture of the lens in the lens group is 3.5 mm.

[0107] According to the relationship of 30 < (F1 + F3) * Q < 44 proposed in this example of the present application, while ensuring sufficient positive optical power, the maximum aperture of the lens is controlled to achieve a balance between the compactness and efficiency of the AR lens module.

[0108] Specifically, by controlling the value of F1 + F3, it can be ensured that the AR lens module has appropriate positive optical power, which is crucial for imaging quality. Insufficient positive optical power may lead to blurred images, while excessive power may increase aberrations. By restricting the value of Q, it can be ensured that the AR lens module achieves extreme miniaturization while maintaining high performance. A smaller aperture helps to reduce the physical size of the AR lens module, thereby reducing the volume and weight of the entire AR optical display device.

[0109] In addition, an appropriate combination of positive optical power and lens aperture helps to optimize the light propagation path in the AR lens module, reduce light energy loss, and improve light energy utilization efficiency. This is particularly important for augmented reality devices as they need to provide sufficient brightness within a limited volume to produce clear images.

[0110] In some examples of the present application, the AR lens module satisfies: 1.9 < (A1 + A3) / (A2 + A4) < 2.5; where A1 is the air gap between the first lens 1 and the second lens 2, A2 is the air gap between the second lens 2 and the third lens 3, A3 is the air gap between the third lens 3 and the fourth lens 4, A4 is the air gap between the fourth lens 4 and the X - cube dichroic prism 5, and Q is the maximum aperture of the lenses from the first lens 1 to the fourth lens 4.

[0111] According to this example of the present application, by controlling the ratio of the air gaps between different lenses, the light path propagation path within the AR lens module can be adjusted, thereby optimizing aberration correction and imaging quality.

[0112] Specifically, by constraining the ratio range of (A1 + A3) to (A2 + A4), it helps to ensure a reasonable spatial distribution between the lenses while maintaining the compactness of the AR lens module, avoiding an increase in aberrations or a decrease in light energy utilization efficiency caused by excessive compactness. A reasonable air gap distribution helps to reduce stray light and ghost images, improving the clarity of the picture.

[0113] For example, in the embodiment of the present application, the maximum aperture of the lenses in the lens group is 3.5 mm.

[0114] In some examples of the present application, the AR lens module satisfies: 3 < L / (A1 + A2 + A3 + A4) < 3.7; where L is the optical total length of the AR lens module.

[0115] According to this example of the present application, by restricting the ratio of the total optical length L of the AR lens module to the sum of all air gaps, the overall size of the AR lens module can be ensured to be within the design range, meeting the requirements of miniaturization and light weight.

[0116] Reasonable air gap allocation helps improve the space utilization rate inside the AR lens module, enabling each component to be arranged tightly and orderly, reducing unnecessary space waste. Reasonable space allocation helps reduce interference between optical elements and improve the stability of the optical path and imaging quality.

[0117] Specifically, on the premise of ensuring imaging performance, by setting the upper limit of the ratio to 3.7, the overall size of the AR lens module can be effectively controlled to achieve an extremely miniaturized design. Appropriate air gaps help reduce light loss during propagation and improve light energy utilization.

[0118] The lower limit of L / (A1 + A2 + A3 + A4) is 3, ensuring that there is enough space inside the AR lens module to accommodate optical elements and air gaps. This helps avoid overcrowding between optical elements, reduce interference between them, and thus improve imaging quality. Although the lower limit of the ratio helps maintain the compactness of the AR lens module.

[0119] In an example of the present application, the AR lens module satisfies: 1.9 < (A1 + A3) / (A2 + A4) < 2.5, 3 < L / (A1 + A2 + A3 + A4) < 3.7; where A1 is the air gap between the first lens 1 and the second lens 2, A2 is the air gap between the second lens 2 and the third lens 3, A3 is the air gap between the third lens 3 and the fourth lens 4, A4 is the air gap between the fourth lens 4 and the X-cube dichroic prism 5, Q is the maximum aperture of the lenses from the first lens 1 to the fourth lens 4, and L is the total optical length of the AR lens module.

[0120] Combining the two relational expressions in the above example, it can be found that they complement each other in optimizing the design of the AR lens module. Specifically, by simultaneously controlling the ratio of the air gaps and the ratio of the total optical length to the sum of the air gaps, the propagation path of light inside the AR lens module can be more comprehensively optimized, further improving imaging quality and light energy utilization.

[0121] The two relational expressions work together to help achieve an extremely miniaturized design of the AR lens module while maintaining high performance, meeting the strict requirements of augmented reality devices for volume and weight.

[0122] For example, the total optical length L of the AR lens module provided in the embodiment of the present application is 7.53 mm.

[0123] In some examples of the present application, the AR lens module satisfies:

[0124] N1>N2>N4>N3;

[0125] 14<(N1*F1+N3*F3)<20;

[0126] Among them, N1 is the refractive index of the first lens 1, N2 is the refractive index of the second lens 2, N3 is the refractive index of the third lens 3, N4 is the refractive index of the fourth lens 4, F1 is the effective focal length of the first lens 1, and F3 is the effective focal length of the third lens 3.

[0127] In the example of the present application, the design of the AR lens module follows two specific combinations of refractive index and focal length: N1>N2>N4>N3: This means that the refractive index of the first lens 1 is the highest, followed by the second lens 2, the refractive index of the fourth lens 4 is higher than that of the third lens 3, and the refractive index of the third lens 3 is the lowest.

[0128] 14<(N1*F1+N3*F3)<20: This relationship involves the sum of the products of the refractive indices of the first lens 1 and the third lens 3 and their respective effective focal lengths, and this sum is limited to between 14 and 20.

[0129] By carefully selecting the refractive indices of different lenses, the propagation and focusing of light in the AR lens module can be effectively controlled, thereby reducing aberrations and distortions and improving imaging quality.

[0130] Specifically, the configuration of N1>N2>N4>N3 helps to balance the refractive ability of different lenses to light, ensuring that the light can be accurately focused on the imaging plane.

[0131] The high refractive index first lens 1 can refract light more efficiently, thereby reducing the total length required for the AR lens module and helping to achieve a more compact design.

[0132] By optimizing the value of (N1*F1+N3*F3), the size of the AR lens module can be further reduced while maintaining imaging performance. Appropriate refractive index selection and effective focal length configuration help reduce the reflection and scattering of light inside the AR lens module, thereby improving light energy utilization.

[0133] In some examples of the present application, three lenses among the first lens 1 to the fourth lens 4 are plastic aspherical lenses, and another lens is a glass aspherical lens.

[0134] The AR lens module provided in the embodiment of the present application can design three lenses among the first lens 1 to the fourth lens 4 as plastic lenses. This design is conducive to reducing the weight of the entire AR lens module.

[0135] The density of plastic lenses is much lower than that of glass lenses, so using plastic lenses can significantly reduce the weight of the entire AR lens module. For augmented reality (AR) optical display devices, reducing weight is one of the key factors to improve wearing comfort and user experience.

[0136] Plastic materials have good plasticity and formability, which makes it possible to design more complex aspheric lenses. Aspheric lenses can provide better optical performance, such as reducing aberrations and improving imaging quality. Therefore, the use of plastic lenses can increase the flexibility of the entire AR lens module design to meet higher performance optical requirements.

[0137] In addition, compared with glass lenses, plastic lenses have better impact resistance. In application scenarios such as AR optical display devices that are susceptible to accidental collisions or falls, the use of plastic lenses can reduce the risk of lens breakage and improve the durability and reliability of the device.

[0138] In the lens assembly of the present application, another lens may be a glass lens. The glass lens has a high refractive index, low dispersion and good thermal stability, and can produce high-quality images.

[0139] In the AR lens module of the present application, a combination of three plastic lenses and one glass lens is selected. This choice is based on the balance between imaging quality, weight, cost and manufacturability. By using a glass lens, it can be ensured that the AR lens module has excellent imaging performance in key parts, such as reducing chromatic aberration, improving resolution, etc. At the same time, the use of three plastic lenses can reduce the overall weight and cost of the AR lens module. In other words, by combining a glass lens and a plastic lens, the present application achieves an optimized balance between imaging quality and cost. This design not only ensures the high performance of the AR lens module, but also reduces manufacturing costs.

[0140] In some examples of this application, see Figure 1 The first lens 1 is a glass aspherical lens, and the second lens 2, the third lens 3 and the fourth lens 4 are all plastic aspherical lenses.

[0141] In the lens assembly of the present application, the first lens 1 is designed as a glass aspheric mirror. Glass materials have high refractive index, low dispersion and excellent thermal stability, and can produce high-quality images. The aspheric design can effectively reduce spherical aberration and other aberrations and improve imaging quality. Therefore, designing the first lens 1 as a glass aspheric mirror and placing it on the aperture side can ensure that the light can be well corrected when entering the optical transmission device (such as an optical waveguide device) behind it.

[0142] Please continue to see Figure 1 In the lens group of the present application, the second lens 2, the third lens 3 and the fourth lens 4 are all designed as plastic aspherical lenses. Plastic materials have the advantages of light weight, low cost and easy processing. The aspherical design can also reduce aberrations and improve imaging quality. The material and surface shape combination of the second lens 2, the third lens 3 and the fourth lens 4 can reduce the overall weight and manufacturing cost of the AR lens module while ensuring imaging quality.

[0143] In this application, the glass aspherical mirror is used as a lens near the aperture (exit pupil), which can effectively correct the aberration and distortion of light when entering subsequent optical devices, and can provide a better imaging basis. The use of plastic aspherical mirrors, while ensuring lightweight and low cost, also reduces aberrations and distortions, further improving the imaging quality. Overall, this design combination can produce high-definition, low-distortion, and high-contrast images, meeting the needs of AR optical display devices for high-quality imaging.

[0144] In some examples of the present application, the effective focal length F1 of the first lens 1 is 3.2 mm to 3.8 mm, the effective focal length F2 of the second lens 2 is -4.5 mm to -3.7 mm, and the effective focal length F3 of the third lens 3 is 6.9 mm to 7.6 mm.

[0145] The effective focal length F1 of the first lens 1 is: 3.2mm~3.8mm. This shows that the first lens 1 is designed as a positive lens with a relatively short focal length. This design helps to narrow the angle of light and control the aperture of the entire AR lens module, thereby reducing the volume of the AR lens module. The surface shape of the positive lens is a plano-convex lens, which can reduce the spherical aberration caused by the large aperture and improve the imaging quality.

[0146] The effective focal length F2 of the second lens 2 is -4.5mm to -3.7mm. This shows that the second lens 2 is a negative lens, and its absolute focal length is relatively large. The introduction of the negative lens can be matched with the positive focal length of the first lens to offset the aberration, thereby reducing the aberration of the AR lens module and improving the modulation transfer function (MTF).

[0147] The effective focal length F3 of the third lens 3 is 6.9 mm to 7.6 mm. This indicates that the third lens 3 is a positive lens again, and the focal length is relatively long. This design helps to further adjust the convergence of light and optimize the imaging quality. At the same time, when combined with the negative focal length of the adjacent second lens 2, an alternation of positive and negative focal lengths can be formed, which is beneficial to the correction of aberrations.

[0148] In the present application, the effective focal length F4 of the fourth lens 4 is: -80mm to -50mm. This shows that the fourth lens is a negative lens, and the absolute value of the focal length is the largest among the four lenses. This design makes the fourth lens 4 the main negative lens in the entire AR lens group, which helps to further reduce the module volume and optimize aberrations such as field curvature. At the same time, its curved thin meniscus lens shape is also conducive to reducing field curvature and improving the modulation transfer function (MTF).

[0149] The AR lens module of the present application, from the first lens 1 to the fourth lens 4, adopts a combination of positive, negative, positive, and negative focal powers. Through this combination of focal powers, the aberration of the entire AR lens module can be well reduced and the imaging quality can be improved. Among them, the reasonable combination of the angle-contracting effect of the positive lens and the diverging light effect of the negative lens helps to minimize the volume of the AR lens group and meet the demand for miniaturization of AR optical display devices.

[0150] In addition, by controlling the focal length and optical power of each lens, the light propagation path can be optimized, the light energy utilization rate can be improved, and sufficient brightness output can be ensured.

[0151] In some examples of this application, see Figure 1 The AR lens module includes an aperture, which is located on the side of the first lens 1 away from the second lens 2; the air gap between the aperture and the first lens 1 is ≤0.3mm; and the aperture of the aperture is 3.4mm~3.6mm.

[0152] The aperture is located on the side of the first lens 1 away from the second lens 2, that is, the aperture is located at the front end of the AR lens module. The air gap between the aperture and the first lens 1 is ≤0.3mm. This tight layout helps to reduce light scattering and stray light generation.

[0153] By limiting the air gap between the aperture and the first lens 1, the total length of the AR lens module along the optical axis can be reduced while ensuring the imaging quality, which helps to achieve a more compact design.

[0154] The aperture of the aperture is controlled between 3.4 mm and 3.6 mm. This size range helps to confine the light, improve the utilization rate of light energy, and efficiently couple with subsequent optical waveguide devices.

[0155] The aperture design of the aperture helps to achieve efficient coupling with subsequent optical waveguide devices and reduce light loss during the coupling process, thereby improving the optical efficiency and image quality of the entire AR lens module.

[0156] It should be noted that the aperture mentioned in this application is Figure 1 , which is located on the far left of the entire AR lens module. When the entire AR lens module is applied to the AR optical machine, the aperture is the optical machine exit pupil.

[0157] In some examples of the present application, the total optical length L of the AR lens module is 7.53 mm; the maximum effective aperture of the AR lens module is 3.5 mm.

[0158] In this example of the present application, the design parameters of the AR lens module clearly indicate that its total optical length L is 7.53 mm and the maximum effective aperture is 3.5 mm. These two parameters together define the size limit and optical performance basis of the AR lens module.

[0159] Among them, the total optical length L of 7.53mm means that the total length of the entire AR lens module along the optical axis is strictly controlled within a small range. This is crucial for augmented reality (AR) devices, because smaller size means higher wearing comfort and portability.

[0160] Among them, the maximum effective aperture is 3.5mm, which restricts the maximum range of light that the AR lens module can collect. This parameter has a direct impact on the field of view, light throughput and imaging quality of the AR lens module.

[0161] For the AR lens module provided in the embodiment of the present application, the total optical length of 7.53mm makes the entire lens module very compact, which is conducive to the miniaturization and lightweight of the AR optical display device. The compact design also helps to reduce the space occupied inside the device and provide more layout space for other key components (such as batteries, processors, etc.). Despite the compact size, the maximum effective aperture of 3.5mm still ensures sufficient light transmittance, which helps to obtain clear images and high brightness. Through careful optical design, a wider field of view and higher imaging quality can be achieved while maintaining a smaller aperture to meet the needs of AR applications.

[0162] To sum up, the design parameters of the AR lens module in this application, with a total optical length L of 7.53 mm and a maximum effective aperture of 3.5 mm, achieve a good combination of compact design and optimized optical performance, providing users with a better experience.

[0163] In a specific example of this application, see Figure 2, the main parameters of the AR lens module design are:

[0164] Focal length: 5.59mm;

[0165] Field of view: ±12.5°;

[0166] Relative aperture: 1 / 1.56;

[0167] Pixel size: 4μm;

[0168] Working band: 455-630nm.

[0169] In this specific example, the first lens 1 to the X-cube color combining prism 5 in the AR lens module are aspherical lenses, and their optical parameters are shown in Tables 1 and 2 below, respectively.

[0170] Table 1

[0171]

[0172]

[0173] Table 2 (Aspheric parameters of four lenses)

[0174]

[0175] For the optical performance of the AR lens module provided in the embodiments of the present application, see Figure 3 and Figure 4 :

[0176] Figure 3 This is the distortion diagram of the AR lens module, see Figure 3 The AR lens module provided in this specific example has an absolute distortion value of less than 12%, which means that the distortion generated during the imaging process of the AR lens module is small and can fully meet the user's imaging requirements for AR optical display devices.

[0177] Figure 4 This is the modulation transfer function diagram of the AR lens module, see Figure 4 , the MTF of the AR lens module provided in this specific example is >0.55 at 125lp / mm, indicating that the AR lens module has clear imaging.

[0178] According to another embodiment of the present application, an optical display device is provided, comprising the AR lens module and the optical waveguide device as described above, wherein the aperture of the aperture of the AR lens module matches the entrance pupil diameter of the optical waveguide device.

[0179] The AR lens module of the present application is described in detail below through Examples 1 to 4.

[0180] Example 1

[0181] The AR lens module provided in this embodiment 1 is shown in FIG. Figure 5 , including a lens group, an X-cube color combining prism 5 and a display chip 6 arranged along the same optical axis;

[0182] The lens group is composed of a first lens 1, a second lens 2, a third lens 3 and a fourth lens 4 which are arranged in sequence, and the fourth lens 4 is arranged adjacent to the X-cube color combining prism 5;

[0183] The focal power of the first lens 1 is positive, the first lens 1 is a plano-convex glass aspherical lens, the focal power of the second lens 2 is negative, the focal power of the third lens 3 is positive, the focal power of the fourth lens 4 is negative, and the fourth lens 4 is a meniscus lens curved toward the third lens 3;

[0184] The CRA of the AR lens module is 13°, where CRA is the angle between the main ray of the edge field of view and the optical axis of the display chip;

[0185] The AR lens module includes an aperture, and the aperture is located on a side of the first lens 1 away from the second lens 2; the air gap between the aperture and the first lens 1 is ≤0.3 mm;

[0186] The aperture of the aperture is 3.4 mm to 3.6 mm.

[0187] The total optical length L of the AR lens module is 7.53 mm, and the maximum effective aperture of the AR lens module is 3.5 mm.

[0188] In the AR lens module provided in this embodiment 1, the optical parameters of the first lens 1 to the X-cube color combining prism 5 are shown in Table 3 and Table 4 below.

[0189] Table 3

[0190]

[0191]

[0192] Table 4 (Aspheric parameters of four lenses)

[0193]

[0194] For the optical performance of the AR lens module provided in Example 1 of the present application, see Figure 6 :

[0195] Figure 6 This is the modulation transfer function diagram of the AR lens module, see Figure 6The MTF of the AR lens module provided in this embodiment 1 is >0.5 at 125lp / mm, indicating that the AR lens module has clear imaging.

[0196] Example 2

[0197] The AR lens module provided in this embodiment 2 is shown in FIG. Figure 7 , including a lens group, an X-cube color combining prism 5 and a display chip 6 arranged along the same optical axis;

[0198] The lens group is composed of a first lens 1, a second lens 2, a third lens 3 and a fourth lens 4 which are arranged in sequence, and the fourth lens 4 is arranged adjacent to the X-cube color combining prism 5;

[0199] The focal power of the first lens 1 is positive, the first lens 1 is a plano-convex glass aspherical lens, the focal power of the second lens 2 is negative, the focal power of the third lens 3 is positive, the focal power of the fourth lens 4 is negative, and the fourth lens 4 is a meniscus lens curved toward the third lens 3;

[0200] The CRA of the AR lens module is 13°, where CRA is the angle between the main ray of the edge field of view and the optical axis of the display chip;

[0201] The AR lens module includes an aperture, and the aperture is located on a side of the first lens 1 away from the second lens 2; the air gap between the aperture and the first lens 1 is ≤0.3 mm;

[0202] The aperture of the aperture is 3.4 mm to 3.6 mm.

[0203] The total optical length L of the AR lens module is 7.53 mm, and the maximum effective aperture of the AR lens module is 3.5 mm.

[0204] In the AR lens module provided in this embodiment 2, the optical parameters of the first lens 1 to the X-cube color combining prism 5 are shown in Tables 5 and 6 below.

[0205] Table 5

[0206]

[0207] Table 6 (Aspheric parameters of four lenses)

[0208]

[0209] For the optical performance of the AR lens module provided in Example 2 of the present application, see Figure 8 :

[0210] Figure 8 This is the modulation transfer function diagram of the AR lens module, see Figure 8 The MTF of the AR lens module provided in this embodiment 2 is >0.58 at 125lp / mm, indicating that the AR lens module has clear imaging.

[0211] Example 3

[0212] The AR lens module provided in this embodiment 3 is shown in FIG. Fig. 9 , including a lens group, an X-cube color combining prism 5 and a display chip 6 arranged along the same optical axis;

[0213] The lens group is composed of a first lens 1, a second lens 2, a third lens 3 and a fourth lens 4 which are arranged in sequence, and the fourth lens 4 is arranged adjacent to the X-cube color combining prism 5;

[0214] The focal power of the first lens 1 is positive, the first lens 1 is a plano-convex glass aspherical lens, the focal power of the second lens 2 is negative, the focal power of the third lens 3 is positive, the focal power of the fourth lens 4 is negative, and the fourth lens 4 is a meniscus lens curved toward the third lens 3;

[0215] The CRA of the AR lens module is 13°, where CRA is the angle between the main ray of the edge field of view and the optical axis of the display chip;

[0216] The AR lens module includes an aperture, and the aperture is located on a side of the first lens 1 away from the second lens 2; the air gap between the aperture and the first lens 1 is ≤0.3 mm;

[0217] The aperture of the aperture is 3.4 mm to 3.6 mm.

[0218] The total optical length L of the AR lens module is 7.53 mm, and the maximum effective aperture of the AR lens module is 3.5 mm.

[0219] In the AR lens module provided in this embodiment 3, the optical parameters of the first lens 1 to the X-cube color combining prism 5 are shown in Tables 7 and 8 below.

[0220] Table 7

[0221]

[0222] Table 8 (Aspheric parameters of four lenses)

[0223]

[0224]

[0225] For the optical performance of the AR lens module provided in Example 3 of the present application, see Fig.10 :

[0226] Fig.10 This is the modulation transfer function diagram of the AR lens module, see Fig.10 The MTF of the AR lens module provided in this embodiment 3 is >0.6 at 125lp / mm, indicating that the AR lens module has clear imaging.

[0227] Example 4

[0228] The AR lens module provided in this embodiment 4 is shown in FIG. Fig.11 , including a lens group, an X-cube color combining prism 5 and a display chip 6 arranged along the same optical axis;

[0229] The lens group is composed of a first lens 1, a second lens 2, a third lens 3 and a fourth lens 4 which are arranged in sequence, and the fourth lens 4 is arranged adjacent to the X-cube color combining prism 5;

[0230] The focal power of the first lens 1 is positive, the first lens 1 is a plano-convex glass aspherical lens, the focal power of the second lens 2 is negative, the focal power of the third lens 3 is positive, the focal power of the fourth lens 4 is negative, and the fourth lens 4 is a meniscus lens curved toward the third lens 3;

[0231] The CRA of the AR lens module is 13°, where CRA is the angle between the main ray of the edge field of view and the optical axis of the display chip;

[0232] The AR lens module includes an aperture, and the aperture is located on a side of the first lens 1 away from the second lens 2; the air gap between the aperture and the first lens 1 is ≤0.3 mm;

[0233] The aperture of the aperture is 3.4 mm to 3.6 mm.

[0234] The total optical length L of the AR lens module is 7.53 mm, and the maximum effective aperture of the AR lens module is 3.5 mm.

[0235] In the AR lens module provided in this embodiment 4, the optical parameters of the first lens 1 to the X-cube color combining prism 5 are as shown in Tables 9 and 10 below.

[0236] Table 9

[0237]

[0238] Table 10 (Aspheric parameters of four lenses)

[0239]

[0240]

[0241] For the optical performance of the AR lens module provided in Example 4 of the present application, see Fig.12 :

[0242] Fig.12 This is the modulation transfer function diagram of the AR lens module, see Fig.12 , the MTF of the AR lens module provided in this embodiment 4 is >0.6 at 125lp / mm, indicating that the AR lens module has clear imaging.

[0243] 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.

[0244] 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 only for illustration, not for limiting the scope of the present application. It should be understood by those skilled in the art that the above embodiments 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 lens module for a full-color AR optical machine, characterized in that: It includes a lens group, an X-cube dichroic prism (5), and a display chip (6) arranged along the same optical axis; Among them, the lens group is composed of a first lens (1), a second lens (2), a third lens (3), and a fourth lens (4) arranged in sequence, and the fourth lens (4) is adjacent to the X-cube dichroic prism (5); The optical powers of the first lens (1) and the third lens (3) are positive, and the optical powers of the second lens (2) and the fourth lens (4) are negative; The first lens (1) to the fourth lens (4) are all aspherical lenses; The CRA of the AR lens module is 13°, and the CRA is the angle between the chief ray of the peripheral field of view and the optical axis of the display chip (6).

2. The AR lens module according to claim 1, characterized in that: The first lens (1) is a plano-convex lens; The fourth lens (4) is a meniscus lens curved towards the third lens (3); The effective focal length F4 of the fourth lens (4) is -80 mm to -50 mm.

3. The AR lens module according to claim 1, characterized in that: The AR lens module satisfies: 1.2 < (F1 + F3) / L < 1.65; -12 < (F2 + F4) / L < -6; Among them, F1 is the effective focal length of the first lens (1), F2 is the effective focal length of the second lens (2), F3 is the effective focal length of the third lens (3), F4 is the effective focal length of the fourth lens (4), and L is the total optical length of the AR lens module.

4. The AR lens module according to claim 1, characterized in that: The AR lens module satisfies: 30 < (F1 + F3)*Q < 44; where Q is the maximum aperture of the lenses from the first lens (1) to the fourth lens (4).

5. The AR lens module according to claim 1, characterized in that: The AR lens module satisfies: 1.9 < (A1 + A3) / (A2 + A4) < 2.5; where A1 is the air gap between the first lens (1) and the second lens (2), A2 is the air gap between the second lens (2) and the third lens (3), A3 is the air gap between the third lens (3) and the fourth lens (4), A4 is the air gap between the fourth lens (4) and the X-cube dichroic prism (5), and Q is the maximum aperture of the lenses from the first lens (1) to the fourth lens (4).

6. The AR lens module according to claim 5, characterized in that: The AR lens module satisfies: 3 < L / (A1 + A2 + A3 + A4) < 3.7; where L is the total optical length of the AR lens module.

7. The AR lens module according to claim 1, characterized in that: The AR lens module satisfies: N1 > N2 > N4 > N3; 14 < (N1*F1 + N3*F3) < 20; Among them, N1 is the refractive index of the first lens (1), N2 is the refractive index of the second lens (2), N3 is the refractive index of the third lens (3), N4 is the refractive index of the fourth lens (4), F1 is the effective focal length of the first lens (1), and F3 is the effective focal length of the third lens (3).

8. The AR lens module according to claim 1, characterized in that: Among the first lens (1) to the fourth lens (4), three lenses are plastic aspherical lenses, and the other lens is a glass aspherical lens.

9. The AR lens module according to claim 1, characterized in that: The first lens (1) is a glass aspherical lens, and the second lens (2), the third lens (3), and the fourth lens (4) are all plastic aspherical lenses.

10. The AR lens module according to claim 1, characterized in that: The effective focal length F1 of the first lens (1) is 3.2 mm to 3.8 mm; The effective focal length F2 of the second lens (2) is -4.5 mm to -3.7 mm; The effective focal length F3 of the third lens (3) is 6.9 mm to 7.6 mm.

11. The AR lens module according to any one of claims 1 to 10, characterized in that: The AR lens module comprises an aperture, wherein the aperture is located on a side of the first lens (1) away from the second lens (2); The air gap between the aperture and the first lens (1) is ≤0.3 mm; The aperture of the aperture is 3.4 mm to 3.6 mm.

12. The AR lens module according to claim 11, characterized in that: The total optical length L of the AR lens module is 7.53 mm; The maximum effective aperture of the AR lens module is 3.5 mm.

13. An optical display device, characterized in that: include: The AR lens module as claimed in any one of claims 1 to 12; and Optical waveguide device, the aperture of the diaphragm of the AR lens module matches the entrance pupil diameter of the optical waveguide device.

Images