Optical lens and optical display device

Abstract

Embodiments of the present application provide an optical lens and an optical display device; the optical lens comprises, along an optical axis, from an imaging side to an image source side, a first group, a second group, a third group, a fourth group and an imaging chip group; the first group is a double-cemented lens group, comprising two glass spherical lenses, wherein a first lens is a positive lens and a second lens is a negative lens; the second group comprises at least two lenses; the third group comprises at most one glass spherical lens with positive optical power; the fourth group comprises at least one plastic aspherical lens with negative optical power; and the imaging chip group is arranged closest to the image source side.

Description

Technical Field

[0001] This application relates to the field of optical imaging technology, and more specifically, to an optical lens and an optical display device. Background Technology

[0002] With the rapid development of artificial intelligence technology, AR glasses, as a highly promising intelligent display medium, are gradually becoming practical. As the core optical component of AR glasses, the optical lens is responsible for transmitting information from the image processing chip to the optical waveguide device, and its performance directly determines the user's visual experience.

[0003] Currently, most AR lenses on the market have a field of view (FOV) of around 30°, resulting in a poor sense of immersion for users. Although waveguide technology can support a larger FOV, maintaining a large FOV, high resolution, low aberrations, and controllable cost for the matching optical lenses still presents technical challenges. Common optical lens architectures often face difficulties in correcting aberrations (such as chromatic aberration, field curvature, and distortion), excessive system size, or high costs when achieving a large FOV.

[0004] Therefore, there is an urgent need in this field for an optical lens that can achieve a large FOV and high imaging quality while ensuring a compact structure and reasonable cost. Summary of the Invention

[0005] The purpose of this application is to provide a new technical solution for optical lenses and optical display devices to solve the problems of small field of view, poor immersion, and difficulty in balancing cost and performance in existing AR optical lenses.

[0006] In a first aspect, embodiments of this application provide an optical lens, which comprises, along the optical axis from the imaging side to the image source side, the following components in sequence: The first group is a cemented doublet lens group, which contains two glass spherical lenses, where the first lens is a positive lens and the second lens is a negative lens; The second group contains at least two lenses, including one positive lens and one negative lens; The third group contains at most one glass spherical lens with positive optical power; The fourth group comprises at least one plastic aspherical lens with negative optical power; and, The imaging chip group is located closest to the image source.

[0007] Optionally, the first lens is a biconvex lens with a refractive index Nd. 101 Satisfying 1.80 < Nd 101 <1.85, Abbe number Vd 101 >40; The second lens is a biconcave lens with a refractive index of Nd. 102 <1.65, Abbe number Vd 102 <34.

[0008] Optionally, the focal length f1 of the first lens satisfies: 5.3mm ≤ f1 ≤ 5.7mm; The focal length f2 of the second lens satisfies: -9.0mm≤f2≤-9.6mm.

[0009] Optionally, the second group is a doublet lens group, which includes a third lens and a fourth lens bonded together, and both the third lens and the fourth lens are glass spherical lenses; wherein the third lens is a biconcave negative lens and the fourth lens is a biconvex positive lens.

[0010] Optionally, the second group consists of two spaced-apart single lenses, at most one of which is a glass aspherical lens; The two single lenses include a third lens and a fourth lens, wherein: The third lens is a negative lens, and its surface near the first group is concave. The fourth lens is a positive lens, and its surface near the imaging chip group is convex.

[0011] Optionally, the negative lenses in the second group have a refractive index Nd < 1.65 and an Abbe number Vd < 34; The refractive index Nd of the positive lenses in the second group satisfies 1.71 < Nd < 1.85 and Abbe number Vd > 40.

[0012] Optionally, the focal length f3 of the negative lens in the second group satisfies: -4.5mm ≤ f3 ≤ -5.5mm; The focal length f4 of the positive lens in the second group satisfies: 5mm≤f4≤6mm.

[0013] Optionally, the third group includes a fifth lens, which is a biconvex glass spherical lens with a focal length f5 satisfying: 11.0mm≤f5≤11.5mm.

[0014] Optionally, the fourth group includes a sixth lens, which is a plastic aspherical lens with at least one surface being aspherical, and the focal length f6 of the sixth lens satisfies -9mm≤f6≤-8mm; The minimum air gap between the sixth lens and the imaging chip group is 0.3mm to 0.5mm.

[0015] Optionally, the aspherical surface of the aspherical lens is an even-order aspherical surface, and its surface profile sag is defined by the following formula: ; Where z is the surface elevation, c is the reciprocal of the radius of curvature, k is the conic coefficient, and α1 to α8 are even-order aspherical coefficients.

[0016] Optionally, the focal length f of any lens element in the optical lens i The total focal length F of the optical lens satisfies: 0.56 ≤ |f i / F|≤1.5; wherein, the total focal length F of the optical lens is 7.9mm≤F≤8.1mm.

[0017] Optionally, the total length (TTL) of the optical lens is ≤13.5mm.

[0018] Optionally, the total length TTL of the optical lens and the maximum optically effective diameter Ømax of all lenses satisfy: 1 ​​< TTL / Ø max <2.

[0019] Optionally, the effective optical diameter Ø of any lens in the optical lens and its center thickness T satisfy: 2 < Ø / T < 6.

[0020] Optionally, the overall transmittance T of the optical lens is ≥90%.

[0021] Optionally, the optical lens further includes an aperture stop located on the imaging side of the first group; The aperture of the aperture stop is 2.4mm to 2.8mm, and the axial distance between the aperture stop and the first lens closest to the imaging side in the first group is 0.2mm to 0.8mm.

[0022] Secondly, embodiments of this application provide an optical display device, the optical display device including the optical lens as described in the first aspect.

[0023] The beneficial effects of this application are as follows: The optical lens provided in this application employs an asymmetric glass-plastic hybrid optical architecture consisting of a double-laminated glass group, a multi-element group containing positive and negative lenses, a single positive lens glass group, and a plastic aspherical surface group. This architecture effectively increases the field of view (e.g., to at least 60°) without relying on excessive lenses or expensive materials, while simultaneously achieving aberration correction and system miniaturization, thereby improving overall image quality and user experience. The optical design provided in this application overcomes the technical bottlenecks of traditional optical designs, achieving an excellent balance between a large field of view (FOV), high-performance image quality, and small size and low cost.

[0024] Other features and advantages of this specification will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0025] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of this specification and, together with their description, serve to explain the principles of this specification.

[0026] Figure 1 This is one of the structural schematic diagrams of an optical lens provided in an embodiment of this application; Figure 2 for Figure 1 The diagram shows the optical path of the lens. Figure 3 This is one of the dot diagrams of the optical lens provided in the embodiments of this application; Figure 4 This is one of the modulation transfer function diagrams of the optical lens provided in the embodiments of this application; Figure 5 This is one of the MTF curves of the optical lens provided in the embodiments of this application under different fields of view; Figure 6 One of the field curvature and distortion diagrams of the optical lens provided in the embodiments of this application; Figure 7 One of the relative illumination diagrams of the optical lens provided in the embodiments of this application; Figure 8 This is one of the defocus modulation transfer function diagrams of the optical lens provided in the embodiments of this application; Figure 9 This is a second schematic diagram of the structure of an optical lens provided in an embodiment of this application; Figure 10 for Figure 9 The diagram shows the optical path of the lens. Figure 11 A second dot diagram of an optical lens provided in an embodiment of this application; Figure 12 The second diagram of the modulation transfer function of the optical lens provided in the embodiments of this application; Figure 13 The second MTF curve of the optical lens provided in the embodiments of this application under different fields of view; Figure 14 The second field curvature and distortion diagram of the optical lens provided in the embodiments of this application; Figure 15 A second relative illumination diagram of an optical lens provided in an embodiment of this application; Figure 16 The second diagram shows the defocus modulation transfer function of the optical lens provided in the embodiments of this application.

[0027] Explanation of reference numerals in the attached figures: 100. First group; 101. First lens; 102. Second lens; 200. Second group; 201. Third lens; 202. Fourth lens; 300, Group 3; 301, Lens 5; 400, Group 4; 401, Lens 6; 500, Imaging chip group; 01, Aperture. Detailed Implementation

[0028] Various exemplary embodiments of this application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of this application.

[0029] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0030] Technologies and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies and equipment should be considered part of the specification.

[0031] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0032] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0033] The optical lens and optical display device provided in the embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0034] According to one embodiment of this application, an optical lens is provided, see [link to relevant documentation]. Figure 1 and Figure 2 The optical lens, along the optical axis from the imaging side to the image source side, sequentially comprises: a first group 100, a second group 200, a third group 300, a fourth group 400, and an imaging chip group 500. The first group 100 is a cemented doublet lens group, containing two glass spherical lenses, where the first lens 101 is a positive lens and the second lens 102 is a negative lens. The second group 200 contains at least two lenses, including one positive lens and one negative lens. The third group 300 contains at most one glass spherical lens with positive optical power. The fourth group 400 contains at least one plastic aspherical lens with negative optical power. The imaging chip group 500 is located closest to the image source side.

[0035] This application provides an optical lens comprising, along its optical axis, a plurality of lens groups with specific optical powers and functions, and an imaging chip group 500. The optical lens provided in this application employs an asymmetric glass-plastic hybrid optical architecture, achieving excellent optical performance through the synergistic effect of the various groups. In other words, the optical architecture provided in this application, through the different roles and synergistic cooperation of each group in the optical path, aims to efficiently achieve a large field of view and high-level aberration correction.

[0036] The optical lens provided in this application embodiment includes a first group 100, which is located on the image source side of the aperture stop 01. See also Figure 1 and Figure 2 The first group 100 is a cemented doublet glass lens group, which includes a positive lens (i.e., the first lens 101) adjacent to the aperture 01 on the optical axis and a negative lens (i.e., the second lens 102). In the optical path, the imaging light from the imaging chip group 500 passes sequentially through the fourth group 400, the third group 300 and the second group 200, enters the first group 100, and finally exits through the aperture 01 to the peripheral optical waveguide device to enter the human eye.

[0037] The first group 100, as the last lens group that light passes through before entering the aperture 01, mainly undertakes the function of correcting the axial chromatic aberration of the system, and lays the foundation for the optical lens to achieve a large field of view by converging the light. Among them, the first lens 101 is a positive lens with high refractive index characteristics, while the second lens 102 is a negative lens with low refractive index characteristics. This combination of materials constitutes an effective means of correcting chromatic aberration.

[0038] The optical lens provided in this application embodiment includes a second group 200, which performs core aberration correction and optical path control functions within the optical lens. The second group 200 is designed to include at least two lenses, specifically at least one positive lens and one negative lens. See [link to relevant documentation]. Figure 1 and Figure 2 Through its specific combination of optical power, this second group 200 becomes a key component in correcting off-axis aberrations such as field curvature, astigmatism, and coma, effectively flattening the image plane and thus ensuring high-quality, clear imaging across the entire field of view from the center to the edge.

[0039] In terms of optical path transmission, the second group 200 receives light from the third group 300 and manages the beam aperture and propagation angle in the lens through its reasonable optical power distribution, laying the foundation for the efficient transmission of light to the subsequent first group 100 and ensuring the smoothness and stability of the entire optical path system.

[0040] Furthermore, the second group 200 offers significant design flexibility. See also Figure 1As shown, it can be implemented as a double-laminated lens assembly; or see [link to documentation]. Figure 3 As shown, a two-element single-lens structure with spacing can be used, allowing the inclusion of a glass aspherical lens. This flexible configuration provides additional degrees of freedom for optical design in aberration correction, particularly beneficial for targeted correction of higher-order aberrations, thereby further optimizing the overall imaging performance of the optical lens without significantly increasing costs.

[0041] The optical lens provided in this application embodiment includes a third group 300, which plays a crucial role in core ray convergence and residual aberration balancing within the optical lens. The third group 300 comprises at most one glass spherical lens with positive optical power. (See also...) Figure 1 and Figure 3 In the optical path, light rays from the fourth group 400 enter the third group 300.

[0042] The third group 300, as a key light-converging unit in the optical lens, is responsible for effectively converging the light from the fourth group, laying the necessary optical path foundation for the light beam to enter the subsequent second group 200 and finally form an image.

[0043] While achieving light convergence, the third group 300 is also used to correct residual aberrations in the optical lens, such as spherical aberration. Its optical power and position are systematically optimized to work in conjunction with the front and rear optical groups to further improve optical performance, specifically by optimizing the dot plot to reduce blur spots and improving the consistency of the MTF curve.

[0044] Furthermore, the third group 300 is designed with a maximum of one lens element, a key consideration in achieving a balance between high performance and low cost in optical lenses. This design effectively controls the total number of lenses, system complexity, and production costs while ensuring necessary light-gathering energy and correcting residual aberrations.

[0045] The optical lens provided in this application includes a fourth group 400, which plays a crucial role in image plane flatness and system integration within the optical lens. The fourth group 400 comprises at least one negative optical power plastic aspherical lens. (See also...) Figure 1 and Figure 2 In the optical path, the light from the imaging chip group 500 first enters the fourth group 400.

[0046] The fourth group 400, as the first optical lens group in the light propagation path, has a negative optical power that is crucial for a flat image plane, effectively compensating for field curvature that may be caused by subsequent positive optical power groups. Simultaneously, its use of at least one aspherical surface is the most effective means of correcting optical distortion and spherical aberration, ensuring that the projected image has low distortion characteristics and maintains high clarity from the center to the edges.

[0047] Regarding the size of the optical lens, the fourth group 400 directly determines the back focal length of the optical lens, i.e., its axial distance to the imaging chip group 500. Optimizing this distance is key to achieving miniaturization of the overall lens structure and ensuring good matching with the display chip. This fourth group 400 acts as the initial control unit of the optical lens, responsible for the initial shaping and correction of the light emitted from the imaging chip group 500, laying a good foundation for further processing by subsequent groups.

[0048] In addition, the fourth group 400 uses plastic aspherical lenses, which achieves complex surface processing while taking into account manufacturing costs and lightweight requirements, reflecting the optimized balance between performance and cost in optical lenses.

[0049] The optical lens provided in this embodiment includes an imaging chip group 500, which serves as the image source and physical protection unit of the optical lens and is located at the beginning of the optical path. See [link to previous section]. Figure 2 .

[0050] The imaging chip group 500 includes a display chip (such as LCD, DLP, or LCOS), whose function is to convert the input electrical signal into an optical signal carrying image information, forming the starting point of the entire optical imaging process. Structurally, the imaging chip group 500 may also include protective glass, etc. Although this flat optical element does not participate in imaging, it provides crucial sealing and dust protection, preventing contaminants from directly contacting the display chip surface, thereby ensuring the imaging reliability and stability of the optical lens during long-term use.

[0051] In the complete optical path, the image light generated by the imaging chip group 500 is transmitted and corrected sequentially through the fourth group 400, the third group 300, the second group 200 and the first group 100, and finally enters the waveguide device through the aperture 01 and reaches the human eye to complete the optical display process.

[0052] The display chip has a size of 0.49 inches and a pixel size of 5.6 micrometers.

[0053] The optical lens provided in this application, through the cooperation of the aforementioned five groups, constitutes a functionally defined and collaborative optical system. Each group plays a specific role in the optical path and forms an effective complement: the imaging chip group 500 serves as the system starting point, providing the original image light signal; the fourth group 400, as the key to image plane flatness and integration optimization, performs initial shaping of light and corrects distortion; the third group 300 undertakes the core light convergence function; the second group 200, as the main force for off-axis aberration correction, ensures uniform image quality across the entire field of view; and the first group 100 mainly performs chromatic aberration correction, completing the final aberration balance. Through this innovative asymmetric glass-plastic hybrid architecture, the optical lens provided in this application integrates multiple core performance advantages. Specifically: Wide field of view: It achieves a diagonal field of view (FOV) of 60° and above, far exceeding the approximately 30° level of traditional AR lenses, significantly enhancing the visual immersion.

[0054] High resolution: At a high spatial frequency of 89 lp / mm, the MTF of the entire field of view is >0.6, which is close to the diffraction limit, ensuring clear reproduction of image details.

[0055] Compact size: The total length TTL of the optical lens is controlled within 13.5mm, while the optical architecture meets the requirements of compact size and aspect ratio, which strongly supports the miniaturization design of AR devices.

[0056] Reasonable cost: By adopting a hybrid solution that primarily uses glass spherical lenses and applies plastic aspherical lenses in key areas, excellent cost control is achieved while ensuring high performance.

[0057] In summary, this application provides an optical solution for AR display devices that achieves an excellent balance between immersion, clarity, size, and cost through architectural innovation and parameter optimization.

[0058] In summary, the optical lens provided in this application overcomes the technical bottlenecks of traditional optical designs by employing an asymmetric glass-plastic hybrid architecture composed of a double-laminated glass group, a multi-element group containing positive and negative lenses, a single positive lens glass group, and a plastic aspherical group. This optical design significantly expands the field of view of the optical lens to over 60° without relying on excessive lenses or special expensive materials, while achieving high resolution performance with an MTF value greater than 0.6 at a spatial frequency of 89 lp / mm across the entire field of view. Through precise allocation of optical power among the groups and effective use of aspherical technology, the system maintains excellent aberration correction capabilities while keeping the total optical length within 13.5mm, achieving an excellent balance between a large field of view, high image quality, compact size, and reasonable cost, providing a high-performance optical solution for AR display devices.

[0059] See some examples in this application. Figure 1 The first lens 101 is a biconvex lens with a refractive index Nd. 101 Satisfying 1.80 < Nd 101 <1.85, Abbe number Vd 101 >40. Please continue reading. Figure 1 The second lens 102 is a biconcave lens with a refractive index Nd. 102 <1.65, Abbe number Vd 102 <34.

[0060] In the example provided in this application, the first group 100 serves as a doublet lens assembly, and its specific structure and material selection reflect a sophisticated optical design. Specifically: The first lens 101 is designed as a biconvex positive lens, and its optical material has a high refractive index (such as its refractive index Nd). 101 Satisfying 1.80 < Nd 101 <1.85) and high Abbe numbers (such as Abbe number Vd) 101 The material selection allows the first lens 101 to effectively control the effect of chromatic aberration on image quality while providing the necessary positive optical power.

[0061] The second lens 102 is designed as a biconcave negative lens, and its optical material has a low refractive index (such as its refractive index Nd). 102 <1.65) and low Abbe numbers (such as Abbe number Vd) 102 <34) characteristics. This material exhibits relatively high dispersion characteristics, which contrasts sharply with the material of the first lens 101.

[0062] In the first group 100, two glass lenses with opposite optical powers and significantly different dispersion characteristics are bonded together to form an achromatic cemented group. When light passes through the cemented interface between the two lenses, the significant difference in the Abbe number of the two materials can effectively cause different wavelengths of light to converge to the same point after passing through the group, thereby achieving excellent color difference correction effect.

[0063] The specific optical design in this example can bring the following beneficial effects to the optical lens: By employing a combination of high and low Abbe number materials in the first group 100, the optical lens effectively corrects axial chromatic aberration caused by focal length differences in different wavelengths of light during the final stage of light propagation. This design eliminates chromatic dispersion in imaging, providing crucial assurance for the optical system to achieve high resolution with an MTF > 0.6 at a spatial frequency of 89 lp / mm.

[0064] The cemented doublet structure not only helps correct spherical aberration, but the power distribution of its positive and negative lenses also creates conditions for controlling the propagation path of large-angle light rays. This optical architecture enables the lens to support a large field of view (FOV) of over 60° while maintaining good illumination uniformity across the entire image plane.

[0065] As the last lens group to pass through in the light propagation path, the first group 100 undertakes the main chromatic aberration correction function, allowing the preceding lens groups to focus on correcting other aberrations. This aberration correction allocation strategy enhances the overall robustness of the optical lens while reducing sensitivity to manufacturing tolerances, thereby improving product consistency and production yield.

[0066] Compared to solutions that use special ultra-low dispersion glass or increase the number of lenses, this design scheme, which optimizes the combination of properties of conventional glass materials, effectively controls material costs and processing complexity while ensuring excellent optical performance. It is an innovative technical path to achieve a balance between high performance and low cost.

[0067] This optical design allows light emitted from the imaging chip group 500 to pass through the control of each lens group in sequence, ultimately forming a high-quality optical image that meets the stringent optical performance requirements of AR display devices.

[0068] In some examples of this application, the focal length f1 of the first lens 101 satisfies: 5.3mm≤f1≤5.7mm; and the focal length f2 of the second lens 102 satisfies: -9.0mm≤f2≤-9.6mm.

[0069] This application example optimizes the optical power of two lenses in the first group 100.

[0070] The positive focal length of the first lens 101 (5.3mm ≤ f1 ≤ 5.7mm) and the negative focal length of the second lens 102 (-9.0mm ≤ f2 ≤ -9.6mm) form an optimized optical power ratio. This specific combination ensures that the first group 100 can precisely control the refraction angle of light when performing its optical function as the final correction unit, laying the foundation for good aberration balance in the optical lens.

[0071] In this example, with the optical power configuration, the first group 100 can effectively handle large-angle light rays from the second group 200, ensuring that these rays enter the aperture stop 01 at the appropriate angle. This control is crucial for maintaining the image plane flatness and edge image quality of the optical lens at large field of view (e.g., FOV ≥ 60°), while ensuring that light rays can be smoothly coupled into subsequent waveguide devices.

[0072] This specific selection of optical power range enables the first group 100 to achieve optimal optical correction within a limited space. Precise optical power control not only helps control the total length TTL of the optical lens (e.g., TTL ≤ 13.5 mm), but also improves the tolerance of the optical lens to manufacturing tolerances, enhancing product consistency and stability.

[0073] By limiting the optical power within this optimized range, optical lenses can meet design requirements without relying on special optical materials or complex lens structures. This design effectively controls manufacturing costs while ensuring optical performance, providing a feasible technical solution for mass production.

[0074] The optical power design proposed in this example ensures that the light emitted from the imaging chip group 500, after undergoing step-by-step adjustment by each lens group, can ultimately form a high-quality optical image that meets the requirements, satisfying the stringent optical performance requirements of AR display devices.

[0075] See some examples in this application. Figure 1 and Figure 2 The second group 200 is a doublet lens group, which includes a third lens 201 and a fourth lens 202 bonded together, and both the third lens 201 and the fourth lens 202 are glass spherical lenses; wherein, the third lens 201 is a biconcave negative lens and the fourth lens 202 is a biconvex positive lens.

[0076] In this example of the application, see Figure 1 and Figure 2 The second group 200 is specifically implemented as a cemented doublet lens group, which is formed by cementing a third lens 201 and a fourth lens 202 together, both of which are spherical glass lenses. The third lens 201 is a biconcave negative lens, and the fourth lens 202 is a biconvex positive lens.

[0077] The optical design in this example constitutes a correction unit. The cemented structure effectively corrects chromatic aberration, while its negative-positive power combination and spherical surface shape primarily focus on correcting field curvature and astigmatism, ensuring uniform image quality across the entire field of view. In this configuration, the second group 200 undertakes important aberration correction functions, thus requiring a subsequent third group 300 (i.e., the fifth lens element 301) to further converge light and balance residual aberrations. The entire optical lens requires a total of six lenses. See [link to relevant documentation]. Figure 1 In the optical path, it receives light from the third group 300, corrects for aberrations, and then transmits the light to the first group 100.

[0078] See some examples in this application. Figure 9 and Figure 10The second group 200 consists of two spaced-apart single lenses, at most one of which is a glass aspherical lens; the two single lenses include a third lens 201 and a fourth lens 202, wherein: the third lens 201 is a negative lens, and its surface near the first group 100 is concave; the fourth lens 202 is a positive lens, and its surface near the imaging chip group 500 is convex.

[0079] In this example of the application, see Figure 9 and Figure 10 The second group 200 employs another implementation, consisting of two spaced-apart single lenses. These two lenses include a third lens 201 and a fourth lens 202, wherein the third lens 201 is a negative lens with a concave surface near the first group 100; and the fourth lens 202 is a positive lens with a convex surface near the imaging chip group 500. Crucially, one of the third lens 201 and the fourth lens 202 is a glass aspherical lens.

[0080] The core advantage of the optical design in this example lies in the introduction of aspherical technology. Aspherical lenses provide powerful and precise control over the correction of advanced aberrations such as distortion and coma. Since the addition of aspherical lenses greatly enhances the aberration correction capability and design freedom of the second group 200, its optical performance has been fully optimized. Therefore, in this embodiment, the original third group 300 can be omitted, thereby reducing the total number of lenses in the entire optical lens to five, achieving further miniaturization and cost control. In the optical path, it directly receives light from the fourth group 400, performs more efficient aberration correction, and then transmits the light to the first group 100.

[0081] See each Figure 1 and Figure 9 As shown, two examples from this application illustrate the different technical approaches and design flexibility adopted by the second group 200 in achieving the system's optical objectives: Figure 1 The implementation shown employs mature spherical bonding technology to construct a stable and reliable aberration correction module. Figure 9 The illustrated implementation innovatively incorporates aspherical technology, optimizing optical performance while reducing the number of lenses. These two differentiated solutions embody the design philosophy of this application, which precisely balances and optimizes optical performance, system size, and manufacturing cost.

[0082] See some examples in this application. Figure 9 and Figure 10The optical architecture shown has the following characteristics: the refractive index Nd of the negative lens in the second group 200 is <1.65, and the Abbe number Vd is <34; the refractive index Nd of the positive lens in the second group 200 satisfies 1.71 < Nd < 1.85, and the Abbe number Vd > 40.

[0083] In this example of the application, see Figure 9 and Figure 10 The optical architecture shown optimizes the material properties of the two independent lenses in the second group 200: the negative lens, i.e., the third lens 201, uses a glass material with low refractive index (Nd < 1.65) and low Abbe number (Vd < 34), while the positive lens, i.e., the fourth lens 202, uses a glass material with high refractive index (1.71 < Nd < 1.85) and high Abbe number (Vd > 40).

[0084] The material combination design in this example aims to construct an achromatic and aberration balancing unit within the second group 200. Utilizing the significant difference in Abbe numbers between the two materials, this second group 200 can effectively correct magnification chromatic aberration and off-axis chromatic aberration generated during field-of-view expansion of the optical lens. Simultaneously, the use of a high-refractive-index positive lens helps reduce lens curvature while maintaining optical power, thereby effectively controlling spherical aberration and higher-order aberrations. This provides a crucial guarantee for maintaining high image quality even after reducing the number of lens elements.

[0085] See some examples in this application. Figure 9 and Figure 10 In the optical architecture shown, the focal length f3 of the negative lens in the second group 200 satisfies: -4.5mm≤f3≤-5.5mm; and the focal length f4 of the positive lens in the second group 200 satisfies: 5mm≤f4≤6mm.

[0086] In this example of the application, see Figure 9 and Figure 10 The optical architecture shown optimizes the optical power of the two lenses in the second group 200: the focal length f3 of the negative lens, i.e., the third lens 201, is -4.5mm≤f3≤-5.5mm, and the focal length f4 of the positive lens, i.e., the fourth lens 202, is 5mm≤f4≤6mm.

[0087] This focal length ratio is key to realizing the core optical functions of the second group 200. The specific optical power of the negative lens is mainly responsible for flattening the image plane and controlling field curvature; while the specific optical power of the positive lens is responsible for light convergence and balancing the total optical power of the system. Working together, they ensure that light is transmitted to the first group 100 in optimal condition after passing through the second group 200. This design allows the second group 200 to efficiently perform the core functions of off-axis aberration correction and optical path conversion in a simplified architecture that omits the third group 300. It is the core design element for achieving a balance between high performance, small size, and low cost in optical lenses.

[0088] See some examples in this application. Figure 1 The third group 300 includes a fifth lens 301, which is a biconvex glass spherical lens with a focal length f5 satisfying: 11.0mm≤f5≤11.5mm.

[0089] In this example of the application, see Figure 1 The third group 300 includes a fifth lens 301, which is designed as a biconvex glass spherical lens with a relatively long positive focal length (11.0mm ≤ f5 ≤ 11.5mm). In the optical path, light from the fourth group 400 enters this fifth lens 301. Its core function is to converge the light, gathering the beam transmitted from the preceding lens group, i.e., the fourth group 400, creating optimal conditions for the light to enter the subsequent second group 200 and undergo aberration correction.

[0090] In the third group 300, the fifth lens 301, as a positive lens, not only performs the converging function but also undertakes the crucial task of balancing and correcting residual aberrations in the system. Its specific focal length range and biconvex spherical form, after system optimization, can effectively compensate for some of the astigmatism and field curvature generated by the front lens group (i.e., the fourth group 400) and help control spherical aberration, thereby synergistically improving the overall image quality of the optical lens. Specifically, this is manifested in optimizing the dot plot and improving the consistency of the MTF curve. See [link to relevant documentation]. Figure 3 and Figure 4 .

[0091] The optimized design of the third group 300, which incorporates a single glass spherical lens with an optimized focal length, represents a design trade-off: it provides the necessary optical functions and ensures stable optical performance while avoiding the increased costs associated with using aspherical or special materials. This design ensures an excellent balance between optical performance, structural complexity, and manufacturing cost for the optical lens.

[0092] See some examples in this application. Figure 1 and Figure 2 ,as well as Figure 9 and Figure 10 The fourth group 400 includes a sixth lens 401, which is a plastic aspherical lens with at least one aspherical surface. The focal length f6 of the sixth lens 401 satisfies -9mm≤f6≤-8mm. The minimum air gap between the sixth lens 401 and the imaging chip group 500 is 0.3mm~0.5mm.

[0093] The fourth group 400 includes a sixth lens 401, designed as a plastic aspherical lens with a specific negative optical power (focal length f6 satisfies -9mm ≤ f6 ≤ -8mm). In the optical path, the fourth group 400 serves as the initial control unit for the imaging beam, directly receiving the initial light from the imaging chip group 500. Its negative optical power can be used to balance the total optical power of the lens and also to perform preliminary correction of the image plane curvature, laying the foundation for subsequent aberration control in the optical path.

[0094] The fourth group 400 includes a sixth lens element 401, designed as a plastic aspherical lens with a specific negative optical power (focal length f6 satisfies -9mm ≤ f6 ≤ -8mm). In the optical path, the fourth group 400 serves as the initial control unit for the imaging beam, directly receiving the initial light from the imaging chip group 500. Its negative optical power plays a dual role in the optical system: on the one hand, it balances the total optical power of the lens; on the other hand, its specific optical power distribution compensates for the inherent field curvature of the lens, making the image plane tend to be flat. This field correction performed at the front end lays an important foundation for aberration control in subsequent lens groups.

[0095] The minimum air gap of 0.3mm to 0.5mm between the sixth lens 401 and the imaging chip group 500 is an optimized back focal length parameter. This design, while ensuring the physical space of the display chip, greatly compresses the total length TTL of the optical lens (TTL≤13.5mm), achieving a synergy between optical performance and mechanical compactness. It is an important guarantee for the overall miniaturization and high integration of the optical lens.

[0096] Using molded aspherical lenses made of plastic materials combines the flexibility of complex surface shapes with cost control. This approach fully leverages the correction capabilities of aspherical technology while effectively reducing system manufacturing costs and weight.

[0097] In some examples of this application, the aspherical surface of the aspherical lens is an even-order aspherical surface, and its surface profile sag is defined by the following formula: ; Where z is the surface elevation, c is the reciprocal of the radius of curvature, k is the conic coefficient, and α1 to α8 are even-order aspherical coefficients.

[0098] In the various examples of this application, all aspherical lenses (including the plastic aspherical lenses in the fourth group 400 and the glass aspherical lenses that may exist in the second group 200) adopt an even-order aspherical design. The aspherical surface shape is defined by the standard even-order aspherical formula, and high-order mathematical control of the mirror's sagitta is achieved through the conic coefficient k and multiple even-order aspherical coefficients (α1 to α8, specific values ​​are shown in Table 2 of Example 1 and Table 4 of Example 2). This coefficient configuration provides the optical lens with sufficient adjustment dimensions, enabling precise correction of various aberrations and is a key technical means to achieve excellent image quality.

[0099] In practice, the configuration of aspherical lenses offers design flexibility: see [link to relevant documentation]. Figure 1 and Figure 2 In the first embodiment shown, the optical lens has only one aspherical lens in the fourth group 400; while see... Figure 9 and Figure 10 The illustrated embodiment two employs a dual aspherical configuration in the optical lens, including one aspherical lens (second lens 202) in the second group 200 and one aspherical lens (sixth lens 401) in the fourth group 400. This differentiated aspherical configuration strategy embodies the diverse solutions offered by this application to balance the complexity and manufacturing cost of optical lenses while meeting optical performance requirements.

[0100] Referring to Table 3 in Example 1 and Table 6 in Example 2 below, this application systematically optimizes the conic coefficient and aspheric coefficient of each aspherical surface. By precisely configuring these parameters (such as the conic coefficient k=-15.956 and the fourth-order coefficient α1=-1.04E-02 for the tenth surface in Table 2), aspherical surfaces can accurately correct specific aberrations in large field-of-view optical lenses, including distortion, spherical aberration, and astigmatism. This precise coefficient optimization enables the system to achieve high resolution with MTF>0.6 while keeping the number of lenses minimal.

[0101] In the complete imaging optical path, light from the imaging chip group 500 first passes through the fourth group 400, which has aspherical surfaces. The aspherical surfaces of the fourth group 400 perform the initial image field flattening and distortion correction functions; when the second group 200 contains aspherical lenses, they further play a role in correcting astigmatism and coma. This multi-aspherical collaborative design strategy enables the optical lens to achieve a large 60° field of view while effectively controlling field curvature and maintaining high relative illumination, ensuring uniformity and sharpness of image quality across the entire field of view.

[0102] In some examples of this application, the focal length f of any lens in the optical lens i The total focal length F of the optical lens satisfies: 0.56 ≤ |fi / F|≤1.5; wherein, the total focal length F of the optical lens is 7.9mm≤F≤8.1mm.

[0103] In the optical lens design of this application, the focal length f of each lens element is... i The proportional relationship between the focal length F of the optical lens and the total focal length F of the lens has been optimized, requiring that the focal length f of any lens element... i The total focal length F of the optical lens must satisfy: 0.85 ≤ |f i / F|≤3, while the total focal length F of the optical lens is controlled within the range of 7.9mm to 8.1mm. This ratio ensures a reasonable distribution of optical power among the lenses in the system.

[0104] In the first group 100: the ratio of the focal length f1 of the first lens 101 to the total focal length F of the optical lens is 0.65≤|f1 / F|≤0.72; the ratio of the focal length f2 of the second lens 102 to the total focal length F of the optical lens is 1.11≤|f2 / F|≤1.21.

[0105] In the second group 200: the ratio of the focal length f3 of the third lens 201 to the total focal length F of the optical lens is 0.56≤|f3 / F|≤0.70; the ratio of the focal length f4 of the fourth lens 202 to the total focal length F of the optical lens is 0.62≤|f4 / F|≤0.76.

[0106] In the third group 300: the ratio of the focal length f5 of the fifth lens 301 to the total focal length F of the optical lens is 1.36≤|f5 / F|≤1.45; In the fourth group 400: the ratio of the focal length f6 of the sixth lens 401 to the total focal length F of the optical lens is 0.99≤|f6 / F|≤1.14.

[0107] The ratio of the focal length of each lens element to the total focal length of the optical lens has been optimized to avoid lenses with excessively strong or weak light, thus ensuring a smooth transition of light within the optical lens.

[0108] By limiting the optical power of each lens element within a reasonable range, optical lenses can achieve optimal aberration correction. Excessive optical power can easily introduce higher-order aberrations, while insufficient optical power is difficult to effectively participate in aberration correction. This configuration design allows each lens element to work together to undertake the aberration correction task.

[0109] The parameter design in this example effectively controls the overall length of the optical lens (TTL≤13.5mm) while ensuring optical performance. Precise total focal length F control (F≈8mm) combined with reasonable optical power distribution enables the optical lens to achieve a wide 60° field of view while maintaining excellent optical performance (MTF>0.6@89lp / mm) and compact structural dimensions.

[0110] This focal length ratio scheme reflects the innovation of this application at the optical architecture level and is one of the key technical features for achieving high-performance, small-size, and high-yield optical lenses.

[0111] In some examples of this application, the total length (TTL) of the optical lens is ≤13.5 mm.

[0112] This application controls the total length TTL of the optical lens to within 13.5mm. Its beneficial effect is that it directly promotes the miniaturization and weight reduction of the optical lens, which is crucial for wearable devices such as AR glasses with limited space. This allows the device to maintain a wide field of view and high-resolution imaging performance while also providing excellent wearing comfort and product portability.

[0113] In some examples of this application, the total length TTL of the optical lens and the maximum optically effective diameter Ømax of all lenses satisfy: 1 ​​< TTL / Ø max <2.

[0114] In this example of the application, by controlling the ratio of the total length TTL of the optical lens to the maximum effective diameter of the lens between 1 and 2, the synergistic optimization of the radial and axial dimensions of the optical lens is ensured. This allows the optical lens to achieve a compact structure while maintaining balanced optical performance and excellent mechanical stability, providing a more flexible and reliable optical solution for AR optical display devices.

[0115] If the ratio of the total length (TTL) of the optical lens to the maximum effective optical diameter (Ømax) is less than 1 < TTL / Ø max <2 will result in the following defects: When TTL / Ø max When the distance is ≤1, the optical lens is too short and thick. This means that the lens curvature is too steep or the focal length is too concentrated, which will introduce advanced aberrations that are difficult to correct, while also causing a sharp drop in edge field illumination and a deterioration in image plane flatness. In addition, the excessive compression of the lens spacing can easily cause stray light and significantly increase the difficulty of assembly.

[0116] When TTL / Ø max When the length is ≥2, the optical lens becomes too long and thin. While this may reduce the difficulty of aberration correction, it will significantly increase the overall optical length, which contradicts the core requirement of AR devices for a compact size.

[0117] Therefore, controlling the ratio between 1 and 2 is the key to achieving a balance between optical performance and structural compactness in this application.

[0118] In some examples of this application, the effective optical diameter Ø of any lens in the optical lens and its center thickness T satisfy: 2 < Ø / T < 6.

[0119] This example of the present application achieves the following effect by limiting the ratio of the effective optical diameter Ø of any lens element in the optical lens to its center thickness T to between 2 and 6: To avoid grinding deformation caused by excessively thin lenses (too large Ø / T), and to prevent waste of optical materials and increased weight caused by excessively thick lenses (too small Ø / T); Within this ratio range, the propagation path of light within the lens is reasonably controlled, effectively suppressing aberrations such as spherical aberration and coma introduced by the lens shape factor, thus providing a foundation for the lens to achieve high resolution with MTF>0.6; This ratio balances the feasibility of molding / grinding processes, avoids yield reduction caused by extreme ratios, and improves mass production economy while ensuring optical performance.

[0120] This demonstrates that this design allows the optical lens to achieve a comprehensive optimization of reliability, performance, and cost while pursuing a large field of view and miniaturization.

[0121] In some examples of this application, the overall transmittance T of the optical lens is ≥90%.

[0122] This application increases the overall transmittance of the optical lens to 90% or more, which significantly improves the light energy utilization rate. This not only directly enhances the display brightness and energy efficiency of AR devices and reduces power consumption, but also effectively avoids the decrease in image contrast and stray light problems caused by light loss, thereby providing users with a brighter, more vivid and clearer visual experience.

[0123] See some examples in this application. Figure 1 and Figure 9 The optical lens further includes an aperture stop 01 located on the imaging side of the first group 100; the aperture of the aperture stop 01 is 2.4mm~2.8mm, and the axial distance between the aperture stop 01 and the first lens 101 closest to the imaging side in the first group 100 is 0.2mm~0.8mm.

[0124] Positioning the aperture stop 01 on the imaging side of the first group 100 (aperture stop 01 is a front aperture stop), and limiting its aperture to 2.4mm~2.8mm and its axial distance from the first lens 101 to 0.2mm~0.8mm, this design brings multiple benefits: First, the precise aperture size effectively controls the amount of light entering and matches the F-number of the optical lens, balancing aberrations and lens brightness; Second, this position and distance can optimally define the optical lens aperture stop, effectively suppressing off-axis aberrations (such as coma and astigmatism) and ensuring imaging quality at the edge of the field of view at large field of view angles; Third, this compact layout reserves space for the subsequent optical path from aperture stop 01 to the waveguide, which is the key to achieving a compact structure and optimized performance of the entire optical system.

[0125] The optical lens of this application will be described in detail below through Examples 1 and 2.

[0126] Example 1 See Figure 1 and Figure 2 As shown, the optical lens includes, along the optical axis from the imaging side to the image source side, the following groups in sequence: a first group 100, a second group 200, a third group 300, a fourth group 400, and an imaging chip group 500; wherein, the imaging chip group 500 is located closest to the image source side. The first group 100 is a doublet lens group, which includes two glass spherical lenses, wherein the first lens 101 is a biconvex positive lens and the second lens 102 is a biconcave negative lens; The second group 200 is a doublet lens group, comprising a third lens 201 and a fourth lens 202 bonded together, wherein the third lens 201 and the fourth lens 202 are both glass spherical lenses; wherein the third lens 201 is a biconcave negative lens and the fourth lens 202 is a biconvex positive lens.

[0127] The third group 300 includes a fifth lens 301, which is a biconvex glass spherical lens with positive optical power; The fourth group 400 includes a sixth lens 401, which is a plastic aspherical lens with negative optical power, and at least one of its surfaces is aspherical.

[0128] In this embodiment 1, by rationally allocating the optical power and lens material optimization of each group, the performance indicators and aberration suppression of the optical lens can be balanced. The optimized design indicators are shown in Table 1: Table 1: Design Parameter Table

[0129] Please refer to Table 2 below for the optical parameters of the six lenses in this embodiment 1. This embodiment 1 includes an aspherical lens, which is the sixth lens 401 (including the ninth and eleventh surfaces) in the fourth group 400. Please refer to Table 3 for the aspherical coefficient of the sixth lens 401.

[0130] Table 2: Optical Parameter Table

[0131] Table 3: Aspheric Coefficients

[0132] Figure 3 This is a dot array diagram of the optical lens provided in Embodiment 1. Due to aberrations, when light rays converge on the image plane, they are not a single point, but rather a diffuse spot distributed within a certain range. The diameter of this diffuse spot and the concentration of light rays represent the magnitude of the aberration. From... Figure 3 As can be seen, the root mean square radius of the diffuse spot is ≤1.6 micrometers (0.3 pixels), indicating that the aberrations have been well corrected.

[0133] from Figure 4 and Figure 5 The adjusted transfer function plot shows that at a cutoff frequency of 89 lp / mm, the MTF of each field of view is close to the diffraction limit, and the MTF > 0.6, indicating that this optical lens has strong resolution and can reproduce the details of the image very well.

[0134] See Figure 6 The optical distortion of this lens is ≤10%, the field curvature is less than or equal to 0.06mm, and the aberrations are suppressed to a low level. Figure 7 In the relative illumination map, a relative illumination greater than 68% is a high value, which can effectively avoid the phenomenon of uneven brightness distribution (bright center and dark edges) caused by edge light loss. Figure 8 The graph shows the defocus modulation transfer function at room temperature (20℃). Figure 8 As can be seen, Through focus MTF > 0.6, the image quality is high and it can well represent the details of the projected image.

[0135] Example 2 See Figure 9 and Figure 10 As shown, the optical lens includes, along the optical axis from the imaging side to the image source side, the following components in sequence: a first group 100, a second group 200, a fourth group 400, and an imaging chip group 500; wherein, the imaging chip group 500 is located closest to the image source side. The first group 100 is a doublet lens group, which includes two glass spherical lenses, wherein the first lens 101 is a biconvex positive lens and the second lens 102 is a biconcave negative lens; The second group 200 consists of two spaced-apart single lenses, at most one of which is a glass aspherical lens; the two single lenses include a third lens 201 and a fourth lens 202, wherein: the third lens 201 is a negative lens with a concave surface near the first group 100, and the fourth lens 202 is a positive lens with a convex surface near the imaging chip group 500. The fourth group 400 includes a sixth lens 401, which is a plastic aspherical lens with negative optical power, and at least one of its surfaces is aspherical.

[0136] In this embodiment 2, by rationally allocating the optical power and lens material optimization of each group, the performance indicators and aberration suppression of the optical lens can be balanced. The optimized design indicators are shown in Table 4: Table 4: Design Parameter Table

[0137] Please refer to Table 5 below for the optical parameters of the five lenses in this embodiment 2. This embodiment 2 includes two aspherical lenses, namely: the fourth lens 202 (including the seventh and eighth surfaces) in the second group 200 and the sixth lens 401 (including the ninth and eleventh surfaces) in the fourth group 400. Please refer to Table 6 for the aspherical coefficients of the fourth lens 202 and the sixth lens 401.

[0138] Table 5: Optical Parameter Table

[0139] Table 6: Aspheric Coefficients

[0140] Figure 11 This is a dot array diagram of the optical lens provided in Embodiment 2. Due to aberrations, when light rays converge on the image plane, it is not a single point, but rather a diffuse spot distributed within a certain range. The diameter of this diffuse spot and the concentration of light rays represent the magnitude of the aberration. From... Figure 11 As can be seen, the root mean square radius of the diffuse spot is ≤1.8 micrometers (0.3 pixels), indicating that the aberrations have been well corrected.

[0141] from Figure 12 and Figure 13The adjusted transfer function plot shows that at a cutoff frequency of 89 lp / mm, the MTF of each field of view is close to the diffraction limit, and the MTF > 0.6, indicating that this optical lens has strong resolution and can reproduce the details of the image very well.

[0142] See Figure 14 The optical distortion of this lens is ≤10%, the field curvature is less than or equal to 0.06mm, and the aberrations are suppressed to a low level. Figure 15 In the relative illuminance map, a relative illuminance greater than 68% is a high value, which can effectively avoid the phenomenon of uneven brightness distribution (bright center and dark edges) caused by edge light loss. Figure 16 The graph shows the defocus modulation transfer function at room temperature (20℃). Figure 16 As can be seen, though focusMTF > 0.6, the image quality is high and it can well represent the details of the projected image.

[0143] According to another embodiment of this application, an optical display device is provided, the optical display device including the optical lens as described above.

[0144] The optical lens can be used to project image light onto the coupling area of ​​the optical waveguide device. Through the conduction and beam expansion effect of the optical waveguide device, the magnified virtual image is finally transmitted to the human eye.

[0145] The optical display devices provided in this application are, for example, AR optical devices, such as AR smart glasses.

[0146] The specific implementation of the optical display device in this application can refer to the various embodiments of the optical lens described above. Therefore, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be described in detail here.

[0147] The above embodiments mainly describe the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be elaborated here.

[0148] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. An optical lens, characterized in that, Along the optical axis from the imaging side to the image source side, the following are included in sequence: The first group (100) is a doublet lens group, which consists of a first lens (101) and a second lens (102) along the optical axis from the imaging side to the image source side. The first lens (101) is a positive lens and the second lens (102) is a negative lens. The second group (200) consists of a third lens (201) and a fourth lens (202) along the optical axis from the imaging side to the image source side. The third lens (201) is a negative lens and the fourth lens (202) is a positive lens. The third group (300) is composed of a fifth lens (301), which is a glass spherical lens with positive optical power; The fourth group (400) is composed of a sixth lens (401), which is a plastic aspherical lens with negative optical power; and, An imaging chip group (500) is positioned closest to the image source; The focal length f of each lens element in the optical lens i The total focal length F of the optical lens satisfies: 0.56 ≤ |f i / F|≤1.5; wherein, the total focal length F of the optical lens is 7.9mm≤F≤8.1mm, 1≤i≤6.

2. The optical lens according to claim 1, characterized in that, The first lens (101) is a biconvex lens with a refractive index Nd. 101 Satisfying 1.80 < Nd 101 <1.85, Abbe number Vd 101 >40; The second lens (102) is a biconcave lens with an Abbe number Vd. 102 <34.

3. The optical lens according to claim 1 or 2, characterized in that, The focal length f1 of the first lens (101) satisfies: 5.3mm≤f1≤5.7mm; The focal length f2 of the second lens (102) satisfies: -9.0mm≤f2≤-9.6mm.

4. The optical lens according to claim 1, characterized in that, The second group (200) is a doublet lens group, the third lens (201) and the fourth lens (202) are both glass spherical lenses, the third lens (201) is a biconcave negative lens and the fourth lens (202) is a biconvex positive lens.

5. The optical lens according to claim 1 or 4, characterized in that, The Abbe number Vd of the negative lens in the second group (200) is <34; The refractive index Nd of the positive lens in the second group (200) satisfies 1.71 < Nd < 1.85 and Abbe number Vd > 40.

6. The optical lens according to claim 5, characterized in that, The focal length f3 of the negative lens in the second group (200) satisfies: -4.5mm ≤ f3 ≤ -5.5mm; The focal length f4 of the positive lens in the second group (200) satisfies: 5mm≤f4≤6mm.

7. The optical lens according to claim 4, characterized in that, The fifth lens (301) is a biconvex glass spherical lens with a focal length f5 satisfying: 11.0mm≤f5≤11.5mm.

8. The optical lens according to claim 1, characterized in that, The sixth lens (401) is a plastic aspherical lens, at least one of its surfaces is aspherical, and the focal length f6 of the sixth lens (401) satisfies -9mm≤f6≤-8mm.

9. The optical lens according to claim 8, characterized in that, The aspherical surface of the aspherical lens is an even-order aspherical surface, and its surface profile sag is defined by the following formula: ； Where z is the surface elevation, c is the reciprocal of the radius of curvature, k is the conic coefficient, and α1 to α8 are even-order aspherical coefficients.

10. The optical lens according to claim 1, characterized in that, The total length of the optical lens is TTL≤13.5mm.

11. The optical lens according to claim 10, characterized in that, The total length TTL of the optical lens and the maximum effective optical diameter Ømax of all lenses satisfy: 1 ​​< TTL / Ø max <2.

12. The optical lens according to claim 1, characterized in that, The overall transmittance T of the optical lens is ≥90%.

13. The optical lens according to claim 1, characterized in that, The optical lens also includes an aperture stop (01) located on the imaging side of the first group (100); The aperture of the aperture stop (01) is 2.4mm to 2.8mm, and the axial distance between the aperture stop (01) and the first lens (101) closest to the imaging side in the first group (100) is 0.2mm to 0.8mm.

14. An optical display device, characterized in that, include: The optical lens as described in any one of claims 1-13.

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