Eyepiece system and optical device

Abstract

Embodiments of the present application provide an eyepiece system and an optical device; wherein the eyepiece system comprises, in order from an image source side to a human eye side along an optical axis, a second imaging element group, a third imaging element group and a first imaging element group; the second imaging element group has positive optical power; the third imaging element group comprises a third lens, a surface of the third lens close to the human eye side is a concave surface and is provided with a light splitting element, and the third lens is configured to be movable along the optical axis; the first imaging element group has positive optical power and comprises, in order from the image source side to the human eye side, a second lens and a first lens, and a surface of the second lens close to the third imaging element group is provided with a first optical functional film layer, the first optical functional film layer comprises a first phase retarder and a polarization reflector stacked.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the field of optical imaging technology, and more particularly, to an eyepiece system and an optical device. BACKGROUND

[0002] In the field of optical design of traditional eyepiece systems, straight-through optical solutions have long dominated. They rely on light passing through multiple lenses to achieve imaging. To achieve specific optical performance indicators such as clear imaging and appropriate focal length, a large number of lenses are often configured. However, this design has the following problems: the stacking of numerous lenses makes the eyepiece system bulky, which not only increases the weight of the device but also limits its application in scenarios that require strict space requirements, such as portable observation devices and head-mounted display devices; at the same time, the field of view of the straight-through eyepiece system is small, and the range of the user's field of view is limited, making it difficult to meet the needs of fields that require wide observation. In the early days, straight-through designs were relatively simple in design and manufacturing process, and could meet the basic optical observation needs and provide basic visual magnification and imaging functions. However, with the advancement of technology, the performance requirements of eyepiece systems have increased in various industries. In the pursuit of higher imaging quality, smaller device size, and larger field of view, the limitations of straight-through designs have become increasingly prominent, and they have been unable to meet the diverse needs of modern society. Therefore, there is an urgent need to develop new eyepiece systems that can overcome the above-mentioned defects. SUMMARY

[0003] The purpose of the present application is to provide a new technical solution for an eyepiece system and an optical device, which realizes a large field of view, high imaging quality, and diopter adjustment in a small volume.

[0004] In a first aspect, embodiments of the present application provide an eyepiece system, which comprises, in order from an image source side to an eye side along an optical axis:

[0005] a second imaging element group having positive optical power;

[0006] a third imaging element group comprising a third lens, a surface of the third lens close to the eye side being a concave surface and provided with a light splitting element, and the third lens being configured to be movable along the optical axis; and

[0007] a first imaging element group having positive optical power and comprising, in order from the image source side to the eye side, a second lens and a first lens, and a first optical functional film layer being provided on a surface of the second lens close to the third imaging element group, the first optical functional film layer comprising a first phase retarder and a polarized reflector stacked.

[0008] Optionally, a radius of curvature R3 of the concave surface of the third lens close to the eye side satisfies: -90mm≤R3≤-50mm.

[0009] The optical power of the third lens satisfies: -0.009≤φ3≤-0.006.

[0010] The air gap P of the third lens and the second lens on the optical axis satisfies: 10mm≤P≤13mm.

[0011] Optionally, the third lens is configured to provide diopter adjustment by moving along the optical axis:

[0012] Moving towards the first imaging element group to adapt to a myopic state;

[0013] Moving towards the second imaging element group to adapt to a hyperopic state.

[0014] Optionally, the third lens is configured to be movable from an initial position along the optical axis, to provide diopter adjustment by changing its relative position to the first imaging element group:

[0015] Moving 3mm to 6mm towards the first imaging element group to achieve a diopter adjustment range of 0 to -5D;

[0016] Moving 2.5mm to 3.5mm towards the second imaging element group to achieve a diopter adjustment range of 0 to +5D

[0017] Wherein, at the initial position, the air gap P of the third lens and the second lens on the optical axis satisfies: 10mm≤P≤13mm.

[0018] Optionally, the first phase retarder is located on the optical path between the light splitting element and the polarized reflector;

[0019] The first optical function film layer further comprises a first polarizer, which is stacked on the side surface of the polarized reflector away from the first phase retarder.

[0020] Optionally, the space between the first imaging element group and the third imaging element group is an air medium;

[0021] The radius of curvature R1 of the surface of the second lens close to the third imaging element group and the radius of curvature R3 of the concave surface of the third lens close to the human eye side satisfy the relationship: 0≤R3 / R1≤0.5.

[0022] Optionally, the optical power φ1 of the first imaging element group satisfies: 0<φ1≤0.004.

[0023] Optionally, the second imaging element group comprises at least two lenses;

[0024] The second imaging element group comprises a fifth lens and a fourth lens arranged in sequence from the image source side to the human eye side along the optical axis, and the optical power φ2 thereof satisfies 0.02 ≤ φ2 ≤ 0.04.

[0025] Optionally, the eyepiece system further comprises a display screen arranged at the image source side of the second imaging element group.

[0026] Optionally, the eyepiece system further comprises a second optical functional film layer comprising a second phase retarder, a second polarizer and a third phase retarder stacked in sequence from the image source side to the human eye side.

[0027] The second optical functional film layer is arranged on one side surface of the third lens close to the second imaging element group; or,

[0028] The second imaging element group comprises a fifth lens and a fourth lens arranged in sequence from the image source side to the human eye side along the optical axis, and the second optical functional film layer is arranged on one side surface of the fourth lens close to the third imaging element group.

[0029] Optionally, the total effective focal length F of the eyepiece system satisfies 35mm ≤ F ≤ 39mm.

[0030] Optionally, the optical power φ11 of the first lens satisfies 0.003 ≤ φ11 ≤ 0.007;

[0031] The optical power φ2 of the second lens satisfies -0.004 ≤ φ12 ≤ -0.001.

[0032] Optionally, the optical power φ21 of the fourth lens satisfies 0.015 ≤ φ21 ≤ 0.02;

[0033] The optical power φ22 of the fifth lens satisfies 0.015 ≤ φ22 ≤ 0.025.

[0034] In a second aspect, the embodiments of the present application provide an optical device, which comprises:

[0035] The eyepiece system as described in the first aspect; and,

[0036] An objective lens system.

[0037] The present application has the following beneficial effects:

[0038] The eyepiece system provided in this application embodiment includes a second imaging element group and a first imaging element group with positive optical power arranged along the optical axis, and a third imaging element group disposed between these two imaging element groups. This third imaging element group includes a third lens that is movable along the optical axis, has a concave surface near the human eye, and is equipped with a beam-splitting element. Simultaneously, a first optical functional film layer comprising a stacked first phase retarder and polarizing reflector is disposed on the surface of the second lens near the third imaging element group. The beam-splitting element and the first optical functional film layer cooperate to form a folded optical path, effectively optimizing the optical structure of the eyepiece system. The movement of the third lens enables flexible zoom functionality. This application achieves a large field of view, high image quality, and adjustable diopter within a relatively small volume.

[0039] 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

[0040] 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.

[0041] Figure 1 This is one of the schematic diagrams of the optical structure and optical path of the eyepiece system provided in the embodiments of this application;

[0042] Figure 2 A schematic diagram of the first optical functional film layer provided in the embodiments of this application;

[0043] Figure 3 This is a schematic diagram of the second optical functional film layer provided in an embodiment of this application;

[0044] Figure 4 for Figure 1 The provided dot array diagram of the eyepiece system;

[0045] Figure 5 for Figure 1 MTF chart of the provided eyepiece system;

[0046] Figure 6 for Figure 1 Field curvature and distortion diagrams of the provided eyepiece system;

[0047] Figure 7 for Figure 1 A chromatic aberration diagram of the provided eyepiece system;

[0048] Figure 8 A second schematic diagram of the optical structure and optical path of the eyepiece system provided in the embodiments of this application;

[0049] Figure 9 for Figure 2The provided dot array diagram of the eyepiece system;

[0050] Figure 10 for Figure 2 MTF chart of the provided eyepiece system;

[0051] Figure 11 for Figure 2 Field curvature and distortion diagrams of the provided eyepiece system;

[0052] Figure 12 for Figure 2 The provided vertical chromatic aberration diagram of the eyepiece system.

[0053] Explanation of reference numerals in the attached figures:

[0054] 1. Display screen; 2. Protective glass;

[0055] G1, First imaging element group; G2, Second imaging element group; G3, Third imaging element group;

[0056] 3. Fifth lens; 31. Ninth surface; 32. Tenth surface;

[0057] 4. Fourth lens; 41. Seventh surface; 42. Eighth surface;

[0058] 5. Third lens; 51. Fifth surface; 52. Sixth surface;

[0059] 6. Second lens; 61. Third surface; 62. Fourth surface;

[0060] 7. First lens; 71. First surface; 72. Second surface;

[0061] 8. Spectroscopic element;

[0062] 9. First optical functional film layer; 91. First phase retarder; 92. Polarizing reflector; 93. First polarizer; 94. First anti-reflection film;

[0063] 10. Second optical functional film layer; 1001. Second phase retarder; 1002. Second polarizer; 1003. Third phase retarder; 1004. Second anti-reflection film;

[0064] 01. The human eye. Detailed Implementation

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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 exemplary embodiments can have different values.

[0069] It should be noted that like reference numerals and letters refer to like items throughout the attached drawings, and thus once an item is defined in one drawing, it is not necessary to discuss it further in subsequent drawings.

[0070] The eyepiece system and optical device provided by the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0071] According to an embodiment of the present application, an eyepiece system is provided, referring to Figure 1 and Figure 8 , the eyepiece system comprises, in order from the image source side to the human eye side along the optical axis, a second imaging element group G2, a third imaging element group G3, and a first imaging element group G1. The second imaging element group G2 has positive optical power. The third imaging element group G3 comprises a third lens 5, a surface of the third lens 5 close to the human eye side is concave and provided with a light splitting element 8, and the third lens 5 is configured to be movable along the optical axis. The first imaging element group G1 has positive optical power and comprises a second lens 6 and a first lens 7 arranged in order from the image source side to the human eye side, and a surface of the second lens 6 close to the third imaging element group G3 is provided with a first optical functional film layer 9, referring to Figure 2 , the first optical functional film layer 9 comprises a first phase retarder 91 and a polarization reflector 92 arranged in stack.

[0072] The eyepiece system provided by the embodiments of the present application is arranged in order from the image source side to the human eye side along the optical axis with the second imaging element group G2, the third imaging element group G3, and the first imaging element group G1, referring to Figure 1 and Figure 8The second imaging element group G2 is designed to have positive focal length and provide basic light converging capability for the eyepiece system, and mainly performs aberration correction to improve the image quality of the eyepiece system. The third imaging element group G3 includes a third lens 5, a surface of which close to the human eye side (a side where the human eye 01 is located) is designed as a concave surface and integrated with a light splitting element 8, and can be flexibly moved along the optical axis to realize the zoom function of the eyepiece system. The first imaging element group G1 also has positive focal length and is composed of a second lens 6 and a first lens 7 (having a second surface 72 close to the human eye 01 and a first surface 71 close to the second lens 6) arranged in order from the image source side to the human eye side, and the surface of the second lens 6 close to the third imaging element group G3 is provided with a first optical functional film layer 9, which includes a first phase retarder 91 and a polarization reflector 92 stacked together, and cooperates with the light splitting element 8 to form a folded light path, effectively optimizing the optical structure of the eyepiece system and ensuring accurate transmission and high-quality imaging of light in a limited space. This design not only improves the imaging performance of the eyepiece system, but also realizes a more compact system size, bringing an innovative technical breakthrough to the near-eye optical display field.

[0073] Referring to Figure 1 and Figure 8 , the eyepiece system of the embodiment of the present application includes three imaging element groups, namely: a first imaging element group G1 located on the human eye 01 side, a second imaging element group G2 located on the image source side, and a third imaging element group G3 located between the first imaging element group G1 and the second imaging element group G2. The three imaging element groups are described in detail as follows.

[0074] The first imaging element group G1 is designed to have positive focal length, and is composed of, for example, the second lens 6 and the first lens 7 arranged in order along the optical axis from the image source side to the human eye side. Among them, a special first optical functional film layer 9 is provided on the surface of the second lens 6 close to the third imaging element group G3 (i.e. the third surface 61 shown in Figure 1 and Figure 8 , which specifically includes a first phase retarder 91 and a polarization reflector 92 stacked together. Among them, the first phase retarder 91 is, for example, a quarter-wave plate, and the polarization reflector 92 is, for example, a polarization reflection film.

[0075] In the present application, the first imaging element group G1 undertakes the task of correcting chromatic aberration under large field of view. In particular, the first imaging element group G1 can effectively correct the chromatic dispersion phenomenon caused by the wavelength difference of light in a large field of view (such as FOV of 30°-35°) environment, reduce the deviation and blur of different color light during imaging, ensure that clear and color accurate images can also be presented in a large field of view range, and improve the overall imaging quality.

[0076] The second imaging element group G2 is also designed to have positive optical power, which undertakes the role of converging light from the image source in the entire eyepiece system, lays the foundation for subsequent light processing and imaging, and helps light propagate in the right direction and angle to achieve clear imaging effect.

[0077] In the present application, the optical design of the second imaging element group G2 mainly plays the role of aberration correction. Through the optimization design of the optical power range, it can optimize various aberrations such as spherical aberration, coma, astigmatism, etc. in the eyepiece system, thereby effectively improving the imaging quality of the eyepiece system, making the finally formed image clearer, sharper, and the detail performance more outstanding, which can provide the observer with high-quality visual experience.

[0078] The third imaging element group G3: as the zoom group of the entire eyepiece system, undertakes the key role of flexibly adjusting the focal length to adapt to different imaging needs. Among them, the third lens 5 is the core optical component of the third imaging element group G3, and the surface (i.e. the sixth surface 52 shown in FIGS. 1 and 2) near the eye side is specially designed as a concave surface. Figure 1 And Figure 8 The concave structure is not arbitrary, but is precisely calculated by optical calculation, which can accurately guide the light according to a certain path, and lay the foundation for subsequent optical processing.

[0079] At the same time, the concave surface is provided with a light splitting element 8, which can reflect and transmit part of the incident light. This light processing method cooperates with the first optical functional film layer 9 to realize the folding function of the light path. Through this folded light path design, the light can be efficiently transmitted and imaged in a limited space, greatly optimizing the optical structure of the eyepiece system, making the entire eyepiece system more compact while maintaining high performance.

[0080] Especially, the third lens 5 is designed to move left and right along the optical axis. This design gives the eyepiece system a zoom function. In practical applications, whether it is a myopia case that needs to zoom in to clearly observe near objects, or a hyperopia case that needs to zoom out to focus on distant objects, moving the third lens 5 can adjust the focal length, so as to adapt to the imaging of objects of different distances and sizes, and bring users a more convenient and flexible use experience.

[0081] The eyepiece system provided in the present application includes a plurality of optical films for forming a folded optical path, for example, including a light splitting element 8, a first phase retarder 91, and a polarization reflector 92.

[0082] The light splitting element 8, for example, is a thin film or coating with specific light splitting properties, which can be used to reflect and transmit incident light in a certain proportion.

[0083] Specifically, the light splitting element 8 used in the present application is a semi-transparent and semi-reflective film, which can transmit part of the light and reflect another part of the light.

[0084] It should be noted that the reflectivity and transmissivity of the light splitting element 8 can be flexibly adjusted according to specific needs, which is not limited in the embodiments of the present application.

[0085] The first phase retarder 91 can be used to change the polarization state of light, for example, to convert linearly polarized light into circularly polarized light, or to convert circularly polarized light into linearly polarized light.

[0086] The first phase retarder 91 used in the present application, for example, is a quarter-wave plate, which is located between the light splitting element 8 and the polarization reflector 92, and adjusts the phase of light to ensure that the light can be correctly reflected or transmitted in the subsequent path.

[0087] The polarization reflector 92 is an optical device that reflects horizontally linearly polarized light and transmits vertically linearly polarized light, or any other specific angle linearly polarized light and transmits linearly polarized light perpendicular to the angle. That is, the polarization reflector 92 is responsible for reflecting or transmitting according to the polarization state of the light. In the present application, it interacts with a specific state of polarized light (such as S-polarized light or P-polarized light) to achieve specific path control of light.

[0088] The polarization reflector 92 used in the present application, for example, is a polarization reflection film.

[0089] The eyepiece system provided by the embodiments of the present application has three imaging element groups cooperating with each other. For example, the second imaging element group G2 converges the light rays emitted from the image source, laying a foundation for subsequent processing of the light rays. The third imaging element group G3 serves as a zoom group of the system, and the third lens 5 in the third imaging element group G3 can be flexibly moved left and right along the optical axis direction, so that the light path can be flexibly and accurately adjusted according to different use scenarios, such as myopia or hyperopia, to realize the zoom function and ensure that the light rays enter the subsequent optical elements in the best state. The first imaging element group G1 forms a folded light path by means of the light splitting element 8 and the first optical functional film layer 9, and accurately processes and regulates the light rays.

[0090] Through the above-mentioned mode of cooperative work of the three imaging element groups, the eyepiece system can effectively correct various aberrations and significantly reduce optical distortion. Even in a larger field of view (FOV, for example, 30°-35°), clear and high-quality imaging can be achieved. Figure 4 and Figure 9 As can be seen from the spot diagram, the maximum value of the image points is less than 22 μm, which indicates that the distribution of the light rays on the image surface is relatively concentrated, and the clarity of the imaging is higher. As can be seen from the Figure 5 and Figure 10 As can be seen from the MTF, the MTF is greater than 0.25 at 40 lp / mm, which indicates that the eyepiece system can still maintain good contrast transfer capability at a higher spatial frequency, and the imaging details are rich. As can be seen from the Figure 6 and Figure 11 As can be seen from the optical distortion of the eyepiece system, the absolute value of the optical distortion is less than 2%, which means that the geometric shape distortion of the image is extremely small. As can be seen from the Figure 7 and Figure 12 As can be seen from the maximum chromatic aberration of the eyepiece system, the maximum chromatic aberration value is less than 65 μm, which effectively avoids the color deviation of the image caused by dispersion, which indicates that the imaging quality is significantly improved.

[0091] The eyepiece system of the present application adopts a folded light path design, which utilizes the unique optical characteristics of the light splitting element 8 and the first optical functional film layer 9. The light splitting element 8 can partially reflect and partially transmit the light rays, and the first optical functional film layer 9 further regulates the light rays, so that the light rays undergo multiple reflections and refractions inside the eyepiece system. Through this complex and orderly light path folding, the light rays can complete the transmission and imaging process from the image source to the human eye in a limited space.

[0092] Compared with the traditional straight-through optical scheme, the traditional scheme needs multiple lenses to be stacked in sequence to realize the transmission and imaging of light, resulting in a large volume of formed eyepiece system, which occupies a large space. The folding optical path design of the eyepiece system provided in the application effectively avoids this problem, and realizes a more compact system volume. This compact optical structure design not only facilitates the miniaturization and portability of the device, but also provides more possibilities for the optimization of the device in other aspects, and is very suitable for scenes with extremely strict space requirements, such as portable observation devices, thereby improving the practicality and portability of the device.

[0093] It should be noted that the third lens 5 in the third imaging element group G3 provided in the application has the function of moving along the optical axis to realize zooming. This feature not only enables the eyepiece system of the application to adapt to the imaging needs of objects of different distances and sizes, but also exhibits unique advantages in the adjustment and adaptation of myopia and hypermetropia.

[0094] When the third lens 5 moves along the optical axis towards the direction of approaching the imaging surface (towards the first imaging element group G1), it changes the optical power of the eyepiece system. Just like wearing a concave lens with the appropriate degree number for correction of myopia, by adjusting the position of the third lens 5 relative to the first imaging element group G1, the light rays originally converging in front of the imaging surface can be moved backward and accurately focused on the imaging surface, so that the observer can clearly see the distant objects, effectively adapting to the imaging needs in the case of myopia without the need for additional complex correction lenses or components, simplifying the system structure.

[0095] When the third lens 5 moves along the optical axis away from the imaging surface (towards the second imaging element group G2), the propagation path length of the light rays in the eyepiece system is increased, and the refraction angle and convergence degree of the light rays are changed. This is similar to wearing a convex lens for correction of hypermetropia. Through this movement, the convergence ability of the eyepiece system for light rays can be enhanced, so that the light rays originally converging behind the imaging surface can be moved forward and accurately fall on the imaging surface, allowing the observer to clearly observe the nearby objects, and also achieving effective adaptation to the case of hypermetropia in a simple manner.

[0096] The eyepiece system provided by the embodiments of the present application has the second imaging element group G2 and the first imaging element group G1 with positive focal power arranged along the optical axis, and a third imaging element group G3 is arranged between the two imaging element groups. The third imaging element group G3 includes a third lens 5 that is movable along the optical axis, has a concave surface close to the human eye side, and is provided with a light splitting element 8. Meanwhile, a first optical functional film layer 9 including a first phase retarder 91 and a polarization reflector 92 stacked together is arranged on the surface of a second lens 6 close to the third imaging element group G3. The light splitting element 8 and the first optical functional film layer 9 cooperate to form a folded optical path, which effectively optimizes the optical structure of the system. Meanwhile, the movement of the third lens 5 can realize flexible zooming function. The present application realizes the functions of large field of view, high imaging quality and adjustable diopter in a small volume.

[0097] In some examples of the present application, the radius of curvature R3 of the concave surface close to the human eye side of the third lens 5 satisfies: -90mm≤R3≤-50mm. The focal power φ3 of the third lens 5 satisfies: -0.009≤φ3≤-0.006. The air gap P of the third lens 5 and the second lens 6 on the optical axis satisfies: 10mm≤P≤13mm.

[0098] In the examples provided by the present application, the surface (i.e. Figure 1 and Figure 8 the sixth surface 52 shown in FIG. 6) close to the human eye side of the third lens 5 is a concave surface, and the radius of curvature R3 of the concave surface is optimally designed to be in the range of -90mm to -50mm.

[0099] The third lens 5 undertakes the task of zooming in the eyepiece system. It has the ability to move left and right along the optical axis direction, and this movement characteristic enables the eyepiece system to flexibly adapt to the imaging needs in different myopia and hyperopia situations. For example, when the observer has myopia, it means that the light reflected from a distant object will be shifted to the front of the imaging plane (simulated retina position) after passing through the eyepiece system. At this time, moving the third lens 5 in a specific direction along the optical axis can change the focal power distribution and light propagation path of the eyepiece system, so that the light originally converging in front of the imaging plane is moved backward, thereby accurately focusing on the imaging plane, allowing the myopic observer to clearly see the distant object. Similarly, when the observer has hyperopia, the light reflected from a nearby object will converge behind the imaging plane, and by moving the third lens 5, the convergence ability of the eyepiece system can be enhanced, so that the light is moved forward and accurately falls on the imaging plane, meeting the clear observation needs of the hyperopic observer for the nearby object. This zooming function expands the application range of the eyepiece system, enabling it to adapt to the use of users with different vision conditions in different scenarios.

[0100] Specifically, the surface of the third lens 5 close to the human eye is designed as a concave surface, and the curvature radius R3 of the concave surface is optimized and limited in the range of -90mm to -50mm. From the perspective of optics, the shape and curvature radius of the concave surface play a decisive role in the refraction of light. The negative curvature radius value indicates that it is an inwardly concave curved surface, and when the light is incident on this concave surface, it will be refracted according to the curvature of the concave surface. Different curvature radii will result in different angles and degrees of light refraction. In the design of the eyepiece system, this specific range of concave curvature radius is to accurately control the direction of light refraction and the focusing position. It is also related to the zoom function of the third lens 5. By adjusting the position of the third lens 5, combined with the refraction characteristics of this concave surface, the propagation path of the light can be more accurately adjusted, so that the light is accurately focused on the imaging surface according to the system design requirements, thereby achieving high-quality imaging effect. At the same time, reasonable design of the concave curvature radius also helps to reduce the aberration of light during propagation, which is beneficial to improve the clarity of imaging and provide users with a high-quality visual experience.

[0101] In this example of the present application, the optical power of the third lens 5 is in the range of -0.009 to -0.006. In the eyepiece system of the present application, this specific range of optical power design is to cooperate with the optical architecture of the entire eyepiece system. Since the eyepiece system adopts a folded optical path optical scheme, and the third lens 5 is part of the zoom group, its diverging effect can help adjust the propagation direction and focusing position of the light, and work with other lenses in the eyepiece system to achieve adjustment in different myopia and hyperopia conditions. For example, in the correction of myopia, appropriate diverging effect can make the light that converges in front of the imaging plane move backward, so that it is clearly imaged on the imaging plane.

[0102] The air gap P between the third lens 5 and the second lens 6 on the optical axis is optimized to be between 10mm and 13mm. The size of this air gap has an important influence on the performance of the eyepiece system. If the air gap is too small (such as less than 10mm), it may cause interference and other adverse phenomena when the light propagates between the two lenses, affecting the imaging quality; and too small a gap will also limit the installation and adjustment space of the lenses, increasing the difficulty of manufacturing the eyepiece system. If the air gap is too large (such as greater than 13mm), it will increase the volume of the entire eyepiece system, which does not meet the requirements of compact optical structure. At the same time, a suitable air gap can also ensure that there is enough space for light transmission and optical adjustment when the light propagates from the second lens 6 to the third lens 5, ensuring that the light can accurately enter the third lens 5 and follow the design requirements for subsequent refraction and focusing, thereby ensuring that the eyepiece system can achieve clear and stable imaging in different use scenarios.

[0103] In some examples of the present application, the third lens 5 is configured to provide diopter adjustment by moving along the optical axis:

[0104] moving towards the first group of imaging elements G1 to accommodate the myopic state;

[0105] moving towards the second group of imaging elements G2 to accommodate the hyperopic state.

[0106] In this example provided by the present application, the third lens 5 achieves diopter adjustment by moving along the optical axis to accommodate the myopic and hyperopic states respectively. This design ingeniously utilizes the optical principles and the effect of lens movement on the light propagation path, which is described below from the two states of myopia and hyperopia.

[0107] The third lens 5 moves towards the first group of imaging elements G1 to accommodate the myopic state.

[0108] Myopia is usually caused by the excessive length of the anterior-posterior diameter of the eyeball, or the excessive curvature of the lens that is not easily restored, resulting in the light reflected from a distant object being imaged in front of the retina after being refracted by the eyeball, rather than accurately falling on the retina, so that the myopic patient cannot see the distant object clearly. In an eyepiece system, this situation means that the original convergence point of the light from the distance (relative to the system) is before the imaging surface (simulating the retina).

[0109] The optical effect of the movement of the third lens 5 is that when the third lens 5 moves towards the first group of imaging elements G1, it changes the refractive power distribution of the entire eyepiece system. The third lens 5 is equivalent to an element with specific optical properties, and its movement changes the refraction angle and path of the light when passing through the lens. Specifically, when moving towards the first group of imaging elements G1, the third lens 5 enhances the divergence of light (because its position change affects the interaction of light and lens). This divergence is similar to wearing a suitable concave lens for myopic users, which can move the light that was converging in front of the imaging surface back, thereby accurately focusing the light on the imaging surface. In this way, the observer can clearly see the originally blurred distant objects, achieving accommodation for the myopic state.

[0110] The third lens 5 moves towards the second group of imaging elements G2 to accommodate the hyperopic state.

[0111] Hyperopia is caused by the excessive shortness of the anterior-posterior diameter of the eyeball, or the decrease in the elasticity of the lens, resulting in the light reflected from a near object being imaged behind the retina after being refracted by the eyeball, so that the hyperopic patient cannot see the near object clearly. In the eyepiece system of the present application, the corresponding situation is that the original convergence point of the light from the near object is after the imaging surface.

[0112] The optical effect of the movement of the third lens 5: when the third lens 5 moves towards the second imaging element group G2, the change in its position changes the propagation path of the light rays in the eyepiece system. At this time, the converging effect of the third lens 5 on the light rays is relatively enhanced. It can move the light rays that were originally converging behind the imaging plane forward, and then accurately focus on the imaging plane. This is like wearing a convex lens to correct the vision of a hypermetropic user, by enhancing the converging ability of the light rays, the light rays of near objects can be clearly imaged on the retina (imaging plane).

[0113] This design of adjusting the diopter by moving the third lens 5 along the optical axis improves the versatility and adaptability of the eyepiece system, without the need to replace lenses or complex optical components. By simply moving the lens, it can meet the observation needs of users with different vision conditions (myopia and hypermetropia), reducing the cost and difficulty of operation. This design maintains the overall stability and optical performance of the eyepiece system, and does not significantly affect other optical parameters of the eyepiece system during the adjustment of the diopter, ensuring the stability of the imaging quality and providing users with a clear and comfortable visual experience.

[0114] In some examples of the present application, the third lens 5 is configured to be able to move along the optical axis from an initial position to provide diopter adjustment by changing its relative position to the first imaging element group G1:

[0115] Moving 3mm to 6mm towards the first imaging element group G1 to achieve a diopter adjustment range of 0 to -5D;

[0116] Moving 2.5mm to 3.5mm towards the second imaging element group G2 to achieve a diopter adjustment range of 0 to +5D;

[0117] Wherein, in the initial position, the air gap P of the third lens 5 and the second lens 6 on the optical axis satisfies: 10mm≤P≤13mm.

[0118] In examples of the present application, the "initial position" has a clear definition, which refers to the position of the third lens 5 when the observer is in a vision state of neither myopia nor hypermetropia, and the diopter adjustment is accurately set to 0D. When the eyepiece system is in the initial state, there is a specific air gap P between the third lens 5 and the second lens 6 of the first imaging element group G1. Through optimized design, it is determined that the air gap P satisfies the range requirement of 10mm≤P≤13mm.

[0119] In actual application scenarios, according to different design requirements and performance optimization directions, the air gap P of the third lens 5 and the second lens 6 on the optical axis has two settings, for example, 10mm or 12.7mm.

[0120] When the third lens 5 moves 3-6 mm towards the first imaging element group G1, it changes the refraction path of the light passing through the lens. When moving 3 mm, it may correspond to a slight myopia correction, suitable for lower myopia degrees. When the moving distance reaches 6 mm, a diopter adjustment of, for example, -5D can be achieved, which can meet the correction needs of higher myopia degrees.

[0121] When the third lens 5 moves 2.5-3.5 mm towards the second imaging element group G2, the position change affects the propagation of light in the system. When moving 2.5 mm, it may correspond to a slight hyperopia correction, suitable for lower hyperopia degrees. When the moving distance reaches 3.5 mm, a diopter adjustment of, for example, +5D can be achieved, which can meet the correction needs of higher hyperopia degrees.

[0122] This design makes the eyepiece system highly flexible and adaptable. By moving the third lens 5 along the optical axis by a limited distance, a wide range of diopter adjustment from -5D to +5D can be covered, meeting the needs of most myopia and hyperopia patients. Moreover, this adjustment method is relatively simple and reliable, without the need for complex mechanical structures or the replacement of multiple lenses, reducing the cost and complexity of the eyepiece system while ensuring the stability and imaging quality of the eyepiece system, providing users with a convenient and efficient visual correction solution.

[0123] In some examples of the present application, referring to Figure 2 , the first phase retarder 91 is located on the optical path between the light splitting element 8 and the polarization reflector 92; the first optical function film layer 9 further comprises a first polarizer 93, which is stacked on the side surface of the polarization reflector 92 away from the first phase retarder 91.

[0124] Among them, the first polarizer 93 is a polarizing film, which can selectively transmit or reflect light vibration in a specific direction.

[0125] In the eyepiece system of the present application, by introducing the first polarizer 93 and setting it on the side of the polarization reflector 92 away from the first phase retarder 91, this design can reduce the interference of stray light.

[0126] Specifically, stray light is usually undesired light generated by reflection, scattering or refraction of light at the interface. By setting the first polarizer 93 on the side of the polarization reflector 92 away from the first phase retarder 91, stray light that is not consistent with the direction of the main light can be filtered out, reducing their interference with the imaging quality. This helps to improve the contrast and clarity of the image, making the user's viewing of virtual images more realistic and immersive.

[0127] The reduction of stray light directly improves the imaging quality. In virtual reality applications, high-contrast and clear images are the basis for providing a high-quality visual experience. The introduction of the first polarizer 93 enables the system to better control the propagation direction and state of the light, reducing unnecessary light interference, thereby improving the overall presentation effect of the image.

[0128] In addition to directly improving image quality, the introduction of the first polarizer 93 also helps to improve the overall efficiency of the optical module. By reducing the propagation and energy loss of stray light, the eyepiece system can more efficiently utilize light energy and concentrate more energy in the imaging process.

[0129] In this example of the present application, the first phase retarder 91, the polarization reflector 92, and the first polarizer 93 are sequentially stacked to form the first optical functional film layer 9. By stacking multiple optical elements together, a highly integrated composite optical film material is formed, which not only simplifies the structure of the eyepiece system, but also significantly reduces the volume of the eyepiece system.

[0130] The close arrangement of elements in the first optical functional film layer 9 helps to optimize the propagation path of light, reducing energy loss and aberration when light is transmitted between elements. In particular, the close cooperation of the first phase retarder 91 with the first polarizer 93 and the polarization reflector 92 allows more precise control of the polarization state and reflection direction of the light, thereby improving the imaging quality.

[0131] Traditional optical modules require the installation and adjustment of each element one by one, while the design of the first optical functional film layer 9 simplifies the assembly process, allowing the composite film material to be installed as a whole unit into the system, thereby improving production efficiency.

[0132] Optionally, referring to Figure 2 A first anti-reflection film 94 can also be introduced into the first optical functional film layer 9, which can reduce the reflection of light on the lens surface, thereby increasing the transmittance of light. This not only improves the brightness of the image, but also improves the overall optical performance of the eyepiece system.

[0133] In some examples of the present application, the space between the first imaging element group G1 and the third imaging element group G3 is an air medium. The radius of curvature R1 of the surface of the second lens 6 close to the third imaging element group G3 and the radius of curvature R3 of the concave surface of the third lens 5 close to the human eye side satisfy the relationship: 0≤R3 / R1≤0.5.

[0134] In the present application, the first imaging element group G1 and the third imaging element group G3 are arranged as air medium, which has important significance in many aspects. From the optical point of view, the refractive index of air ≈1, which is in sharp contrast with other optical lens materials (refractive index is usually greater than 1). The existence of such air medium provides a relatively simple and pure transition environment for the propagation of light in the eyepiece system. n

[0135] When the light exits from the first imaging element group G1, it enters the third imaging element group G3 through the air medium. The air medium does not produce complex refraction to the light as optical lenses do, thereby reducing the additional disturbance and aberration introduction of the light in the propagation process. This helps to keep the propagation direction and optical properties of the light relatively stable, providing a good foundation for the subsequent precise regulation of the lens to the light.

[0136] Ghosting is a stray light phenomenon caused by multiple reflections and refractions of light in the optical system, which can interfere with normal imaging and reduce the contrast and clarity of the image. In the present application, the curvature radius of the surface of the second lens 6 close to the third imaging element group G3 (i.e. the third surface 61 of the second lens 6 shown in FIGS. 1 and 2) is R1, and the curvature radius of the concave surface of the third lens 5 close to the human eye (i.e. the sixth surface 52 of the third lens 5 shown in FIGS. 1 and 2) is R3, which satisfy the relationship of 0≤R3 / R1≤0.5. This specific curvature radius ratio can effectively control the reflection and refraction path of the light on the lens surface. Figure 1 Figure 8 When the light enters the lens surface, the size of the curvature radius will affect the reflection angle and energy distribution of the light. A reasonable R3 / R1 ratio can make the reflected light propagate at a specific angle, avoiding the reflected light from entering the imaging light path again to form ghosting. For example, if the value of R3 / R1 is too large or too small, it may cause the reflected light to reflect multiple times in the optical system, forming obvious ghosting and affecting the imaging quality. However, satisfying the relationship of 0≤R3 / R1≤0.5 can guide the reflected light to the area that does not affect the imaging, thereby effectively reducing the ghosting of the system and improving the purity of the image. Figure 1 Figure 8 The third imaging element group G3 (including the third lens 5) has the function of moving along the optical axis direction to realize the diopter adjustment in the eyepiece system. The ratio of the curvature radius R3 of the concave surface of the third lens 5 close to the human eye to the curvature radius R1 of the surface of the second lens 6 close to the third imaging element group G3 has an important influence on the moving range of the third lens 5.

[0137]

[0138] The third imaging element group G3 (including the third lens 5) has the function of moving along the optical axis direction to realize the diopter adjustment in the eyepiece system. The ratio of the curvature radius R3 of the concave surface of the third lens 5 close to the human eye to the curvature radius R1 of the surface of the second lens 6 close to the third imaging element group G3 has an important influence on the moving range of the third lens 5.

[0139] ​​​​When 0≤R3 / R1≤0.5, the structural design and light propagation characteristics of the eyepiece system enable the third lens 5 to maintain good optical performance and imaging quality during movement. Serious problems such as failure of light to accurately focus on the imaging surface and rapid increase in aberration will not occur due to movement.

[0140] The relationship 0≤R3 / R1≤0.5 can reduce the sensitivity of diopter adjustment. This is because a reasonable ratio of curvature radii can optimize the light propagation path and focusing characteristics in the eyepiece system, making the influence of lens movement on diopter more gentle and controllable.

[0141] The air medium spacing between the first imaging element group G1 and the third imaging element group G3 and the ratio of the specific curvature radii of the second lens 6 and the third lens 5 work together to achieve optimization effects such as reducing ghosting, increasing the movement range of the third lens 5, reducing the sensitivity of diopter adjustment, and improving the adjustment accuracy. It is of great significance to improve the performance of the entire eyepiece system and the user experience.

[0142] In some examples of the present application, the optical power φ1 of the first imaging element group G1 satisfies: 0<φ1≤0.004.

[0143] The optical power φ1 of the first imaging element group G1 is greater than 0, which means that the imaging element group as a whole has a converging effect on light. In the eyepiece system provided in the present application, this converging effect helps to focus and arrange light from the image source and guide the light to propagate in the correct direction, laying the foundation for subsequent imaging.

[0144] Further, the optical power φ1 of the first imaging element group G1 is optimized to be within 0.004, indicating that the converging effect of the first imaging element group G1 is relatively weak. This design is carefully considered, and the weak converging effect can avoid excessive change in the refraction angle of light when passing through the imaging element group, thereby reducing the generation of aberrations such as chromatic aberration.

[0145] In the eyepiece system provided in the present application, other element groups such as the second imaging element group G2 and the third imaging element group G3 are also needed to further regulate and focus light to achieve clear imaging and diopter adjustment functions. If the converging effect of the first imaging element group G1 is too strong, it may limit the adjustment range of other elements and increase the difficulty and complexity of the design of the eyepiece system.

[0146] In some examples of the present application, the second imaging element group G2 includes at least two lenses. The second imaging element group G2 includes a fifth lens 3 and a fourth lens 4 arranged in sequence from the image source side to the human eye side along the optical axis, and the optical power φ2 thereof satisfies: 0.02≤φ2≤0.04.

[0147] The second imaging element group G2 adopts a design of at least two lenses, which is to better realize the performance optimization of the eyepiece system. Different lenses have different optical properties, such as curvature, thickness, material, etc. By reasonably combining multiple lenses, the advantages of each lens can be fully utilized to improve the imaging quality.

[0148] The second imaging element group G2 provided by the present application arranges the fifth lens 3 and the fourth lens 4 in sequence from the image source side to the human eye side along the optical axis: this specific arrangement order is the result of optical design and optimization. The image source side is the starting point of light entering the second imaging element group G2, and the human eye side is the final position of light. Arranging the fifth lens 3 and the fourth lens 4 in this order can properly regulate the light when it passes through each lens. For example, the fifth lens 3 can first focus and correct the aberration of the light, and then the fourth lens 4 can finely adjust the light to ensure that the light can be accurately focused on the retina of the human eye in the subsequent process, forming a clear image.

[0149] The optical power φ2 of the second imaging element group G2 is designed to be ≥0.02, which means that this imaging element group has a significant (relative to the first imaging element group G1) converging effect on light. In the eyepiece system, this converging effect is the key to realizing clear imaging. At the same time, the optical power φ2 of the second imaging element group G2 is also designed to be ≤0.04, which limits the optical power φ2 within 0.04, in order to avoid some problems caused by too strong converging effect. If the optical power is too large, the light will produce a large change in refraction angle when passing through the second imaging element group G2, thereby increasing the generation of aberration, especially high-order aberration (such as coma, astigmatism, etc.). High-order aberration will seriously affect the imaging quality, causing the image to appear blurred, distorted, color distortion, etc.

[0150] Therefore, by controlling the optical power φ2 of the second imaging element group G2 within the range of 0.02≤φ2≤0.04, the generation of aberration can be effectively controlled while ensuring sufficient converging ability, thereby providing a good imaging basis for the entire near-eye optical system.

[0151] In some examples of the present application, referring to Figure 1 and Figure 8 , the eyepiece system further includes a display screen 1 arranged on the image source side of the second imaging element group G2.

[0152] The eyepiece system provided by the embodiments of the present application is provided with a protective glass 2 on the light-emitting surface of the display screen 1. Specifically, the protective glass 2 in front of the display screen 1 can effectively isolate dust, fingerprints and other dirt from the outside, thereby keeping the surface of the display screen 1 clean. This is crucial for the optical module, because any dirt on the screen surface can affect light transmission and image quality. By introducing the protective glass 2 with a certain thickness, the tolerance of the eyepiece system to dirt on the surface of the display screen 1 is significantly improved, ensuring the stability and reliability of the optical module.

[0153] The protective glass 2 can not only isolate dirt, but also effectively prevent the display screen 1 from being scratched, collided and physically damaged. This is of great significance to prolong the service life of the display screen 1 and improve the overall durability of the device.

[0154] In some examples of the present application, the eyepiece system further comprises a second optical functional film layer 10, as shown in Figure 1 and Figure 3 The second optical functional film layer 10 comprises a second phase retarder 1001, a second polarizer 1002 and a third phase retarder 1003 stacked in sequence from the image source side to the human eye side.

[0155] The second optical functional film layer 10 is arranged on one side surface of the third lens 5 close to the second imaging element group G2; or the second imaging element group G2 comprises a fifth lens 3 and a fourth lens 4 arranged in sequence along the optical axis from the image source side to the human eye side, and the second optical functional film layer 10 is arranged on one side surface of the fourth lens 4 close to the third imaging element group G3.

[0156] The second phase retarder 1001 and the third phase retarder 1003 are both quarter-wave plates. The second polarizer 1002 is a polarizing film.

[0157] Optionally, as shown in Figure 3 A second anti-reflection film 1004 can also be introduced into the second optical functional film layer 10, which can reduce the reflection of light on the lens surface, thereby increasing the transmittance of light. This not only can improve the brightness of the image, but also can improve the overall optical performance of the optical system.

[0158] In the examples provided by the present application, the display screen 1 is configured to emit circularly polarized light or natural light. In the case of the display screen 1 emitting natural light, the light-emitting surface of the display screen 1 can be provided with, for example, the second optical functional film layer 10, which can be used to convert natural light into circularly polarized light.

[0159] In the examples provided in the present application, the design advantage of the two second optical function film layers 10 is that the arrangement can be flexibly arranged according to the specific structure of the optical system, the light propagation path can be optimized, the light reflection, scattering and other losses between the lenses can be reduced, the imaging clarity and quality can be improved, and the specific optical performance can be targetedly regulated.

[0160] In some examples of the present application, the total effective focal length F of the eyepiece system satisfies: 35mm≤F≤39mm.

[0161] The effective focal length F can balance the imaging size and clarity of the eyepiece system, ensure a sufficient field of view, make the imaging clear and sharp, and adapt to different image sources, thereby improving the overall performance and use experience of the eyepiece system.

[0162] In some examples of the present application, the optical power φ11 of the first lens 7 is 0.003≤φ11≤0.007, and the optical power φ12 of the second lens 6 is -0.004≤φ12≤-0.001.

[0163] In the first imaging element group G1, the positive optical power of the first lens 7 and the negative optical power of the second lens 6 are matched and within a reasonable range, can compensate for aberrations, balance light convergence and divergence, and make the first imaging element group G1 better focus light, thereby improving the imaging clarity and quality.

[0164] In some examples of the present application, the optical power φ21 of the fourth lens 4 is 0.015≤φ21≤0.02, and the optical power φ22 of the fifth lens 3 is 0.015≤φ22≤0.025.

[0165] The optical powers of the two lenses in the second imaging element group G2 are both positive and within a reasonable range, can synergistically converge light, effectively correct aberrations generated by each other, improve the imaging clarity and quality, and reasonably distribute the optical power, thereby enhancing the flexibility and stability of the second imaging element group G2 in regulating light.

[0166] In some examples of the present application, the total optical length TTL of the eyepiece system satisfies: 45mm≤TTL≤65mm.

[0167] The eyepiece system provided in the embodiments of the present application can realize a shorter total optical length in a field of view of 30°~35°, which effectively controls the size of the eyepiece system.

[0168] The refractive index of each lens in the eyepiece system provided in the embodiments of the present application n and the dispersion system v satisfies: 1.4< n <2.0, and 20< v <90.

[0169] The eyepiece system provided by the embodiment of the present application, wherein the central thickness of the first lens 7, the fourth lens 4 and the fifth lens 3 ranges from 1mm to 12mm. Each of the three lenses comprises two optical surfaces, which can be aspherical or spherical, and the surfaces are provided with an anti-reflection film layer.

[0170] The eyepiece system provided by the embodiment of the present application, wherein the central thickness of the third lens 5 ranges from 1mm to 12mm.

[0171] The eyepiece system provided by the embodiment of the present application, wherein the central thickness of the second lens 6 ranges from 2mm to 10mm.

[0172] The eyepiece system provided by the present application is described below by way of Examples 1 to 2.

[0173] Example 1

[0174] The eyepiece system provided by the embodiment 1, referring to Figure 1 , comprises, in sequence from the image source side to the human eye side along the optical axis:

[0175] a display screen 1;

[0176] a second imaging element group G2 having positive focal power, comprising, in sequence from the image source side to the human eye side along the optical axis, a fifth lens 3 and a fourth lens 4;

[0177] a third imaging element group G3 comprising a third lens 5, wherein the surface of the third lens 5 close to the human eye side is a concave surface and is provided with a light splitting element 8, and the third lens 5 is configured to be movable along the optical axis; and

[0178] a first imaging element group G1 having positive focal power and comprising, in sequence from the image source side to the human eye side, a second lens 6 and a first lens 7, and the surface of the second lens 6 close to the third imaging element group G3 is provided with a first optical functional film layer 9, wherein the first optical functional film layer 9 comprises, in sequence from the image source side to the human eye side, a first phase retarder 91, a polarized reflector 92, a first polarizer 93 and a first anti-reflection film 94, referring to Figure 2 ;

[0179] The eyepiece system further comprises a second optical functional film layer 10, and the second optical functional film layer 10 is arranged on the surface of the fourth lens 4 close to the third imaging element group G3; wherein the second optical functional film layer 10 comprises, in sequence from the image source side to the human eye side, a second phase retarder 1001, a second polarizer 1002, a third phase retarder 1003 and a second anti-reflection film 1004, referring to Figure 3 .

[0180] In the case where the observer is neither myopic nor hyperopic, i.e. the accommodation is set to 0D, the air gap P between the third surface 61 of the second lens 6 and the sixth surface 52 of the third lens 5 is 10 mm;

[0181] When the observer needs to adapt -5D, the third lens 5 is configured to move along the optical axis towards the first group of imaging elements G1 so that the air gap P between the third surface 61 of the second lens 6 and the sixth surface 52 of the third lens 5 is 6.4 mm;

[0182] When the observer needs to adapt 5D, the third lens 5 is configured to move along the optical axis towards the second group of imaging elements G2 so that the air gap P between the third surface 61 of the second lens 6 and the sixth surface 52 of the third lens 5 is 12.8 mm;

[0183] The refractive index of the first lens 7 is n 1.49 and the dispersion coefficient v1 is 70;

[0184] The refractive index of the second lens 6 is n 2.65 and the dispersion coefficient v2 is 21.5;

[0185] The refractive index of the third lens 5 is n 3.55 and the dispersion coefficient v3 is 56;

[0186] The refractive index of the fourth lens 4 is n 4.55 and the dispersion coefficient v4 is 56;

[0187] The refractive index of the fifth lens 3 is n 5.55 and the dispersion coefficient v5 is 56.

[0188] The total effective focal length of the eyepiece system provided in this embodiment 1 is 37.1 mm;

[0189] The total optical length of the eyepiece system provided in this embodiment 1 is 48.6 mm.

[0190] The optical parameters of the lenses in this embodiment 1 are shown in Table 1 below.

[0191] Table 1

[0192]

[0193] The optical power of the five lenses in this embodiment 1 is shown in Table 2 below.

[0194] Table 2

[0195]

[0196] The eyepiece system provided in Embodiment 1 has optical performance as shown in Figures 4 to 7 Figure 4 is a point array diagram, Figure 5 is an MTF curve diagram, Figure 6 is a field curvature and distortion diagram, Figure 7 is an axial chromatic aberration diagram. The following analyzes Figures 4 to 7

[0197] Referring to Figure 4 , the eyepiece system provided in Embodiment 1 has an image point maximum value less than 22 μm in the point array diagram.

[0198] Referring to Figure 5 , the eyepiece system provided in Embodiment 1 has an MTF >0.4 at 20 lp / mm.

[0199] Referring to Figure 6 , the eyepiece system provided in Embodiment 1 has a maximum distortion occurring at 1 field of view, and an absolute value less than 2%.

[0200] Referring to Figure 7 , the eyepiece system provided in Embodiment 1 has a maximum chromatic aberration value less than 65 μm.

[0201] Referring to Figure 1 , the optical path diagram shown in FIG. 8 shows that the light emitted by the display screen 1 is transmitted through the protective glass 2, the fifth lens 3, and the fourth lens 4 in sequence. After the light passes through the second optical function film layer 10 on the eighth surface 42 of the fourth lens 4, the light becomes circularly polarized light. After the light is transmitted through the third lens 5, the light passes through the first phase retarder 91 on the third surface 61 of the second lens 6 to become linearly polarized light (e.g., S-polarized light). The light is reflected by the polarized reflector 92, and then passes through the first phase retarder 91 again to become circularly polarized light. The light is reflected by the light splitting element 8 on the sixth surface 52 of the third lens 5, and then passes through the first phase retarder 91 for the third time to become linearly polarized light (e.g., P-polarized light) which is transmitted. Finally, the light is transmitted through the second lens 6 and the first lens 7 in sequence and enters the human eye 01.

[0202] Embodiment 2

[0203] The eyepiece system provided in Embodiment 2 includes, in order from an image source side to a human eye side along an optical axis, a display screen 1, a first imaging element group G1 having a positive focal power, a second imaging element group G2 having a positive focal power, and a third imaging element group G3 having a positive focal power. Figure 8

[0204] The display screen 1;

[0205] The second imaging element group G2 has a positive focal power and includes, in order from an image source side to a human eye side along an optical axis, a fifth lens 3 and a fourth lens 4.

[0206] ​​​The third imaging element group G3 includes a third lens 5 having a concave surface on the side close to the human eye and provided with a light splitting element 8, and is configured to be movable along the optical axis; and

[0207] The first imaging element group G1 has a positive focal power, and includes a second lens 6 and a first lens 7 arranged in order from the image source side to the human eye side, and the second lens 6 is provided with a first optical functional film layer 9 on the surface close to the third imaging element group G3, the first optical functional film layer 9 includes a first phase retarder 91, a polarization reflector 92, a first polarizer 93 and a first anti-reflection film 94 arranged in order from the image source side to the human eye side, see Figure 2 ;

[0208] The eyepiece system further includes a second optical functional film layer 10 arranged on the surface of the third lens 5 on the side close to the second imaging element group G2; wherein the second optical functional film layer 10 includes a second phase retarder 1001, a second polarizer 1002, a third phase retarder 1003 and a second anti-reflection film 1004 arranged in order from the image source side to the human eye side, see Figure 3 .

[0209] When the observer does not need to adjust the diopter, i.e. the diopter adjustment is accurately set to 0D, the air gap P between the third surface 61 of the second lens 6 and the fourth surface 62 of the third lens 5 is 12.7mm;

[0210] When the observer needs to adjust the diopter to -5D, the third lens 5 is configured to move along the optical axis to the first imaging element group G1, so that the air gap P between the third surface 61 of the second lens 6 and the sixth surface 52 of the third lens 5 is 7.2mm;

[0211] When the observer needs to adjust the diopter to 5D, the third lens 5 is configured to move along the optical axis to the second imaging element group G2, so that the air gap P between the third surface 61 of the second lens 6 and the sixth surface 52 of the third lens 5 is 15.8mm.

[0212] The refractive index n1 of the first lens 7 is 1.49, and the dispersion coefficient v1 is 70; n 1 is 1.49, and the dispersion coefficient v1 is 70;

[0213] The refractive index n2 of the second lens 6 is 1.53, and the dispersion coefficient v2 is 55.5; n 2 is 1.53, and the dispersion coefficient v2 is 55.5;

[0214] The refractive index n3 of the third lens 5 is 1.55, and the dispersion coefficient v3 is 56; n 3 is 1.55, and the dispersion coefficient v3 is 56;

[0215] The refractive index n4 of the fourth lens 4 isn 4 is 1.55, and the dispersion coefficient v4 is 56;

[0216] the refractive index of the fifth lens 3 n 5 is 1.55, and the dispersion coefficient v5 is 56.

[0217] The total effective focal length of the eyepiece system provided in Embodiment 2 is 37.2 mm.

[0218] The total optical length of the eyepiece system provided in Embodiment 2 is 60 mm.

[0219] The optical parameters of each lens in Embodiment 2 are shown in Table 3 below.

[0220] Table 3

[0221]

[0222] The refractive powers of the five lenses in Embodiment 2 are shown in Table 4 below.

[0223] Table 4

[0224]

[0225] The optical performance of the eyepiece system provided in Embodiment 2 is shown in Figures 9 to 12 : Figure 9 is a schematic diagram of a spot diagram, Figure 10 is a MTF curve diagram, Figure 11 is a field curvature and distortion diagram, Figure 12 is an axial chromatic aberration diagram. The following analyzes Figures 9 to 12 :

[0226] Referring to Figure 9 , the maximum value of the image point in the spot diagram of the eyepiece system provided in Embodiment 2 is less than 12 μm.

[0227] Referring to Figure 10 , the MTF of the eyepiece system provided in Embodiment 2 is > 0.25 at 40 lp / mm.

[0228] Referring to Figure 11 , the maximum distortion of the eyepiece system provided in Embodiment 2 occurs at 1 field of view, and the absolute value is less than 2%.

[0229] Referring to Figure 12 , the maximum chromatic aberration value of the eyepiece system provided in Embodiment 2 is less than 65 μm.

[0230] Referring to Figure 8The light path diagram shows that the light emitted by the display screen 1 is transmitted through the surface protection glass 2, the fifth lens 3, the fourth lens 4 and the third lens 5 in sequence, becomes circularly polarized light after passing through the second optical function film layer 10 on the fifth surface 51 of the third lens 5, becomes linearly polarized light (such as S polarized light) after passing through the first phase retarder 91 on the third surface 61 of the second lens 6, is reflected by the polarized reflector 92, becomes circularly polarized light again after passing through the first phase retarder 91, is reflected by the light splitting element 8 on the sixth surface 52 of the third lens 5, becomes linearly polarized light (P polarized light) for the third time after passing through the first phase retarder 91, is transmitted through the second lens 6 and the first lens 7 in sequence, and finally hits the human eye 01.

[0231] According to another embodiment of the present application, there is provided an optical device comprising the eyepiece system as described above and an objective lens system.

[0232] The eyepiece system provided by the embodiments of the present application is suitable for optical devices such as sighting devices.

[0233] The specific implementation of the optical device of the embodiments of the present application can refer to the above-mentioned embodiments of the eyepiece system, and therefore at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described here again.

[0234] The above embodiments mainly describe the differences between the embodiments, and the different optimization features between the embodiments can be combined to form a better embodiment as long as they are not contradictory. Considering the brevity of the writing, it will not be described here again.

[0235] 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, but 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 eyepiece system, characterized in that, The eyepiece system has 5 lenses with optical power, and the eyepiece system includes, along the optical axis from the image source side to the human eye side, the following components in sequence: The second imaging element group (G2) has positive optical power; The third imaging element group (G3) includes a third lens (5) having a negative optical power. The surface of the third lens (5) near the human eye is concave and has a beam splitter (8). The third lens (5) is configured to move along the optical axis. The first imaging element group (G1) has an optical power φ1 that satisfies: 0 < φ1 ≤ 0.004, and includes a second lens (6) and a first lens (7) arranged sequentially from the image source side to the human eye side. The second lens (6) has a first optical functional film layer (9) on its surface near the third imaging element group (G3). The first optical functional film layer (9) includes a first phase retarder (91) and a polarizing reflector (92) stacked together.

2. The eyepiece system according to claim 1, characterized in that, The radius of curvature R3 of the concave surface of the third lens (5) near the human eye satisfies: -90mm≤R3≤-50mm; The optical power of the third lens (5) is φ3, which satisfies the following condition: -0.009≤φ3≤-0.006; The air gap P between the third lens (5) and the second lens (6) on the optical axis satisfies: 10mm≤P≤13mm.

3. The eyepiece system according to claim 1, characterized in that, The third lens (5) is configured to provide diopter adjustment by moving along the optical axis: Move toward the first imaging element group (G1) to adapt to the myopic state; It moves toward the second imaging element group (G2) to adapt to the farsighted state.

4. The eyepiece system according to claim 1, characterized in that, The third lens (5) is configured to move from an initial position along the optical axis to provide diopter adjustment by changing its relative position to the first imaging element group (G1): Move 3mm to 6mm toward the first imaging element group (G1) to achieve a diopter adjustment range of 0 to -5D; Move 2.5 mm to 3.5 mm toward the second imaging element group (G2) to achieve a diopter adjustment range of 0 to +5D; Wherein, at the initial position, the air gap P between the third lens (5) and the second lens (6) on the optical axis satisfies: 10mm≤P≤13mm.

5. The eyepiece system according to claim 1, characterized in that, The first phase delayer (91) is located in the optical path between the beam splitter (8) and the polarizing reflector (92); The first optical functional film layer (9) also includes a first polarizer (93), which is stacked on the side surface of the polarizing reflector (92) facing away from the first phase delayer (91).

6. The eyepiece system according to claim 1, characterized in that, The space between the first imaging element group (G1) and the third imaging element group (G3) is an air medium; The radius of curvature R1 of the surface of the second lens (6) near the third imaging element group (G3) and the radius of curvature R3 of the concave surface of the third lens (5) near the human eye satisfy the relationship: 0≤R3 / R1≤0.

5.

7. The eyepiece system according to claim 1, characterized in that, The second imaging element group (G2) includes at least two lenses; The second imaging element group (G2) includes a fifth lens (3) and a fourth lens (4) arranged sequentially along the optical axis from the image source side to the human eye side, and its optical power φ2 satisfies: 0.02≤φ2≤0.

04.

8. The eyepiece system according to claim 1, characterized in that, The eyepiece system also includes a display screen (1) disposed on the image source side of the second imaging element group (G2).

9. The eyepiece system according to claim 1, characterized in that, The eyepiece system also includes a second optical functional film layer (10), which includes a second phase retarder (1001), a second polarizer (1002) and a third phase retarder (1003) stacked sequentially from the image source side to the human eye side. The second optical functional film layer (10) is disposed on the surface of the third lens (5) near the second imaging element group (G2); or, The second imaging element group (G2) includes a fifth lens (3) and a fourth lens (4) arranged sequentially along the optical axis from the image source side to the human eye side, and the second optical functional film layer (10) is disposed on the side surface of the fourth lens (4) near the third imaging element group (G3).

10. The eyepiece system according to claim 1, characterized in that, The total effective focal length F of the eyepiece system satisfies: 35mm≤F≤39mm.

11. The eyepiece system according to claim 1, characterized in that, The optical power φ11 of the first lens (7) is 0.003≤φ11≤0.007; The optical power φ2 of the second lens (6) is -0.004≤φ12≤-0.

001.

12. The eyepiece system according to claim 7, characterized in that, The optical power φ21 of the fourth lens (4) is 0.015≤φ21≤0.02; The optical power φ22 of the fifth lens (3) is 0.015≤φ22≤0.

025.

13. An optical device, characterized in that, include: The eyepiece system as described in any one of claims 1-12; as well as, Objective lens system.

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