Visual system

Abstract

The present application discloses a visual system, which includes a lens barrel and a first lens, a reflective polarizing element, a quarter-wave plate, a second lens, a third lens, and a partially reflective element assembled therein. Among them, the first lens has a positive optical power, and the first side is a convex surface; the second lens has an optical power, and the first side is a plane; the third lens has an optical power, and the second side is a convex surface; there are first and second spacer elements between the first and second lenses and between the second and third lenses respectively; the visual system satisfies the conditional expressions 9.15 < d2s / CT2 < 12.6, 0.13 ≤ |d1s - d1m| / T12 ≤ 1.96, and 3.3 < f / (CP1 + EP12) < 7.9.

Description

Technical Field

[0001] This application relates to the field of optical elements, and more particularly, to a visual system. Background Art

[0002] With the rapid progress of computer technology and multimedia technology, virtual reality (VR) technology has developed rapidly and is widely used in various industries. With the help of VR technology, a highly realistic virtual environment can be constructed, allowing users to interact with three-dimensional models in the virtual space from the first-person perspective, providing users with an immersive experience. In this experience, as the output terminal of the virtual world, the display device with excellent imaging effects and a light, comfortable application feeling is particularly important.

[0003] However, although the existing folded optical path-based catadioptric optical design scheme performs well in shortening the lens length, there is still room for improvement in optical performance. For example, stray light is likely to be generated on the inner wall of the spacer element between the first and second lenses close to the human eye side in the system, interfering with the imaging system and affecting the imaging quality and clarity; in addition, relatively serious system aberrations also affect the user's visual experience. Summary of the Invention

[0004] This application provides a visual system, which may include a lens barrel and a lens group and a spacer element group assembled in the lens barrel. The lens group includes a first lens, a reflective polarizing element, a quarter-wave plate, a second lens, a third lens, and a partially reflective element arranged in sequence along the optical axis from the first side to the second side. Among them, the first lens has a positive optical power, and its first side is a convex surface; the second lens has a positive or negative optical power, and its first side is a flat surface; the third lens has a positive or negative optical power, and its second side is a convex surface. The spacer element group includes: a first spacer element located between the first lens and the second lens and abutted against the second side of the first lens; a second spacer element located between the second lens and the third lens and abutted against the second side of the second lens. The visual system can satisfy the conditions 9.15 < d2s / CT2 < 12.6, 0.13 ≤ |d1s - d1m| / T12 ≤ 1.96, and 3.3 < f / (CP1 + EP12) < 7.9, where d2s is the inner diameter of the first side of the second spacer element, CT2 is the central thickness of the second lens on the optical axis, d1s is the inner diameter of the first side of the first spacer element, d1m is the inner diameter of the second side of the first spacer element, T12 is the distance on the optical axis from the second side of the first lens to the first side of the second lens, f is the effective focal length of the visual system, CP1 is the maximum thickness of the first spacer element, and EP12 is the distance on the optical axis from the second side of the first spacer element to the first side of the second spacer element.

[0005] In one embodiment, the effective focal length f1 of the first lens and the outer diameter D1s of the first side surface of the first spacing element may satisfy: 1.95 <f1 / D1s<3.2。

[0006] In one embodiment, the effective focal length f3 of the third lens, the inner diameter d0m of the second side end surface of the lens barrel, and the outer diameter D0m of the second side end surface of the lens barrel may satisfy: 1.05<|f3| / (d0m+D0m)<1.95.

[0007] In one embodiment, the distance EP01 from the first side end face of the lens barrel to the first side face of the first spacing element on the optical axis and 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 may satisfy: 5.01≤EP01 / (CTR+CTQ)≤11.44.

[0008] In one embodiment, the curvature radius R1 of the first side surface of the first lens, the curvature radius R6 of the second side surface of the third lens, and the distance L from the first side end surface of the lens barrel to the second side end surface of the lens barrel on the optical axis may satisfy: -9.55mm≤(R1 / R6)×L≤-7.35mm.

[0009] In one embodiment, an outer diameter D2m of the second side surface of the second spacer element, an outer diameter D1m of the second side surface of the first spacer element, and a center thickness CT2 of the second lens on the optical axis may satisfy: 3.00mm≤(D2m / D1m)×CT2≤4.11mm.

[0010] In one embodiment, the inner diameter d2m of the second side surface of the second spacing element, the dispersion coefficient V3 of the third lens, and the refractive index N3 of the third lens may satisfy: 0.95 mm <d2m / (V3 / N3)<2.55mm。

[0011] In one embodiment, the refractive index N1 of the first lens, the effective focal length f1 of the first lens, and the outer diameter D0s of the first side end surface of the lens barrel may satisfy: 2.93≤(N1×f1) / D0s≤4.75.

[0012] In one embodiment, the outer diameter D0m of the second side end surface of the lens barrel, the inner diameter d0s of the first side end surface of the lens barrel, and the distance L from the first side end surface to the second side end surface of the lens barrel on the optical axis may satisfy: 12.6mm<(D0m / d0s)×L<13.8mm.

[0013] In one embodiment, the maximum thickness CP2 of the second spacer element, the outer diameter D2s of the first side surface of the second spacer element, and the inner diameter d2s of the first side surface of the second spacer element may satisfy: 0.9 <CP2 / (D2s-d2s)<2.5。

[0014] In one embodiment, the outer diameter D0m of the second side end face of the lens barrel, the outer diameter D2m of the second side face of the second spacer element, and the central thickness CT3 of the third lens on the optical axis may satisfy: 0.7 < (D0m - D2m) / CT3 < 1.65.

[0015] In one embodiment, the distance EP01 on the optical axis from the first side end face of the lens barrel to the first side face of the first spacer element, the distance EP12 on the optical axis from the second side face of the first spacer element to the first side face of the second spacer element, and the distance L on the optical axis from the first side end face of the lens barrel to the second side end face of the lens barrel may satisfy: 0.25 < (EP01 + EP12) / L < 0.55.

[0016] In one embodiment, the inner diameter d1s of the first side face of the first spacer element and the entrance pupil diameter EPD of the visual system may satisfy: 8.40 ≤ d1s / EPD ≤ 8.79.

[0017] In one embodiment, the distance TD on the optical axis from the first side face of the first lens to the second side face of the third lens, the maximum thickness CP1 of the first spacer element, and the maximum thickness CP2 of the second spacer element may satisfy: 3.4 < TD / (CP1 + CP2) < 5.0.

[0018] The visual system disclosed in this application includes a first lens, a reflective polarizing element, a quarter-wave plate, a second lens, a third lens, and a partial reflection element that are sequentially arranged along the optical axis from the first side to the second side in the lens barrel. Among them, the first lens has a positive optical power, and its first side face is convex; the second lens has a positive or negative optical power, and its first side face is flat; the third lens has a positive or negative optical power, and its second side face is convex; there is a first spacer element abutted against the second side face of the first lens between the first lens and the second lens, and there is a second spacer element abutted against the second side face of the second lens between the second lens and the third lens. By reasonably configuring the visual system and controlling the inner diameter d2s of the first side face of the second spacer element and the central thickness CT2 of the second lens on the optical axis to satisfy the conditional expression 9.15 < d2s / CT2 < 12.6; the inner diameter d1s of the first side face of the first spacer element, the inner diameter d1m of the second side face of the first spacer element, and the distance T12 on the optical axis from the second side face of the first lens to the first side face of the second lens satisfy the conditional expression 0.13 ≤ |d1s - d1m| / T12 ≤ 1.96; the effective focal length f of the visual system, the maximum thickness CP1 of the first spacer element, and the distance EP12 on the optical axis from the second side face of the first spacer element to the first side face of the second spacer element satisfy the conditional expression 3.3 < f / (CP1 + EP12) < 7.9, which can effectively reduce the interference of stray light at the first spacer element on the imaging system and is beneficial to improving the imaging clarity. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Other features, purposes and advantages of the present application will become more apparent through the following detailed description of non-limiting embodiments in conjunction with the accompanying drawings. In the accompanying drawings:

[0020] Figure 1 A schematic diagram showing the structure and some parameters of a visual system according to an exemplary embodiment of the present application is shown;

[0021] Figure 2 A schematic diagram of the structure of a visual system according to Example 1 of the present application is shown;

[0022] Figure 3 A schematic diagram of the structure of a visual system according to Embodiment 2 of the present application is shown;

[0023] Figure 4 A schematic structural diagram of a visual system according to Embodiment 3 of the present application is shown;

[0024] Figure 5 The MTF (Modulation Transfer Function) curves of the visual systems according to Embodiment 1, Embodiment 2 and Embodiment 3 of the present application are shown;

[0025] Figure 6 A schematic diagram of the structure of a visual system according to Embodiment 4 of the present application is shown;

[0026] Figure 7 A schematic diagram of the structure of a visual system according to Embodiment 5 of the present application is shown;

[0027] Figure 8 A schematic diagram of the structure of a visual system according to Example 6 of the present application is shown;

[0028] Fig. 9 The MTF curves of the visual systems according to Embodiment 4, Embodiment 5 and Embodiment 6 of the present application are shown;

[0029] Fig.10 A schematic diagram of the structure of a visual system according to Embodiment 7 of the present application is shown;

[0030] Fig.11 A schematic diagram of the structure of a visual system according to Example 8 of the present application is shown;

[0031] Fig.12 A schematic diagram of the structure of a visual system according to Example 9 of the present application is shown;

[0032] Fig.13 The MTF curves of the visual systems according to Embodiment 7, Embodiment 8 and Embodiment 9 of the present application are shown;

[0033] Fig.14 and Fig.15 A schematic diagram of the reflected stray light generated by the inner wall of the first spacing element of the visual system and a stray light diagram of the imaging effect of the visual system are respectively shown when the conditional formulas d2s / CT2=8.5, |d1s-d1m| / T12=0.05 and f / (CP1+EP12)=2.2 are satisfied;

[0034] Fig.16 and Fig.17 A schematic diagram of the reflected stray light generated inside the first spacing element of the visual system and a stray light diagram of the visual system imaging effect are respectively shown when the conditional expressions d2s / CT2=14, |d1s-d1m| / T12=3.1 and f / (CP1+EP12)=9.5 are satisfied;

[0035] Fig.18 and Fig.19 A schematic diagram showing a situation in which a visual system satisfying the conditions d2s / CT2=10, |d1s-d1m| / T12=1.5 and f / (CP1+EP12)=5.3 can intercept reflected stray light generated by the inner wall of the first spacing element and a stray light diagram of the imaging effect of the visual system are shown respectively. DETAILED DESCRIPTION

[0036] 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 are not intended to limit the scope of the present 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.

[0037] 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.

[0038] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of explanation. 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 only examples and are not drawn strictly to scale.

[0039] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the convex position 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 concave position is not defined, it means that the lens surface is concave at least in the paraxial region.

[0040] It should also be understood that the terms "comprises", "including", "having", "includes" 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 expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "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.

[0041] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as 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 a meaning consistent with 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.

[0042] It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The following embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can also be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0043] The features, principles and other aspects of the present application are described in detail below.

[0044] A visual system according to an exemplary embodiment of the present application may include a lens barrel, and a lens group and a spacer element group assembled in the lens barrel.

[0045] In an exemplary embodiment, the lens group may include a first lens, a reflective polarizing element, a quarter wave plate, a second lens, a third lens, and a partial reflective element arranged in sequence from a first side to a second side along an optical axis.

[0046] In an exemplary embodiment, the first lens may have positive optical power, and the first side surface thereof may be convex.

[0047] In example embodiments, the second lens may have positive or negative power, and the first side surface thereof may be a plane.

[0048] In exemplary embodiments, the third lens may have positive or negative power, and the second side surface thereof may be a convex surface.

[0049] In an exemplary embodiment, the spacer element group may include a first spacer element located between the first lens and the second lens, and the first spacer element may abut against the second side surface of the first lens.

[0050] In an exemplary embodiment, the spacer element group may include a second spacer element located between the second lens and the third lens, and the second spacer element may abut against the second side surface of the second lens.

[0051] In an exemplary embodiment, a quarter-wave plate may be disposed on the first side surface of the second lens; a reflective polarizing element may be disposed on the first side surface of the quarter-wave plate; a partially reflective element may be disposed on the second side surface of the third lens.

[0052] It can be understood that in the direction along the optical axis, the surface of each element or structure in the visual system that is closer to the first side and farther from the second side may be the first side surface of the element or structure, and the surface of each element that is closer to the second side and farther from the first side may be the second side surface of the element or structure.

[0053] 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 in, for example, a variety of VR devices or apparatuses.

[0054] In an exemplary embodiment, the visual system of the present application may satisfy the conditional formula 9.15 < d2s / CT2 < 12.6, where d2s is the inner diameter of the first side surface of the second spacer element, and CT2 is the central thickness of the second lens on the optical axis.

[0055] In an exemplary embodiment, the visual system of the present application may satisfy the conditional formula 0.13 ≤ |d1s - d1m| / T12 ≤ 1.96, where d1s is the inner diameter of the first side surface of the first spacer element, d1m is the inner diameter of the second side surface of the first spacer element, and T12 is the distance on the optical axis from the second side surface of the first lens to the first side surface of the second lens.

[0056] In an exemplary embodiment, the visual system of the present application may satisfy the conditional formula 3.3 < f / (CP1 + EP12) < 7.9, where f is the effective focal length of the visual system, CP1 is the maximum thickness of the first spacer element, and EP12 is the distance on the optical axis from the second side surface of the first spacer element to the first side surface of the second spacer element. It can be understood that the thickness of the spacer element may refer to the thickness of the spacer element in the direction along the optical axis or parallel to the optical axis.

[0057] The visual system provided according to an exemplary embodiment of the present application includes a first lens, a reflective polarizing element, a quarter-wave plate, a second lens, a third lens, and a partial reflection element that are sequentially arranged along the optical axis from the first side to the second side in a lens barrel. Among them, the first lens has a positive optical power, and its first side is a convex surface; the second lens has a positive or negative optical power, and its first side is a flat surface; the third lens has a positive or negative optical power, and its second side is a convex surface; there is a first spacer element抵设于 the second side of the first lens between the first lens and the second lens, and there is a second spacer element抵设于 the second side of the second lens between the second lens and the third lens. By reasonably configuring the visual system and controlling the inner diameter d2s of the first side of the second spacer element and the central thickness CT2 of the second lens on the optical axis to satisfy the conditional formula 9.15 < d2s / CT2 < 12.6; the inner diameter d1s of the first side of the first spacer element, the inner diameter d1m of the second side of the first spacer element, and the distance T12 on the optical axis from the second side of the first lens to the first side of the second lens satisfy the conditional formula 0.13 ≤ |d1s - d1m| / T12 ≤ 1.96; the effective focal length f of the visual system, the maximum thickness CP1 of the first spacer element, and the distance EP12 on the optical axis from the second side of the first spacer element to the first side of the second spacer element satisfy the conditional formula 3.3 < f / (CP1 + EP12) < 7.9, it is possible to effectively reduce the interference of stray light at the first spacer element on the imaging system and is beneficial to improving the clarity of imaging.

[0058] In an exemplary embodiment, the lens group and spacer element group of the visual system are configured as described above. At the same time, by setting the above three conditional formulas d2s / CT2, |d1s - d1m| / T12, and f / (CP1 + EP12) to satisfy different numerical ranges respectively, the following three different visual system solutions can be formed:

[0059] For the visual system 1 of the first solution, the values of the conditional formulas d2s / CT2, |d1s - d1m| / T12, and f / (CP1 + EP12) are d2s / CT2 = 8.5, |d1s - d1m| / T12 = 0.05, and f / (CP1 + EP12) = 2.2 respectively. It can be seen that the values of each conditional formula are respectively less than the lower limit values of the ranges defined by the above conditional formulas 9.15 < d2s / CT2 < 12.6, 0.13 ≤ |d1s - d1m| / T12 ≤ 1.96, and 3.3 < f / (CP1 + EP12) < 7.9. In this case, as Fig.14 shown, there is a situation of generating reflected stray light on the inner wall of the first spacer element in the visual system. The stray light diagram of the imaging effect of the visual system is as Fig.15 shown. It can be seen that in this case, the stray light is relatively concentrated and has a high intensity, which has a great impact on the imaging effect.

[0060] For the visual system 2 of the second solution, the values of the conditional expressions d2s / CT2, |d1s - d1m| / T12, and f / (CP1 + EP12) are d2s / CT2 = 14, |d1s - d1m| / T12 = 3.1, and f / (CP1 + EP12) = 9.5 respectively. It can be seen that the values of each conditional expression are all greater than the upper limit values of the ranges defined by the above conditional expressions 9.15 < d2s / CT2 < 12.6, 0.13 ≤ |d1s - d1m| / T12 ≤ 1.96, and 3.3 < f / (CP1 + EP12) < 7.9. In this case, as Fig.16 shown, there is also a situation where reflected stray light is generated inside the first spacer element in the visual system. The stray light pattern of the imaging effect of the visual system is as Fig.17 shown. It can be seen that in this case, the stray light dispersion area is relatively large and the intensity is also relatively high, which has a greater impact on the imaging effect.

[0061] For the visual system 3 of the third solution, the values of the conditional expressions d2s / CT2, |d1s - d1m| / T12, and f / (CP1 + EP12) are d2s / CT2 = 10, |d1s - d1m| / T12 = 1.5, and f / (CP1 + EP12) = 5.3 respectively. It can be seen that the values of each conditional expression are all within the ranges defined by the above conditional expressions 9.15 < d2s / CT2 < 12.6, 0.13 ≤ |d1s - d1m| / T12 ≤ 1.96, and 3.3 < f / (CP1 + EP12) < 7.9. In this case, as Fig.18 shown, the reflected stray light inside the first spacer element in the visual system can be effectively intercepted. The stray light pattern of the imaging effect of the visual system is as Fig.19 shown. It can be seen that in this case, the stray light is reduced and the stray light intensity is significantly weakened, which has a smaller impact on the imaging effect and is beneficial to improving the imaging clarity.

[0062] Therefore, by reasonably configuring the system and controlling to meet the conditional expressions 9.15 < d2s / CT2 < 12.6, 0.13 ≤ |d1s - d1m| / T12 ≤ 1.96, and 3.3 < f / (CP1 + EP12) < 7.9, the visual system according to the present application can effectively reduce the interference of the stray light at the first spacer element to the imaging system and is beneficial to improving the imaging clarity.

[0063] In an exemplary embodiment, the visual system of the present application can satisfy the conditional formula 1.95 < f1 / D1s < 3.2, where f1 is the effective focal length of the first lens and D1s is the outer diameter of the first side surface of the first spacer element. By reasonably controlling the range of this conditional formula, on the one hand, the first lens can generate positive spherical aberration, which cancels out the negative spherical aberration generated by other lenses in the system, thereby ensuring good imaging; on the other hand, it ensures the stability of the bearing between the lens and the spacer element, and at the same time improves the feasibility of processing the lens and the spacer element.

[0064] In an exemplary embodiment, the visual system of the present application can satisfy the conditional formula 1.05 < |f3| / (d0m + D0m) < 1.95, where f3 is the effective focal length of the third lens, d0m is the inner diameter of the second side end face of the lens barrel, and D0m is the outer diameter of the second side end face of the lens barrel. It can be understood that the first side end face of the lens barrel can be the end face or surface of the lens barrel closest to the first side and perpendicular or approximately perpendicular to the optical axis; the second side end face of the lens barrel can be the end face or surface of the lens barrel closest to the second side and perpendicular or approximately perpendicular to the optical axis. By reasonably controlling the range of this conditional formula, the lens barrel can be kept small in volume, while ensuring that the optical system has a large field of view angle, so that the entire lens group is more compact, which is conducive to realizing the miniaturized design of the device.

[0065] In an exemplary embodiment, the visual system of the present application can satisfy the conditional formula 5.01 ≤ EP01 / (CTR + CTQ) ≤ 11.44, where EP01 is the distance on the optical axis from the first side end face of the lens barrel to the first side surface of the first spacer element, CTR is the central thickness of the reflective polarizing element on the optical axis, and CTQ is the central thickness of the quarter-wave plate on the optical axis. By reasonably controlling the range of this conditional formula, the optical power of the first lens can be standardized, which is beneficial to restricting the field of view angle of the system, meeting the wide-angle requirements of the system or device, and can also restrict the thickness of the first lens to be small, which is beneficial to the miniaturization of the system.

[0066] In an exemplary embodiment, the visual system of the present application can satisfy the conditional formula -9.55 mm ≤ (R1 / R6) × L ≤ -7.35 mm, where R1 is the radius of curvature of the first side surface of the first lens, R6 is the radius of curvature of the second side surface of the third lens, and L is the distance on the optical axis from the first side end face of the lens barrel to the second side end face of the lens barrel. By reasonably controlling the range of this conditional formula, the optical power of the overall lens is controlled, which is beneficial to correcting the system aberration.

[0067] In an exemplary embodiment, the visual system of the present application can satisfy the conditional formula 3.00 mm ≤ (D2m / D1m) × CT2 ≤ 4.11 mm, where D2m is the outer diameter of the second side surface of the second spacer element, D1m is the outer diameter of the second side surface of the first spacer element, and CT2 is the central thickness of the second lens on the optical axis. By reasonably controlling the range of this conditional formula, on the one hand, the stability of the second lens assembly can be improved, and on the other hand, the thickness ratio of the second lens is restricted, which is beneficial to improving the forming performance of the second lens.

[0068] In an exemplary embodiment, the visual system of the present application can satisfy the conditional formula 0.95 mm < d2m / (V3 / N3) < 2.55 mm, where d2m is the inner diameter of the second side surface of the second spacer element, V3 is the dispersion coefficient of the third lens, and N3 is the refractive index of the third lens. By reasonably controlling the range of this conditional formula, it is beneficial to reduce the overall chromatic aberration of the system, improve the imaging quality of the system, and thus improve the application experience of consumers.

[0069] In an exemplary embodiment, the visual system of the present application can satisfy the conditional formula 2.93 ≤ (N1 × f1) / D0s ≤ 4.75, where N1 is the refractive index of the first lens, f1 is the effective focal length of the first lens, and D0s is the outer diameter of the first side end face of the lens barrel. By reasonably controlling the range of this conditional formula, on the one hand, the lens strength of the first lens can be controlled, which is beneficial to forming; on the other hand, the optical power of the first lens can be regulated, which is beneficial to restricting the field of view angle of the system and meeting the wide-angle requirements of the system or equipment.

[0070] In an exemplary embodiment, the visual system of the present application can satisfy the conditional formula 12.6 mm < (D0m / d0s) × L < 13.8 mm, where D0m is the outer diameter of the second side end face of the lens barrel, d0s is the inner diameter of the first side end face of the lens barrel, and L is the distance on the optical axis from the first side end face of the lens barrel to the second side end face of the lens barrel. By reasonably controlling the range of this conditional formula, the wall thickness of the lens barrel is indirectly controlled. On the one hand, the stability of the lens and spacer element assembly can be improved, and on the other hand, the lens barrel can have a larger field of view angle.

[0071] In an exemplary embodiment, the visual system of the present application can satisfy the conditional formula 0.9 < CP2 / (D2s - d2s) < 2.5, where CP2 is the maximum thickness of the second spacer element, D2s is the outer diameter of the first side surface of the second spacer element, and d2s is the inner diameter of the first side surface of the second spacer element. By reasonably controlling the range of this conditional formula, it is beneficial to the assembly of the second lens and the third lens, and can reduce the deformation after the assembly of the lens and the spacer element.

[0072] In an exemplary embodiment, the visual system of the present application can satisfy the conditional formula 0.7 < (D0m - D2m) / CT3 < 1.65, where D0m is the outer diameter of the second side end face of the lens barrel, D2m is the outer diameter of the second side face of the second spacer element, and CT3 is the central thickness of the third lens on the optical axis. By reasonably controlling the range of this conditional formula, the focal length of the system can be indirectly controlled, thereby restricting the size of the system field of view. At the same time, the thickness ratio of the third lens can be ensured, which is beneficial to the molding of the third lens.

[0073] In an exemplary embodiment, the visual system of the present application can satisfy the conditional formula 0.25 < (EP01 + EP12) / L < 0.55, where EP01 is the distance on the optical axis from the first side end face of the lens barrel to the first side face of the first spacer element, EP12 is the distance on the optical axis from the second side face of the first spacer element to the first side face of the second spacer element, and L is the distance on the optical axis from the first side end face of the lens barrel to the second side end face of the lens barrel. By reasonably controlling the range of this conditional formula, on the one hand, it is beneficial to the miniaturization of the system, and on the other hand, it is beneficial to the surface film pasting of the second lens.

[0074] In an exemplary embodiment, the visual system of the present application can satisfy the conditional formula 8.40 ≤ d1s / EPD ≤ 8.79, where d1s is the inner diameter of the first side face of the first spacer element, and EPD is the entrance pupil diameter of the visual system. By reasonably controlling the range of this conditional formula, the light input amount can be effectively controlled, the generation of stray light can be reduced, and the imaging clarity can be improved.

[0075] In an exemplary embodiment, the visual system of the present application can satisfy the conditional formula 3.4 < TD / (CP1 + CP2) < 5.0, where TD is the distance on the optical axis from the first side face of the first lens to the second side face of the third lens, CP1 is the maximum thickness of the first spacer element, and CP2 is the maximum thickness of the second spacer element. By reasonably controlling the range of this conditional formula, on the one hand, the height and length of the lens barrel are indirectly restricted, which is beneficial to the miniaturization of the lens; on the other hand, the deformation after the lens and the spacer element are assembled can be reduced, which is beneficial to improving the assembly stability.

[0076] 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 of 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.

[0077] 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.

[0078] On the one hand, according to the visual system of the above-described embodiment of the present application, by providing a first lens, a reflective polarizing element, a quarter-wave plate, a second lens, a third lens, and a partial reflection element that are sequentially arranged along the optical axis from the first side to the second side and assembled in the lens barrel, wherein the first lens has a positive optical power and its first side is convex; the second lens has a positive or negative optical power and its first side is flat; the third lens has a positive or negative optical power and its second side is convex; and a first spacer element located between the first lens and the second lens and abutting against the second side of the first lens, and a second spacer element located between the second lens and the third lens and abutting against the second side of the second lens are provided; at the same time, the inner diameter d2s of the first side of the second spacer element and the central thickness CT2 of the second lens on the optical axis satisfy the conditional formula 9.15 < d2s / CT2 < 12.6; the inner diameter d1s of the first side of the first spacer element, the inner diameter d1m of the second side of the first spacer element, and the distance T12 on the optical axis from the second side of the first lens to the first side of the second lens satisfy the conditional formula 0.13 ≤ |d1s - d1m| / T12 ≤ 1.96; the effective focal length f of the visual system, the maximum thickness CP1 of the first spacer element, and the distance EP12 on the optical axis from the second side of the first spacer element to the first side of the second spacer element satisfy the conditional formula 3.3 < f / (CP1 + EP12) < 7.9, which can effectively reduce the interference of stray light at the first spacer element on the imaging system and is beneficial to improving the clarity of imaging.

[0079] On the other hand, according to the visual system of the above embodiments of the present application, by providing a first lens, a reflective polarizing element, a quarter-wave plate, a second lens, a third lens, and a partial reflection element that are sequentially arranged along the optical axis from the first side to the second side in the lens barrel, wherein the first lens has a positive optical power and its first side is convex; the second lens has a positive or negative optical power and its first side is flat; the third lens has a positive or negative optical power and its second side is convex; and a first spacer element located between the first lens and the second lens and abutting against the second side of the first lens, and a second spacer element located between the second lens and the third lens and abutting against the second side of the second lens; at the same time, controlling the inner diameter d1s of the first side of the first spacer element and the entrance pupil diameter EPD of the visual system to satisfy the conditional expression 8.40 ≤ d1s / EPD ≤ 8.79; the inner diameter d1s of the first side of the first spacer element, the inner diameter d1m of the second side of the first spacer element, and the distance T12 on the optical axis from the second side of the first lens to the first side of the second lens satisfy the conditional expression 0.13 ≤ |d1s - d1m| / T12 ≤ 1.96; the effective focal length f of the visual system, the maximum thickness CP1 of the first spacer element, and the distance EP12 on the optical axis from the second side of the first spacer element to the first side of the second spacer element satisfy the conditional expression 3.3 < f / (CP1 + EP12) < 7.9, which can effectively control the amount of incident light, reduce the generation of stray light, and improve the clarity of system imaging.

[0080] The visual system according to the embodiment of the present application adopts a three-piece folded design scheme, which not only further compresses the height of the device but also significantly improves the imaging quality of the system. The visual system according to the embodiment of the present application can significantly improve the user's visual experience by enhancing the correction ability of system aberrations, making the immersion feeling more real and strong during the user's use process.

[0081] In addition, the present application also provides a VR device, which may include the visual system provided by any one of the above embodiments, wherein the first side is the human eye side and the second side is the display side. The VR device can have at least one beneficial effect such as miniaturization, light weight, and high imaging quality, and can enable the user to obtain a better application experience.

[0082] The following further describes specific embodiments of the visual system applicable to the above embodiments with reference to the accompanying drawings.

[0083] Embodiment 1

[0084] The following refers to Figure 2 Describe the visual system according to Embodiment 1 of the present application. Figure 2 The structural schematic diagram of the visual system according to Embodiment 1 of the present application is shown.

[0085] like Figure 2 As shown, the visual system includes a lens barrel P0 and the following components, which are assembled in the lens barrel P0 and are arranged in sequence from the first side to the second side along the optical axis: a first lens E1, a reflective polarizing element RP, a quarter wave plate QWP, a second lens E2, a third lens E3, and a partial reflection element BS. The quarter wave plate QWP is disposed on the first side surface of the second lens E2, the reflective polarizing element RP is disposed on the first side surface of the quarter wave plate QWP, and the partial reflection element BS is disposed on the second side surface of the third lens E3. The first lens E1 has positive focal power, and its first side surface S2 is a convex surface, and its second side surface S3 is a convex surface; the second lens E2 has negative focal power, and its first side surface S14 is a plane surface, and its second side surface S15 is a concave surface; the third lens E3 has positive focal power, and its first side surface S16 is a convex surface, and its second side surface S17 is a convex surface.

[0086] In this embodiment, the visual system further includes: a first spacing element P1, located between the first lens E1 and the second lens E2, and the first spacing element P1 is disposed against the second side surface of the first lens E1; and a second spacing element P2, located between the second lens E2 and the third lens E3, and the second spacing element P2 is disposed against the second side surface of the second lens E2.

[0087] In this embodiment, the first side may be, for example, a human eye side, and the second side may be, for example, a display side. The second side of the visual system has an image surface IMG.

[0088] 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 both millimeters (mm).

[0089] Table 1

[0090]

[0091] In Example 1, the first side surface S2 and the second side surface S3 of the first lens E1, the second side surface S15 of the second lens E2, and the first side surface S16 and the second side surface S17 of the third lens E3 are all aspherical surfaces, and the surface shape of each aspherical surface can be defined by but not limited to the following aspherical surface formula:

[0092] (1)

[0093] in, The aspheric surface is at a height of h When the position is , the distance vector height from the vertex of the aspherical surface; c is the paraxial curvature of the aspheric surface, c =1 / R (i.e., paraxial curvature c is the reciprocal of the radius of curvature R in Table 1 above); kis the cone coefficient; Ai Aspheric i Table 2 below gives the high-order coefficients that can be used for each aspheric surface S2-S3 and S15-S17 in Example 1: A 4 , A 6 , A 8 , A 10 , A 12 , A 14 , A 16 , A 18 and A 20 .

[0094] Table 2

[0095]

[0096] Referring to Table 7, the values ​​of the following structural parameters in this embodiment are respectively shown in the column 'Example 1' in Table 7: d1s is the inner diameter of the first side surface of the first spacer element P1; d1m is the inner diameter of the second side surface of the first spacer element P1; D1s is the outer diameter of the first side surface of the first spacer element P1; D1m is the outer diameter of the second side surface of the first spacer element P1; d2s is the inner diameter of the first side surface of the second spacer element P2; d2m is the inner diameter of the second side surface of the second spacer element P2; D2s is the outer diameter of the first side surface of the second spacer element P2; D2m is the outer diameter of the second side surface of the second spacer element P2; d0s is The inner diameter of the first side end face of the lens barrel P0; d0m is the inner diameter of the second side end face of the lens barrel P0; D0s is the outer diameter of the first side end face of the lens barrel P0; D0m is the outer diameter of the second side end face of the lens barrel P0; EP01 is the distance on the optical axis from the first side end face of the lens barrel P0 to the first side face of the first spacing element P1; CP1 is the maximum thickness of the first spacing element P1; EP12 is the distance on the optical axis from the second side face of the first spacing element P1 to the first side face of the second spacing element P2, CP2 is the maximum thickness of the second spacing element P2; and, L is the distance on the optical axis from the first side end face of the lens barrel P0 to its second side end face. The units of the above parameters shown in Table 7 are all millimeters (mm), and the schematic diagram of the above parameters in the visual system structure diagram can be referred to. Figure 1 .

[0097] Example 2

[0098] The following reference Figure 3 Describe the visual system according to Example 2 of the present application.

[0099] like Figure 3 As shown, in this embodiment, the visual system also includes a lens barrel P0 and the following components, which are assembled in the lens barrel P0 and are arranged in sequence from the first side to the second side along the optical axis: a first lens E1, a reflective polarizing element RP, a quarter wave plate QWP, a second lens E2, a third lens E3, and a partial reflection element BS; wherein the quarter wave plate QWP is arranged on the first side surface of the second lens E2, the reflective polarizing element RP is arranged on the first side surface of the quarter wave plate QWP, and the partial reflection element BS is arranged on the second side surface of the third lens E3. As in Embodiment 1, the first lens E1 has positive focal power, and its first side surface S2 is a convex surface, and its second side surface S3 is a convex surface; the second lens E2 has negative focal power, and its first side surface S14 is a plane surface, and its second side surface S15 is a concave surface; the third lens E3 has positive focal power, and its first side surface S16 is a convex surface, and its second side surface S17 is a convex surface.

[0100] The visual system of this embodiment also includes a first spacing element P1 located between the first lens E1 and the second lens E2 and against the second side surface of the first lens E1, and a second spacing element P2 located between the second lens E2 and the third lens E3 and against the second side surface of the second lens E2. In this embodiment, the first side may be, for example, the human eye side, and the second side may be, for example, the display side. The second side of the visual system has an image surface IMG.

[0101] The basic parameter table of the visual system of this embodiment is the same as Table 1 in Example 1, and the high-order coefficient table of the aspherical mirror surface is the same as Table 2 in Example 1.

[0102] The values ​​of the structural parameters of the visual system of this embodiment are shown in the 'Example 2' column of Table 7. The specific description of the meaning represented by each parameter is the same as that in the above Example 1, and will not be repeated here.

[0103] Example 3

[0104] The following reference Figure 4 Describe the visual system according to Example 3 of the present application.

[0105] like Figure 4As shown, in this embodiment, the visual system also includes a lens barrel P0 and the following components, which are assembled in the lens barrel P0 and are arranged in sequence from the first side to the second side along the optical axis: a first lens E1, a reflective polarizing element RP, a quarter wave plate QWP, a second lens E2, a third lens E3, and a partial reflection element BS; wherein the quarter wave plate QWP is arranged on the first side surface of the second lens E2, the reflective polarizing element RP is arranged on the first side surface of the quarter wave plate QWP, and the partial reflection element BS is arranged on the second side surface of the third lens E3. As in Embodiment 1, the first lens E1 has positive focal power, and its first side surface S2 is a convex surface, and its second side surface S3 is a convex surface; the second lens E2 has negative focal power, and its first side surface S14 is a plane surface, and its second side surface S15 is a concave surface; the third lens E3 has positive focal power, and its first side surface S16 is a convex surface, and its second side surface S17 is a convex surface.

[0106] The visual system of this embodiment also includes a first spacing element P1 located between the first lens E1 and the second lens E2 and against the second side surface of the first lens E1, and a second spacing element P2 located between the second lens E2 and the third lens E3 and against the second side surface of the second lens E2. In this embodiment, the first side may be, for example, the human eye side, and the second side may be, for example, the display side. The second side of the visual system has an image surface IMG.

[0107] The basic parameter table of the visual system of this embodiment is also the same as Table 1 in Example 1, and the high-order coefficient table of the aspheric mirror surface is also the same as Table 2 in Example 1.

[0108] The values ​​of the structural parameters of the visual system of this embodiment are shown in the 'Example 3' column of Table 7. The specific description of the meaning represented by each parameter is the same as that in the above Example 1, and will not be repeated here.

[0109] Figure 5 The MTF curves of the visual systems of Embodiment 1, Embodiment 2 and Embodiment 3 are shown. The MTF curves can represent the optical modulation function values ​​corresponding to different spatial frequencies. Figure 5 It can be seen that the visual systems provided in Example 1, Example 2 and Example 3 can achieve good imaging quality.

[0110] Example 4

[0111] The following reference Figure 6 Describe the visual system according to Example 4 of the present application.

[0112] like Figure 6As shown, in this embodiment, the visual system includes a lens barrel P0 and the following components, which are assembled in the lens barrel P0 and are arranged in sequence from the first side to the second side along the optical axis: a first lens E1, a reflective polarizing element RP, a quarter wave plate QWP, a second lens E2, a third lens E3, and a partial reflection element BS. Among them, the quarter wave plate QWP is arranged on the first side surface of the second lens E2, the reflective polarizing element RP is arranged on the first side surface of the quarter wave plate QWP, and the partial reflection element BS is arranged on the second side surface of the third lens E3. In this embodiment, the first lens E1 has positive focal power, and its first side surface S2 is a convex surface, and its second side surface S3 is a concave surface; the second lens E2 has positive focal power, and its first side surface S14 is a plane surface, and its second side surface S15 is a convex surface; the third lens E3 has positive focal power, and its first side surface S16 is a convex surface, and its second side surface S17 is a convex surface.

[0113] In this embodiment, the visual system further includes: a first spacing element P1, located between the first lens E1 and the second lens E2, and the first spacing element P1 is disposed against the second side surface of the first lens E1; and a second spacing element P2, located between the second lens E2 and the third lens E3, and the second spacing element P2 is disposed against the second side surface of the second lens E2.

[0114] In this embodiment, the first side may be, for example, a human eye side, and the second side may be, for example, a display side. The second side of the visual system has an image surface IMG.

[0115] Table 3 shows the basic parameters of the visual system of Example 4, where the units of the radius of curvature and thickness / distance are both in millimeters (mm). In this embodiment, the first side surface S2 and the second side surface S3 of the first lens E1, the second side surface S15 of the second lens E2, and the first side surface S16 and the second side surface S17 of the third lens E3 are all aspherical surfaces. Table 4 shows the high-order coefficients of the aspherical surfaces S2-S3, S15-S17 that can be used in Example 4. A 4 , A 6 , A 8 , A 10 , A 12 , A 14 , A 16 , A 18 and A 20 , wherein the surface shape of each aspheric surface can be defined by the formula (1) given in the above embodiment 1.

[0116] Table 3

[0117]

[0118] Table 4

[0119]

[0120] Referring to Table 7, the values ​​of the structural parameters of the visual system of this embodiment are respectively shown in the 'Example 4' column of Table 7, wherein the specific description of the meaning represented by each parameter is the same as that in the above Example 1 and will not be repeated here.

[0121] Example 5

[0122] The following reference Figure 7 Describe the visual system according to Example 5 of the present application.

[0123] like Figure 7 As shown, in this embodiment, the visual system also includes a lens barrel P0 and the following components, which are assembled in the lens barrel P0 and are arranged in sequence from the first side to the second side along the optical axis: a first lens E1, a reflective polarizing element RP, a quarter wave plate QWP, a second lens E2, a third lens E3, and a partial reflection element BS; wherein the quarter wave plate QWP is arranged on the first side surface of the second lens E2, the reflective polarizing element RP is arranged on the first side surface of the quarter wave plate QWP, and the partial reflection element BS is arranged on the second side surface of the third lens E3. As in Embodiment 4, the first lens E1 has positive focal power, its first side surface S2 is a convex surface, and its second side surface S3 is a concave surface; the second lens E2 has positive focal power, its first side surface S14 is a plane surface, and its second side surface S15 is a convex surface; the third lens E3 has positive focal power, its first side surface S16 is a convex surface, and its second side surface S17 is a convex surface.

[0124] The visual system of this embodiment also includes a first spacing element P1 located between the first lens E1 and the second lens E2 and against the second side surface of the first lens E1, and a second spacing element P2 located between the second lens E2 and the third lens E3 and against the second side surface of the second lens E2. In this embodiment, the first side may be, for example, the human eye side, and the second side may be, for example, the display side. The second side of the visual system has an image surface IMG.

[0125] The basic parameter table of the visual system of this embodiment is the same as Table 3 in Example 4, and the high-order coefficient table of the aspheric mirror surface is the same as Table 4 in Example 4.

[0126] The values ​​of the structural parameters of the visual system of this embodiment are shown in the column of 'Example 5' in Table 7. The specific description of the meaning represented by each parameter is the same as that in the above-mentioned Example 1, and will not be repeated here.

[0127] Example 6

[0128] The following reference Figure 8 Describe the visual system according to Example 6 of the present application.

[0129] like Figure 8 As shown, in this embodiment, the visual system also includes a lens barrel P0 and the following components, which are assembled in the lens barrel P0 and are arranged in sequence from the first side to the second side along the optical axis: a first lens E1, a reflective polarizing element RP, a quarter wave plate QWP, a second lens E2, a third lens E3, and a partial reflection element BS; wherein the quarter wave plate QWP is arranged on the first side surface of the second lens E2, the reflective polarizing element RP is arranged on the first side surface of the quarter wave plate QWP, and the partial reflection element BS is arranged on the second side surface of the third lens E3. As in Embodiment 4, the first lens E1 has positive focal power, its first side surface S2 is a convex surface, and its second side surface S3 is a concave surface; the second lens E2 has positive focal power, its first side surface S14 is a plane surface, and its second side surface S15 is a convex surface; the third lens E3 has positive focal power, its first side surface S16 is a convex surface, and its second side surface S17 is a convex surface.

[0130] The visual system of this embodiment also includes a first spacing element P1 located between the first lens E1 and the second lens E2 and against the second side surface of the first lens E1, and a second spacing element P2 located between the second lens E2 and the third lens E3 and against the second side surface of the second lens E2. In this embodiment, the first side may be, for example, the human eye side, and the second side may be, for example, the display side. The second side of the visual system has an image surface IMG.

[0131] The basic parameter table of the visual system of this embodiment is also the same as Table 3 in Example 4, and the high-order coefficient table of the aspheric mirror surface is also the same as Table 4 in Example 4.

[0132] The values ​​of the structural parameters of the visual system of this embodiment are shown in the 'Example 6' column of Table 7. The specific description of the meaning represented by each parameter is the same as that in the above Example 1, and will not be repeated here.

[0133] Fig. 9 The visual system MTF curves of Example 4, Example 5 and Example 6 are shown. Fig. 9 It can be seen that the visual systems provided in Examples 4, 5 and 6 can achieve good imaging quality.

[0134] Example 7

[0135] The following reference Fig.10 Describe the visual system according to Example 7 of the present application. Fig.10A schematic diagram of the structure of the visual system according to Example 7 of the present application is shown.

[0136] like Fig.10 As shown, in this embodiment, the visual system includes a lens barrel P0 and the following components, which are assembled in the lens barrel P0 and are arranged in sequence from the first side to the second side along the optical axis: a first lens E1, a reflective polarizing element RP, a quarter wave plate QWP, a second lens E2, a third lens E3, and a partial reflection element BS. Among them, the quarter wave plate QWP is arranged on the first side surface of the second lens E2, the reflective polarizing element RP is arranged on the first side surface of the quarter wave plate QWP, and the partial reflection element BS is arranged on the second side surface of the third lens E3. In this embodiment, the first lens E1 has positive focal power, and its first side surface S2 is a convex surface, and its second side surface S3 is a convex surface; the second lens E2 has positive focal power, and its first side surface S14 is a plane surface, and its second side surface S15 is a convex surface; the third lens E3 has negative focal power, and its first side surface S16 is a concave surface, and its second side surface S17 is a convex surface.

[0137] In this embodiment, the visual system further includes: a first spacing element P1, located between the first lens E1 and the second lens E2, and the first spacing element P1 is disposed against the second side surface of the first lens E1; and a second spacing element P2, located between the second lens E2 and the third lens E3, and the second spacing element P2 is disposed against the second side surface of the second lens E2.

[0138] In this embodiment, the first side may be, for example, a human eye side, and the second side may be, for example, a display side. The second side of the visual system has an image surface IMG.

[0139] Table 5 shows the basic parameters of the visual system of Example 7, where the units of the radius of curvature and thickness / distance are both in millimeters (mm). In this embodiment, the first side surface S2 and the second side surface S3 of the first lens E1, the second side surface S15 of the second lens E2, and the first side surface S16 and the second side surface S17 of the third lens E3 are all aspherical surfaces. Table 6 shows the high-order coefficients of the aspherical surfaces S2-S3, S15-S17 that can be used in Example 7. A 4 , A 6 , A 8 , A 10 , A 12 , A 14 , A 16 , A 18 and A 20, wherein the surface shape of each aspheric surface can be defined by the formula (1) given in the above embodiment 1.

[0140] Table 5

[0141]

[0142] Table 6

[0143]

[0144] Referring to Table 7, the values ​​of the structural parameters of the visual system of this embodiment are respectively shown in the 'Example 7' column of Table 7, wherein the specific description of the meaning represented by each parameter is the same as that in the above Example 1 and will not be repeated here.

[0145] Example 8

[0146] The following reference Fig.11 Describe the visual system according to Example 8 of the present application.

[0147] like Fig.11 As shown, in this embodiment, the visual system also includes a lens barrel P0 and the following components, which are assembled in the lens barrel P0 and are arranged in sequence from the first side to the second side along the optical axis: a first lens E1, a reflective polarizing element RP, a quarter wave plate QWP, a second lens E2, a third lens E3, and a partial reflection element BS; wherein the quarter wave plate QWP is arranged on the first side surface of the second lens E2, the reflective polarizing element RP is arranged on the first side surface of the quarter wave plate QWP, and the partial reflection element BS is arranged on the second side surface of the third lens E3. As in Embodiment 7, the first lens E1 has positive focal power, and its first side surface S2 is a convex surface, and its second side surface S3 is a convex surface; the second lens E2 has positive focal power, and its first side surface S14 is a plane surface, and its second side surface S15 is a convex surface; the third lens E3 has negative focal power, and its first side surface S16 is a concave surface, and its second side surface S17 is a convex surface.

[0148] The visual system of this embodiment also includes a first spacing element P1 located between the first lens E1 and the second lens E2 and against the second side surface of the first lens E1, and a second spacing element P2 located between the second lens E2 and the third lens E3 and against the second side surface of the second lens E2. In this embodiment, the first side may be, for example, the human eye side, and the second side may be, for example, the display side. The second side of the visual system has an image surface IMG.

[0149] The basic parameter table of the visual system of this embodiment is the same as Table 5 in Example 7, and the high-order coefficient table of the aspheric mirror surface is the same as Table 6 in Example 7.

[0150] The values ​​of the structural parameters of the visual system of this embodiment are shown in the 'Example 8' column of Table 7. The specific description of the meaning represented by each parameter is the same as that in the above Example 1, and will not be repeated here.

[0151] Example 9

[0152] The following reference Fig.12 Describe the visual system according to Example 9 of the present application.

[0153] like Fig.12 As shown, in this embodiment, the visual system also includes a lens barrel P0 and the following components, which are assembled in the lens barrel P0 and are arranged in sequence from the first side to the second side along the optical axis: a first lens E1, a reflective polarizing element RP, a quarter wave plate QWP, a second lens E2, a third lens E3, and a partial reflection element BS; wherein the quarter wave plate QWP is arranged on the first side surface of the second lens E2, the reflective polarizing element RP is arranged on the first side surface of the quarter wave plate QWP, and the partial reflection element BS is arranged on the second side surface of the third lens E3. As in Embodiment 7, the first lens E1 has positive focal power, and its first side surface S2 is a convex surface, and its second side surface S3 is a convex surface; the second lens E2 has positive focal power, and its first side surface S14 is a plane surface, and its second side surface S15 is a convex surface; the third lens E3 has negative focal power, and its first side surface S16 is a concave surface, and its second side surface S17 is a convex surface.

[0154] The visual system of this embodiment also includes a first spacing element P1 located between the first lens E1 and the second lens E2 and against the second side surface of the first lens E1, and a second spacing element P2 located between the second lens E2 and the third lens E3 and against the second side surface of the second lens E2. In this embodiment, the first side may be, for example, the human eye side, and the second side may be, for example, the display side. The second side of the visual system has an image surface IMG.

[0155] The basic parameter table of the visual system of this embodiment is also the same as Table 5 in Example 7, and the high-order coefficient table of the aspheric mirror surface is also the same as Table 6 in Example 7.

[0156] The values ​​of the structural parameters of the visual system of this embodiment are shown in the 'Example 9' column of Table 7. The specific description of the meaning represented by each parameter is the same as that in the above Example 1, and will not be repeated here.

[0157] Fig.13 The visual system MTF curves of Example 7, Example 8 and Example 9 are shown. Fig.13 It can be seen that the visual systems provided in Examples 7, 8 and 9 can achieve good imaging quality.

[0158] Table 7

[0159]

[0160] In addition, in Examples 1 to 9, the effective focal length f of the visual system, the effective focal length f1 of the first lens, the effective focal length f2 of the second lens, the effective focal length f3 of the third lens, the entrance pupil diameter EPD of the visual system, and the distance TD from the first side surface of the first lens to the second side surface of the third lens on the optical axis are respectively shown in Table 8 below.

[0161] Table 8

[0162]

[0163] And, Examples 1 to 9 respectively satisfy the conditions shown in Table 9 below.

[0164] Table 9

[0165]

[0166] The present application also provides an imaging device, which is provided with an electronic photosensitive element for imaging, and the electronic photosensitive element can be a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS). The imaging device can be an independent imaging device such as a digital camera, or an imaging module integrated in a mobile electronic device such as a mobile phone. The imaging device is equipped with the visual system described above.

[0167] 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 protection 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 concept of the present application. For example, the above features are replaced with the technical features with similar functions disclosed in the present application (but not limited to) to form a technical solution.

Claims

1. A visual system, characterized in that: The invention comprises a lens barrel and a lens group and a spacer element group assembled in the lens barrel, wherein: The lens group includes a first lens, a reflective polarizing element, a quarter wave plate, a second lens, a third lens and a partial reflective element arranged in sequence from a first side to a second side along an optical axis, wherein the first lens has positive optical power, and a first side surface thereof is a convex surface; the second lens has positive optical power or negative optical power, and a first side surface thereof is a plane surface; the third lens has positive optical power or negative optical power, and a second side surface thereof is a convex surface; The spacer element group includes: a first spacer element, located between the first lens and the second lens, and abutting against the second side surface of the first lens; a second spacer element, located between the second lens and the third lens, and abutting against the second side surface of the second lens; The visual system meets the following requirements: 9.15 <d2s / CT2<12.6; 0.13≤|d1s-d1m| / T12≤1.96; 3.3 <f / (CP1+EP12)<7.9; Among them, d2s is the inner diameter of the first side of the second spacer element, CT2 is the center thickness of the second lens on the optical axis, d1s is the inner diameter of the first side of the first spacer element, d1m is the inner diameter of the second side of the first spacer element, T12 is the distance from the second side of the first lens to the first side of the second lens on the optical axis, f is the effective focal length of the visual system, CP1 is the maximum thickness of the first spacer element, and EP12 is the distance from the second side of the first spacer element to the first side of the second spacer element on the optical axis.

2. The visual system according to claim 1, characterized in that: The effective focal length f1 of the first lens and the outer diameter D1s of the first side surface of the first spacing element satisfy: 1.95 <f1 / D1s<3.2。 3. The visual system according to claim 1, characterized in that: The effective focal length f3 of the third lens, the inner diameter d0m of the second side end surface of the lens barrel, and the outer diameter D0m of the second side end surface of the lens barrel satisfy: 1.05<|f3| / (d0m+D0m)<1.

95.

4. The visual system according to claim 1, characterized in that: The distance EP01 from the first side end surface of the lens barrel to the first side surface of the first spacing element on 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 satisfy: 5.01≤EP01 / (CTR+CTQ)≤11.

44.

5. The visual system according to claim 1, characterized in that: The curvature radius R1 of the first side surface of the first lens, the curvature radius R6 of the second side surface of the third lens, and the distance L from the first side end surface of the lens barrel to the second side end surface of the lens barrel on the optical axis satisfy: -9.55mm≤(R1 / R6)×L≤-7.35mm.

6. The visual system according to claim 1, characterized in that: The outer diameter D2m of the second side surface of the second spacing element and the outer diameter D1m of the second side surface of the first spacing element satisfy: 3.00mm≤(D2m / D1m)×CT2≤4.11mm.

7. The visual system according to claim 1, characterized in that: The inner diameter d2m of the second side surface of the second spacer element, the dispersion coefficient V3 of the third lens, and the refractive index N3 of the third lens satisfy: 0.95mm <d2m / (V3 / N3)<2.55mm。 8. The visual system according to claim 1, characterized in that: The refractive index N1 of the first lens, the effective focal length f1 of the first lens and the outer diameter D0s of the first side end surface of the lens barrel satisfy: 2.93≤(N1×f1) / D0s≤4.

75.

9. The visual system according to claim 1, characterized in that: The outer diameter D0m of the second side end surface of the lens barrel, the inner diameter d0s of the first side end surface of the lens barrel, and the distance L from the first side end surface of the lens barrel to the second side end surface of the lens barrel on the optical axis satisfy: 12.6mm<(D0m / d0s)×L<13.8mm.

10. The visual system according to claim 1, characterized in that: The maximum thickness CP2 of the second spacer element, the outer diameter D2s of the first side surface of the second spacer element, and the inner diameter d2s of the first side surface of the second spacer element satisfy: 0.9 <CP2 / (D2s-d2s)<2.5。 11. The visual system according to claim 1, characterized in that: The outer diameter D0m of the second side end surface of the lens barrel, the outer diameter D2m of the second side surface of the second spacer element and the center thickness CT3 of the third lens on the optical axis satisfy: 0.7<(D0m-D2m) / CT3<1.

65.

12. The visual system according to claim 1, characterized in that: The distance EP01 from the first side end surface of the lens barrel to the first side surface of the first spacing element on the optical axis and the distance L from the first side end surface of the lens barrel to the second side end surface of the lens barrel on the optical axis satisfy: 0.25<(EP01+EP12) / L<0.

55.

13. The visual system according to claim 1, characterized in that: The inner diameter d1s of the first side surface of the first spacing element and the entrance pupil diameter EPD of the visual system satisfy: 8.40≤d1s / EPD≤8.

79.

14. The visual system according to claim 1, characterized in that: The distance TD between the first side surface of the first lens and the second side surface of the third lens on the optical axis and the maximum thickness CP2 of the second spacing element satisfy: 3.4 <TD / (CP1+CP2)<5.0。

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