Visual system

Abstract

The utility model discloses a visual system. The visual system comprises a lens cone, an optical element group and a lens cone auxiliary spacer, wherein the optical element group and the lens cone auxiliary spacer are arranged in the lens cone; the optical element group comprises a first lens, a reflective polarizing element, a quarter-wave plate, a second lens and a third lens which are sequentially arranged from the first side to the second side along the optical axis, and the first lens, the second lens and the third lens have positive focal power or negative focal power; a lens barrel auxiliary spacer disposed on and in contact with a first side of the first lens; wherein the total effective focal length f of the visual system and the maximum length L of the lens barrel in the direction of the optical axis meet the following conditions: 1.4 lt; f / Llt; 2.0); and the effective focal length f1 of the first lens, the inner diameter d0bs of the first side surface of the lens barrel auxiliary spacer, and the outer diameter D0bs of the first side surface of the lens barrel auxiliary spacer satisfy: 0.2 lt; (d0bs + D0bs) / f1lt; and 0.9.

Description

Technical Field

[0001] This application relates to the field of optical devices, and particularly to a catadioptric optical system. Background Art

[0002] With the proposal of the concept of the metaverse, virtual reality technology and augmented reality technology for human-computer interaction have迎来了第二次发展的契机。目视系统作为人机交互的重要入口,在其中发挥着关键作用。然而,传统的目视系统通常包括非球面镜片或菲涅尔镜片,其存在着本体长度较长、重量较重、重心位置靠前等问题,从而会影响用户佩戴其时的佩戴体验感。 (The English for "迎来了第二次发展的契机" is not clear. It might be something like "ushered in a second opportunity for development". And the description about traditional visual systems also has some unclear parts in the original Chinese. The following is a rough translation based on the overall context.) With the proposal of the concept of the metaverse, virtual reality technology and augmented reality technology for human-computer interaction have ushered in a second opportunity for development. As an important entry point for human-computer interaction, the visual system plays a crucial role in this. However, traditional visual systems usually include aspherical lenses or Fresnel lenses, which have problems such as a relatively long body length, heavy weight, and a forward center of gravity position, thus affecting the wearing experience of users when wearing them. Utility Model Content

[0003] This application provides a visual system that can at least solve or partially solve at least one problem or other problems existing in the prior art.

[0004] One aspect of this application provides such a visual system, which includes a lens barrel, an optical element group disposed in the lens barrel, and a lens barrel auxiliary spacer; the optical element group includes a first lens, a reflective polarizing element, a quarter-wave plate, a second lens, and a third lens arranged in sequence along the optical axis from the first side to the second side, and the first lens, the second lens, and the third lens have positive or negative optical powers; the lens barrel auxiliary spacer is disposed on the first side surface of the first lens and is in contact with the first side surface of the first lens; wherein, the total effective focal length f of the visual system and the maximum length L of the lens barrel in the direction of the optical axis satisfy: 1.4 < f / L < 2.0; and the effective focal length f1 of the first lens, the inner diameter d0bs of the first side surface of the lens barrel auxiliary spacer, and the outer diameter D0bs of the first side surface of the lens barrel auxiliary spacer satisfy: 0.2 < (d0bs + D0bs) / |f1| < 0.9.

[0005] According to an exemplary embodiment of this application, the total effective focal length f of the visual system, the inner diameter d0s of the first side end surface of the lens barrel, and the inner diameter d0m of the second side end surface of the lens barrel satisfy: 0.8 < (d0m - d0s) / f < 1.2.

[0006] According to an exemplary embodiment of this application, the entrance pupil diameter EPD of the visual system and the outer diameter D0s of the first side end surface of the lens barrel satisfy: 6.0 < D0s / EPD < 9.0.

[0007] According to an exemplary embodiment of this application, the outer diameter D0m of the second side end surface of the lens barrel and the effective focal length f3 of the third lens satisfy: 0.2 < D0m / |f3| < 1.2.

[0008] According to an exemplary embodiment of the present application, the center thickness CT1 of the first lens on the optical axis, the inner diameter d0bm of the second side of the lens barrel auxiliary spacer, and the outer diameter D0bm of the second side of the lens barrel auxiliary spacer satisfy: 0.1 <CT1 / (D0bm-d0bm)<1.1。

[0009] According to an exemplary embodiment of the present application, the visual system further includes a first spacer disposed between the first lens and the second lens; wherein the combined focal length fz of the first lens, the reflective polarizing element, and the quarter-wave plate and the inner diameter d1s of the first side surface of the first spacer satisfy: -0.2 <d1s / fz<0.5。

[0010] According to an exemplary embodiment of the present application, the visual system also includes a first spacer placed between the first lens and the second lens; wherein the refractive index N1 of the first lens, the refractive index N2 of the second lens, the inner diameter d1m of the second side surface of the first spacer, and the outer diameter D1m of the second side surface of the first spacer satisfy: 1.0<(N2 / N1)×(D1m / d1m)<1.4.

[0011] According to an exemplary embodiment of the present application, the visual system further includes a second spacer disposed between the second lens and the third lens; wherein the combined focal length f23 of the second lens and the third lens and the inner diameter d2s of the first side surface of the second spacer satisfy: 1.7 <f23 / d2s<3.7。

[0012] According to an exemplary embodiment of the present application, the visual system further includes a second spacer disposed between the second lens and the third lens; wherein the curvature radius R4 of the second side surface of the second lens and the curvature radius R5 of the first side surface of the third lens satisfy: 0.7<|R5 / R4|<1.1; the inner diameter d2m of the second side surface of the second spacer and the outer diameter D2m of the second side surface of the second spacer satisfy: 1.0 <D2m / d2m<1.3。

[0013] According to an exemplary embodiment of the present application, the visual system further includes a second spacer disposed between the second lens and the third lens; wherein the curvature radius R6 of the second side surface of the third lens and the outer diameter D2s of the first side surface of the second spacer satisfy: -1.7 <D2s / R6<-0.7。

[0014] According to an exemplary embodiment of the present application, the visual system further includes a first spacer disposed between the first lens and the second lens and a second spacer disposed between the second lens and the third lens; wherein, the axial distance T12 from the second side surface of the first lens to the first side surface of the second lens, the axial distance T23 from the second side surface of the second lens to the first side surface of the third lens, and the interval EP12 of the first spacer and the second spacer along the optical axis satisfy: 0.1 < (T12 + T23) / EP12 < 0.7.

[0015] According to an exemplary embodiment of the present application, the visual system further includes a first spacer disposed between the first lens and the second lens and a second spacer disposed between the second lens and the third lens; wherein, the maximum thickness CP0b of the barrel auxiliary spacer, the maximum thickness CP1 of the first spacer, and the maximum thickness CP2 of the second spacer satisfy: 1.4 < (CP0b + CP1) / CP2 < 2.1.

[0016] The visual system provided by the present application is configured as a catadioptric optical system with three lenses, effectively shortening the body length of the visual system, and by making the visual system satisfy "1.4 < f / L < 2.0", as much as possible to ensure that the visual system has a reasonable focal length and a small size, realizing the miniaturization of the visual system; at the same time, by cooperating with restricting the ratio of the sum of the inner and outer diameters of the first side surface of the barrel auxiliary spacer to the absolute value of the effective focal length of the first lens, the size of the first side surface of the barrel auxiliary spacer can be constrained within a certain range, avoiding the problem of poor support performance caused by too small a size of the first side surface of the barrel auxiliary spacer, and avoiding the problem of poor structural strength caused by too large a size of the first side surface of the barrel auxiliary spacer, improving the assembly stability of the visual system while ensuring good processability of the barrel auxiliary spacer. Description of the Drawings

[0017] Other features, objects, and advantages of the present application will become more apparent by reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings. Among them:

[0018] Figure 1 It shows a schematic diagram of parameter markings of the visual system according to the present application;

[0019] Figure 2 It shows a schematic structural diagram of the visual system according to Embodiment 1 of the present application;

[0020] Figure 3 It shows a schematic structural diagram of the visual system according to Embodiment 2 of the present application;

[0021] FIG. 4A to FIG. 4C It respectively shows the axial chromatic aberration curve, astigmatism curve, and distortion curve of the visual system according to Embodiments 1 and 2 of the present application;

[0022] Figure 5 A schematic structural diagram of a visual system according to Embodiment 3 of the present application is shown;

[0023] Figure 6 A schematic diagram of the structure of a visual system according to Embodiment 4 of the present application is shown;

[0024] FIG. 7A to FIG. 7C The axial chromatic aberration curve, astigmatism curve and distortion curve of the visual system according to Embodiments 3 and 4 of the present application are respectively shown;

[0025] Figure 8 A schematic diagram of the structure of a visual system according to Embodiment 5 of the present application is shown;

[0026] Fig. 9 A schematic diagram of the structure of a visual system according to Example 6 of the present application is shown;

[0027] FIG. 10A to FIG. 10C The axial chromatic aberration curve, the astigmatism curve and the distortion curve of the visual system according to Examples 5 and 6 of the present application are respectively shown;

[0028] Fig.11 A schematic diagram of the structure of a visual system according to Embodiment 7 of the present application is shown;

[0029] Fig.12 A schematic diagram of the structure of a visual system according to Embodiment 8 of the present application is shown; and

[0030] FIG. 13A to FIG. 13C The axial chromatic aberration curve, astigmatism curve and distortion curve of the visual system according to Examples 7 and 8 of the present application are respectively shown. DETAILED DESCRIPTION

[0031] In order to better understand the present application, a more detailed description will be made of various aspects of the present application with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of exemplary embodiments of the present application, and do not limit the scope of the present application in any way. Throughout the specification, the same figure numerals refer to the same elements.

[0032] It should be noted that in this specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the features. Therefore, without departing from the teaching of the present application, the first lens discussed below may also be referred to as the second lens or the third lens.

[0033] In the 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 shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are for illustration only and are not drawn strictly to scale.

[0034] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface 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 position of the concave surface 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 first side (e.g., the human eye side) is called the first side surface of the lens, and the surface of each lens closest to the second side (e.g., the display screen side) is called the second side surface of the lens.

[0035] It should also be understood that the terms "include", "comprising", "having", "including" 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. In addition, when describing embodiments of the present application, the term "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0036] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as those commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0037] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0038] The features, principles and other aspects of the present application are described in detail below.

[0039] refer to Figure 2 , Figure 3 , Figure 5 , Figure 6 , Figure 8 , Fig. 9 , Fig.11 and Fig.12In a first aspect of the present application, a visual system is provided, which may include an optical element group, which may include a first lens, a reflective polarizing element, a quarter wave plate, a second lens, and a third lens arranged in sequence from a first side to a second side along an optical axis. In an example, the first lens, the second lens, and the third lens may have positive optical power or negative optical power.

[0040] In an exemplary embodiment, the visual system may further include a lens barrel. The lens barrel includes a first side end surface, a second side end surface, an outer annular surface, and an inner annular surface, wherein the end surface of the lens barrel closest to the first side is the first side end surface of the lens barrel, and the end surface of the lens barrel closest to the second side is the second side end surface of the lens barrel; in a direction perpendicular to the optical axis, the surface of the lens barrel farthest from the optical axis is the outer annular surface, and the surface of the lens barrel closest to the optical axis is the inner annular surface. In the example, the optical element group is placed in the lens barrel.

[0041] In an exemplary embodiment, the visual system may further include one or more of a lens barrel auxiliary spacer, a first spacer, and a second spacer. In an example, the lens barrel auxiliary spacer, the first spacer, and the second spacer are placed in the lens barrel. The lens barrel auxiliary spacer may be placed between the first side end of the lens barrel and the first lens, for example, the lens barrel auxiliary spacer is placed on the first side of the first lens and at least partially contacts with the first side of the first lens. The first spacer may be placed between the first lens and the second lens, for example, the first spacer is at least partially in contact with the second side of the first lens or the first side of the second lens. The second spacer may be placed between the second lens and the third lens, for example, the second spacer is at least partially in contact with the second side of the second lens or the first side of the third lens. The reasonable use of spacers can effectively avoid stray light risks, reduce interference with image quality, and thus improve the imaging quality of the visual system.

[0042] In an exemplary embodiment, the first side may be the human eye side, and the second side may be the display screen side. Accordingly, the first side of each element (first lens, second lens, third lens, reflective polarizing element, quarter wave plate) may be referred to as the side near the human eye, and the second side may be referred to as the side near the screen.

[0043] In an exemplary embodiment, the reflective polarizing element and the quarter wave plate are laminated to form a film layer, and the laminated film layer is attached to the second side surface of the first lens, wherein the reflective polarizing element is located on the first side surface of the quarter wave plate. By laminating the reflective polarizing element and the quarter wave plate together to form a film layer, the number of attached surfaces of the film layer can be reduced, and the attachment yield of the film layer can be improved.

[0044] As an example, the second side surface of the first lens can be configured as a plane, and the film layer formed by laminating the reflective polarizing element and the quarter-wave plate is attached to the second side surface of the first lens. Adopting a planar film laminating method to attach the composite film layer to the plane is conducive to improving the stability of the film layer after attachment, thereby improving the edge field performance of the visual system.

[0045] In an exemplary embodiment, the visual system may further include a partial reflective layer, which may be attached to the second side surface of the third lens. The partial reflective layer has a semi-transmissive and semi-reflective effect on light. By providing a partial reflective layer on the second side surface of the third lens, and combining a reflective polarizing element and a quarter-wave plate, the light can be refracted multiple times, effectively reducing the length of the main body of the visual system.

[0046] In an exemplary embodiment, the visual system may further include an aperture, which is disposed between the first side and the first lens. The image light on the display screen is refracted and reflected multiple times by the third lens, the second lens, the quarter wave plate, the reflective polarizing element, the first lens, etc., and is finally projected to the user's eyes.

[0047] In an exemplary embodiment, an image surface may be provided on the second side of the visual system, and a display screen may be provided on the image surface. The image light from the display screen sequentially passes through the third lens, the second lens, and the quarter-wave plate to reach the reflective polarizing element located on the second side of the first lens, and then reflects at the reflective polarizing element to form a first reflected image light. The first reflected image light passes through the quarter-wave plate, the second lens, the third lens and reaches the partial reflective layer located on the second side of the third lens, and then reflects at the partial reflective layer to form a second reflected image light. The second reflected image light sequentially passes through the third lens, the second lens, the quarter-wave plate, the reflective polarizing element, the first lens to the aperture and is finally projected into the user's eyes. The visual system provided in the present application folds the required optical path without affecting the projection quality by combining light reflection and refraction, thereby effectively shortening the main body length of the visual system.

[0048] In an exemplary embodiment, the total effective focal length f of the visual system and the maximum length L of the barrel along the optical axis direction may satisfy: 1.4 < f / L < 2.0; the effective focal length f1 of the first lens, the inner diameter d0bs of the first side surface of the barrel auxiliary spacer, and the outer diameter D0bs of the first side surface of the barrel auxiliary spacer may satisfy: 0.2 < (d0bs + D0bs) / |f1| < 0.9. The visual system provided in this application is configured as a catadioptric optical system with three lenses, effectively shortening the body length of the visual system. And by making the visual system satisfy "1.4 < f / L < 2.0", it is possible to ensure that the visual system has a reasonable focal length and a small size as much as possible, realizing the miniaturization of the visual system; at the same time, by restricting the ratio of the sum of the inner and outer diameters of the first side surface of the barrel auxiliary spacer to the absolute value of the effective focal length of the first lens, the size of the first side surface of the barrel auxiliary spacer can be constrained within a certain range, avoiding the problem of poor support performance caused by too small a size of the first side surface of the barrel auxiliary spacer, and avoiding the problem of poor structural strength caused by too large a size of the first side surface of the barrel auxiliary spacer. While ensuring good machinability of the barrel auxiliary spacer, the assembly stability of the visual system is improved.

[0049] In an exemplary embodiment, the total effective focal length f of the visual system, the inner diameter d0s of the first side end surface of the barrel, and the inner diameter d0m of the second side end surface of the barrel may satisfy: 0.8 < (d0m - d0s) / f < 1.2. By controlling the ratio of the difference between the inner diameters of the second side end surface and the first side end surface of the barrel to the total effective focal length of the visual system, the shape of the inner ring surface of the barrel can be constrained, thereby ensuring that the barrel has an appropriate opening angle, avoiding the problem of poor machinability of the barrel caused by too large a difference in the inner diameters of the second side end surface and the first side end surface of the barrel, and avoiding the problem of high lens processing difficulty caused by too small a difference in the inner diameters of the second side end surface and the first side end surface of the barrel, improving the machinability of the barrel and the lens.

[0050] In an exemplary embodiment, the entrance pupil diameter EPD of the visual system and the outer diameter D0s of the first side end surface of the barrel may satisfy: 6.0 < D0s / EPD < 9.0. By controlling the ratio of the outer diameter of the first side end surface of the barrel to the entrance pupil diameter of the visual system, the entrance pupil diameter of the visual system can be constrained within a reasonable range; at the same time, by restricting the outer diameter of the first side end surface of the barrel, while ensuring that the structural strength of the barrel meets the design requirements, the problem of occupying too much space of the whole machine and affecting the wearing effect of the whole machine caused by too large an outer diameter of the first side end surface of the barrel is avoided, improving the wearing experience of the user.

[0051] In an exemplary embodiment, the outer diameter D0m of the second side end face of the lens barrel and the effective focal length f3 of the third lens may satisfy: 0.2 < D0m / |f3| < 1.2. By controlling the ratio of the outer diameter of the second side end face of the lens barrel to the absolute value of the effective focal length of the third lens, it is beneficial to optimize the light path, ensure that the light path is more reasonable, and improve the imaging quality of the visual system.

[0052] In an exemplary embodiment, the central thickness CT1 of the first lens on the optical axis, the inner diameter d0bm of the second side face of the lens barrel auxiliary spacer, and the outer diameter D0bm of the second side face of the lens barrel auxiliary spacer may satisfy: 0.1 < CT1 / (D0bm - d0bm) < 1.1. By controlling the ratio of the central thickness of the first lens on the optical axis to the difference between the outer and inner diameters of the second side face of the lens barrel auxiliary spacer, the central thickness of the first lens on the optical axis can be constrained within a reasonable range, improving the processability of the first lens; at the same time, by restricting the difference between the outer and inner diameters of the second side face of the lens barrel auxiliary spacer, it is possible to avoid the problem of poor processability caused by too large a difference between the outer and inner diameters of the second side face of the lens barrel auxiliary spacer, and avoid the problems of poor support performance and high lens processing difficulty caused by too small a difference between the outer and inner diameters of the second side face of the lens barrel auxiliary spacer. While ensuring the processability of the lens barrel auxiliary spacer and the lens, the assembly stability of the visual system is improved.

[0053] In an exemplary embodiment, the combined focal length fz of the first lens, the reflective polarizing element, and the quarter-wave plate and the inner diameter d1s of the first side face of the first spacer may satisfy: -0.2 < d1s / fz < 0.5. By controlling the ratio of the inner diameter of the first side face of the first spacer to the combined focal length of the first lens, the reflective polarizing element, and the quarter-wave plate, the combined focal length of the first lens, the reflective polarizing element, and the quarter-wave plate can be restricted within a reasonable range, thereby constraining the incident angle and the exit angle of the light to meet the usage conditions of the reflective polarizing element and the quarter-wave plate, preventing chromatic aberration and light leakage of the quarter-wave plate, and preventing a significant reduction in the reflectivity and transmittance of the reflective polarizing element, which may affect the light efficiency of the visual system.

[0054] In an exemplary embodiment, the refractive index N1 of the first lens, the refractive index N2 of the second lens, the inner diameter d1m of the second side surface of the first spacer, and the outer diameter D1m of the second side surface of the first spacer may satisfy: 1.0 < (N2 / N1) × (D1m / d1m) < 1.4. By controlling the above conditional expression, the refractive indices of the first lens and the second lens can be constrained, thereby restricting the optical powers of the first lens and the second lens, enabling the entire visual system to achieve the best imaging effect and the largest image plane, and also facilitating the selection of low-stress materials for the first lens and the second lens; at the same time, by cooperating with restricting the ratio of the outer diameter to the inner diameter of the second side surface of the first spacer, it is possible to avoid the problem of poor processability caused by too large a difference between the inner diameter and the outer diameter of the second side surface of the first spacer, and avoid the problem of poor support performance caused by too small a difference between the inner diameter and the outer diameter of the second side surface of the first spacer. While ensuring that the support performance of the first spacer meets the design requirements, the processability of the first spacer is improved.

[0055] In an exemplary embodiment, the combined focal length f23 of the second lens and the third lens and the inner diameter d2s of the first side surface of the second spacer may satisfy: 1.7 < f23 / d2s < 3.7. By controlling the ratio of the combined focal length of the second lens and the third lens to the inner diameter of the first side surface of the second spacer, it is beneficial to optimize the light path, ensure that the light path is more reasonable, and improve the imaging quality of the visual system.

[0056] In an exemplary embodiment, the curvature radius R4 of the second side surface of the second lens and the curvature radius R5 of the first side surface of the third lens may satisfy: 0.7 < |R5 / R4| < 1.1; the inner diameter d2m of the second side surface of the second spacer and the outer diameter D2m of the second side surface of the second spacer may satisfy: 1.0 < D2m / d2m < 1.3. When the visual system satisfies "0.7 < |R5 / R4| < 1.1", by controlling the ratio of the outer diameter to the inner diameter of the second side surface of the second spacer, it is possible to avoid the problem of poor processability caused by too large a difference between the inner diameter and the outer diameter of the second side surface of the second spacer, and avoid the problem of poor support performance caused by too small a difference between the inner diameter and the outer diameter of the second side surface of the second spacer. While ensuring that the support performance of the second spacer meets the design requirements, the processability of the second spacer is improved.

[0057] In an exemplary embodiment, the ratio of the outer diameter D2s of the first side surface of the second spacer to the radius of curvature R6 of the second side surface of the third lens may satisfy: -1.7 < D2s / R6 < -0.7. By controlling the ratio of the outer diameter of the first side surface of the second spacer to the radius of curvature of the second side surface of the third lens, the radius of curvature of the second side surface of the third lens can be constrained within a reasonable range, which is beneficial to reducing the sensitivity of the third lens and improving the assembly yield rate of the third lens; at the same time, in cooperation with restricting the outer diameter of the first side surface of the second spacer, while ensuring good processability of the second spacer, the problem of excessive occupation of the lens barrel space and excessive occupation of the overall machine space caused by too large an outer diameter of the first side surface of the second spacer, which affects the wearing effect of the overall machine, is avoided, and the user's wearing experience is improved.

[0058] In an exemplary embodiment, the on-axis distance T12 from the second side surface of the first lens to the first side surface of the second lens, the on-axis distance T23 from the second side surface of the second lens to the first side surface of the third lens, and the interval EP12 of the first spacer and the second spacer along the optical axis may satisfy: 0.1 < (T12 + T23) / EP12 < 0.7. By controlling the above conditional expression, the on-axis distance from the second side surface of the first lens to the first side surface of the second lens and the on-axis distance from the second side surface of the second lens to the first side surface of the third lens can be respectively constrained within a reasonable range, which is beneficial to correcting the field curvature of the entire visual system and ensuring that the optical performance of the visual system meets the requirements; at the same time, in cooperation with restricting the interval of the first spacer and the second spacer along the optical axis, the edge thicknesses of the second lens and the third lens can be constrained, and the processability of the second lens and the third lens can be improved.

[0059] In an exemplary embodiment, the maximum thickness CP0b of the lens barrel auxiliary spacer, the maximum thickness CP1 of the first spacer, and the maximum thickness CP2 of the second spacer may satisfy: 1.4 < (CP0b + CP1) / CP2 < 2.1. By controlling the above conditional expression, the thicknesses of the lens barrel auxiliary spacer, the first spacer, and the second spacer can be reasonably allocated, and the processability of the lens barrel auxiliary spacer, the first spacer, and the second spacer can be improved while ensuring the assembly stability of the visual system.

[0060] The visual system according to the above embodiment of the present application may employ multiple lenses, such as the three lenses described above. By reasonably allocating the parameters of the reflective polarizing element, the quarter-wave plate, each lens, the lens barrel, and each spacer, the body length of the visual system can be reduced, and the processability, assembly stability, and imaging quality of the visual system can be improved. The visual system configured as above has the characteristics of miniaturization, large field of view angle, and good imaging quality, can well meet the use requirements of various portable electronic products in the projection scenario, and the center of gravity of the visual system and the device including the visual system moves backward, improving the user's wearing experience.

[0061] In an embodiment of the present application, at least one of the surfaces of each of the first lens to the third lens is an aspherical surface. The characteristic of an aspherical lens is that the curvature continuously changes from the center of the lens to the periphery of the lens. Different from a spherical lens with a constant curvature from the center of the lens to the periphery of the lens, an aspherical lens has better curvature radius characteristics and has the advantages of improving distortion aberration and improving astigmatism aberration. After using an aspherical lens, it is possible to eliminate the aberration that appears during imaging as much as possible, thereby improving the imaging quality.

[0062] However, those skilled in the art should understand that without departing from the technical solution claimed in the present application, the number of lenses constituting the visual system can be changed to obtain the various results and advantages described in this specification.

[0063] A second aspect of the present application provides such a visual system, which may include a lens barrel and an optical element group and a second spacer disposed in the lens barrel; the optical element group includes a first lens, a reflective polarizing element, a quarter-wave plate, a second lens, and a third lens arranged in sequence along the optical axis from the first side to the second side, and the first lens, the second lens, and the third lens have positive or negative optical powers. The second spacer is disposed between the second lens and the third lens.

[0064] The radius of curvature R4 of the second side surface of the second lens and the radius of curvature R5 of the first side surface of the third lens may satisfy: 0.7 < |R5 / R4| < 1.1; the inner diameter d2m of the second side surface of the second spacer and the outer diameter D2m of the second side surface of the second spacer may satisfy: 1.0 < D2m / d2m < 1.3. The visual system provided by the present application is configured as a catadioptric optical system with three lenses, effectively shortening the body length of the visual system, and when the visual system satisfies "0.7 < |R5 / R4| < 1.1", by controlling the ratio of the outer diameter to the inner diameter of the second side surface of the second spacer, it is possible to avoid the problem of poor processability caused by too large a difference between the inner diameter and the outer diameter of the second side surface of the second spacer, and avoid the problem of poor support performance caused by too small a difference between the inner diameter and the outer diameter of the second side surface of the second spacer. While ensuring that the support performance of the second spacer meets the design requirements, the processability of the second spacer is improved.

[0065] The following further describes specific embodiments of the visual system applicable to the above embodiments with reference to the accompanying drawings.

[0066] Example 1

[0067] The following refers to Figure 2 Describe the visual system according to Embodiment 1 of the present application.

[0068] As Figure 2As shown, the visual system may include a lens barrel P0 and an optical element group placed in the lens barrel P0, and the optical element group includes a first lens E1, a reflective polarizing element RP, a quarter wave plate QWP, a second lens E2, and a third lens E3 arranged in sequence from the first side to the second side along the optical axis. A stop STO (not shown) may also be provided between the first side and the first lens E1. The second side of the third lens E3 may also be provided with a partial reflection layer BS (not shown). The visual system may also include a lens barrel auxiliary spacer P0b, a first spacer P1, and a second spacer P2 placed in the lens barrel P0. In the present embodiment, the first side refers to the human eye side, and the second side refers to the display screen side. The first side of each element (the first lens E1, the second lens E2, the third lens E3, the reflective polarizing element RP, and the quarter wave plate QWP) is referred to as the near human eye side, and the second side is referred to as the near screen side.

[0069] The first lens E1 has positive focal power, and its side surface S1 near the human eye is convex, and its side surface S2 near the screen is flat. The reflective polarizer RP has a side surface near the human eye and a side surface near the screen, and the side surface near the human eye of the reflective polarizer RP is attached to the side surface S2 near the screen of the first lens E1. The quarter-wave plate QWP has a side surface near the human eye and a side surface near the screen, and its side surface near the human eye is attached to the side surface near the screen of the reflective polarizer RP. The second lens E2 has negative focal power, and its side surface S3 near the human eye is convex, and its side surface S4 near the screen is concave. The third lens E3 has positive focal power, and its side surface S5 near the human eye is convex, and its side surface S6 near the screen is convex. The partial reflection layer BS can be attached to the side surface S6 near the screen of the third lens E3.

[0070] In this example, an image surface IMG may be provided on the second side of the visual system, and the image surface IMG may be provided with a display screen, for example. After the image light from the image surface IMG passes through the third lens E3, the second lens E2, the quarter-wave plate QWP in sequence and reaches the reflective polarizing element RP located on the near-screen side of the first lens E1, a first reflection occurs at the reflective polarizing element RP. After the light reflected for the first time passes through the quarter-wave plate QWP, the second lens E2, the third lens E3 and reaches the partially reflective layer BS located on the near-screen side S6 of the third lens E3, a second reflection occurs at the partially reflective layer BS. The light reflected for the second time passes through the third lens E3, the second lens E2, the quarter-wave plate QWP, the reflective polarizing element RP, the first lens E1 in sequence and is finally projected onto a target object (not shown) in space. For example, the light of the visual system after two reflections is finally projected into the eyes of the user.

[0071] Table 1 shows the basic parameters of the visual system of Example 1, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm). The image light from the image surface IMG passes through the components in the order of sequence number 19 to sequence number 1 and is finally projected into the human eye.

[0072]

[0073]

[0074] Table 1

[0075] In this embodiment, the first side surface S1 of the first lens E1, the first side surface S3 and the second side surface S4 of the second lens E2, and the first side surface S5 and the second side surface S6 of the third lens E3 are all aspherical surfaces, and the surface shape x of each aspherical lens can be defined by but not limited to the following aspherical surface formula:

[0076]

[0077] Wherein, x is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at a height of h along the optical axis; c is the paraxial curvature of the aspheric surface, c=1 / R (i.e., the paraxial curvature c is the reciprocal of the curvature radius R in Table 1 above); k is the cone coefficient; Ai is the correction coefficient of the i-th order of the aspheric surface. Table 2 shows the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A36, A37, A38, A39, A 10 , A 12 , A 14 , A 16 , A 18 and A 20 .

[0078] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S1 -6.1153E-01 -3.3166E-01 8.0580E-03 -1.1441E-02 -2.5244E-03 8.2930E-03 1.6853E-03 0.0000E+00 0.0000E+00 S3 -6.0641E-01 2.6268E-01 -7.4653E-02 8.7985E-02 -2.9213E-02 1.9815E-03 -7.5513E-04 0.0000E+00 0.0000E+00 S4 -1.0827E+00 -2.2629E-01 -5.0583E-02 5.2634E-02 -2.9721E-02 1.0318E-02 5.9363E-04 0.0000E+00 0.0000E+00 S5 -1.6093E+00 -1.2201E-01 1.8394E-02 -3.2984E-02 1.2357E-02 -1.0253E-02 1.6463E-03 0.0000E+00 0.0000E+00 S6 4.2211E-03 -1.3171E-02 -1.4171E-03 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00

[0079] Table 2

[0080] Example 2

[0081] The following reference Figure 3 Describe the visual system according to Example 2 of the present application.

[0082] like Figure 3As shown, the visual system may include a lens barrel P0 and an optical element group placed in the lens barrel P0, the optical element group including a first lens E1, a reflective polarizing element RP, a quarter wave plate QWP, a second lens E2 and a third lens E3 arranged in sequence from the first side to the second side along the optical axis. A stop STO (not shown) may be provided between the first side and the first lens E1. A second side of the third lens E3 may be provided with a partial reflection layer BS (not shown). The visual system also includes a lens barrel auxiliary spacer P0b, a first spacer P1 and a second spacer P2 placed in the lens barrel P0.

[0083] The structure of the optical element group of this embodiment is the same as that of the optical element group of embodiment 1, that is, the basic parameter table of the visual system of this embodiment is the same as Table 1, and the aspheric coefficient table is the same as Table 2. The difference between this embodiment and embodiment 1 is that the structural dimensions of the lens barrel P0, the lens barrel auxiliary spacer P0b, the first spacer P1, and the second spacer P2 are different. For example, the parameters such as d1s, d1m, D1m, d2s, d2m, D2s, D2m, d0s, d0m, D0s, D0m, d0bs, d0bm, D0bs, D0bm, CP0b, CP1, EP12, CP2 and L are different.

[0084] Figure 4A The axial chromatic aberration curves of the visual systems of Examples 1 and 2 are shown, which indicate the deviation of the focal point of light of different wavelengths after passing through the visual system. Figure 4B The astigmatism curves of the visual systems of Examples 1 and 2 are shown, which represent the meridional image plane curvature and sagittal image plane curvature corresponding to different field angles. Figure 4C The distortion curves of the visual systems of Examples 1 and 2 are shown, which represent the distortion values ​​corresponding to different field angles. FIG. 4A to FIG. 4C It can be seen that the visual systems provided in Examples 1 and 2 can achieve good imaging quality.

[0085] Example 3

[0086] The following reference Figure 5 Describe the visual system according to Example 3 of the present application.

[0087] like Figure 5As shown, the visual system may include a lens barrel P0 and an optical element group placed in the lens barrel P0, and the optical element group includes a first lens E1, a reflective polarizing element RP, a quarter wave plate QWP, a second lens E2, and a third lens E3 arranged in sequence from the first side to the second side along the optical axis. A stop STO (not shown) may also be provided between the first side and the first lens E1. The second side of the third lens E3 may also be provided with a partial reflection layer BS (not shown). The visual system may also include a lens barrel auxiliary spacer P0b, a first spacer P1, and a second spacer P2 placed in the lens barrel P0. In the present embodiment, the first side refers to the human eye side, and the second side refers to the display screen side. The first side of each element (the first lens E1, the second lens E2, the third lens E3, the reflective polarizing element RP, and the quarter wave plate QWP) is referred to as the near human eye side, and the second side is referred to as the near screen side.

[0088] The first lens E1 has positive focal power, and its side surface S1 near the human eye is convex, and its side surface S2 near the screen is flat. The reflective polarizer RP has a side surface near the human eye and a side surface near the screen, and the side surface near the human eye of the reflective polarizer RP is attached to the side surface S2 near the screen of the first lens E1. The quarter-wave plate QWP has a side surface near the human eye and a side surface near the screen, and its side surface near the human eye is attached to the side surface near the screen of the reflective polarizer RP. The second lens E2 has positive focal power, and its side surface S3 near the human eye is convex, and its side surface S4 near the screen is concave. The third lens E3 has positive focal power, and its side surface S5 near the human eye is convex, and its side surface S6 near the screen is convex. The partial reflection layer BS can be attached to the side surface S6 near the screen of the third lens E3.

[0089] In this example, an image surface IMG may be provided on the second side of the visual system, and the image surface IMG may be provided with a display screen, for example. After the image light from the image surface IMG passes through the third lens E3, the second lens E2, the quarter-wave plate QWP in sequence and reaches the reflective polarizing element RP located on the near-screen side of the first lens E1, a first reflection occurs at the reflective polarizing element RP. After the light reflected for the first time passes through the quarter-wave plate QWP, the second lens E2, the third lens E3 and reaches the partially reflective layer BS located on the near-screen side S6 of the third lens E3, a second reflection occurs at the partially reflective layer BS. The light reflected for the second time passes through the third lens E3, the second lens E2, the quarter-wave plate QWP, the reflective polarizing element RP, the first lens E1 in sequence and is finally projected onto a target object (not shown) in space. For example, the light of the visual system after two reflections is finally projected into the eyes of the user.

[0090] Table 3 shows the basic parameters of the visual system of Example 3, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm). The image light from the image surface IMG passes through the components in the order of sequence number 19 to sequence number 1 and is finally projected into the human eye.

[0091]

[0092]

[0093] Table 3

[0094] In this embodiment, the first side surface S1 of the first lens E1, the first side surface S3 and the second side surface S4 of the second lens E2, and the first side surface S5 and the second side surface S6 of the third lens E3 are all aspherical surfaces. Table 4 lists the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A36, A37, A38, A39, A40, A41, A42, A43, A44, A45, A46, A47, A48, A49, A50, A51, A 10 , A 12 , A 14 , A 16 , A 18 and A 20 .

[0095] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S1 -7.7832E-02 -8.0278E-02 -4.4280E-02 1.4286E-02 -4.7680E-03 -5.9445E-04 -3.2749E-04 0.0000E+00 0.0000E+00 S3 -5.2647E-01 1.7378E-02 1.4687E-03 -5.6363E-04 -5.7278E-03 -2.4342E-03 4.0963E-04 0.0000E+00 0.0000E+00 S4 -2.6318E-01 1.4742E-01 -2.4382E-01 4.3098E-02 -4.1613E-03 -1.4102E-02 3.0397E-03 0.0000E+00 0.0000E+00 S5 -6.2284E-01 1.6363E-01 -1.1425E-01 1.3515E-02 6.2756E-03 -5.2626E-03 1.3959E-03 0.0000E+00 0.0000E+00 S6 6.3214E-03 -1.1485E-02 -1.2245E-03 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00

[0096] Table 4

[0097] Example 4

[0098] The following reference Figure 6 Describe the visual system according to Example 4 of the present application.

[0099] like Figure 6 As shown, the visual system may include a lens barrel P0 and an optical element group placed in the lens barrel P0, the optical element group including a first lens E1, a reflective polarizing element RP, a quarter wave plate QWP, a second lens E2 and a third lens E3 arranged in sequence from the first side to the second side along the optical axis. A stop STO (not shown) may be provided between the first side and the first lens E1. A second side of the third lens E3 may be provided with a partial reflection layer BS (not shown). The visual system also includes a lens barrel auxiliary spacer P0b, a first spacer P1 and a second spacer P2 placed in the lens barrel P0.

[0100] The structure of the optical element group of this embodiment is the same as that of the optical element group of embodiment 3, that is, the basic parameter table of the visual system of this embodiment is the same as that of table 3, and the aspheric coefficient table is the same as that of table 4. The difference between this embodiment and embodiment 3 is that the structure dimensions of the lens barrel P0, the lens barrel auxiliary spacer P0b, the first spacer P1, and the second spacer P2 are different. For example, the parameters such as d1s, d1m, D1m, d2s, d2m, D2s, D2m, d0s, d0m, D0s, D0m, d0bs, d0bm, D0bs, D0bm, CP0b, CP1, EP12, CP2, and L are different.

[0101] Fig. 7A The axial chromatic aberration curves of the visual systems of Examples 3 and 4 are shown, which indicate the deviation of the focal point of light of different wavelengths after passing through the visual system. Figure 7B The astigmatism curves of the visual systems of Examples 3 and 4 are shown, which represent the meridional image plane curvature and sagittal image plane curvature corresponding to different field angles. Figure 7C The distortion curves of the visual systems of Examples 3 and 4 are shown, which represent the distortion values ​​corresponding to different field angles. FIG. 7A to FIG. 7C It can be seen that the visual systems provided in Examples 3 and 4 can achieve good imaging quality.

[0102] Example 5

[0103] The following reference Figure 8 Describe the visual system according to Example 5 of the present application.

[0104] like Figure 8 As shown, the visual system may include a lens barrel P0 and an optical element group placed in the lens barrel P0, and the optical element group includes a first lens E1, a reflective polarizing element RP, a quarter wave plate QWP, a second lens E2, and a third lens E3 arranged in sequence from the first side to the second side along the optical axis. A stop STO (not shown) may also be provided between the first side and the first lens E1. The second side of the third lens E3 may also be provided with a partial reflection layer BS (not shown). The visual system may also include a lens barrel auxiliary spacer P0b, a first spacer P1, and a second spacer P2 placed in the lens barrel P0. In the present embodiment, the first side refers to the human eye side, and the second side refers to the display screen side. The first side of each element (the first lens E1, the second lens E2, the third lens E3, the reflective polarizing element RP, and the quarter wave plate QWP) is referred to as the near human eye side, and the second side is referred to as the near screen side.

[0105] The first lens E1 has negative focal power, and its side surface S1 near the human eye is concave, and its side surface S2 near the screen is convex. The reflective polarizer RP has a side surface near the human eye and a side surface near the screen, and the side surface near the human eye of the reflective polarizer RP is attached to the side surface S2 near the screen of the first lens E1. The quarter-wave plate QWP has a side surface near the human eye and a side surface near the screen, and its side surface near the human eye is attached to the side surface near the screen of the reflective polarizer RP. The second lens E2 has positive focal power, and its side surface S3 near the human eye is concave, and its side surface S4 near the screen is convex. The third lens E3 has negative focal power, and its side surface S5 near the human eye is concave, and its side surface S6 near the screen is convex. The partial reflection layer BS can be attached to the side surface S6 near the screen of the third lens E3.

[0106] In this example, an image surface IMG may be provided on the second side of the visual system, and the image surface IMG may be provided with a display screen, for example. After the image light from the image surface IMG passes through the third lens E3, the second lens E2, the quarter-wave plate QWP in sequence and reaches the reflective polarizing element RP located on the near-screen side of the first lens E1, a first reflection occurs at the reflective polarizing element RP. After the light reflected for the first time passes through the quarter-wave plate QWP, the second lens E2, the third lens E3 and reaches the partially reflective layer BS located on the near-screen side S6 of the third lens E3, a second reflection occurs at the partially reflective layer BS. The light reflected for the second time passes through the third lens E3, the second lens E2, the quarter-wave plate QWP, the reflective polarizing element RP, the first lens E1 in sequence and is finally projected onto a target object (not shown) in space. For example, the light of the visual system after two reflections is finally projected into the eyes of the user.

[0107] Table 5 shows the basic parameters of the visual system of Example 5, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm). The image light from the image surface IMG passes through the components in the order of sequence number 19 to sequence number 1 and is finally projected into the human eye.

[0108]

[0109]

[0110] Table 5

[0111] In this embodiment, the first side surface S1 and the second side surface S2 of the first lens E1, the first side surface S3 and the second side surface S4 of the second lens E2, and the first side surface S5 and the second side surface S6 of the third lens E3 are all aspherical surfaces. Table 6 lists the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A36, A37, A38, A39, A40, A41, A42, A43, A44, A45, A46, A47, A48, A49, A50, A51, A52, A53, A54, A55, A56, A57, A58, A59, A60, A61, A71, A72, A73, A74, A75 10 , A 12 , A 14 , A 16 , A18 and A 20 .

[0112] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S1 -1.1242E-01 2.1702E-02 1.8514E-01 -2.8267E-03 1.3801E-02 -1.4578E-02 3.2945E-03 0.0000E+00 0.0000E+00 S2 -5.2829E-02 1.0902E-01 3.1306E-02 6.8431E-03 1.6485E-03 6.1464E-04 -9.2957E-04 0.0000E+00 0.0000E+00 S3 -1.5098E+00 3.4975E-01 -2.2104E-01 4.1582E-02 -5.3277E-02 1.1293E-02 -9.2157E-03 0.0000E+00 0.0000E+00 S4 -3.9932E-01 -3.5499E-02 7.9833E-02 1.7820E-02 3.6225E-02 -4.3785E-03 1.6630E-03 0.0000E+00 0.0000E+00 S5 1.1224E+00 -1.0458E-01 6.5785E-02 -1.9573E-02 2.5698E-02 -3.9078E-03 3.1698E-03 0.0000E+00 0.0000E+00 S6 9.3449E-03 -1.3907E-03 -1.2398E-04 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00

[0113] Table 6

[0114] Example 6

[0115] The following reference Fig. 9 Describe the visual system according to Example 6 of the present application.

[0116] like Fig. 9 As shown, the visual system may include a lens barrel P0 and an optical element group placed in the lens barrel P0, the optical element group including a first lens E1, a reflective polarizing element RP, a quarter wave plate QWP, a second lens E2 and a third lens E3 arranged in sequence from the first side to the second side along the optical axis. A stop STO (not shown) may be provided between the first side and the first lens E1. A second side of the third lens E3 may be provided with a partial reflection layer BS (not shown). The visual system also includes a lens barrel auxiliary spacer P0b, a first spacer P1 and a second spacer P2 placed in the lens barrel P0.

[0117] The structure of the optical element group of this embodiment is the same as that of the optical element group of embodiment 5, that is, the basic parameter table of the visual system of this embodiment is the same as that of table 5, and the aspheric coefficient table is the same as that of table 6. The difference between this embodiment and embodiment 5 is that the structure dimensions of the lens barrel P0, the lens barrel auxiliary spacer P0b, the first spacer P1, and the second spacer P2 are different. For example, the parameters such as d1s, d1m, D1m, d2s, d2m, D2s, D2m, d0s, d0m, D0s, D0m, d0bs, d0bm, D0bs, D0bm, CP0b, CP1, EP12, CP2, and L are different.

[0118] Fig. 10A The axial chromatic aberration curves of the visual systems of Examples 5 and 6 are shown, which indicate the deviation of the focal point of light of different wavelengths after passing through the visual system. Fig. 10B The astigmatism curves of the visual systems of Examples 5 and 6 are shown, which represent the meridional image plane curvature and sagittal image plane curvature corresponding to different field angles. Fig. 10C The distortion curves of the visual systems of Examples 5 and 6 are shown, which represent the distortion values ​​corresponding to different field angles. FIG. 10A to FIG. 10C It can be seen that the visual systems provided in Examples 5 and 6 can achieve good imaging quality.

[0119] Example 7

[0120] The following reference Fig.11 Describe the visual system according to Example 7 of the present application.

[0121] like Fig.11 As shown, the visual system may include a lens barrel P0 and an optical element group placed in the lens barrel P0, and the optical element group includes a first lens E1, a reflective polarizing element RP, a quarter wave plate QWP, a second lens E2, and a third lens E3 arranged in sequence from the first side to the second side along the optical axis. A stop STO (not shown) may also be provided between the first side and the first lens E1. The second side of the third lens E3 may also be provided with a partial reflection layer BS (not shown). The visual system may also include a lens barrel auxiliary spacer P0b, a first spacer P1, and a second spacer P2 placed in the lens barrel P0. In the present embodiment, the first side refers to the human eye side, and the second side refers to the display screen side. The first side of each element (the first lens E1, the second lens E2, the third lens E3, the reflective polarizing element RP, and the quarter wave plate QWP) is referred to as the near human eye side, and the second side is referred to as the near screen side.

[0122] The first lens E1 has positive focal power, and its side surface S1 near the human eye is convex, and its side surface S2 near the screen is convex. The reflective polarizer RP has a side surface near the human eye and a side surface near the screen, and the side surface near the human eye of the reflective polarizer RP is attached to the side surface S2 near the screen of the first lens E1. The quarter-wave plate QWP has a side surface near the human eye and a side surface near the screen, and its side surface near the human eye is attached to the side surface near the screen of the reflective polarizer RP. The second lens E2 has negative focal power, and its side surface S3 near the human eye is concave, and its side surface S4 near the screen is convex. The third lens E3 has positive focal power, and its side surface S5 near the human eye is convex, and its side surface S6 near the screen is convex. The partial reflection layer BS can be attached to the side surface S6 near the screen of the third lens E3.

[0123] In this example, an image surface IMG may be provided on the second side of the visual system, and the image surface IMG may be provided with a display screen, for example. After the image light from the image surface IMG passes through the third lens E3, the second lens E2, the quarter-wave plate QWP in sequence and reaches the reflective polarizing element RP located on the near-screen side of the first lens E1, a first reflection occurs at the reflective polarizing element RP. After the light reflected for the first time passes through the quarter-wave plate QWP, the second lens E2, the third lens E3 and reaches the partially reflective layer BS located on the near-screen side S6 of the third lens E3, a second reflection occurs at the partially reflective layer BS. The light reflected for the second time passes through the third lens E3, the second lens E2, the quarter-wave plate QWP, the reflective polarizing element RP, the first lens E1 in sequence and is finally projected onto a target object (not shown) in space. For example, the light of the visual system after two reflections is finally projected into the eyes of the user.

[0124] Table 7 shows the basic parameters of the visual system of Example 7, where the units of the radius of curvature and thickness / distance are all in millimeters (mm). The image light from the image surface IMG passes through the components in the order of sequence number 19 to sequence number 1 and is finally projected into the human eye.

[0125]

[0126]

[0127] Table 7

[0128] In this embodiment, the first side surfaces and the second side surfaces of the first lens E1 to the third lens E3 are all aspherical surfaces.

[0129] Table 8 shows the high-order coefficients A4, A6, A8, A4, A6, A8, A6, A7, A7, A8, A9, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A 10 , A 12 , A 14 , A 16 , A 18 and A 20 .

[0130] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S1 -2.3507E-01 -7.2111E-02 -4.9613E-02 -5.2795E-04 -7.3031E-03 1.7584E-04 -4.7630E-04 0.0000E+00 0.0000E+00 S2 1.6857E-01 1.5702E-02 1.5198E-03 -6.4110E-04 -2.8373E-03 1.3518E-04 1.1613E-04 0.0000E+00 0.0000E+00 S3 -4.4543E-01 2.4933E-02 -1.3528E-03 2.6530E-03 -7.6516E-03 1.9565E-03 1.7073E-03 0.0000E+00 0.0000E+00 S4 -2.3022E-01 1.5647E-01 -2.4706E-01 3.1457E-02 -3.8328E-04 -9.1639E-03 2.8351E-03 0.0000E+00 0.0000E+00 S5 -6.4525E-01 1.5977E-01 -1.1449E-01 1.5670E-02 6.5357E-03 -4.8091E-03 1.2567E-03 0.0000E+00 0.0000E+00 S6 6.3214E-03 -1.1485E-02 -1.2245E-03 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00

[0131] Table 8

[0132] Example 8

[0133] The following reference Fig.12 Describe the visual system according to Example 8 of the present application.

[0134] like Fig.12 As shown, the visual system may include a lens barrel P0 and an optical element group placed in the lens barrel P0, the optical element group including a first lens E1, a reflective polarizing element RP, a quarter wave plate QWP, a second lens E2 and a third lens E3 arranged in sequence from the first side to the second side along the optical axis. A stop STO (not shown) may be provided between the first side and the first lens E1. A second side of the third lens E3 may be provided with a partial reflection layer BS (not shown). The visual system also includes a lens barrel auxiliary spacer P0b, a first spacer P1 and a second spacer P2 placed in the lens barrel P0.

[0135] The structure of the optical element group of this embodiment is the same as that of the optical element group of embodiment 7, that is, the basic parameter table of the visual system of this embodiment is the same as that of table 7, and the aspheric coefficient table is the same as that of table 8. The difference between this embodiment and embodiment 7 is that the structure dimensions of the lens barrel P0, the lens barrel auxiliary spacer P0b, the first spacer P1, and the second spacer P2 are different. For example, the parameters such as d1s, d1m, D1m, d2s, d2m, D2s, D2m, d0s, d0m, D0s, D0m, d0bs, d0bm, D0bs, D0bm, CP0b, CP1, EP12, CP2, and L are different.

[0136] Fig.13A The axial chromatic aberration curves of the visual systems of Examples 7 and 8 are shown, which indicate the deviation of the focal point of light of different wavelengths after passing through the visual system. Fig. 13B The astigmatism curves of the visual systems of Examples 7 and 8 are shown, which represent the meridional image plane curvature and sagittal image plane curvature corresponding to different field angles. Fig. 13C The distortion curves of the visual systems of Examples 7 and 8 are shown, which represent the distortion values ​​corresponding to different field angles. FIG. 13A to FIG. 13C It can be seen that the visual systems provided in Examples 7 and 8 can achieve good imaging quality.

[0137] Table 9 gives the values ​​of parameters such as fz, f23, f1, f2, f3, EPD, f, etc. of each embodiment in Examples 1 to 8. The units of the parameters listed in Table 9 are all millimeters (mm).

[0138] Parameters / Examples 1 2 3 4 5 6 7 8 fz 113.80 113.80 121.98 121.98 -228.45 -228.45 91.35 91.35 f23 109.20 109.20 77.77 77.77 109.38 109.38 99.38 99.38 f1 113.80 113.80 121.98 121.98 -224.02 -224.02 91.32 91.32 f2 -82.65 -82.65 3289.20 3289.20 56.52 56.52 -452.24 -452.24 f3 48.66 48.66 79.22 79.22 -139.15 -139.15 82.53 82.53 EPD 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 f 15.66 15.66 15.99 15.99 14.39 14.39 15.89 15.89

[0139] Table 9

[0140] Table 10 gives the values ​​of parameters such as d1s, d1m, D1m, d2s, d2m, D2s, D2m, d0s, d0m, D0s, D0m, d0bs, d0bm, D0bs, D0bm, CP0b, CP1, EP12, CP2 and L in each embodiment 1-8. The above parameters can be calculated according to Figure 1 The parameters listed in Table 10 are measured using the marking method shown in the figure, and the units of the parameters listed in Table 10 are all millimeters (mm).

[0141]

[0142]

[0143] Table 10

[0144] In summary, Table 11 shows the values ​​of the conditional expressions of each of Examples 1 to 8.

[0145] Conditional / Example 1 2 3 4 5 6 7 8 (d0bs+D0bs) / |f1| 0.66 0.66 0.66 0.66 0.23 0.23 0.86 0.88 d1s / fz 0.35 0.35 0.33 0.33 -0.11 -0.11 0.43 0.43 f23 / d2s 2.50 2.51 1.78 1.77 3.65 3.66 2.35 2.35 (N2 / N1)×(D1m / d1m) 1.29 1.28 1.08 1.08 1.09 1.09 1.12 1.12 (d0m-d0s) / f 1.10 1.09 0.94 0.93 1.07 1.10 0.82 0.83 D0s / EPD 8.41 8.36 8.99 8.99 6.16 6.10 8.91 8.91 f / L 1.61 1.63 1.70 1.70 1.93 1.93 1.46 1.46 (T12+T23) / EP12 0.19 0.19 0.48 0.54 0.67 0.62 0.28 0.28 D0m / |f3| 1.10 1.10 0.67 0.66 0.29 0.28 0.61 0.61 |R5 / R4| 0.93 0.93 0.77 0.77 1.02 1.02 0.85 0.85 D2m / d2m 1.15 1.14 1.08 1.07 1.21 1.21 1.09 1.09 CT1 / (D0bm-d0bm) 0.62 0.61 0.67 0.66 0.15 0.15 0.89 1.06 D2s / R6 -0.83 -0.82 -0.77 -0.77 -1.68 -1.68 -0.97 -0.97 (CP0b+CP1) / CP2 2.00 2.00 1.84 1.41 2.00 2.00 2.00 2.00

[0146] Table 11

[0147] The present application also provides an optical device, which may be an independent projection device such as a projector, or a projection module integrated in a mobile electronic device such as a virtual reality device. The optical device is equipped with the visual system described above.

[0148] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the utility model involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with the technical features with similar functions disclosed in the present application (but not limited to) by each other.

Claims

1. A visual system, characterized in that: Comprising: An optical element group, including a first lens, a reflective polarizing element, a quarter-wave plate, a second lens, and a third lens arranged in sequence along the optical axis from the first side to the second side; the first lens, the second lens, and the third lens have positive or negative optical powers; A barrel auxiliary spacer, placed on the first side surface of the first lens and in contact with the first side surface of the first lens; A barrel, with the optical element group and the barrel auxiliary spacer placed inside the barrel; Wherein, the total effective focal length f of the visual system and the maximum length L of the barrel in the direction of the optical axis satisfy: 1.4 < f / L < 2.0; and The effective focal length f1 of the first lens, the inner diameter d0bs of the first side surface of the barrel auxiliary spacer, and the outer diameter D0bs of the first side surface of the barrel auxiliary spacer satisfy: 0.2 < (d0bs + D0bs) / |f1| < 0.

9.

2. The visual system according to claim 1, characterized in that: The total effective focal length f of the visual system, the inner diameter d0s of the first side end face of the barrel, and the inner diameter d0m of the second side end face of the barrel satisfy: 0.8 < (d0m - d0s) / f < 1.

2.

3. The visual system according to claim 1, characterized in that: The entrance pupil diameter EPD of the visual system and the outer diameter D0s of the first side end face of the barrel satisfy: 6.0 < D0s / EPD < 9.

0.

4. The visual system according to claim 1, characterized in that: The outer diameter D0m of the second side end face of the barrel and the effective focal length f3 of the third lens satisfy: 0.2 < D0m / |f3| < 1.

2.

5. The visual system according to claim 1, characterized in that: The central thickness CT1 of the first lens on the optical axis, the inner diameter d0bm of the second side surface of the barrel auxiliary spacer, and the outer diameter D0bm of the second side surface of the barrel auxiliary spacer satisfy: 0.1 < CT1 / (D0bm - d0bm) < 1.

1.

6. The visual system according to any one of claims 1 to 5, characterized in that: The visual system further includes a first spacer placed between the first lens and the second lens; Wherein, the combined focal length fz of the first lens, the reflective polarizing element, and the quarter-wave plate and the inner diameter d1s of the first side surface of the first spacer satisfy: -0.2 < d1s / fz < 0.

5.

7. The visual system according to any one of claims 1 to 5, characterized in that: The visual system further includes a first spacer placed between the first lens and the second lens; Wherein, the refractive index N1 of the first lens, the refractive index N2 of the second lens, the inner diameter d1m of the second side surface of the first spacer, and the outer diameter D1m of the second side surface of the first spacer satisfy: 1.0 < (N2 / N1)×(D1m / d1m) < 1.

4.

8. The visual system according to any one of claims 1 to 5, characterized in that: The visual system further includes a second spacer placed between the second lens and the third lens; Wherein, the combined focal length f23 of the second lens and the third lens and the inner diameter d2s of the first side surface of the second spacer satisfy: 1.7 < f23 / d2s < 3.

7.

9. The visual system according to any one of claims 1 to 5, characterized in that: The visual system further includes a second spacer placed between the second lens and the third lens; The curvature radius R4 of the second side surface of the second lens and the curvature radius R5 of the first side surface of the third lens satisfy: 0.7<|R5 / R4|<1.1; the inner diameter d2m of the second side surface of the second spacer and the outer diameter D2m of the second side surface of the second spacer satisfy: 1.0 <D2m / d2m<1.3。 10. The visual system according to any one of claims 1 to 5, characterized in that: The visual system further includes a second spacer disposed between the second lens and the third lens; The curvature radius R6 of the second side surface of the third lens and the outer diameter D2s of the first side surface of the second spacer satisfy: -1.7 <D2s / R6<-0.7。 11. The visual system according to any one of claims 1 to 5, characterized in that: The visual system further includes a first spacer disposed between the first lens and the second lens and a second spacer disposed between the second lens and the third lens; Among them, the on-axis distance T12 from the second side surface of the first lens to the first side surface of the second lens, the on-axis distance T23 from the second side surface of the second lens to the first side surface of the third lens, and the interval EP12 between the first spacer and the second spacer along the optical axis satisfy: 0.1<(T12+T23) / EP12<0.

7.

12. The visual system according to any one of claims 1 to 5, characterized in that: The visual system further includes a first spacer disposed between the first lens and the second lens and a second spacer disposed between the second lens and the third lens; The maximum thickness CP0b of the lens barrel auxiliary spacer, the maximum thickness CP1 of the first spacer, and the maximum thickness CP2 of the second spacer satisfy: 1.4<(CP0b+CP1) / CP2<2.1.

Images