An eyepiece imaging system

Abstract

The application discloses an objective lens imaging system, comprising: a lens barrel, a first lens group, a second lens group, a third lens group, a plurality of supporting elements and a light source; the first lens group comprises a first lens; the second lens group comprises a second lens; the third lens group comprises a third lens; the first lens, the second lens and the third lens are sequentially arranged from the outside to the inside along the optical axis; and the plurality of supporting elements comprises a first supporting element and a second supporting element. Wherein, the effective focal length f2 of the second lens, the outer diameter D2m of the inner side surface of the second supporting element and the inner diameter d2m of the inner side surface of the second supporting element satisfy: 1 < f2^2 / (π*(D2m^2-d2m^2)) < 3. By reasonably setting the effective focal length of the second lens and the inner and outer diameters of the second supporting element, the shape of the second lens is effectively controlled, meanwhile, the supporting elements are all partially supported with the inner wall of the lens barrel, the straight size is reasonably controlled, the lens assembly process difficulty is reduced, and the assembly process yield is improved.

Description

Technical Field

[0001] This application belongs to the field of optics, and in particular relates to an eyepiece imaging system. Background Technology

[0002] Since the concept of the "metaverse" was proposed, AR / VR has ushered in its second opportunity for development. As the entry point for human-computer interaction, VR imaging lenses play a crucial role. On the one hand, the image quality of VR imaging lenses needs to meet the resolution requirements of the human eye; on the other hand, early aspherical or Fresnel lenses were relatively long, resulting in a forward center of gravity when worn on the head, leading to a poor user experience, which urgently needed improvement.

[0003] Based on the aforementioned needs, a folded optical path solution has been proposed. This solution folds the optical path, compressing the lens body length to half its original length, thereby shifting the center of gravity of the head-mounted device rearward and improving the user experience. Currently, a two-piece folded optical path device based on optical path folding has been released. From a user experience perspective, its external field of view is relatively blurry, and the image quality of the two-piece lens needs improvement. This patent designs a three-piece folded optical path solution and adopts a planar attachment of a single-piece composite film design, which can better compress the body height and improve image quality. Summary of the Invention

[0004] This application aims to provide an eyepiece imaging system that adopts a three-piece folded optical path scheme, reducing the thickness of the VR system, solving the problem of poor imaging at the edge of the field of view, reducing dizziness, and enhancing the consumer experience.

[0005] This application proposes an eyepiece imaging system, which includes: a lens barrel, a first lens group, a second lens group, a third lens group, multiple support elements, and a light source;

[0006] The first lens group includes a first lens;

[0007] The second lens group includes a second lens;

[0008] The third lens group includes a third lens;

[0009] The first lens, the second lens, and the third lens are arranged sequentially from the outside to the inside along the optical axis; each of the first lens to the third lens has at least one outer surface away from the light source and one inner surface close to the light source;

[0010] The plurality of supporting elements includes a first supporting element and a second supporting element;

[0011] The first support element includes at least one outer side away from the light source and one inner side close to the light source. The first support element is placed between the first lens and the second lens, and its outer side along the optical axis is closest to the first lens compared to the outer sides of other support elements.

[0012] The second support element includes at least one outer side away from the light source and an inner side close to the light source. The second support element is placed between the second lens and the third lens, and its outer side along the optical axis is closest to the second lens compared to the outer sides of other support elements.

[0013] Wherein, the effective focal length f2 of the second lens, the outer diameter D2m of the inner surface of the second supporting element, and the inner diameter d2m of the inner surface of the second supporting element satisfy: 1 <f2^2 / (π*(D2m^2-d2m^2))<3。

[0014] According to one embodiment provided in this application, the eyepiece imaging system further includes a reflective polarizing element and a quarter-wave plate;

[0015] The reflective polarizing element and the quarter-wave plate are located in the first lens group, and the reflective polarizing element and the quarter-wave plate are attached to the outer surface of the first lens;

[0016] The outer surface of the third lens has a partial reflective layer.

[0017] According to one embodiment provided in this application, the entrance pupil diameter EPD of the eyepiece imaging system, the outer diameter D0s of the outer surface of the lens barrel, and the inner diameter d0s of the outer surface of the lens barrel satisfy: 50mm <EPD*(D0s+d0s) / (D0s-d0s)<85mm。

[0018] According to one embodiment provided in this application, the back focal length FL of the eyepiece imaging system, and the inner diameter d0m of the inner side surface of the lens barrel satisfy: 8.5 <d0m / FL<9.5。

[0019] According to one embodiment provided in this application, the inner diameter d2m of the inner side of the second supporting element, the radius of curvature R5 of the outer side of the third lens, and the radius of curvature R6 of the inner side of the third lens satisfy: -4.5<(R5+R6) / d2m<-3.

[0020] According to one embodiment provided in this application, the refractive index N2 of the second lens, the maximum thickness CP2 of the second supporting element, and the distance T23 between the second lens and the third lens on the optical axis satisfy: 1 <CP2 / T23*N2<37。

[0021] According to one embodiment provided in this application, the dispersion coefficient V1 of the first lens, the effective focal length f1 of the first lens, and the inner diameter d1m of the inner surface of the first supporting element satisfy: -65 <V1*f1 / d1m<-62。

[0022] According to one embodiment provided in this application, the dispersion coefficient V2 of the second lens, the inner diameter d2s of the outer surface of the second bearing element, and the effective focal length f2 of the second lens satisfy: 73 <V2*f2 / d2s<82。

[0023] According to one embodiment provided in this application, the horizontal distance EP12 between the first support element and the second support element, the horizontal distance EP01 between the lens barrel and the first support element, and the maximum length L of the lens barrel satisfy: 0.5 < (EP01 + EP12) / L < 0.6.

[0024] According to one embodiment provided in this application, the thickness CT2 of the second lens on the optical axis is equal to the maximum thickness CP2 of the second supporting element, and the maximum thickness CP1 of the first supporting element satisfies: 0.1 <CP1+CP2 / CT2<0.5。

[0025] According to one embodiment provided in this application, half of the maximum field of view (semi-FOV) of the eyepiece imaging system, the maximum length L of the lens barrel, the outer diameter D0m of the inner side of the lens barrel, and the outer diameter D0s of the outer side of the lens barrel satisfy: 2.5 <TAN(semi-FOV)*L / (D0m-D0s)<5.5。

[0026] According to one embodiment provided in this application, the focal length f1 of the first lens, the inner diameter d1m of the inner side of the first supporting element, and the outer diameter D1m of the inner side of the first supporting element satisfy: 29<|f1 / (D1m-d1m)|<39.

[0027] According to one embodiment provided in this application, the first lens and the second lens have opposite refractive forces.

[0028] According to one embodiment provided in this application, the visible light reflectivity of at least one supporting element is less than 15%.

[0029] The beneficial effects of this application are:

[0030] The eyepiece imaging system provided in this application includes multiple lenses, such as a first lens to a third lens. A first support element and a second support element are provided between adjacent lenses. By reasonably setting the effective focal length of the second lens and the inner and outer diameters of the second support element, the shape of the second lens is effectively controlled, reducing the difficulty of forming the second lens. Simultaneously, the support elements all abut against the inner wall of the lens barrel, reasonably controlling the vertical dimensions, reducing the line profile requirements of the mating parts between the lens barrel and the support elements, lowering the difficulty of the lens assembly process, and improving the assembly yield. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the eyepiece imaging system of this application;

[0033] Figure 2 This is a schematic diagram of the eyepiece imaging system in Example 1;

[0034] Figure 3 This is a schematic diagram of the eyepiece imaging system in Example 1;

[0035] Figure 4 This is a schematic diagram of the eyepiece imaging system in Example 1;

[0036] Figures 5a to 5d These are the on-axis chromatic aberration curve, astigmatism curve, distortion curve, and relative illumination curve of Embodiment 1 of the eyepiece imaging system of this application, respectively.

[0037] Figure 6 This is a schematic diagram of the eyepiece imaging system in Example 2;

[0038] Figure 7 This is a schematic diagram of the eyepiece imaging system in Example 2;

[0039] Figure 8 This is a schematic diagram of the eyepiece imaging system in Example 1;

[0040] Figures 9a to 9d These are the on-axis chromatic aberration curve, astigmatism curve, distortion curve, and relative illumination curve of the eyepiece imaging system embodiment 2 of this application, respectively.

[0041] Figure 10 This is a schematic diagram of the eyepiece imaging system in Example 3;

[0042] Figure 11This is a schematic diagram of the eyepiece imaging system in Example 3;

[0043] Figure 12 This is a schematic diagram of the eyepiece imaging system in Example 3;

[0044] Figures 13a to 13d These are the on-axis chromatic aberration curve, astigmatism curve, distortion curve, and relative illumination curve of the eyepiece imaging system embodiment 3 of this application, respectively. Detailed Implementation

[0045] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0046] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of this application, the first lens discussed below may also be referred to as the second lens or the third lens.

[0047] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0048] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0049] In the description of this application, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region. If the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0050] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formalized manner unless expressly so specified herein.

[0051] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The features, principles, and other aspects of this application will now be described in detail with reference to the accompanying drawings and embodiments.

[0052] Exemplary Implementation

[0053] refer to Figure 1As shown in the figure, an exemplary eyepiece imaging system of the present application includes: a barrel, a first lens group, a second lens group, a third lens group, a plurality of supporting elements, and a light source; the first lens group includes a first lens; the second lens group includes a second lens; the third lens group includes a third lens; the first lens, the second lens, and the third lens are arranged in sequence along the optical axis from the outside to the inside; each of the first lens to the third lens has at least one outer side facing away from the light source and an inner side facing the light source; the plurality of supporting elements include a first supporting element and a second supporting element; the first supporting element includes at least one outer side facing away from the light source and an inner side facing the light source, the first supporting element is placed between the first lens and the second lens, and its outer side is closer to the first lens along the optical axis direction than the outer sides of other supporting elements; the second supporting element includes at least one outer side facing away from the light source and an inner side facing the light source, the second supporting element is placed between the second lens and the third lens, and its outer side is closer to the second lens along the optical axis direction than the outer sides of other supporting elements; wherein, the effective focal length f2 of the second lens, the outer diameter D2m of the inner side of the second supporting element, and the inner diameter d2m of the inner side of the second supporting element satisfy: 1 < f2^2 / (π * (D2m^2 - d2m^2)) < 3. The three-piece eyepiece imaging system is provided with a first supporting element and a second supporting element between adjacent lenses. By reasonably setting the effective focal length of the second lens and the inner and outer diameters of the second supporting element, the shape of the second lens is effectively controlled, the forming difficulty of the second lens is reduced. At the same time, the supporting elements are all partially supported by the inner wall of the barrel, the straight position dimension is reasonably controlled, the line profile requirement of the matching part between the barrel and the supporting element is reduced, the lens assembly process difficulty is reduced, and the assembly process yield is improved. More specifically, the effective focal length f2 of the second lens, the outer diameter D2m of the inner side of the second supporting element, and the inner diameter d2m of the inner side of the second supporting element satisfy: 1.30 < f2^2 / (π * (D2m^2 - d2m^2)) < 2.95.

[0054] In an exemplary embodiment of the present application, the reflective polarizing element and the quarter-wave plate are located in the first lens group, and the reflective polarizing element and the quarter-wave plate are adhered to the outer side of the first lens; a partial reflective layer is provided on the outer side of the third lens. By placing the reflective polarizing element and the quarter-wave plate on the first lens and adhering them to the outer side of the first lens, the folding effect of the imaging light path is achieved by using the phase addition function of the quarter-wave plate for polarized light and the beam splitting function of the reflective polarizing element, as well as the reflection function of the partial reflective layer in the third lens; the reflective polarizing element and the quarter-wave plate are both adhered to the outer side of the first lens, so that the reflective polarizing element and the quarter-wave plate can be combined. The required structure can be obtained through one adhesion operation instead of two, reducing the angular position error caused by adhesion and improving the imaging quality.

[0055] In an exemplary embodiment of the present application, the entrance pupil diameter EPD of the eyepiece imaging system, the outer diameter D0s of the outer side surface of the lens barrel, and the inner diameter d0s of the outer side surface of the lens barrel satisfy: 50 mm < EPD*(D0s + d0s) / (D0s - d0s) < 85 mm. By controlling the entrance pupil diameter of the optical system to meet ergonomics, it is beneficial to the immersive experience of the VR lens; at the same time, by controlling the outer diameter of the lens, on the one hand, the size of the lens barrel is minimized, thereby reducing the overall size of the machine; on the other hand, a certain ratio is maintained between the diameter of the lens barrel and the diameter of the lens, and the uniform wall thickness of the lens barrel is beneficial to stabilizing the reliability of the lens. More specifically, the entrance pupil diameter EPD of the eyepiece imaging system, the outer diameter D0s of the outer side surface of the lens barrel, and the inner diameter d0s of the outer side surface of the lens barrel satisfy: 54 mm < EPD*(D0s + d0s) / (D0s - d0s) < 84 mm.

[0056] In an exemplary embodiment of the present application, the back focal length FL of the eyepiece imaging system and the inner diameter d0m of the inner side surface of the lens barrel satisfy: 8.5 < d0m / FL < 9.5. By controlling the back focal length of the optical imaging system, the field angle of the system is effectively restricted, so that the system meets the characteristics of a large field of view of the eyepiece. More specifically, the back focal length FL of the eyepiece imaging system and the inner diameter d0m of the inner side surface of the lens barrel satisfy: 8.9 < d0m / FL < 9.2.

[0057] In an exemplary embodiment of the present application, the inner diameter d2m of the inner side surface of the second supporting element, the curvature radius R5 of the outer side surface of the third lens, and the curvature radius R6 of the inner side surface of the third lens satisfy: -4.5 < (R5 + R6) / d2m < -3. By controlling this condition, the curvature radii of the near-light surface and the far-light surface of the second lens are restricted, which is beneficial to reducing the sensitivity of the second lens, thereby improving the yield of assembly; secondly, the inner diameter of the near-light surface of the second supporting element can be restricted to ensure its machinability. More specifically, the inner diameter d2m of the inner side surface of the second supporting element, the curvature radius R5 of the outer side surface of the third lens, and the curvature radius R6 of the inner side surface of the third lens satisfy: -4.1 < (R5 + R6) / d2m < -3.8.

[0058] In an exemplary embodiment of the present application, the refractive index N2 of the second lens, the maximum thickness CP2 of the second supporting element, and the distance T23 between the second lens and the third lens on the optical axis satisfy: 1 < CP2 / T23 * N2 < 37. By controlling the interval between the second lens and the third lens, it is beneficial to reduce the body height and indirectly control the thickness of the second spacer element, both of which are beneficial to the miniaturization of the VR lens; by controlling the refractive index of the second lens, the optical power of the second lens can be controlled. Combining with the air interval of the lens, the focal length of the system can be controlled, thereby restricting the system field angle to meet the wide-angle requirement of the head-mounted device. More specifically, the refractive index N2 of the second lens, the maximum thickness CP2 of the second supporting element, and the distance T23 between the second lens and the third lens on the optical axis satisfy: 1.5 < CP2 / T23 * N2 < 36.5.

[0059] In an exemplary embodiment of the present application, the Abbe number V1 of the first lens, the effective focal length f1 of the first lens, and the inner diameter d1m of the inner side surface of the first supporting element satisfy: -65 < V1 * f1 / d1m < -62. By controlling the ratio of the effective focal length and Abbe number of the first lens to the inner diameter of the first lens on the near-light source side, it is beneficial to set the optical power and Abbe number of the first lens, and can effectively control the shape of the first lens, which is beneficial to blocking the extra light generated at the edge after the light passes through the first lens by refraction and reflection by the first spacer, and obtaining the best image quality. More specifically, the Abbe number V1 of the first lens, the effective focal length f1 of the first lens, and the inner diameter d1m of the inner side surface of the first supporting element satisfy: -64 < V1 * f1 / d1m < -62.5.

[0060] In an exemplary embodiment of the present application, the Abbe number V2 of the second lens, the outer diameter d2s of the outer side surface of the second supporting element, and the effective focal length f2 of the second lens satisfy: 73 < V2 * f2 / d2s < 82. By controlling the focal length and Abbe number of the second lens, on the premise of meeting the system focal length, it is beneficial to correct the chromatic aberration of the system and improve the system imaging quality; by controlling the ratio of the effective focal length and Abbe number of the second lens to the inner diameter of the first spacer on the human eye side, it is beneficial to set the optical power and Abbe number of the second lens, and can effectively control the shape of the second lens, which is beneficial to blocking the extra light generated at the edge after the light passes through the first lens by refraction and reflection by the first spacer, and obtaining the best image quality for the effective light after passing through the first lens by refraction or reflection. More specifically, the Abbe number V2 of the second lens, the outer diameter d2s of the outer side surface of the second supporting element, and the effective focal length f2 of the second lens satisfy: 74 < V2 * f2 / d2s < 81.

[0061] In an exemplary embodiment of the present application, the distance EP12 between the first bearing element and the second bearing element in the horizontal direction, the distance EP01 between the lens barrel and the first bearing element in the horizontal direction, and the maximum length L of the lens barrel satisfy: 0.5 < (EP01 + EP12) / L < 0.6. Through the above relational expression, the top surface thickness of the lens barrel and the thickness of the second lens can be controlled, ensuring the processability and bearing stability of the bearing lens. In addition, a smaller L makes the entire lens group more compact, which is beneficial to miniaturized design. More specifically, the distance EP12 between the first bearing element and the second bearing element in the horizontal direction, the distance EP01 between the lens barrel and the first bearing element in the horizontal direction, and the maximum length L of the lens barrel satisfy: 0.51 < (EP01 + EP12) / L < 0.55.

[0062] In an exemplary embodiment of the present application, the thickness CT2 of the second lens on the optical axis, the maximum thickness CP2 of the second bearing element, and the maximum thickness CP1 of the first bearing element satisfy: 0.1 < (CP1 + CP2) / CT2 < 0.5. By controlling the above relational expression, the center thickness of the second lens and the thickness of the bearing element are controlled. First, it is beneficial to reduce the overall length of the machine and is conducive to the miniaturization of the system. Second, it is beneficial to reduce the deformation after the lens and the spacer element are assembled, making a certain contribution to the assembly stability. More specifically, the thickness CT2 of the second lens on the optical axis, the maximum thickness CP2 of the second bearing element, and the maximum thickness CP1 of the first bearing element satisfy: 0.15 < (CP1 + CP2) / CT2 < 0.45.

[0063] In an exemplary embodiment of the present application, half of the maximum field angle semi - FOV of the eyepiece imaging system, the maximum length L of the lens barrel, the outer diameter D0m of the inner side surface of the lens barrel, and the outer diameter D0s of the outer side surface of the lens barrel satisfy: 2.5 < TAN(semi - FOV) * L / (D0m - D0s) < 5.5. Through the above relational expression, the field angle of the system is effectively restricted, so that the system meets the characteristics of a large field angle of the VR lens; at the same time, by restricting the inner and outer diameter dimensions of the image source side of the lens barrel, the step structure in the radial direction of the system is reduced, improving the yield rate during the lens assembly process. At the same time, by restricting the outer shape dimensions of the lens barrel, on the premise of ensuring the processability of the lens barrel, the outer shape dimensions of the lens barrel are minimized as much as possible, thereby reducing the overall machine size. More specifically, half of the maximum field angle semi - FOV of the eyepiece imaging system, the maximum length L of the lens barrel, the outer diameter D0m of the inner side surface of the lens barrel, and the outer diameter D0s of the outer side surface of the lens barrel satisfy: 3.0 < TAN(semi - FOV) * L / (D0m - D0s) < 5.2.

[0064] In an exemplary embodiment of this application, the focal length f1 of the first lens, the inner diameter d1m of the inner side of the first supporting element, and the outer diameter D1m of the inner side of the first supporting element satisfy: 29 < |f1 / (D1m-d1m)| < 39. By controlling this condition, the light path can be effectively controlled, avoiding the problem of excessive lens sensitivity caused by overly steep light rays. By controlling the range of the inner and outer diameters of the near-light surface of the first spacer element, excess light is blocked, contributing to the overall improvement of lens stray light. More specifically, the focal length f1 of the first lens, the inner diameter d1m of the inner side of the first supporting element, and the outer diameter D1m of the inner side of the first supporting element satisfy: 29.5 < |f1 / (D1m-d1m)| < 38.8.

[0065] In an exemplary embodiment of this application, the first lens and the second lens have opposite refractive forces. Chromatic aberration of the eyepiece is optimized by controlling the focal length.

[0066] In an exemplary embodiment of this application, the visible light reflectance of at least one supporting element is less than 15%.

[0067] In this exemplary embodiment, the outer and inner surfaces of any one of the first lens E1 to the third lens E3 are aspherical, and the surface shape x of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0068]

[0069] Where x is the distance vector from the vertex of the aspherical surface along the optical axis at a height of h; c is the paraxial curvature of the aspherical surface, c = 1 / R (that is, the paraxial curvature c is the reciprocal of the radius of curvature R in Table 1); k is the conic coefficient; Ai is the correction coefficient of the i-th order of the aspherical surface.

[0070] In this exemplary embodiment, the eyepiece imaging system may further include an aperture stop. The aperture stop may be positioned as needed, for example, it may be positioned on the object side, away from the light source from the first lens.

[0071] The eyepiece imaging system according to the above embodiments of this application can employ multiple lenses, such as the three lenses mentioned above. By rationally allocating the optical power, surface shape, center thickness of each lens, and on-axis spacing between each lens, the eyepiece imaging system has a small size and volume, a wide imaging range, and high imaging quality, while ensuring the ultra-thinness of the mobile phone.

[0072] In an exemplary embodiment, at least one of the mirror surfaces of each lens is an aspherical mirror surface; that is, at least one mirror surface from the outer surface of the first lens to the inner surface of the third lens is an aspherical mirror surface. The characteristic of an aspherical lens is that its curvature changes continuously from the lens center to the lens periphery. Unlike a spherical lens, which has a constant curvature from the lens center to the lens periphery, an aspherical lens has better curvature radius characteristics, offering advantages in improving distortion aberrations and astigmatism. By using an aspherical lens, aberrations occurring during imaging can be eliminated as much as possible, thereby improving image quality. Optionally, at least one of the outer and inner surfaces of each of the first, second, and third lenses is an aspherical mirror surface. Optionally, both the outer and inner surfaces of each of the first, second, and third lenses are aspherical mirror surfaces.

[0073] However, those skilled in the art will understand that the number of lenses constituting the eyepiece imaging system can be changed without departing from the technical solutions claimed in this application to obtain the various results and advantages described in this specification. For example, although three lenses are described as an example in the embodiments, the eyepiece imaging system is not limited to including three lenses, and may include other numbers of lenses if needed.

[0074] The following describes a specific embodiment of the eyepiece imaging system applicable to the above embodiments with reference to the accompanying drawings. Specific Implementation Example 1

[0076] Figures 2 to 4 The diagram shows three structural schematics of Embodiment 1 of the eyepiece imaging system of this application. The eyepiece imaging system, along the optical axis from the object side to the image side, includes: an aperture stop STO, a reflective polarizing element RP, a quarter-wave plate QWP, a first lens E1, a second lens E2, a third lens E3, and a light source S9. The first lens, the second lens, and the third lens are arranged sequentially from the outermost to the innermost position along the optical axis. Each lens from the first lens to the third lens has at least one outer surface away from the light source and one inner surface close to the light source. A first supporting element is provided between the first lens E1 and the second lens E2. The first supporting element includes at least one outer surface away from the light source and one inner surface close to the light source. The first supporting element is positioned between the first lens and the second lens, and its outer surface along the optical axis is closest to the first lens compared to the outer surfaces of other supporting elements. A second supporting element is provided between the second lens E2 and the third lens E3. The second supporting element includes at least one outer side away from the light source and an inner side close to the light source. The second supporting element is placed between the second lens and the third lens, and its outer side is closest to the second lens along the optical axis direction compared to the outer side of other supporting elements.

[0077] The light source emits circularly polarized light, which passes through a third lens, a second lens, a first lens, and a quarter-wave plate to become linearly polarized light. After being reflected by a reflective polarizing element, it passes through a quarter-wave plate, a first lens, and a second lens, and is partially reflected by a reflective layer on the third lens. Finally, it passes through a second lens, a first lens, a quarter-wave plate, and a reflective polarizing element before entering the human eye.

[0078] Table 1 shows the basic parameters of the eyepiece imaging system in Example 1, where the units for radius of curvature, thickness, and focal length are all millimeters (mm).

[0079]

[0080] Table 1

[0081] As shown in Table 2, in Example 1, the total effective focal length of the eyepiece imaging system is f = 30.12 mm, the focal length of the first lens E1 is f1 = -216.52 mm, the focal length of the second lens E2 is f2 = 88.22 mm, and the focal length of the third lens E3 is f3 = 213.41 mm.

[0082]

[0083]

[0084] Table 2

[0085] The three eyepiece imaging systems in Example 1 satisfy the following:

[0086] f2^2 / (π*(D2m^2-d2m^2))=1.36 / 1.42 / 1.42. Where f2 is the effective focal length of the second lens, D2m is the outer diameter of the inner surface of the second supporting element P2, and d2m is the inner diameter of the inner surface of the second supporting element P2.

[0087] EPD*(D0s+d0s) / (D0s-d0s)=57.00 / 83.58 / 83.58. Where EPD is the entrance pupil diameter of the eyepiece, D0s is the outer diameter of the outer surface of the lens barrel P0, and d0s is the inner diameter of the outer surface of the lens barrel P0.

[0088] d0m / FL = 9.15 / 9.09 / 9.09. Where FL is the back focal length of the eyepiece, and d0m is the inner diameter of the inner surface of the lens barrel P0.

[0089] (R5+R6) / d2m=-4.02 / -4.02 / -4.02. Where d2m is the inner diameter of the inner surface of the second supporting element P2, R5 is the radius of curvature of the outer surface of the third lens, and R6 is the radius of curvature of the inner surface of the third lens.

[0090] CP2 / T23*N2=1.54 / 1.54 / 1.54. Where N2 is the refractive index of the second lens, CP2 is the maximum thickness of the second supporting element P2, and T23 is the distance between the second and third lenses on the optical axis.

[0091] V1*f1 / d1m=-62.81 / -62.81 / -62.81. Where V1 is the dispersion coefficient of the first lens, f1 is the effective focal length of the first lens, and d1m is the inner diameter of the inner surface of the first supporting element P1.

[0092] V2*f2 / d2s=80.03 / 80.03 / 80.03. Where V2 is the dispersion coefficient of the second lens, d2s is the inner diameter of the outer surface of the second supporting element P2, and f2 is the effective focal length of the second lens.

[0093] (EP01+EP12) / L=0.53 / 0.53 / 0.53. Where EP12 is the horizontal distance between the first support element P1 and the second support element P2, EP01 is the horizontal distance between the lens barrel P0 and the first support element P1, and L is the maximum length of the lens barrel.

[0094] CP1 + CP2 / CT2 = 0.21 / 0.21 / 0.21. Where CT2 is the thickness of the second lens on the optical axis, CP2 is the maximum thickness of the second supporting element P2, and CP1 is the maximum thickness of the first supporting element P1.

[0095] TAN(semi-FOV)*L / (D0m-D0s)=4.78 / 3.04 / 3.04. Where, semi-FOV is half of the maximum field of view of the eyepiece, L is the maximum length of the lens barrel, D0m is the outer diameter of the inner side of the lens barrel P0, and D0s is the outer diameter of the outer side of the lens barrel P0.

[0096] |f1 / (D1m-d1m)|=29.52 / 31.68 / 31.68. Where f1 is the focal length of the first lens, d1m is the inner diameter of the inner surface of the first supporting element P1, and D1m is the outer diameter of the inner surface of the first supporting element P1.

[0097] In Example 1, the outer and inner surfaces of any one of the first lens E1 to the third lens E3 are aspherical. Table 3 shows the higher-order coefficients A0, A1, A2, and A3 that can be used for each aspherical mirror S4, S5, S6, S7, and S8 in Example 1.

[0098] Face number A0 A1 A2 A3 S4 -6.6432E-02 1.8077E-01 -2.3484E-02 8.3382E-02 S5 2.6555E-01 2.5411E-02 -1.4336E-01 5.3124E-02 S6 -1.6482E-01 -3.0792E-01 6.8021E-03 -9.2293E-03 S7 1.3559E-01 2.0474E-04 -3.9216E-02 -4.7567E-03 S8 -2.4170E-02 -2.7007E-01 -1.9162E-01 -2.1132E-01

[0099] Table 3

[0100] Figure 5aThe on-axis chromatic aberration curve of the optical system of Embodiment 1 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 5b The astigmatism curves of the optical system of Embodiment 1 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 5c The distortion curves of the optical system of Example 1 are shown, representing the magnitude of distortion under different viewing angles. Figure 5d The relative illumination curves of the optical system of Example 1 are shown, representing the relative illumination corresponding to different field angles on the imaging plane. According to... Figures 5a to 5d As shown, the optical system given in Example 1 can achieve good imaging quality. Specific Implementation Example 2

[0102] Figures 6 to 8 The diagram shows three structural schematics of Embodiment 2 of the eyepiece imaging system of this application. The eyepiece imaging system, along the optical axis from the object side to the image side, includes: an aperture stop STO, a reflective polarizing element RP, a quarter-wave plate QWP, a first lens E1, a second lens E2, a third lens E3, and a light source S9. The first lens, the second lens, and the third lens are arranged sequentially from the outermost to the innermost position along the optical axis. Each lens from the first lens to the third lens has at least one outer surface away from the light source and one inner surface close to the light source. A first supporting element is provided between the first lens E1 and the second lens E2. The first supporting element includes at least one outer surface away from the light source and one inner surface close to the light source. The first supporting element is positioned between the first lens and the second lens, and its outer surface along the optical axis is closest to the first lens compared to the outer surfaces of other supporting elements. A second supporting element is provided between the second lens E2 and the third lens E3. The second supporting element includes at least one outer side away from the light source and an inner side close to the light source. The second supporting element is placed between the second lens and the third lens, and its outer side is closest to the second lens along the optical axis direction compared to the outer side of other supporting elements.

[0103] The light source emits circularly polarized light, which passes through a third lens, a second lens, a first lens, and a quarter-wave plate to become linearly polarized light. After being reflected by a reflective polarizing element, it passes through a quarter-wave plate, a first lens, and a second lens, and is partially reflected by a reflective layer on the third lens. Finally, it passes through a second lens, a first lens, a quarter-wave plate, and a reflective polarizing element before entering the human eye.

[0104] Table 4 shows the basic parameters of the eyepiece imaging system in Example 2, where the units for radius of curvature, thickness, and focal length are all millimeters (mm).

[0105]

[0106]

[0107] Table 4

[0108] As shown in Table 5, in Example 2, the total effective focal length of the eyepiece imaging system is f = 30.11 mm, the focal length of the first lens E1 is f1 = -220.59 mm, the focal length of the second lens E2 is f2 = 88.83 mm, and the focal length of the third lens E3 is f3 = 218.17 mm.

[0109]

[0110] Table 5

[0111] The three eyepiece imaging systems in Example 2 satisfy the following:

[0112] f2^2 / (π*(D2m^2-d2m^2))=2.48 / 1.44 / 2.79. Where f2 is the effective focal length of the second lens, D2m is the outer diameter of the inner surface of the second supporting element P2, and d2m is the inner diameter of the inner surface of the second supporting element P2.

[0113] EPD*(D0s+d0s) / (D0s-d0s)=54.56 / 56.60 / 56.60. Where EPD is the entrance pupil diameter of the eyepiece, D0s is the outer diameter of the outer surface of the lens barrel P0, and d0s is the inner diameter of the outer surface of the lens barrel P0.

[0114] d0m / FL = 9.00 / 8.94 / 8.94. Where FL is the back focal length of the eyepiece, and d0m is the inner diameter of the inner surface of the lens barrel P0.

[0115] (R5+R6) / d2m=-3.82 / -4.05 / -3.88. Where d2m is the inner diameter of the inner surface of the second supporting element P2, R5 is the radius of curvature of the outer surface of the third lens, and R6 is the radius of curvature of the inner surface of the third lens.

[0116] CP2 / T23*N2=1.54 / 1.54 / 35.24. Where N2 is the refractive index of the second lens, CP2 is the maximum thickness of the second supporting element P2, and T23 is the distance between the second and third lenses on the optical axis.

[0117] V1*f1 / d1m=-63.99 / -63.99 / -63.99. Where V1 is the dispersion coefficient of the first lens, f1 is the effective focal length of the first lens, and d1m is the inner diameter of the inner surface of the first supporting element P1.

[0118] V2*f2 / d2s=80.59 / 80.59 / 74.68. Where V2 is the dispersion coefficient of the second lens, d2s is the inner diameter of the outer surface of the second supporting element P2, and f2 is the effective focal length of the second lens.

[0119] (EP01+EP12) / L=0.52 / 0.52 / 0.53. Where EP12 is the horizontal distance between the first support element P1 and the second support element P2, EP01 is the horizontal distance between the lens barrel P0 and the first support element P1, and L is the maximum length of the lens barrel.

[0120] (CP1+CP2) / CT2=0.2I / 0.21 / 0.43. Where CT2 is the thickness of the second lens on the optical axis, CP2 is the maximum thickness of the second supporting element P2, and CP1 is the maximum thickness of the first supporting element P1.

[0121] TAN(semi-FOV)*L / (D0m-D0s)=5.02 / 5.02 / 4.94. Where, semi-FOV is half of the maximum field of view of the eyepiece, L is the maximum length of the lens barrel, D0m is the outer diameter of the inner side of the lens barrel P0, and D0s is the outer diameter of the outer side of the lens barrel P0.

[0122] |f1 / (D1m-d1m)|=30.08 / 32.28 / 32.28. Where f1 is the focal length of the first lens, d1m is the inner diameter of the inner surface of the first supporting element P1, and D1m is the outer diameter of the inner surface of the first supporting element P1.

[0123] In Example 2, the outer and inner surfaces of any one of the first lens E1 to the third lens E3 are aspherical. Table 6 shows the higher-order coefficients A0, A1, A2, and A3 that can be used for each aspherical mirror S4, S5, S6, S7, and S8 in Example 2.

[0124] Face number A0 A1 A2 A3 S4 -6.1614E-02 1.7339E-01 -2.4843E-02 7.8343E-02 S5 2.6900E-01 1.7790E-02 -1.4264E-01 4.7371E-02 S6 -1.6866E-01 -3.0515E-01 9.9349E-03 -9.4345E-03 S7 1.3929E-01 -4.9698E-04 -3.9605E-02 -4.7729E-03 S8 -3.2983E-02 -2.7075E-01 -1.9221E-01 -2.0574E-01

[0125] Table 6

[0126] Figure 9a The on-axis chromatic aberration curve of the optical system of Embodiment 2 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 9b The astigmatism curves of the optical system of Embodiment 2 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 9c The distortion curves of the optical system of Example 2 are shown, representing the magnitude of distortion under different viewing angles. Figure 9d The relative illumination curves of the optical system in Example 2 are shown, representing the relative illumination corresponding to different field angles on the imaging plane. According to... Figures 9a to 9d As shown, the optical system given in Example 2 can achieve good imaging quality. Specific Implementation Example 3

[0128] Figures 10 to 12The diagram shows three structural schematics of the eyepiece imaging system embodiment 3 of this application. The eyepiece imaging system, along the optical axis from the object side to the image side, includes: an aperture stop STO, a reflective polarizing element RP, a quarter-wave plate QWP, a first lens E1, a second lens E2, a third lens E3, and a light source S9. The first lens, the second lens, and the third lens are arranged sequentially from the outermost to the innermost position along the optical axis. Each lens from the first lens to the third lens has at least one outer surface away from the light source and one inner surface close to the light source. A first supporting element is provided between the first lens E1 and the second lens E2. The first supporting element includes at least one outer surface away from the light source and one inner surface close to the light source. The first supporting element is positioned between the first lens and the second lens, and its outer surface along the optical axis is closest to the first lens compared to the outer surfaces of other supporting elements. A second supporting element is provided between the second lens E2 and the third lens E3. The second supporting element includes at least one outer side away from the light source and an inner side close to the light source. The second supporting element is placed between the second lens and the third lens, and its outer side is closest to the second lens along the optical axis direction compared to the outer side of other supporting elements.

[0129] The light source emits circularly polarized light, which passes through a third lens, a second lens, a first lens, and a quarter-wave plate to become linearly polarized light. After being reflected by a reflective polarizing element, it passes through a quarter-wave plate, a first lens, and a second lens, and is partially reflected by a reflective layer on the third lens. Finally, it passes through a second lens, a first lens, a quarter-wave plate, and a reflective polarizing element before entering the human eye.

[0130] Table 7 shows the basic parameters of the eyepiece imaging system in Example 3, where the units for radius of curvature, thickness, and focal length are all millimeters (mm).

[0131]

[0132]

[0133] Table 7

[0134] As shown in Table 8, in Example 3, the total effective focal length of the eyepiece imaging system is f = 30.12 mm, the focal length of the first lens E1 is f1 = -218.40 mm, the focal length of the second lens E2 is f2 = 88.34 mm, and the focal length of the third lens E3 is f3 = 217.23 mm.

[0135]

[0136] Table 8

[0137] The three eyepiece imaging systems in Example 3 satisfy the following:

[0138] f2^2 / (π*(D2m^2-d2m^2))=1.37 / 1.49 / 2.94. Where f2 is the effective focal length of the second lens, D2m is the outer diameter of the inner surface of the second supporting element P2, and d2m is the inner diameter of the inner surface of the second supporting element P2.

[0139] EPD*(D0s+d0s) / (D0s-d0s)=54.56 / 58.83 / 75.17. Where EPD is the entrance pupil diameter of the eyepiece, D0s is the outer diameter of the outer surface of the lens barrel P0, and d0s is the inner diameter of the outer surface of the lens barrel P0.

[0140] d0m / FL = 9.18 / 9.06 / 9.06. Where FL is the back focal length of the eyepiece, and d0m is the inner diameter of the inner surface of the lens barrel P0.

[0141] (R5+R6) / d2m=-4.06 / -4.06 / -3.86. Where d2m is the inner diameter of the inner surface of the second supporting element P2, R5 is the radius of curvature of the outer surface of the third lens, and R6 is the radius of curvature of the inner surface of the third lens.

[0142] CP2 / T23*N2=1.54 / 1.54 / 36.34. Where N2 is the refractive index of the second lens, CP2 is the maximum thickness of the second supporting element P2, and T23 is the distance between the second and third lenses on the optical axis.

[0143] V1*f1 / d1m=-63.05 / -63.05 / -63.05. Where V1 is the dispersion coefficient of the first lens, f1 is the effective focal length of the first lens, and d1m is the inner diameter of the inner surface of the first supporting element P1.

[0144] V2*f2 / d2s=80.15 / 80.15 / 74.20. Where V2 is the dispersion coefficient of the second lens, d2s is the inner diameter of the outer surface of the second supporting element P2, and f2 is the effective focal length of the second lens.

[0145] (EP01+EP12) / L=0.53 / 0.53 / 0.54. Where EP12 is the horizontal distance between the first support element P1 and the second support element P2, EP01 is the horizontal distance between the lens barrel P0 and the first support element P1, and L is the maximum length of the lens barrel.

[0146] (CP1+CP2) / CT2=0.20 / 0.20 / 0.43. Where CT2 is the thickness of the second lens on the optical axis, CP2 is the maximum thickness of the second supporting element P2, and CP1 is the maximum thickness of the first supporting element P1.

[0147] TAN(semi-FOV)*L / (D0m-D0s)=5.02 / 5.02 / 5.15. Where, semi-FOV is half of the maximum field of view of the eyepiece, L is the maximum length of the lens barrel, D0m is the outer diameter of the inner side of the lens barrel P0, and D0s is the outer diameter of the outer side of the lens barrel P0.

[0148] |f1 / (D1m-d1m)|=32.55 / 38.25 / 38.25. Where f1 is the focal length of the first lens, d1m is the inner diameter of the inner surface of the first supporting element P1, and D1m is the outer diameter of the inner surface of the first supporting element P1.

[0149] In Example 3, the outer and inner surfaces of any one of the first lens E1 to the third lens E3 are aspherical. Table 9 shows the higher-order coefficients A0, A1, A2, and A3 that can be used for each aspherical mirror S4, S5, S6, S7, and S8 in Example 3.

[0150] Face number A0 A1 A2 A3 S4 -6.6527E-02 1.8159E-01 -2.4477E-02 8.0683E-02 S5 2.6579E-01 2.6581E-02 -1.4476E-01 4.9900E-02 S6 -1.6607E-01 -3.0752E-01 5.8513E-03 -9.0554E-03 S7 1.3990E-01 -1.1824E-03 -3.8568E-02 -4.6415E-03 S8 -2.9602E-02 -2.6835E-01 -1.9086E-01 -2.1205E-01

[0151] Table 9

[0152] Figure 13a The on-axis chromatic aberration curve of the optical system of Embodiment 3 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 13b The astigmatism curves of the optical system of Embodiment 3 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 13c The distortion curves of the optical system of Example 3 are shown, representing the magnitude of distortion under different viewing angles. Figure 13d The relative illumination curves of the optical system in Example 3 are shown, representing the relative illumination corresponding to different field angles on the imaging plane. According to... Figures 13a to 13d As shown, the optical system given in Example 3 can achieve good imaging quality.

[0153] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, improvements, or equivalent substitutions made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An eyepiece imaging system, characterized in that, The eyepiece imaging system has three lenses and includes: a lens barrel, a first lens group, a second lens group, a third lens group, multiple support elements, and a light source. The first lens group includes a first lens; The second lens group includes a second lens; The third lens group includes a third lens; The first lens, the second lens, and the third lens are arranged sequentially from the outside to the inside along the optical axis; each of the first lens to the third lens has at least one outer surface away from the light source and one inner surface close to the light source; The plurality of supporting elements includes a first supporting element and a second supporting element; The first support element includes at least one outer side away from the light source and one inner side close to the light source. The first support element is placed between the first lens and the second lens, and its outer side along the optical axis is closest to the first lens compared to the outer sides of other support elements. The second support element includes at least one outer side away from the light source and an inner side close to the light source. The second support element is placed between the second lens and the third lens, and its outer side along the optical axis is closest to the second lens compared to the outer sides of other support elements. Wherein, the effective focal length f2 of the second lens, the outer diameter D2m of the inner surface of the second supporting element, and the inner diameter d2m of the inner surface of the second supporting element satisfy: 1 <f2^2 / (π*(D2m^2-d2m^2))<3; The eyepiece imaging system also includes a reflective polarizing element and a quarter-wave plate; The reflective polarizing element and the quarter-wave plate are located in the first lens group, and the reflective polarizing element and the quarter-wave plate are attached to the outer surface of the first lens; The outer surface of the third lens has a partial reflective layer.

2. The eyepiece imaging system according to claim 1, characterized in that, The entrance pupil diameter EPD of the eyepiece imaging system, the outer diameter D0s of the outer surface of the lens barrel, and the inner diameter d0s of the outer surface of the lens barrel satisfy the following condition: 50mm <EPD*(D0s+d0s) / (D0s-d0s)<85mm。 3. The eyepiece imaging system according to claim 1, characterized in that, The back focal length FL of the eyepiece imaging system, and the inner diameter d0m of the inner side of the lens barrel satisfy: 8.5 <d0m / FL<9.5。 4. The eyepiece imaging system according to claim 1, characterized in that, The inner diameter d2m of the inner side of the second supporting element, the radius of curvature R5 of the outer side of the third lens, and the radius of curvature R6 of the inner side of the third lens satisfy the following: -4.5<(R5+R6) / d2m<-3.

5. The eyepiece imaging system according to claim 1, characterized in that, The refractive index N2 of the second lens, the maximum thickness CP2 of the second supporting element, and the distance T23 between the second lens and the third lens on the optical axis satisfy: 1 <CP2 / T23*N2<37。 6. The eyepiece imaging system according to claim 1, characterized in that, The dispersion coefficient V1 of the first lens, the effective focal length f1 of the first lens, and the inner diameter d1m of the inner surface of the first bearing element satisfy: -65 <V1*f1 / d1m<-62。 7. The eyepiece imaging system according to claim 1, characterized in that, The dispersion coefficient V2 of the second lens, the inner diameter d2s of the outer surface of the second bearing element, and the effective focal length f2 of the second lens satisfy: 73 <V2*f2 / d2s<82。 8. The eyepiece imaging system according to claim 1, characterized in that, The horizontal distance EP12 between the first support element and the second support element, the horizontal distance EP01 between the lens barrel and the first support element, and the maximum length L of the lens barrel satisfy: 0.5 < (EP01 + EP12) / L < 0.

6.

9. The eyepiece imaging system according to claim 1, characterized in that, Given the thickness CT2 of the second lens on the optical axis, and the maximum thickness CP2 of the second supporting element, the maximum thickness CP1 of the first supporting element satisfies: 0.1 <CP1+CP2 / CT2<0.5。 10. The eyepiece imaging system according to claim 1, characterized in that, The semi-FOV (half of the maximum field of view) of the eyepiece imaging system, the maximum length L of the lens barrel, the outer diameter D0m of the inner side of the lens barrel, and the outer diameter D0s of the outer side of the lens barrel satisfy: 2.5 <TAN(semi-FOV)*L / (D0m-D0s)<5.5。 11. The eyepiece imaging system according to claim 1, characterized in that, The focal length f1 of the first lens, the inner diameter d1m of the inner side of the first supporting element, and the outer diameter D1m of the inner side of the first supporting element satisfy: 29<|f1 / (D1m-d1m)|<39.

12. The eyepiece imaging system according to claim 1, characterized in that, The first lens and the second lens have opposite refractive forces.

13. The eyepiece imaging system according to any one of claims 1 to 12, characterized in that, At least one supporting element has a visible light reflectance of less than 15%.

Images