Ar lens module and optical display device

Abstract

Embodiments of the present application provide an AR lens module and an optical display device; wherein the AR lens module is used for a full-color AR light machine, which comprises a lens group, an X-cube color combining prism and a display chip 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 arranged in sequence, the fourth lens is adjacent to the X-cube color combining prism; 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; the first lens to the fourth lens are all aspheric lenses; the CRA of the AR lens module is 13°, and the CRA is the included angle between the edge field chief ray and the optical axis of the display chip.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of optical display, and more particularly, to an AR lens module and an optical display device. BACKGROUND

[0002] With the development of augmented reality technology, the market puts forward higher and higher requirements on the volume and weight of wearable AR optical display devices. For wearable AR optical display devices (such as smart glasses), smaller volume and lighter weight can significantly improve the wearing comfort of users. However, the volume and weight of the current wearable AR optical display devices are largely dependent on the AR lens module inside. The traditional AR lens module often leads to a bulky optical display device and a heavy weight due to the complex illumination light path and the large imaging lens (including many lenses).

[0003] Therefore, it has become a key problem to be solved in the field of augmented reality technology to develop an AR lens module that can significantly reduce the volume and weight while ensuring excellent imaging quality. SUMMARY

[0004] The purpose of the present application is to provide a new technical solution of 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 light machine, which includes a lens group, an X-cube color combining 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 is adjacent to the X-cube color combining prism.

[0007] The first lens and the third lens have positive optical power, and the second lens and the fourth lens have negative optical power.

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

[0009] The CRA of the AR lens module is 13°, and the CRA is the included angle between the edge field chief ray 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 towards 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 among 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 prism, and Q is the maximum aperture of the lenses among 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 lenses among 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 plastic aspherical lenses.

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

[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 6.9mm to 7.6mm.

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

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

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

[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] An 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 present application has the following beneficial effects:

[0036] The AR lens module provided by the embodiments of the present application realizes the miniaturization design of the AR lens module, while ensuring the high-quality imaging effect; the optimized CRA design not only reduces the volume, but also effectively improves the light energy utilization rate and enhances the display effect. The design of the four aspheric lenses effectively reduces the spherical aberration caused by the large aperture, significantly improves the imaging quality. The design of the positive, negative, positive and negative focal length further offsets the aberration, which is conducive to reducing the aberration of the entire AR lens module, thereby ensuring the high definition of the image.

[0037] The present application realizes the extremely miniaturization of the AR lens module, while maintaining excellent imaging effect, and provides strong technical support for the development of augmented reality devices.

[0038] Other features of the present application and their advantages will become apparent from the following detailed description of exemplary embodiments of the present application with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

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

[0040] Figure 1Structure schematic diagram of AR lens module provided for an embodiment of the present application;

[0041] Figure 2 Structure schematic diagram of AR lens module provided for an embodiment of the present application;

[0042] Figure 3 Structure schematic diagram of AR lens module provided for an embodiment of the present application; Figure 2 Distortion diagram of AR lens module provided for an embodiment of the present application;

[0043] Figure 4 Modulation transfer function diagram of AR lens module provided for an embodiment of the present application; Figure 2 Modulation transfer function diagram of AR lens module provided for an embodiment of the present application;

[0044] Figure 5 Structure schematic diagram of AR lens module provided for an embodiment of the present application;

[0045] Figure 6 Modulation transfer function diagram of AR lens module provided for an embodiment of the present application; Figure 5 Modulation transfer function diagram of AR lens module provided for an embodiment of the present application;

[0046] Figure 7 Structure schematic diagram of AR lens module provided for an embodiment of the present application;

[0047] Figure 8 Modulation transfer function diagram of AR lens module provided for an embodiment of the present application; Figure 7 Modulation transfer function diagram of AR lens module provided for an embodiment of the present application;

[0048] Figure 9 Structure schematic diagram of AR lens module provided for an embodiment of the present application;

[0049] Figure 10 Modulation transfer function diagram of AR lens module provided for an embodiment of the present application; Figure 9 Modulation transfer function diagram of AR lens module provided for an embodiment of the present application;

[0050] Figure 11 Structure schematic diagram of AR lens module provided for an embodiment of the present application;

[0051] Figure 12 Modulation transfer function diagram of AR lens module provided for an embodiment of the present application. Figure 11 Modulation transfer function diagram of AR lens module provided for an embodiment of the present application.

[0052] Explanation of reference signs:

[0053] 1, first lens; 2, second lens; 3, third lens; 4, fourth lens; 5, X-cube 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. Note that the relative arrangement, numerical expressions, and numerical values of components and steps set forth in these embodiments are not limiting to the scope of the present application unless otherwise specifically stated.

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

[0056] Techniques and devices known to those of ordinary skill in the relevant art can not be discussed in detail herein, but should be considered as part of the specification.

[0057] In all of the examples shown and discussed herein, any specific values should be interpreted as merely exemplary, and not as a limitation. Thus, other examples of the exemplary embodiments can have different values.

[0058] It should be noted that like reference numerals and letters refer to like items throughout the attached drawings, and once an item is defined in one drawing, it is not necessary to discuss it further in subsequent drawings.

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

[0060] According to an embodiment of the present application, an AR lens module for a full-color AR light machine is provided, which comprises a lens group, an X-cube color combining prism 5 and a display chip 6 arranged along the same optical axis; 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, the fourth lens 4 is arranged adjacent to the X-cube color combining prism 5; 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 mirrors; the CRA of the AR lens module is 13°, and the CRA is the included angle between the chief ray of the edge field of view and the optical axis of the display chip 6.

[0061] The AR lens module provided by the embodiments of the present application is a miniaturized AR lens module for a full-color AR lens. The AR lens module of the embodiments of the present application not only realizes significant miniaturization in volume, but also realizes the reduction of the overall weight, while ensuring excellent imaging quality, thereby 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 by the embodiments of the present application can still 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 a full-color AR light machine. Specifically, the AR lens module comprises a lens group, an X-cube color combiner 5, and a display chip 6. The lens group is composed of four lenses, i.e., a first lens 1, a second lens 2, a third lens 3, and a fourth lens 4, which are arranged in sequence along the same optical axis. This arrangement helps to orderly transfer light and control imaging quality. Figure 1 The first lens 1 is located near the aperture, and the fourth lens 4 is adjacent to the X-cube color combiner 5.

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

[0065] The AR lens module provided in the embodiment of the present application adopts a specific design of focal power combination: the focal power of the first lens 1 and the third lens 3 is positive, and the focal power of the second lens 2 and the fourth lens 4 is negative. In this way, according to the order from the first lens 1 to the fourth lens 4, this positive-negative-positive-negative focal power combination can create more higher-order aberrations to offset primary aberrations, significantly reduce the total aberration of the entire AR lens module, improve the modulation transfer function (MTF), and thus ensure the high definition of the image.

[0066] The AR lens module provided in the embodiment of the present application further comprises an X-cube color combiner 5 and a display chip 6.

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

[0068] The display chip 6 is the light emitting source, also known as the light emitting panel. By precisely controlling the light emitting angle and brightness of the display chip 6, and cooperating with the CRA design, efficient light energy utilization and high-quality display effect are achieved.

[0069] In the embodiment of the present application, the CRA of the AR lens module is set to 13°. The CRA is the included angle between the edge field chief ray and the optical axis of the display chip 6. Setting the CRA to 13° is a key innovation point, which helps to reduce the size of the AR lens module while maintaining a high light energy utilization rate. A larger CRA angle allows the lens group to receive more light from the display chip 6, thereby enhancing the display effect, especially in the edge field area.

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

[0071] The AR lens module provided by the embodiments of the present application can achieve the following technical effects:

[0072] (1) High-quality imaging effect: the aspherical lens and the positive and negative focal length combination significantly reduce aberration, improve the clarity and contrast of the image.

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

[0074] (3) High efficiency of light energy utilization: the optimized CRA design ensures sufficient light passing 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 combiner 5 is applied in combination with the lens group to achieve high-quality full-color display, improving the user's visual experience.

[0076] The AR lens module provided by the embodiments of the present application realizes the miniaturization design of the AR lens module while ensuring high-quality imaging effect; the optimized CRA design not only reduces the volume but also effectively improves the light energy utilization, enhancing the display effect. The design of the four aspherical lenses effectively reduces the spherical aberration caused by the large aperture, significantly improving the imaging quality. The design of the positive, negative, positive and negative focal length combination further offsets the aberration, which is conducive to reducing the aberration of the entire AR lens module, thereby ensuring the high definition of the image.

[0077] The present application realizes the extremely miniaturization of the AR lens module while maintaining excellent imaging effect, providing strong technical support for the development of augmented reality devices.

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

[0079] The lens group of the present application, the first lens 1 (close to the diaphragm) is designed as a plano-convex lens, 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 exit to the external light output device such as the light waveguide device through the diaphragm.

[0080] By reasonably 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, avoiding the problem of aberration caused by large aperture, and also helping to realize the miniaturization of 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, the spherical aberration can be further reduced, which helps to improve the imaging quality and ensure the clarity of the image.

[0082] In the lens group of the present application, the fourth lens 4 is a meniscus lens curved towards 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 curved towards the third lens 3, and both sides of the fourth lens 4 are curved, with the curved direction being towards the third lens 3. The special shape of the meniscus lens can effectively correct the field curvature, which is crucial for improving the flatness and consistency of the image.

[0084] Due to the special shape and 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 realize the miniaturization and light weight of the lens module.

[0085] In the present application, the effective focal length F4 of the fourth lens 4 is -80 mm to -50 mm. This indicates that the fourth lens is a negative lens with a relatively large absolute value of focal length. This design makes the fourth lens 4 become the main negative lens in the entire AR lens group, which helps to further reduce the volume of the module and optimize the aberration such as field curvature. At the same time, its curved thin meniscus lens shape is also conducive to reducing the 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 examples 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 towards the third lens 3, and the effective focal length F4 of the fourth lens 4 is -80 mm to -50 mm. This combination of designs 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 effect and ensure the clarity of the image.

[0089] (2) Miniaturization and lightweight of the AR lens module: The surface design of both lenses helps to realize the miniaturization and lightweight of the AR lens module.

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

[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] Wherein 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 certain relationships between focal length and total optical length L, which aims to achieve minimal size and high performance of the AR lens module through optical design parameters control.

[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 F1 and F3 are both 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 ensure that the AR lens module has an appropriate distribution of positive focal power, neither too concentrated nor too dispersed, thereby helping to achieve good imaging quality and compact structure 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 focal power in the AR lens module. By limiting this sum within a certain negative value range, it can ensure that the entire AR lens module has sufficient negative focal power to balance the positive focal power, achieve effective convergence and divergence of light, control aberration and improve imaging quality. In addition, this distribution of negative focal 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 an embodiment of the present application is 7.53 mm.

[0100] The restriction of the relationship in this example of the present application helps to achieve extreme miniaturization of the AR lens module while maintaining high performance. By reasonably distributing positive and negative optical power, 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 to efficiently propagate light in the AR lens module, reduces light energy loss, and improves light energy utilization. This is particularly 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; where Q is the maximum aperture of the lenses in the first lens 1 to the fourth lens 4.

[0103] According to this example of the present application, this relationship relates the product of the sum of the effective focal lengths of the first lens 1 and the third lens 3 (F1+F3) and the maximum aperture Q of 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 their sum determines the ability of the AR lens module to collect and converge light.

[0105] Q: as the maximum aperture of the lenses 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. The larger the aperture, generally means the more light that can be received, but it can also result in an increase in the size of the AR lens module.

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

[0107] According to the relationship 30<(F1+F3)*Q<44 proposed in this example of the present application, the maximum aperture of the lens is controlled while ensuring sufficient positive focal power, so as to achieve a balance between the compactness and high 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 focal power, which is crucial for imaging quality. Insufficient positive focal power can cause image blur, while excessive positive focal power can increase aberration. By limiting the value of Q, it can be ensured that the AR lens module is highly performant while being extremely miniaturized. 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, the combination of appropriate positive focal power and lens aperture helps to optimize the propagation path of light in the AR lens module, reduce light energy loss, and improve light energy utilization. This is particularly important for augmented reality devices, which 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 combiner 5, and Q is the maximum aperture of the lenses in the first lens 1 to the fourth lens 4.

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

[0112] Specifically, by restricting the ratio range of (A1+A3) to (A2+A4), it helps to ensure reasonable spatial distribution between lenses while maintaining the compactness of the AR lens module, avoiding increased aberration or reduced light energy utilization due to excessive compactness. Reasonable air gap distribution helps to reduce stray light and ghosting, and improve image clarity.

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

[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 total optical length of the AR lens module.

[0115] According to the example of the present application, by limiting the proportion of the total optical length L of the AR lens module and the sum of all air gaps, it can be ensured that the overall size of the AR lens module is within the design range, meeting the needs of miniaturization and light weight.

[0116] Reasonable air gap distribution helps to improve the space utilization rate inside the AR lens module, so that the components can be arranged closely and orderly, reducing unnecessary space waste. Reasonable space distribution helps to reduce interference between optical elements, improve the stability of the optical path and imaging quality.

[0117] Specifically, under the premise of ensuring imaging performance, by setting the upper limit of the proportion to 3.7, the overall size of the AR lens module can be effectively controlled, and extremely miniaturized design can be achieved. Proper air gap helps to reduce light loss during propagation and improve light energy utilization.

[0118] The lower limit of L / (A1+A2+A3+A4) is 3, which ensures that there is enough space inside the AR lens module to accommodate optical elements and air gaps. This helps to avoid excessive crowding between optical elements and reduce interference between them, thereby improving imaging quality. Although the lower limit of the proportion helps to 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; wherein 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 color combiner 5, Q is the maximum aperture of the lenses among 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 relationship formulas in the above example, it can be found that they form a complement in optimizing the design of the AR lens module. Specifically, by simultaneously controlling the proportion of the air gap and the proportion of the total optical length and the sum of the air gaps, the propagation path of the light in the AR lens module can be more comprehensively optimized, further improving the imaging quality and light energy utilization.

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

[0122] For example, the AR lens module provided by the embodiments of the present application has a total optical length L of 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] wherein 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 examples 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, which means that the refractive index of the first lens 1 is the highest, followed by the second lens 2, the fourth lens 4 has a higher refractive index than the third lens 3, and the third lens 3 has the lowest refractive index.

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

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

[0131] The first lens 1 with high refractive index can refract light more effectively, 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. Proper refractive index selection and effective focal length configuration help to reduce light reflection and scattering inside the AR lens module, thereby improving light energy utilization.

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

[0134] The AR lens module provided in the embodiments of the present application can design three lenses among the first lens 1 to the fourth lens 4 as plastic lenses, which is beneficial to reduce the weight of the entire AR lens module.

[0135] The density of a plastic lens is much lower than that of a glass lens, so using a plastic lens can significantly reduce the weight of the entire AR lens module. For an augmented reality (AR) optical display device, 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 aspherical lenses. Aspherical lenses can provide better optical performance, such as reducing aberration and improving imaging quality. Therefore, using 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 prone to accidental collisions or drops, using plastic lenses can reduce the risk of lens breakage and improve the durability and reliability of the device.

[0138] In the lens group of the present application, one lens can also use a glass lens. Glass lenses have 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 selection is based on a balance between imaging quality, weight, cost, and manufacturability. By using one glass lens, the AR lens module can have excellent imaging performance in key areas, such as reducing chromatic aberration and improving resolution. At the same time, using three plastic lenses can reduce the overall weight and cost of the AR lens module. In other words, by combining glass lenses and plastic lenses, the present application achieves an optimal balance between imaging quality and cost. This design ensures both high performance and low manufacturing cost of the AR lens module.

[0140] In some examples of the present application, referring to Figure 1 , the first lens 1 is a glass aspherical mirror, and the second lens 2, the third lens 3, and the fourth lens 4 are all plastic aspherical mirrors.

[0141] In the lens set of the present application, the first lens 1 is designed as a glass aspheric lens. Glass material has high refractive index, low dispersion and excellent thermal stability, which can produce high-quality images. Aspheric design can effectively reduce spherical aberration and other aberrations, and improve the imaging quality. Therefore, the first lens 1 is designed as a glass aspheric lens and placed on the stop side, which can ensure that the light can be well corrected when entering the subsequent optical device (such as optical waveguide device).

[0142] Please continue to see Figure 1 In the lens set of the present application, the second lens 2, the third lens 3 and the fourth lens 4 are all designed as plastic aspheric lenses. Plastic material has the advantages of lightweight, low cost and easy to process and shape. The aspheric design can also reduce aberrations and improve imaging quality. The material and surface type 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 the present application, the glass aspheric lens as the lens of the near stop (exit pupil) can effectively correct the aberration and distortion of the light when entering the subsequent optical device, and can provide a better imaging basis. The use of plastic aspheric lenses can reduce aberrations and distortions while ensuring lightweight and low cost, further improving imaging quality. Overall, this design combination can produce high-definition, low-distortion and high-contrast images, meeting the demand for high-quality imaging of AR optical display devices.

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

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

[0146] The effective focal length F2 of the second lens 2 is -4.5mm-3.7mm. This indicates that the second lens 2 is a negative lens with a relatively large absolute value of focal length. 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 6.9mm-7.6mm. This indicates that the third lens 3 is again a positive lens, and the focal length is relatively long. This design helps to further adjust the convergence of light, and optimizes the imaging quality. At the same time, in combination with the negative focal power of the adjacent second lens 2, the positive and negative focal powers are alternated, which is beneficial to the correction of aberration.

[0148] In the present application, the effective focal length F4 of the fourth lens 4 is -80mm--50mm. This indicates 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 become the main negative lens in the whole AR lens group, which helps to further reduce the volume of the module, and optimizes the image field curvature and other aberrations. At the same time, its curved thin crescent lens shape is also beneficial to reduce the field curvature and improve the modulation transfer function (MTF).

[0149] The AR lens module of the present application adopts the focal power combination of positive, negative, positive, and negative from the first lens 1 to the fourth lens 4. Through this combination of focal power, the aberration of the whole AR lens module can be well reduced, and the imaging quality can be improved. Among them, the reasonable combination of the light convergence angle effect of the positive lens and the divergent light effect of the negative lens helps to realize the minimization of the volume of the AR lens group, and meets the demand of AR optical display device for miniaturization.

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

[0151] In some examples of the present application, referring to Figure 1 , the AR lens module includes a stop, the stop is located on the side of the first lens 1 away from the second lens 2; the air gap between the stop and the first lens 1 is ≤0.3mm; the aperture of the stop is 3.4mm-3.6mm.

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

[0153] By limiting the air gap between the stop and the first lens 1, the total length of the AR lens module in the optical axis direction can be reduced under the premise of ensuring the imaging quality, which helps to realize a more compact design.

[0154] The aperture of the stop is controlled to be between 3.4mm-3.6mm, which helps to constrain light, improve light energy utilization, and efficiently couple with subsequent optical waveguide devices.

[0155] The aperture design of the diaphragm helps to achieve efficient coupling with subsequent optical waveguide devices, reduces light loss during coupling, and thus improves the optical efficiency and image quality of the entire AR lens module.

[0156] It should be noted that the diaphragm mentioned in this application refers to Figure 1 which is located at the leftmost side of the entire AR lens module. When the entire AR lens module is applied in an AR light engine, the diaphragm is the exit pupil of the light engine.

[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 the 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 the basis of optical performance of the AR lens module.

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

[0160] Wherein, the maximum effective aperture is 3.5 mm, which constrains 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 image quality of the AR lens module.

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

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

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

[0164] Focal length: 5.59mm;

[0165] Field of view: ±12.5°;

[0166] Relative aperture: 1 / 1.56;

[0167] Pixel size: 4μm;

[0168] Operating wavelength: 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 Table 1 and Table 2 below.

[0170] Table 1

[0171]

[0172]

[0173] Table 2 (Aspherical parameters of the four lenses)

[0174]

[0175] The optical performance of the AR lens module provided in this application embodiment is described in [reference]. Figure 3 and Figure 4 :

[0176] Figure 3 For distortion diagrams of the AR lens module, see [link / reference]. 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 For the modulation transfer function diagram of the AR lens module, see [link / reference]. 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 produces clear images.

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

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

[0180] Example 1

[0181] The AR lens module provided in Embodiment 1, see Figure 5 , comprises 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 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 flat convex glass aspheric 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 towards the third lens 3;

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

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

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

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

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

[0189] Table 3

[0190]

[0191]

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

[0193]

[0194] The optical performance of the AR lens module provided in Embodiment 1, see Figure 6 :

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

[0196] Embodiment 2

[0197] The AR lens module provided in Embodiment 2 includes a lens group, an X-cube color combining prism 5 and a display chip 6 arranged along the same optical axis. Figure 7

[0198] 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 arranged adjacent to the X-cube color combining prism 5.

[0199] The first lens 1 has positive refractive power, is a flat convex glass aspheric lens, the second lens 2 has negative refractive power, the third lens 3 has positive refractive power, the fourth lens 4 has negative refractive power, and the fourth lens 4 is a meniscus lens curved towards the third lens 3.

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

[0201] The AR lens module includes a diaphragm, and the diaphragm is located on the side of the first lens 1 away from the second lens 2; the air gap between the diaphragm and the first lens 1 is less than or equal to 0.3 mm.

[0202] The aperture of the diaphragm 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 Embodiment 2, the optical parameters of the first lens 1 to the X-cube color combining prism 5 are shown in Table 5 and Table 6.

[0205] Table 5

[0206]

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

[0208]

[0209] The optical performance of the AR lens module provided in Embodiment 2 is shown in Figure 8 :

[0210] Figure 8 The modulation transfer function diagram of the AR lens module is shown in​Figure 8 The MTF of the AR lens module provided in Embodiment 2 is greater than 0.58 at 125 lp / mm, indicating that the AR lens module has clear imaging.

[0211] Embodiment 3

[0212] The AR lens module provided in Embodiment 3, as shown in Figure 9 , comprises 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 arranged in sequence, and the fourth lens 4 is arranged adjacent to the X-cube color combining prism 5;

[0214] The first lens 1 has positive focal power, the first lens 1 is a flat convex glass aspheric lens, the second lens 2 has negative focal power, the third lens 3 has positive focal power, the fourth lens 4 has negative focal power, and the fourth lens 4 is a meniscus lens curved towards the third lens 3;

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

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

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

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

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

[0220] Table 7

[0221]

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

[0223]

[0224]

[0225] The optical performance of the AR lens module provided in Embodiment 3, as shown in Figure 10 :

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

[0227] Embodiment 4

[0228] The AR lens module provided in this embodiment 4, see Figure 11 , comprises 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 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 flat convex glass aspheric mirror, 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 towards the third lens 3;

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

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

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

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

[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 Table 9 and Table 10.

[0236] Table 9

[0237]

[0238] Table 10 (aspheric surface parameters of four lenses)

[0239]

[0240]

[0241] The optical performance of the AR lens module provided in Embodiment 4 of the present application is shown in FIG. 4. Figure 12

[0242] Figure 12 FIG. 5 is a modulation transfer function (MTF) diagram of the AR lens module. Figure 12 The MTF of the AR lens module provided in Embodiment 4 of the present application is greater than 0.6 at 125 lp / mm, indicating that the AR lens module has clear imaging.

[0243] The above embodiments mainly describe the differences between the embodiments. The different optimization features of the embodiments can be combined to form a better embodiment without contradiction. In view of the brevity of the text, the details will not be described here.

[0244] Although some specific embodiments of the present application have been described in detail by examples, those skilled in the art should understand that the above examples are only for illustration, not for limiting the scope of the present application. Those skilled in the art should understand that the above embodiments can 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 light engine, characterized in that, The AR lens module comprises a lens group, an X-cube color combining prism (5) and a display chip (6) arranged along the same optical axis. 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 arranged adjacent to the X-cube color combining prism (5). 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 the CRA is the included angle between the edge field chief ray and the optical axis of the display chip (6). The AR lens module satisfies: 1.2 < (F1+F3) / L < 1.65; -12 < (F2+F4) / L < -6; Wherein, 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. 2.The AR lens module of claim 1, wherein, 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 -80mm~ -50mm. 3.The AR lens module of claim 1, wherein, The AR lens module satisfies: 30 < (F1+F3)*Q < 44; wherein Q is the maximum aperture of the lenses in the first lens (1) to the fourth lens (4). 4.The AR lens module of claim 1, wherein, The AR lens module satisfies: 1.9 < (A1+A3) / (A2+A4) < 2.5; wherein 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 color combining prism (5), and Q is the maximum aperture of the lenses in the first lens (1) to the fourth lens (4). 5.The AR lens module of claim 4, wherein, 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. 6.The AR lens module of claim 1, wherein, The AR lens module satisfies: N1 > N2 > N4 > N3; 14 < (N1*F1+N3*F3) < 20; Wherein, 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). 7.The AR lens module of claim 1, wherein, Three of the first lens (1) to the fourth lens (4) are plastic aspherical lenses, and the other one is a glass aspherical lens. 8.The AR lens module of claim 1, wherein, 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. 9.The AR lens module of claim 1, wherein, An effective focal length F1 of the first lens (1) is 3.2mm~3.8mm; An effective focal length F2 of the second lens (2) is -4.5mm~-3.7mm; An effective focal length F3 of the third lens (3) is 6.9mm~7.6mm. 10.The AR lens module according to any one of claims 1-9, wherein, The AR lens module comprises a diaphragm, and the diaphragm is located on a side of the first lens (1) away from the second lens (2); An air gap between the diaphragm and the first lens (1) is ≤0.3mm; An aperture of the diaphragm is 3.4mm~3.6mm. 11.The AR lens module of claim 10, wherein, An optical total length L of the AR lens module is 7.53mm; A maximum effective aperture of the AR lens module is 3.5mm.

12. An optical display device, characterized by The AR lens module comprises: The AR lens module as claimed in any one of claims 1-11; And An optical waveguide device, an aperture of the diaphragm of the AR lens module matches an entrance pupil diameter of the optical waveguide device.

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