Visual system and VR device comprising the same

Abstract

The application discloses a visual system, comprising a lens barrel and a first element group and a second element group arranged in sequence from a first side to a second side along an optical axis in the lens barrel, wherein the first element group has positive focal power and comprises a reflective polarizing element, a quarter-wave plate and a first lens; the second element group comprises a second lens having positive focal power or negative focal power; and a first spacing element is arranged between the first element group and the second element group and abuts against a second side surface of the first lens. An effective focal length FG1 of the first element group, a central thickness CT1 of the first lens along the optical axis, a central thickness CTQ of the quarter-wave plate along the optical axis and a distance EP01 from a first side end surface of the lens barrel to a first side surface of the first spacing element along the optical axis satisfy 0.8<FG1 / (CT1+CTQ+EP01)<2.0.

Description

Technical Field

[0001] This application relates to the field of optical components, and more specifically, to a visual system and a VR device including the visual system. Background Technology

[0002] Virtual reality (VR) technology is a novel and practical technology that emerged in the 20th century, finding applications in various fields such as gaming, video, live streaming, education, and healthcare. VR technology can calculate and generate simulated real-world environments, using an imaging system to project virtual images into the user's eyes, thus immersing the user in that environment. Therefore, the imaging system within a VR system is particularly crucial.

[0003] However, the aspherical or Fresnel lenses in conventional imaging systems are relatively large, making it difficult for users to have a good experience. To address this, those skilled in the art are dedicated to developing an optical system that, through the rational design of the parameters and structural forms of the various optical components constituting the system, such as lenses, spacers, and lens barrels, can achieve optical path reflection, reduce the system's size and height, and simultaneously significantly improve image quality. This would allow users to be more immersed in virtual reality environments and enhance their experience when using VR systems. Summary of the Invention

[0004] This application provides a visual system, which may include a lens barrel and a first element group and a second element group arranged sequentially along the optical axis from a first side to a second side, assembled within the lens barrel. The first element group has positive optical power and includes a reflective polarizing element, a quarter-wave plate, and a first lens. The second element group includes a second lens, which has either positive or negative optical power. A first spacer element is provided between the first element group and the second element group, and the first spacer element abuts against a second side surface of the first lens. The effective focal length FG1 of the first element group, the center thickness CT1 of the first lens along the optical axis, the center thickness CTQ of the quarter-wave plate along the optical axis, and the distance EP01 from the first side surface of the lens barrel to the first side surface of the first spacer element along the optical axis can satisfy: 0.8. <FG1 / (CT1+CTQ+EP01)<2.0。

[0005] In one embodiment, the inner diameter d0m of the second side end face of the lens barrel and the radius of curvature R4 of the second side surface of the second lens can satisfy: 0.6 <d0m / |R4|<1.4。

[0006] In one embodiment, a first auxiliary spacer element is provided between the first spacer element and the second lens, and the first auxiliary spacer element abuts against the second side surface of the first spacer element. The effective focal length f of the visual system, the outer diameter D1bs of the first side surface of the first auxiliary spacer element, and the inner diameter d1bs of the first side surface of the first auxiliary spacer element can satisfy: 2.2 <f / (D1bs-d1bs)<8.9。

[0007] In one embodiment, the air gap T12 between the first lens and the second lens on the optical axis, the center thickness CT2 of the second lens on the optical axis, the outer diameter D1s of the first side of the first spacer element, and the inner diameter d1s of the first side of the first spacer element can satisfy: 0.8 < (T12 + CT2) / (D1s - d1s) < 4.5.

[0008] In one embodiment, the effective focal length FG2 of the second element group, the inner diameter d1bm of the second side of the first auxiliary spacer element, and the outer diameter D1bm of the second side of the first auxiliary spacer element can satisfy: 1.1 < |FG2| / (d1bm+D1bm) < 3.1.

[0009] In one embodiment, the effective focal length FG1 of the first element group, the outer diameter D1m of the second side of the first spacer element, and the inner diameter d1m of the second side of the first spacer element can satisfy: 2.1 <FG1 / (D1m-d1m)<7.7。

[0010] In one embodiment, the outer diameter D0s of the first side end face of the lens barrel, the inner diameter d0s of the first side end face of the lens barrel, and the entrance pupil diameter EPD of the visual system can satisfy: 0.4 < (D0s - d0s) / EPD < 3.0.

[0011] In one embodiment, the distance TD between the first side surface of the first lens and the second side surface of the second lens along the optical axis, the maximum thickness CP1 of the first spacer element along the optical axis, and the maximum thickness CP1b of the first auxiliary spacer element along the optical axis can satisfy: 2.6 <TD / (CP1+CP1b)<5.0。

[0012] In one embodiment, the effective focal length FG2 of the second element group and the outer diameter D0m of the second side end face of the lens barrel can satisfy: 1.8 < |FG2| / D0m < 5.4.

[0013] In one embodiment, the maximum height L of the lens barrel along the optical axis direction, the central thickness CT1 of the first lens on the optical axis, and the central thickness CT2 of the second lens on the optical axis may satisfy: 1.1 < L / (CT1 + CT2) < 1.7.

[0014] In one embodiment, the central thickness CTR of the reflective polarizing element on the optical axis, the central thickness CTQ of the quarter-wave plate on the optical axis, the central thickness CT1 of the first lens on the optical axis, the distance EP01 along the optical axis from the first side end face of the lens barrel to the first side face of the first spacer element, and the effective focal length f of the visual system may satisfy: 0.5 < (CTR + CTQ + CT1 + EP01) / f < 1.1.

[0015] On the other hand, the present application also provides a VR device, which includes the visual system provided by at least one of the above various embodiments. Among them, the first side is the human eye side, and the second side is the display side.

[0016] The visual system disclosed in the present application includes a first element group and a second element group arranged in sequence along the optical axis from the first side to the second side and assembled in the lens barrel. Among them, the first element group has a positive optical power and includes a reflective polarizing element, a quarter-wave plate, and a first lens; the second element group includes a second lens with optical power; and there is a first spacer element abutted against the second side face of the first lens between the first element group and the second element group; at the same time, controlling the effective focal length FG1 of the first element group, the central thickness CT1 of the first lens on the optical axis, the central thickness CTQ of the quarter-wave plate on the optical axis, and the distance EP01 along the optical axis from the first side end face of the lens barrel to the first side face of the first spacer element satisfies the conditional formula 0.8 < FG1 / (CT1 + CTQ + EP01) < 2.0. This setting of the visual system disclosed in the present application can be conducive to controlling the shape of the first lens, thereby facilitating the compression of the overall height of the lens group, making the entire lens group more compact, and facilitating miniaturization design. Description of the Drawings

[0017] Combined with the drawings, through the following detailed description of non-limiting embodiments, other features, purposes, and advantages of the present application will become more obvious. In the drawings:

[0018] Figure 1 Shows a schematic diagram of the structure and partial parameters of the visual system according to an exemplary embodiment of the present application;

[0019] Figure 2 Figure 3 and Figure 4 Respectively show schematic diagrams of the structure of the visual system according to Embodiment 1 of the present application under three embodiments;​

[0020] Figure 5 , Figure 6 and Figure 7 The on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the visual system of Example 1 are shown respectively.

[0021] Figure 8 , Figure 9 and Figure 10 Schematic diagrams of the visual system according to Embodiment 2 of this application are shown in three different implementations.

[0022] Figure 11 , Figure 12 and Figure 13 The on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the visual system of Example 2 are shown respectively.

[0023] Figure 14 , Figure 15 and Figure 16 Schematic diagrams of the visual system according to Embodiment 3 of this application are shown in three different implementations; and

[0024] Figure 17 , Figure 18 and Figure 19 The on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the visual system of Example 3 are shown respectively. Detailed Implementation

[0025] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0026] 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.

[0027] 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.

[0028] In this paper, 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.

[0029] 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.

[0030] 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 a meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formalized sense, unless expressly so specified herein.

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other. The following embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this application. It should be pointed out that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0032] The features, principles and other aspects of this application are described in detail below.

[0033] A visual system according to an exemplary embodiment of this application may include a lens barrel and a first lens group and a second lens group arranged sequentially along the optical axis from a first side to a second side, mounted within the lens barrel.

[0034] In an exemplary embodiment, the first element group may have positive optical power. The first element group may include a reflective polarizing element, a quarter-wave plate, and a first lens.

[0035] In an exemplary embodiment, the second element group may include a second lens. The second lens may have positive or negative optical power.

[0036] In an exemplary embodiment, the visual system may further include a first spacer element located between the first element group and the second element group. The first spacer element may abut against the second side surface of the first lens in the first element group, that is, the first side surface of the first spacer element and the second side surface of the first lens may be at least partially in contact. For each element in the visual system, the surface close to the first side and away from the second side is the first side surface of the element, and the surface close to the second side and away from the first side is the second side surface of the element.

[0037] In an exemplary embodiment, the first side may be, for example, the human eye side, and the second side may be, for example, the display side. The visual system may be used, for example, in a variety of VR display devices.

[0038] In an exemplary embodiment, the visual system of the present application may satisfy the conditional expression 0.8 < FG1 / (CT1 + CTQ + EP01) < 2.0, where FG1 is the effective focal length of the first element group, CT1 is the central thickness of the first lens on the optical axis, CTQ is the central thickness of the quarter-wave plate on the optical axis, and EP01 is the distance along the optical axis from the first side end surface of the lens barrel (i.e., the end surface or surface of the lens barrel closest to the first side) to the first side surface of the first spacer element. By controlling the effective focal length of the first element group, the central thickness of the first lens on the optical axis, the central thickness of the quarter-wave plate on the optical axis, and the distance along the optical axis from the first side end surface of the lens barrel to the first side surface of the first spacer element to satisfy the conditional expression 0.8 < FG1 / (CT1 + CTQ + EP01) < 2.0, it is beneficial to reasonably control the shape of the first lens, thereby facilitating the compression of the overall height of the lens group, making the entire lens group more compact, and being beneficial to miniaturization design.

[0039] In an exemplary embodiment, the visual system of the present application may satisfy the conditional expression 0.6 < d0m / |R4| < 1.4, where d0m is the inner diameter of the second side end surface of the lens barrel (i.e., the end surface or surface of the lens barrel closest to the second side), and R4 is the radius of curvature of the second side surface of the second lens. By controlling the ratio of the inner diameter of the second side end surface of the lens barrel to the absolute value of the radius of curvature of the second side surface of the second lens within this range, not only can the light passing aperture of the optical system be controlled, effectively restricting the field angle of the system, but also the shape of the second lens can be controlled, which is beneficial to the formation of the second lens group.

[0040] In an exemplary embodiment, the visual system may further include a first auxiliary spacer element located between the first spacer element and the second lens, and the first auxiliary spacer element may abut against the second side surface of the first spacer element, that is, the first side surface of the first auxiliary spacer element and the second side surface of the first spacer element may be at least partially in contact.

[0041] In an exemplary embodiment, the visual system of the present application can satisfy the conditional formula 2.2 < f / (D1bs - d1bs) < 8.9, where f is the effective focal length of the visual system, D1bs is the outer diameter of the first side surface of the first auxiliary spacer element, and d1bs is the inner diameter of the first side surface of the first auxiliary spacer element. By controlling the ratio of the effective focal length of the visual system to the difference between the outer diameter and the inner diameter of the first side surface of the first auxiliary spacer element within this range, the interval between the first lens group and the second lens group in the optical axis direction can be reasonably controlled, which is beneficial to controlling the effective focal length of the visual system and also beneficial to the assembly stability of the first auxiliary spacer element.

[0042] In an exemplary embodiment, the visual system of the present application can satisfy the conditional formula 0.8 < (T12 + CT2) / (D1s - d1s) < 4.5, where T12 is the air interval between the first lens and the second lens on the optical axis, CT2 is the central thickness of the second lens on the optical axis, D1s is the outer diameter of the first side surface of the first spacer element, and d1s is the inner diameter of the first side surface of the first spacer element. By controlling the ratio of the sum of the air interval between the first lens and the second lens on the optical axis and the central thickness of the second lens on the optical axis to the difference between the outer diameter and the inner diameter of the first side surface of the first spacer element within this range, the overall height of the optical elements can be controlled, which is beneficial to the miniaturization of the optical elements. In addition, the light flux in the optical elements can also be controlled simultaneously to keep the system brightness at a reasonable level.

[0043] In an exemplary embodiment, the visual system of the present application can satisfy the conditional formula 1.1 < |FG2| / (d1bm + D1bm) < 3.1, where FG2 is the effective focal length of the second lens group, d1bm is the inner diameter of the second side surface of the first auxiliary spacer element, and D1bm is the outer diameter of the second side surface of the first auxiliary spacer element. By controlling the ratio of the absolute value of the effective focal length of the second lens group to the sum of the inner diameter and the outer diameter of the second side surface of the first auxiliary spacer element within this range, the effective focal length of the optical elements can be reasonably controlled, making the system aberration at a reasonable level. At the same time, the shape of the second lens group can also be reasonably controlled, which is beneficial to system imaging.

[0044] In an exemplary embodiment, the visual system of the present application can satisfy the conditional formula 2.1 < FG1 / (D1m - d1m) < 7.7, where FG1 is the effective focal length of the first element group, D1m is the outer diameter of the second side surface of the first spacer element, and d1m is the inner diameter of the second side surface of the first spacer element. By controlling the ratio of the effective focal length of the first element group to the difference between the outer diameter of the second side surface of the first spacer element and the inner diameter of the second side surface of the first spacer element within this range, the effective focal length of the optical element can be reasonably controlled, the system aberration can be made to be at a reasonable level, and at the same time, the shape of the first element group can be reasonably controlled, which is beneficial to system imaging.

[0045] In an exemplary embodiment, the visual system of the present application can satisfy the conditional formula 0.4 < (D0s - d0s) / EPD < 3.0, where D0s is the outer diameter of the first side end face of the lens barrel, d0s is the inner diameter of the first side end face of the lens barrel, and EPD is the entrance pupil diameter of the visual system. By controlling the ratio of the difference between the outer diameter of the first side end face of the lens barrel and the inner diameter of the first side end face of the lens barrel to the entrance pupil diameter of the visual system within this range, the light passing aperture of the optical system can be controlled to meet ergonomics, which is beneficial to the immersive experience of the VR lens. At the same time, the size of the optical element on the first side (near-eye side) can also be controlled, which is beneficial to the overall machine shape optimization.

[0046] In an exemplary embodiment, the visual system of the present application can satisfy the conditional formula 2.6 < TD / (CP1 + CP1b) < 5.0, where TD is the distance along the optical axis from the first side surface of the first lens to the second side surface of the second lens, CP1 is the maximum thickness of the first spacer element along the optical axis direction, and CP1b is the maximum thickness of the first auxiliary spacer element along the optical axis direction. By controlling the ratio of the distance along the optical axis from the first side surface of the first lens to the second side surface of the second lens to the sum of the maximum thickness of the first spacer element along the optical axis direction and the maximum thickness of the first auxiliary spacer element along the optical axis direction within this range, the shape of the optical element can be controlled, which is beneficial to reducing the reflection of redundant light, avoiding stray light generated by the first spacer element, and improving the imaging level.

[0047] In an exemplary embodiment, the visual system of the present application can satisfy the conditional formula 1.8 < |FG2| / D0m < 5.4, where FG2 is the effective focal length of the second element group, and D0m is the outer diameter of the second side end face of the lens barrel. By controlling the ratio of the absolute value of the effective focal length of the second element group to the outer diameter of the second side end face of the lens barrel within this range, the coma of the lens can be controlled within a reasonable range, the sensitivity of the system can be reduced, and good imaging quality can be obtained.

[0048] In an exemplary embodiment, the visual system of the present application can satisfy the conditional formula 1.1 < L / (CT1 + CT2) < 1.7, where L is the maximum height of the lens barrel along the optical axis direction, that is, the maximum distance along the optical axis from the end face of the lens barrel closest to the first side to the end face of the lens barrel closest to the second side, CT1 is the central thickness of the first lens on the optical axis, and CT2 is the central thickness of the second lens on the optical axis. By controlling the ratio of the maximum height of the lens barrel along the optical axis direction to the sum of the central thicknesses of the first lens and the second lens on the optical axis within this range, the distortion contribution of each field of view of the system can be controlled within a reasonable range, which helps to improve the imaging quality and imaging clarity.

[0049] In an exemplary embodiment, the visual system of the present application can satisfy the conditional formula 0.5 < (CTR + CTQ + CT1 + EP01) / f < 1.1, where CTR is the central thickness of the reflective polarizing element on the optical axis, CTQ is the central thickness of the quarter-wave plate on the optical axis, CT1 is the central thickness of the first lens on the optical axis, EP01 is the distance along the optical axis from the first side end face of the lens barrel to the first side face of the first spacer element, and f is the effective focal length of the visual system. By controlling the ratio of the sum of the central thickness of the reflective polarizing element on the optical axis, the central thickness of the quarter-wave plate on the optical axis, the central thickness of the first lens on the optical axis, and the distance along the optical axis from the first side end face of the lens barrel to the first side face of the first spacer element to the effective focal length of the visual system within this range, the center distance of the optical system can be controlled, and the dispersion amount introduced by the reflective polarizing element and the quarter-wave plate can be reasonably controlled, which is beneficial to the chromatic aberration correction of the system.

[0050] In an exemplary embodiment, the visual system of the present application may include at least one aperture stop. The aperture stop can restrict the light path and control the light intensity. The aperture stop can be set at an appropriate position in the visual system as needed. For example, the aperture stop can be set between the first side (the human eye side) and the first lens.

[0051] In an exemplary embodiment, optionally, the above visual system may further include a filter for correcting color deviation and / or a protective glass for protecting the photosensitive element located on the imaging surface.

[0052] The visual system according to the above-described embodiment of the present application is configured by providing a first element group and a second element group that are assembled in a lens barrel and arranged in sequence along the optical axis from the first side to the second side. Among them, the first element group has a positive optical power and includes a reflective polarizing element, a quarter-wave plate, and a first lens; the second element group includes a second lens having an optical power; and there is a first spacer element disposed against the second side surface of the first lens between the first element group and the second element group. At the same time, controlling the effective focal length FG1 of the first element group, the central thickness CT1 of the first lens on the optical axis, the central thickness CTQ of the quarter-wave plate on the optical axis, and the distance EP01 along the optical axis from the first side end surface of the lens barrel to the first side surface of the first spacer element satisfies the conditional expression 0.8 < FG1 / (CT1 + CTQ + EP01) < 2.0. This can facilitate controlling the shape of the first lens, thereby facilitating compressing the overall height of the lens group, making the entire lens group more compact, and being conducive to miniaturized design.

[0053] In addition, for the visual system according to some embodiments of the present application, by reasonably setting the inner and outer diameters of the lens barrel end surface, the curvature radii, central thicknesses of the lenses, and the inner and outer diameters, maximum thicknesses of the spacer elements, and the central thicknesses of the reflective polarizing element and the quarter-wave plate, etc., and reasonably setting the on-axis distance from the first side end surface of the lens barrel to the first spacer element, the maximum thickness of the lens barrel, and the effective focal lengths of the first element group, the second element group, and the system, etc., the light passing aperture of the optical system can be controlled, effectively restricting the field angle of the system; the system brightness can be made to be at a reasonable level, the system aberrations, the coma of the lens, and the distortion contribution amounts of each field can be controlled to be at a reasonable level, reducing the sensitivity of the system, while being conducive to correcting the chromatic aberration of the system, and being conducive to reducing the reflection of redundant light, reducing stray light, and being conducive to obtaining good imaging quality and improving imaging clarity. Moreover, the shape of the lens can be reasonably controlled, which is beneficial for lens molding; beneficial for the standing stability of the element group; and the overall height and size of the optical elements can also be controlled, which is beneficial for the miniaturization of the optical elements and the optimization of the overall machine appearance, and is beneficial for the immersive experience of VR lenses.

[0054] The following further describes specific embodiments of the visual system applicable to the above-described embodiments with reference to the accompanying drawings.

[0055] Example 1

[0056] The following refers to Figure 2 、 Figure 3 、 Figure 4 and Figure 5 [[ID=二十]] Figure 6 and Figure 7 describe the visual system according to Embodiment 1 of the present application. Figure 2 、 Figure 3 and Figure 4 ​The diagrams show the structure of the visual system according to Embodiment 1 of this application under three different implementations (Implementation 1-1, Implementation 1-2, and Implementation 1-3).

[0057] like Figure 2 , Figure 3 and Figure 4 As shown, the visual system includes a lens barrel and, mounted in the lens barrel, the following components arranged sequentially along the optical axis from the first side (eye side) to the second side (display side): a reflective polarizing element RP, a quarter-wave plate QWP, a first lens E1, a second lens E2, and an image surface IMG.

[0058] In this embodiment, the reflective polarizing element RP, the quarter-wave plate QWP, and the first lens E1 constitute a first element group. Specifically, the second side surface of the quarter-wave plate QWP (the surface closer to the display and farther from the human eye) is attached to the first side surface of the first lens E1 (the surface closer to the human eye and farther from the display), and the second side surface of the reflective polarizing element RP (the surface closer to the display and farther from the human eye) is attached to the first side surface of the quarter-wave plate QWP (the surface closer to the human eye and farther from the display). The first element group has positive optical power.

[0059] In this embodiment, the visual system further includes a first spacer element P1 located between the first lens E1 and the second lens E2, the first spacer element P1 abutting against the second side surface of the first lens E1 (the surface near the display side and away from the human eye side); and a first auxiliary spacer element P1b located between the first spacer element P1 and the second lens E2, the first auxiliary spacer element P1b abutting against the second side surface of the first spacer element P1 (the surface near the display side and away from the human eye side).

[0060] Table 1 shows the basic parameters of the visual system of Example 1, where the units for radius of curvature and thickness / distance are millimeters (mm).

[0061]

[0062]

[0063] Table 1

[0064] In Embodiment 1, the first side surface S4 and the second side surface S5 of the first lens E1 and the first side surface S10 and the second side surface S11 of the second lens E2 are both aspherical surfaces. The surface shape x of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0065]

[0066] Where x is the distance vector from the vertex of the aspherical surface at a height of h along the optical axis; c is the paraxial curvature of the aspherical surface, c = 1 / R (i.e., the paraxial curvature c is the reciprocal of the radius of curvature R in Table 1 above); k is the conic coefficient; Ai is the i-th order correction coefficient of the aspherical surface. Table 2 below gives the higher-order coefficients A4, A6, A8, A10, and A11 that can be used for the aspherical mirrors S4, S5, S10, and S11 in Example 1. 10 A 12 A 14 A 16 A 18 and A 20 .

[0067] coefficient\surface S4 S5 S10 S11 A4 0.0000E+00 -3.5187E-01 6.9425E+00 2.4897E+00 A6 0.0000E+00 -8.9789E-02 2.4219E+00 2.0385E+00 A8 0.0000E+00 1.4029E-01 -1.7918E+00 -5.7084E-01 A10 0.0000E+00 -8.1792E-02 4.2250E-02 -2.0160E-01 A12 0.0000E+00 2.5406E-02 4.5085E-02 3.4862E-01 A14 0.0000E+00 -1.8357E-03 1.8781E-01 2.5312E-01 A16 0.0000E+00 0.0000E+00 3.5819E-01 1.0232E+00 A18 0.0000E+00 0.0000E+00 -3.1589E-01 1.3885E-01 A20 0.0000E+00 0.0000E+00 6.4461E-02 3.4558E-01

[0068] Table 2

[0069] The relevant parameter values ​​in this embodiment are shown in Table 7, combined with... Figure 2 , Figure 3 , Figure 4 as well as Figure 1 Wherein, d1s is the inner diameter of the first side of the first spacer element P1; d1m is the inner diameter of the second side of the first spacer element P1; D1s is the outer diameter of the first side of the first spacer element P1; D1m is the outer diameter of the second side of the first spacer element P1; d1bs is the inner diameter of the first side of the first auxiliary spacer element P1b; d1bm is the inner diameter of the second side of the first auxiliary spacer element P1b; D1bs is the outer diameter of the first side of the first auxiliary spacer element P1b; D1bm is the outer diameter of the first auxiliary spacer element P1b. The outer diameter of the second side surface of P1b; d0s is the inner diameter of the first side end face of the lens barrel; d0m is the inner diameter of the second side end face of the lens barrel; D0s is the outer diameter of the first side end face of the lens barrel; D0m is the outer diameter of the second side end face of the lens barrel; EP01 is the distance along the optical axis from the first side end face of the lens barrel to the first side surface of the first spacer element P1; CP1 is the maximum thickness of the first spacer element P1 along the optical axis; CP1b is the maximum thickness of the first auxiliary spacer element P1b along the optical axis; and L is the maximum height of the lens barrel along the optical axis. All parameters shown in Table 7 are in millimeters (mm).

[0070] Figure 5 An on-axis chromatic aberration curve of the visual system of Embodiment 1 is shown, which represents the deviation of the convergence focal point of light of different wavelengths after passing through the lens. Figure 6 The astigmatic curves of the visual system of Embodiment 1 are shown, representing the meridional image plane curvature and the sagittal image plane curvature. Figure 7 The distortion curves of the visual system of Embodiment 1 are shown, representing the distortion magnitude values ​​corresponding to different field of view angles. According to... Figures 5 to 7It can be seen that the visual system given in Example 1 can achieve good imaging quality.

[0071] Example 2

[0072] The following is for reference Figure 8 , Figure 9 , Figure 10 as well as Figure 11 , Figure 12 and Figure 13 A visual system according to Embodiment 2 of this application is described. In this embodiment and the following embodiments, for the sake of brevity, descriptions similar to those in Embodiment 1 will be omitted. Figure 8 , Figure 9 and Figure 10 The diagrams show the structure of the visual system according to Embodiment 2 of this application under three different implementations (Implementation 2-1, Implementation 2-2, and Implementation 2-3).

[0073] like Figure 8 , Figure 9 and Figure 10 As shown, the visual system includes a lens barrel and, mounted in the lens barrel, the following components arranged sequentially along the optical axis from the first side (eye side) to the second side (display side): a reflective polarizing element RP, a quarter-wave plate QWP, a first lens E1, a second lens E2, and an image surface IMG.

[0074] In this embodiment, the reflective polarizing element RP, the quarter-wave plate QWP, and the first lens E1 constitute a first element group. Specifically, the second side surface of the quarter-wave plate QWP (the surface closer to the display and farther from the human eye) is attached to the first side surface of the first lens E1 (the surface closer to the human eye and farther from the display), and the second side surface of the reflective polarizing element RP (the surface closer to the display and farther from the human eye) is attached to the first side surface of the quarter-wave plate QWP (the surface closer to the human eye and farther from the display). The first element group has positive optical power.

[0075] In this embodiment, the visual system further includes a first spacer element P1 located between the first lens E1 and the second lens E2, the first spacer element P1 abutting against the second side surface of the first lens E1 (the surface near the display side and away from the human eye side); and a first auxiliary spacer element P1b located between the first spacer element P1 and the second lens E2, the first auxiliary spacer element P1b abutting against the second side surface of the first spacer element P1 (the surface near the display side and away from the human eye side).

[0076] Table 3 shows the basic parameters of the visual system of Embodiment 2, where the units for radius of curvature and thickness / distance are millimeters (mm). In this embodiment, the first side surface S4 of the first lens E1 and the second side surface S11 of the second lens E2 are aspherical. Table 4 shows the higher-order coefficients A4, A6, A8, and A11 that can be used for the aspherical mirrors S4 and S11 in Embodiment 2. 10 A 12 A 14 A 16 A 18 and A 20 Each aspherical surface shape can be defined by formula (1) given in Example 1 above.

[0077] surface Surface type radius of curvature thickness Refractive index Dispersion coefficient Refraction / Reflection S0 spherical endless endless refraction S1 spherical endless 15.0000 refraction S2 aspherical 94.3701 0.2000 1.50 57.00 refraction S3 aspherical 94.3701 0.2000 1.50 57.00 refraction S4 aspherical 94.3701 13.7200 1.54 56.05 refraction S5 spherical endless -13.7200 1.54 56.05 reflection S6 aspherical 94.3701 -0.2000 1.50 57.00 refraction S7 aspherical 94.3701 0.2000 1.50 57.00 reflection S8 aspherical 94.3701 13.7200 1.54 56.05 refraction S9 spherical endless 7.0476 refraction S10 spherical endless 9.6717 1.54 56.05 refraction S11 aspherical -65.1340 0.1000 refraction S12 spherical endless 0.0000 refraction S13 spherical endless 3.0322 refraction S14 spherical endless 0.0000 refraction

[0078] Table 3

[0079] coefficient\surface S4 S11 A4 -5.4467E-07 -5.0599E-01 A6 1.9270E-10 -2.5871E+00 A8 -1.4347E-13 1.4475E+00 A10 2.9316E-18 -1.0359E+00 A12 1.4951E-20 1.0811E+00 A14 0.0000E+00 -3.9508E-01 A16 0.0000E+00 5.1408E-01 A18 0.0000E+00 -5.2743E-02 A20 0.0000E+00 1.5517E-01

[0080] Table 4

[0081] The relevant parameter values ​​in Example 2 are shown in Table 7. The meaning of each parameter is as described above and will not be repeated here. The unit of each parameter in Table 7 is millimeters (mm).

[0082] Figure 11 The on-axis chromatic aberration curve of the visual system of Embodiment 2 is shown, which represents the deviation of the convergence focal point of light of different wavelengths after passing through the lens. Figure 12 The astigmatic curves of the visual system of Embodiment 2 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 13 The distortion curves of the visual system in Example 2 are shown, representing the distortion magnitude values ​​corresponding to different field of view angles. According to... Figures 11 to 13 It can be seen that the visual system given in Example 2 can achieve good imaging quality.

[0083] Example 3

[0084] The following is for reference Figure 14 , Figure 15 , Figure 16 as well as Figure 17 , Figure 18 and Figure 19 A visual system according to Embodiment 3 of this application is described. Figure 14 , Figure 15 and Figure 16 The diagrams show the structure of the visual system according to Embodiment 3 of this application under three different implementations (Implementation 3-1, Implementation 3-2, and Implementation 3-3).

[0085] like Figure 14, Figure 15 and Figure 16 As shown, the visual system includes a lens barrel and, mounted in the lens barrel, the following components arranged sequentially along the optical axis from the first side (human eye side) to the second side (display side): a reflective polarizing element RP, a first lens E1, a quarter-wave plate QWP, a second lens E2, and an image surface IMG.

[0086] In this embodiment, the reflective polarizing element RP, the first lens E1, and the quarter-wave plate QWP constitute a first element group. Specifically, the second side surface of the reflective polarizing element RP (the surface closer to the display and farther from the human eye) is attached to the first side surface of the first lens E1 (the surface closer to the human eye and farther from the display), and the first side surface of the quarter-wave plate QWP (the surface closer to the human eye and farther from the display) is attached to the second side surface of the first lens E1 (the surface closer to the display and farther from the human eye). The first element group has positive optical power.

[0087] In this embodiment, the visual system further includes a first spacer element P1 located between the first lens E1 and the second lens E2, the first spacer element P1 abutting against the second side surface of the first lens E1 (the surface near the display side and away from the human eye side); and a first auxiliary spacer element P1b located between the first spacer element P1 and the second lens E2, the first auxiliary spacer element P1b abutting against the second side surface of the first spacer element P1 (the surface near the display side and away from the human eye side).

[0088] Table 5 shows the basic parameters of the visual system of Embodiment 3, where the units for radius of curvature and thickness / distance are millimeters (mm). In this embodiment, the second side surface S4 of the first lens E1 and the second side surface S13 of the second lens E2 are aspherical. Table 6 shows the higher-order coefficients A4, A6, A8, and A13 that can be used for the aspherical mirrors S4 and S13 in Embodiment 3. 10 A 12 A 14 A 16 A 18 and A 20 Each aspherical surface shape can be defined by formula (1) given in Example 1 above.

[0089]

[0090]

[0091] Table 5

[0092] coefficient\surface S4 S13 A4 4.3618E-07 1.9248E+00 A6 3.9507E-11 1.5522E+00 A8 2.8660E-13 3.9858E+00 A10 1.7307E-16 -2.8316E+00 A12 2.3184E-21 -2.5660E+00 A14 0.0000E+00 2.0596E-01 A16 0.0000E+00 2.4026E+00 A18 0.0000E+00 -1.5529E+00 A20 0.0000E+00 2.3077E-01

[0093] Table 6

[0094] The relevant parameter values ​​in Example 3 are shown in Table 7. The meaning of each parameter is as described above and will not be repeated here. The unit of each parameter in Table 7 is millimeters (mm).

[0095] Figure 17 The on-axis chromatic aberration curve of the visual system of Embodiment 3 is shown, which represents the deviation of the convergence focal point of light of different wavelengths after passing through the lens. Figure 18 The astigmatic curves of the visual system of Embodiment 3 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 19 The distortion curves of the visual system in Example 3 are shown, representing the distortion magnitude values ​​corresponding to different field of view angles. According to... Figures 17 to 19 It can be seen that the visual system given in Example 3 can achieve good imaging quality.

[0096] Parameters / Examples 1-1 1-2 1-3 2-1 2-2 2-3 3-1 3-2 3-3 d1s 52.173 54.614 52.193 60.536 60.596 60.600 56.338 58.498 58.011 d1m 52.173 53.670 52.193 60.536 60.596 60.600 56.338 56.791 58.011 D1s 63.600 58.638 65.600 72.600 72.000 70.700 67.594 60.843 64.994 D1m 63.600 60.647 65.600 72.600 72.000 70.700 67.594 60.462 64.994 d1bs 54.614 51.774 54.614 62.432 61.532 62.432 57.979 54.057 58.454 d1bm 54.070 51.774 53.270 60.376 59.096 60.024 56.791 54.057 55.791 D1bs 60.200 64.020 62.200 66.634 66.318 65.608 63.747 63.794 61.638 D1bm 61.572 64.020 63.553 65.551 65.025 64.735 60.462 63.794 58.965 d0s 54.670 54.670 54.670 75.393 75.393 75.393 72.007 67.007 67.007 d0m 68.030 68.030 70.430 57.257 55.257 57.257 54.071 53.271 53.271 D0s 67.033 67.132 69.433 78.600 79.400 77.800 74.414 69.414 69.414 D0m 70.600 69.600 74.000 74.396 74.396 74.396 70.210 65.639 65.544 EP01 14.187 13.792 14.436 14.620 14.620 14.620 6.165 5.438 5.538 CP1 0.105 5.443 0.056 0.068 0.210 0.105 0.068 7.178 0.068 CP1b 4.948 0.210 5.023 6.912 6.733 6.733 6.382 0.105 7.110 L 30.656 30.256 31.356 28.839 28.839 28.839 24.355 22.755 22.955

[0097] Table 7

[0098] Furthermore, in Examples 1 to 3, the effective focal length FG1 of the first element group, the effective focal length FG2 of the second element group, the effective focal length f of the visual system, the entrance pupil diameter EPD of the visual system, the distance TD from the first side of the first lens to the second side of the second lens along the optical axis, the center thickness CTR of the reflective polarizing element on the optical axis, and the center thickness CTQ of the quarter-wave plate on the optical axis are shown in Table 8.

[0099] Parameters / Examples 1 2 3 FG1(mm) 29.44 28.50 28.13 FG2(mm) -134.63 178.91 352.44 f(mm) 28.14 28.00 28.12 EPD (mm) 5.00 5.00 5.00 TD(mm) 24.78 30.44 19.21 CTR(mm) 0.20 0.20 0.20 CTQ(mm) 0.20 0.20 0.20

[0100] Table 8

[0101] Examples 1 to 3 respectively satisfy the conditions shown in Table 9.

[0102] Conditional / Example 1-1 1-2 1-3 2-1 2-2 2-3 3-1 3-2 3-3 FG1 / (CT1+CTQ+EP01) 1.05 1.06 1.04 1.00 1.00 1.00 1.87 1.97 1.95 d0m / |R4| 1.33 1.33 1.38 0.88 0.85 0.88 0.68 0.67 0.67 f / (D1bs-d1bs) 5.04 2.30 3.71 6.66 5.85 8.82 4.87 2.89 8.83 (T12+CT2) / (D1s-d1s) 0.97 2.75 0.83 1.39 1.47 1.66 0.94 4.49 1.51 |FG2| / (d1bm+D1bm) 1.16 1.16 1.15 1.42 1.44 1.43 3.01 2.99 3.07 FG1 / (D1m-d1m) 2.58 4.22 2.20 2.36 2.50 2.82 2.50 7.66 4.03 (D0s-d0s) / EPD 2.47 2.49 2.95 0.64 0.80 0.48 0.48 0.48 0.48 TD / (CP1+CP1b) 4.90 4.38 4.88 4.36 4.38 4.45 2.98 2.64 2.68 |FG2| / D0m 1.91 1.93 1.82 2.40 2.40 2.40 5.02 5.37 5.38 L / (CT1+CT2) 1.24 1.23 1.27 1.23 1.23 1.23 1.62 1.52 1.53 (CTR+CTQ+CT1+EP01) / f 1.01 0.99 1.01 1.03 1.03 1.03 0.54 0.52 0.52

[0103] Table 9

[0104] This application also provides an imaging device equipped with an electronic photosensitive element for imaging. The electronic photosensitive element can be a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) device. The imaging device can be a standalone imaging device such as a digital camera, or an imaging module integrated into a mobile electronic device such as a mobile phone. This imaging device is equipped with the visual system described above.

[0105] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of protection involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the concept of this application. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A visual system, characterized in that, It includes a lens barrel and a first element group and a second element group arranged sequentially from the first side to the second side along the optical axis, assembled within the lens barrel, wherein, The first element group has positive optical power and includes a reflective polarizing element, a quarter-wave plate, and a first lens, wherein the second side of the quarter-wave plate is attached to the first side of the first lens, and the second side of the reflective polarizing element is attached to the first side of the quarter-wave plate; or, the second side of the reflective polarizing element is attached to the first side of the first lens, and the first side of the quarter-wave plate is attached to the second side of the first lens. The second element group includes a second lens having positive or negative optical power, wherein the second side surface of the second lens is convex. A first spacer element is provided between the first element group and the second element group, and the first spacer element abuts against the second side surface of the first lens; The number of lenses with optical power in the visual system is two; The visual system satisfies: 1.00≤FG1 / (CT1+CTQ+EP01)<2.0; 0.5<(CTR+CTQ+CT1+EP01) / f≤1.03, Wherein, FG1 is the effective focal length of the first element group, CT1 is the center thickness of the first lens on the optical axis, CTQ is the center thickness of the quarter-wave plate on the optical axis, EP01 is the distance from the first side end face of the lens barrel to the first side face of the first spacer element along the optical axis, CTR is the center thickness of the reflective polarizing element on the optical axis, and f is the effective focal length of the visual system.

2. The visual system according to claim 1, characterized in that, The inner diameter d0m of the second side end face of the lens barrel and the radius of curvature R4 of the second side face of the second lens satisfy the following: 0.67≤d0m / |R4|<1.

4.

3. The visual system according to claim 1, characterized in that, A first auxiliary spacer element is provided between the first spacer element and the second lens, and the first auxiliary spacer element abuts against the second side surface of the first spacer element. The effective focal length f of the visual system, the outer diameter D1bs of the first side of the first auxiliary spacer element, and the inner diameter d1bs of the first side of the first auxiliary spacer element satisfy the following: 2.30≤f / (D1bs-d1bs)≤8.

83.

4. The visual system according to claim 1, characterized in that, The air gap T12 between the first lens and the second lens on the optical axis, the center thickness CT2 of the second lens on the optical axis, the outer diameter D1s of the first side of the first spacer element, and the inner diameter d1s of the first side of the first spacer element satisfy the following: 0.8<(T12+CT2) / (D1s-d1s)<4.

5.

5. The visual system according to claim 3, characterized in that, The effective focal length FG2 of the second element group, the inner diameter d1bm of the second side of the first auxiliary spacer element, and the outer diameter D1bm of the second side of the first auxiliary spacer element satisfy the following: 1.15≤|FG2| / (d1bm+D1bm)<3.

1.

6. The visual system according to claim 1, characterized in that, The effective focal length FG1 of the first element group, the outer diameter D1m of the second side of the first spacer element, and the inner diameter d1m of the second side of the first spacer element satisfy the following: 2.20≤FG1 / (D1m-d1m)<7.

7.

7. The visual system according to claim 1, characterized in that, The outer diameter D0s of the first side end face of the lens barrel, the inner diameter d0s of the first side end face of the lens barrel, and the entrance pupil diameter EPD of the visual system satisfy the following: 0.48≤(D0s-d0s) / EPD<3.

0.

8. The visual system according to claim 3, characterized in that, The distance TD between the first side surface of the first lens and the second side surface of the second lens along the optical axis, the maximum thickness CP1 of the first spacer element along the optical axis, and the maximum thickness CP1b of the first auxiliary spacer element along the optical axis satisfy the following: 2.6 <TD / (CP1+CP1b)≤4.90。 9. The visual system according to any one of claims 1 to 8, characterized in that, The effective focal length FG2 of the second element group and the outer diameter D0m of the second side end face of the lens barrel satisfy the following: 1.8<|FG2| / D0m<5.

4.

10. The visual system according to any one of claims 1 to 8, characterized in that, The maximum height L of the lens barrel along the optical axis, the center thickness CT1 of the first lens on the optical axis, and the center thickness CT2 of the second lens on the optical axis satisfy the following: 1.23≤L / (CT1+CT2)≤1.

62.

11. A VR device comprising a viewing system as described in at least one of claims 1 to 10, wherein, The first side is the eye side, and the second side is the display side.

Images