Virtual reality system

Abstract

The utility model discloses a virtual reality system, which comprises a first optical system and a second optical system, and the first optical system sequentially comprises a first element group, a second element group, a third element group and a fourth wave plate from a first side to a second side along a first optical axis, and the first element group comprises a first lens with focal power, a reflective polarization element and a quarter wave plate; the second element group comprises a second lens with positive focal power; the third element group comprises a third lens with focal power; and a display; the second optical system sequentially comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens from the object side to the image side along a second optical axis, the third lens has negative focal power, and the second lens and the sixth lens have positive focal power.

Description

Technical Field

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

[0002] Virtual Reality (VR) head-mounted display devices are cutting-edge technological products that utilize virtual reality technology to achieve immersive experiences. Currently, they can be applied in various fields such as education, healthcare, and entertainment, and are loved by more and more people. Among them, the visual system can enter the virtual world, and combined with the perspective system that captures real-world images, it enables users to "see" the real world in the virtual world, enhancing the immersive experience of users.

[0003] However, the optical system of current VR head-mounted display devices has poor performance and low imaging quality; in addition, the capture range of the perspective system lens is limited, which seriously affects the user experience.

[0004] Therefore, how to optimize the optical design scheme of the virtual reality system, improve the optical performance of the system, and make it more adaptable to the human eye and have better imaging quality is one of the technical problems that need to be solved currently. Summary of the Utility Model

[0005] According to an embodiment of the present application, a virtual reality system is provided, including a first optical system and a second optical system. Among them, the first optical system sequentially includes, along a first optical axis from a first side to a second side: a first element group, including a first lens, a reflective polarizing element, and a quarter-wave plate; a second element group, including a second lens with positive optical power; a third element group, including a third lens; the second optical system sequentially includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens along a second optical axis from an object side to an image side, where the third lens has negative optical power and the sixth lens has positive optical power; where the distance TD' on the first optical axis from the first side of the first lens to the second side of the third lens in the first optical system, the distance TTL on the second optical axis from the object side of the first lens in the second optical system to the imaging surface of the second optical system, the effective focal length f' of the first optical system, the effective focal length f of the second optical system, the radius of curvature R4 of the image side of the second lens, the radius of curvature R12 of the image side of the sixth lens, the radius of curvature R3' of the first side of the second lens, and the radius of curvature R6' of the second side of the third lens satisfy: 2 < TD' / TTL < 3.5; -2.5 mm < f / (R4 / R12) < 0 mm; and 0 mm < f' / (R3' / R6') < 16.5 mm.

[0006] In one or more embodiments, the effective focal length f' of the first optical system, the effective focal length f of the second optical system, the maximum field of view FOV' of the first optical system, and the maximum field of view FOV of the second optical system satisfy: 5<[f'×tan(FOV' / 2)] / [f×tan(FOV / 2)]<10.5.

[0007] In one or more embodiments, the entrance pupil diameter EPD' of the first optical system and the entrance pupil diameter EPD of the second optical system satisfy: 2 <EPD' / EPD<6.5。

[0008] In one or more embodiments, the effective focal length f' of the first optical system and the effective focal length f of the second optical system satisfy: 6 <f' / f<11。

[0009] In one or more embodiments, the distance TTL' from the first side of the first lens in the first optical system to the first side of the display of the first optical system on the first optical axis, the sum of the thicknesses ∑CT' of the first lens to the third lens in the first optical system on the first optical axis, the sum of the thicknesses ∑CT of the first lens to the sixth lens in the second optical system on the second optical axis, and the distance TTL from the object side of the first lens in the second optical system to the imaging surface on the second optical axis satisfy: 1 <TTL' / ∑CT'<1.6;1.6<TTL / ∑CT<2.1。

[0010] In one or more embodiments, the focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -3.0 <f1 / f2<-0.5。

[0011] In one or more embodiments, the effective focal length f' of the first optical system, the refractive index NR of the reflective polarizing element, and the refractive index NP of the quarter-wave plate satisfy: 5.5 <f' / (NR+NP)<6.1。

[0012] In one or more embodiments, the radius of curvature R1' of the first side surface of the first lens and the radius of curvature R6' of the second side surface of the third lens satisfy: -0.7 <R6' / R1'<0。

[0013] In one or more embodiments, the second optical system further includes an aperture, and a distance SD from the aperture to the image side surface of the sixth lens and a maximum value CTmax of a center thickness of each lens in the second optical system on the second optical axis satisfy: 2.8 <SD / CTmax<3.7。

[0014] In one or more embodiments, the air interval T12′ between the first element group and the second element group on the first optical axis and the air interval T23′ between the second element group and the third element group on the first optical axis satisfy: 1 <T12' / T23'<2。

[0015] In one or more embodiments, the effective focal length f of the second optical system, the focal length f3 of the third lens, the curvature radius R5 of the object side surface of the third lens, and the curvature radius R6 of the image side surface of the third lens satisfy: -4.5 <f3 / f<-1.5;6<(R5+R6)) / f3<11.5。

[0016] In one or more embodiments, the focal length f6 of the sixth lens and the dispersion coefficient V6 of the sixth lens satisfy: 0 <f6 / V6<1.5。

[0017] In one or more embodiments, the effective focal length f of the second optical system, the focal length f4 of the fourth lens, and the focal length f5 of the fifth lens satisfy: 0<|f / f4+f / f5|<1.

[0018] In one or more embodiments, the distance TD' from the first side of the first lens to the second side of the third lens on the first optical axis in the first optical system, and the maximum value ATmax' of the air interval between adjacent lenses in the first optical system on the first optical axis satisfy: 15 <TD' / ATmax'<21。

[0019] The virtual reality system provided according to the embodiment of the present application may include a first optical system and a second optical system. The first optical system may realize optical path folding by using a polarizing element, which is conducive to the thin and light design of the device. The second optical system may include six lenses, wherein the third lens has a negative optical power, and the second lens and the sixth lens have positive optical power, which is conducive to increasing the field of view of the system and expanding the range of perspective capture of real images. Furthermore, by controlling the ratio of the on-axis distance from the first side surface of the first lens to the second side surface of the third lens in the first optical system to the distance from the object side surface of the first lens to the imaging surface on the optical axis in the second optical system, the total length of the first optical system is effectively shortened, which is beneficial to the miniaturization of the equipment; by controlling the ratio of the effective focal length of the second optical system to the radius of curvature of the image side surface of the second lens and the radius of curvature of the image side surface of the sixth lens, the second optical system is made more compact, which is beneficial to the arrangement of the whole machine; and by controlling the ratio of the effective focal length of the first optical system to the radius of curvature of the first side surface of the second lens and the radius of curvature of the second side surface of the third lens, the direction of the light can be controlled to reduce the height of the light, which is beneficial to reducing the size of the screen; in addition, by controlling the shape of the lens, it is beneficial to the convergence of the light in the edge field of view, thereby improving the optical performance and imaging quality of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0021] Figure 1A schematic plan view of a virtual reality system provided according to an embodiment of the present application is shown;

[0022] Figure 2 A schematic structural diagram of a first optical system according to Embodiment 1 of the present application is shown;

[0023] FIG. 3A to FIG. 3C The axial chromatic aberration curve, the astigmatism curve, and the distortion curve of the first optical system according to the first embodiment of the present application are respectively shown;

[0024] Figure 4 A schematic structural diagram of a first optical system according to Embodiment 2 of the present application is shown;

[0025] FIG. 5A to FIG. 5C The axial chromatic aberration curve, the astigmatism curve, and the distortion curve of the first optical system according to the second embodiment of the present application are respectively shown;

[0026] Figure 6 A schematic structural diagram of a first optical system according to Embodiment 3 of the present application is shown;

[0027] FIG. 7A to FIG. 7C The axial chromatic aberration curve, the astigmatism curve, and the distortion curve of the first optical system according to the third embodiment of the present application are respectively shown;

[0028] Figure 8 A schematic structural diagram of a second optical system according to a fourth embodiment of the present application is shown;

[0029] 9A to 9C The axial chromatic aberration curve, the astigmatism curve, and the distortion curve of the second optical system according to the fourth embodiment of the present application are respectively shown;

[0030] Fig.10 A schematic structural diagram of a second optical system according to Embodiment 5 of the present application is shown;

[0031] FIG. 11A to FIG. 11C The axial chromatic aberration curve, the astigmatism curve, and the distortion curve of the second optical system according to the fifth embodiment of the present application are respectively shown;

[0032] Fig.12 A schematic structural diagram of a second optical system according to Embodiment 6 of the present application is shown;

[0033] FIG. 13A to FIG. 13C The axial chromatic aberration curve, the astigmatism curve, and the distortion curve of the second optical system according to the sixth embodiment of the present application are respectively shown;

[0034] Fig.14 shows a schematic structural diagram of a second optical system according to Embodiment 7 of the present application; and

[0035] FIG. 15A to FIG. 15C The axial chromatic aberration curve, the astigmatism curve, and the distortion curve of the second optical system according to the seventh embodiment of the present application are respectively shown. 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 first 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 position of the convex surface is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the position of the concave surface is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the object is called the object side of the lens, and the surface of each lens closest to the imaging plane is called the image side of the lens.

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

[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 examples 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, without departing from the concept of the present application, several variations and improvements can also be made, which all belong to the protection scope of the present application.

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

[0044] refer to Figure 1 As shown, the virtual reality system 10 according to the exemplary embodiment of the present application may include a first optical system 100 and a second optical system 200. By combining the first optical system 100 and the second optical system 200, the virtual reality fusion of the virtual reality system can be achieved. Specifically, the second optical system 200 can be used to image the real scene, and the formed real image is transmitted to the display screen in the form of an electrical signal; the image surface of the first optical system 100 can be located on the display screen, and the first optical system 100 can be used to project the virtual image on the display screen and the above-mentioned real image transmitted to the display screen, such as projecting it into the eyes of the user, so that the user can see a picture combining virtual and real, and improve the user's immersion.

[0045] The first optical system 100 may be configured as a reentrant visual optical system, for example, and the number of the first optical system 100 may be one or more. The second optical system 200 may be configured as a video perspective optical system, for example, and the number of the second optical system 200 may be one or more. In one example, the virtual reality system 10 may include two symmetrically arranged first optical systems 100. In one example, the virtual reality system 10 also includes a body, the first optical system 100 may be arranged on the inner side of the body, and the second optical system 200 may be arranged on the outer side of the body.

[0046] In an exemplary embodiment, the first optical system 100 may include a first element group, a second element group, a third element group and a display arranged in sequence from the first side to the second side along the first optical axis, wherein the first element group may include a first lens, a reflective polarizing element and a quarter wave plate, the second element group may include a second lens, and the third element group may include a third lens.

[0047] In an exemplary embodiment, the first lens may have positive or negative power, the second lens may have positive power, and the third lens may have positive or negative power. An air gap may be provided between the first element group and the second element group, and between the second element group and the third element group.

[0048] In an exemplary embodiment, the first side of the first optical system 100 may be, for example, the human eye side, and the second side may be, for example, the display side. Accordingly, the first side of each element (the first lens, the second lens, the reflective polarizing element, the quarter wave plate, the third lens, etc.) may be a surface close to the human eye side, and the second side may be a surface close to the display side. In the present application, when light passes through the reflective polarizing element, the reflective polarizing element may reflect light in a certain direction and transmit light orthogonal to the reflected light. The quarter wave plate may be used to convert between circularly polarized light and linearly polarized light to achieve the return of the light path, which is conducive to shortening the length of the first optical system 100.

[0049] In an exemplary embodiment, the first side surface or the second side surface of the first lens, the second lens, and the third lens of the first optical system 100 may be an aspherical surface. An aspherical lens has a better curvature radius characteristic, and has the advantages of improving distortion aberration and improving astigmatism aberration. By using an aspherical lens, aberrations occurring during imaging can be eliminated as much as possible, thereby improving imaging quality.

[0050] In an exemplary embodiment, the first optical system 100 may further include a partial reflective element, which may be, for example, a partial reflective layer attached or plated on the second side of the third lens. The partial reflective layer has a semi-transmissive and semi-reflective effect on the light. The image light from the display screen is refracted and reflected multiple times by the third lens, the second lens, the reflective polarizing element, the quarter-wave plate, the first lens, and the partial reflective element, and is finally projected to the user's eyes. By providing a partial reflective layer on the second side of the third lens, and combining the reflective polarizing element and the quarter-wave plate, the light can be folded back multiple times, thereby effectively reducing the main body length of the first optical system.

[0051] In an exemplary embodiment, the second optical system 200 may include a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged in sequence from the object side to the image side along the second optical axis. An air gap may be provided between two adjacent lenses of the first to sixth lenses. In one example, the first lens and the third lens both have negative optical power, the second lens has positive optical power, the fourth lens and the fifth lens may have positive optical power or negative optical power, and the sixth lens may have positive optical power.

[0052] The virtual reality system 10 according to an exemplary embodiment of the present application can be used with a variety of VR display devices, such as VR headset devices, or mixed reality (MR) headset devices.

[0053] In an exemplary embodiment of the present application, the virtual reality system includes a first optical system and a second optical system. The first optical system sequentially includes a first element group, a second element group, and a third element group along a first optical axis from a first side to a second side. Among them, the first element group includes a reflective polarizing element, a quarter-wave plate, and a first lens; the second element group includes a second lens with a positive optical power; the third element group includes a third lens; the second optical system sequentially includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens along a second optical axis from an object side to an image side. The first lens and the third lens have negative optical powers, the fourth lens and the fifth lens can have positive or negative optical powers, and the second lens and the sixth lens have positive optical powers. Among them, the real image formed by the second optical system is transmitted to the display screen in the form of an electrical signal, and the first optical system is used to project the virtual image on the display screen and the real image transmitted to the display screen.

[0054] In an exemplary embodiment, the virtual reality system of the present application can satisfy the following conditional expressions: 2 < TD' / TTL < 3.5; -2.5 mm < f / (R4 / R12) < 0 mm; and 0 mm < f' / (R3' / R6') < 16.5 mm, where TD' is the distance on the first optical axis from the first side of the first lens to the second side of the third lens in the first optical system, TTL is the distance on the second optical axis from the object side of the first lens to the imaging surface of the second optical system, f' is the effective focal length of the first optical system, R4 is the radius of curvature of the image side of the second lens, R12 is the radius of curvature of the image side of the sixth lens, R3' is the radius of curvature of the first side of the second lens, and R6' is the radius of curvature of the second side of the third lens.

[0055] The virtual reality system according to the above embodiments of the present application includes a first optical system and a second optical system. The first optical system can achieve the folding of the optical path by using a polarization element, which is beneficial to the thin and light design of the device. The second optical system may include six lenses, where the third lens has a negative optical power, and the second lens and the sixth lens have positive optical powers, which is beneficial to increasing the field of view angle of the system and expanding the range of capturing the real picture through perspective. And by controlling the ratio between the on-axis distance from the first side of the first lens to the second side of the third lens in the first optical system and the distance from the object side of the first lens to the imaging surface on the optical axis in the second optical system, the total length of the first optical system is effectively shortened, which is beneficial to the miniaturization of the device; by controlling the ratio of the effective focal length of the second optical system to the curvature radius of the image side of the second lens and the curvature radius of the image side of the sixth lens, the second optical system becomes more compact, which is beneficial to the layout of the whole machine; and by controlling the ratio of the effective focal length of the first optical system to the curvature radius of the first side of the second lens and the curvature radius of the second side of the third lens, the direction of light can be controlled, reducing the height of the light, which is beneficial to reducing the size of the screen; in addition, by controlling the shape of the lens, the convergence of the marginal field light is facilitated, thereby improving the optical performance and imaging quality of the system.

[0056] In an exemplary embodiment, the virtual reality system of the present application may satisfy the following conditional formula: 5 < [f'×tan(FOV' / 2)] / [f×tan(FOV / 2)] < 10.5, where f' is the effective focal length of the first optical system, f is the effective focal length of the second optical system, FOV is the maximum field of view angle of the second optical system, and FOV' is the maximum field of view angle of the first optical system. By controlling the ratio of the effective focal length and the maximum field of view angle of the first optical system to those of the second optical system, it is beneficial to increase the field of view angles of the two optical systems. On the one hand, it improves the immersive experience of the user, and on the other hand, it expands the perspective range.

[0057] In an exemplary embodiment, the virtual reality system of the present application may satisfy the following conditional formula: 2 < EPD' / EPD < 6.5, where EPD' is the entrance pupil diameter of the first optical system and EPD is the entrance pupil diameter of the second optical system. By controlling the ratio of the entrance pupil diameter of the first optical system to that of the second optical system, the entrance pupil diameter of the first optical system is made larger than that of the second optical system, which can increase the light flux and the screen brightness while avoiding the phenomenon that the field of view of the human eye is reduced due to the eye box limitation when the head moves and the eyeball rotates.

[0058] In an exemplary embodiment, the virtual reality system of the present application can satisfy the following conditional expression: 6 < f' / f < 11, where f' is the effective focal length of the first optical system and f is the effective focal length of the second optical system. By controlling the ratio of the effective focal length of the first optical system to the effective focal length of the second optical system, the optical power of the two optical systems is reasonably distributed, and the effective focal length of the first optical system is made greater than the effective focal length of the second optical system, which is beneficial to increasing the field of view angle of the second optical system and expanding the perspective range.

[0059] In an exemplary embodiment, the virtual reality system of the present application can satisfy the following conditional expressions: 1 < TTL' / ∑CT' < 1.6; 1.6 < TTL / ∑CT < 2.1, where ∑CT' is the total thickness of the first lens to the third lens on the first optical axis in the first optical system, ∑CT is the total thickness of the first lens to the sixth lens on the second optical axis in the second optical system, TTL is the distance from the object side of the first lens to the imaging surface on the second optical axis in the second optical system, and TTL' is the axial distance from the first side of the first lens to the first side of the display in the first optical system. By controlling the ratio of the axial distance from the first side of the first lens to the first side of the display to the total thickness of the first lens to the third lens on the first optical axis in the first optical system, and the ratio of the distance from the object side of the first lens to the imaging surface on the optical axis to the total thickness of the first lens to the sixth lens on the second optical axis in the second optical system, the structures of the two optical systems are made more compact, which is beneficial to the overall machine layout.

[0060] In an exemplary embodiment, the virtual reality system of the present application can satisfy the following conditional expression: -3.0 < f1 / f2 < -0.5, where f1 is the focal length of the first lens of the second optical system and f2 is the focal length of the second lens of the second optical system. By controlling the ratio of the focal length of the first lens to the focal length of the second lens of the second optical system, the optical power of the two lenses is reasonably distributed, and the focal length of the first lens is made less than the focal length of the second lens, which is beneficial to increasing the field of view angle of the second optical system.

[0061] In an exemplary embodiment, the virtual reality system of the present application can satisfy the following conditional expression: 5.5 < f' / (NR + NP) < 6.1, where f' is the effective focal length of the first optical system, NR is the refractive index of the reflective polarizing element, and NP is the refractive index of the quarter-wave plate. By controlling the ratio of the effective focal length of the first optical system to the refractive index of the reflective polarizing element and the refractive index of the quarter-wave plate, while controlling the total length of the system, it is beneficial to select a polarizing element with a suitable refractive index to avoid affecting the polarization state of the system.

[0062] In an exemplary embodiment, the virtual reality system of the present application can satisfy the following conditional formula: -0.7 < R6' / R1' < 0, where R1' is the radius of curvature of the first side surface of the first lens of the first optical system, and R6' is the radius of curvature of the second side surface of the third lens of the first optical system. By controlling the ratio of the radius of curvature of the second side surface of the third lens of the first optical system to the radius of curvature of the first side surface of the first lens, the shape of the lens can be reasonably controlled, which is beneficial to the molding of the lens and ensures the processability of the lens.

[0063] In an exemplary embodiment, a diaphragm is further included in the second optical system. The virtual reality system of the present application can satisfy the following conditional formula: 2.8 < SD / CTmax < 3.7, where SD is the distance from the diaphragm of the second optical system to the image side surface of the sixth lens, and CTmax is the maximum value of the central thickness of each lens of the second optical system on the second optical axis. By controlling the ratio of the distance from the diaphragm of the second optical system to the second side surface of the last lens to the maximum value of the central thickness on the optical axis, the arrangement of the lenses inside the second optical system is made more compact, which is beneficial to reducing the size of the chip.

[0064] In an exemplary embodiment, the virtual reality system of the present application can satisfy the following conditional formula: 1 < T12' / T23' < 2, where T12' is the air gap between the first element group and the second element group of the first optical system on the first optical axis, and T23' is the air gap between the second element group and the third element group of the first optical system on the first optical axis. By controlling the ratio of the air gap between the first element group and the second element group of the first optical system on the first optical axis to the air gap between the second element group and the third element group of the first optical system on the first optical axis, the gap between the lenses is shortened, which is beneficial to reducing the total length of the system and making the head-mounted display device thinner and lighter.

[0065] In an exemplary embodiment, the virtual reality system of the present application can satisfy the following conditional formulas: -4.5 < f3 / f < -1.5; 6 < (R5 + R6)) / f3 < 11.5, where f is the effective focal length of the second optical system, f3 is the focal length of the third lens of the second optical system, R5 is the radius of curvature of the object side surface of the third lens of the second optical system, and R6 is the radius of curvature of the image side surface of the third lens of the second optical system. By controlling the ratio of the focal length of the third lens of the second optical system to the effective focal length of the second optical system, and the ratio of the sum of the radius of curvature of the object side surface and the image side surface of the third lens to the focal length of the third lens, the shape of the lens is reasonably controlled to ensure the processability of the third lens.

[0066] In an exemplary embodiment, the virtual reality system of the present application may satisfy the following conditional formula: 0 < f6 / V6 < 1.5, where f6 is the focal length of the sixth lens of the second optical system, and V6 is the dispersion coefficient of the sixth lens of the second optical system. By controlling the ratio of the focal length to the dispersion coefficient of the last lens of the second optical system, it is beneficial to reduce the chromatic aberration of the second optical system, thereby improving the imaging quality.

[0067] In an exemplary embodiment, the virtual reality system of the present application may satisfy the following conditional formula: 0 < |f / f4 + f / f5| < 1, where f is the effective focal length of the second optical system, f4 is the focal length of the fourth lens of the second optical system, and f5 is the focal length of the fifth lens of the second optical system. By controlling the ratio of the effective focal length of the second optical system to the focal lengths of the fourth and fifth lenses, the optical power is reasonably distributed. By setting the optical powers of the two lenses to be one positive and one negative, it is beneficial to correct the system aberration and improve the imaging quality.

[0068] In an exemplary embodiment, the virtual reality system of the present application may satisfy the following conditional formula: 15 < TD' / ATmax' < 21, where TD' is the on-axis distance from the first side of the first lens of the first optical system to the second side of the third lens, and ATmax' is the maximum value of the air gap between adjacent lenses of the first optical system on the first optical axis. By controlling the ratio of the on-axis distance from the first side of the first lens of the first optical system to the second side of the last lens to the maximum value of the air gap between adjacent lenses of the first optical system on the optical axis, the length of the optical system is shortened, the arrangement between the lenses is compact, and it is beneficial to miniaturize the head-mounted device.

[0069] In an exemplary embodiment, the virtual reality system of the present application may include at least one aperture stop. The aperture stop can constrain the optical path and control the light intensity. The aperture stop can be set at an appropriate position in the first optical system or the second optical system. In one example, a first aperture stop may be included, and the first aperture stop may be located between the first side (human eye side) of the first optical system and the first element group. In one example, a second aperture stop may also be included, and the second aperture stop may be located between the first lens and the second lens of the second optical system.

[0070] In an exemplary embodiment, the virtual reality system of the present application may further include a protective glass for protecting the photosensitive element located on the imaging surface.

[0071] In an exemplary embodiment, the effective focal length f' of the first optical system may be, for example, in the range of 17.08 mm to 17.94 mm, and the effective focal length f of the second optical system may be, for example, in the range of 1.85 mm to 2.38 mm.

[0072] According to the virtual reality system of some embodiments of the present application, by reasonably setting the radius of curvature, center thickness, surface shape, refractive index and Abbe number of the lens, as well as the effective focal length, entrance pupil diameter and other parameters of the optical system, it is helpful to improve the imaging effect and ensure the optical performance of the system; and by reasonably setting the parameters such as the aperture, the air gap of the lens and the distance to the display or the imaging surface, it is helpful to ensure the molding and strength of the lens and reduce the sensitivity of the lens; at the same time, it is helpful to constrain the total length of the optical system and improve the portability of the equipment; it can also increase the field of view and enhance the wearing experience of consumers.

[0073] Specific embodiments of the optical system applicable to the above-mentioned embodiments will be further described below with reference to the accompanying drawings.

[0074] Embodiment 1

[0075] The following reference Figures 2 to 3C The first optical system according to the first embodiment of the present application is described. Figure 2 A schematic structural diagram of a first optical system according to Embodiment 1 of the present application is shown.

[0076] like Figure 2 As shown, the first optical system includes a first element group, a second element group and a third element group arranged in sequence from the human eye side to the display side along the first optical axis. The first element group includes a first lens E1', a reflective polarizing element RP and a quarter wave plate QWP; the second element group includes a second lens E2'; and the third element group includes a third lens E3'.

[0077] As an exemplary embodiment, the first optical system may further include a first stop STO', and the first stop STO' may be disposed between the first side of the first optical system and the first lens E1'.

[0078] The first optical system may further include a partially reflective element BS, which may be disposed on the second side of the third lens E3'. A display may be disposed on the second side of the first optical system.

[0079] In an exemplary embodiment, the image light from the display screen may sequentially pass through the third lens E3', the second lens E2' and the quarter wave plate QWP to reach the reflective polarizing element RP, then be reflected at the reflective polarizing element RP, and pass through the quarter wave plate QWP, the second lens E2' and the third lens E3' again to reach the partial reflective element BS, after which the light beam is reflected again at the partial reflective element BS and sequentially passes through the third lens E3', the second lens E2', the quarter wave plate QWP, the reflective polarizing element RP and the first lens E1' to be emitted toward the human eye side. According to the first optical system provided in the embodiment of the present application, the required optical path is folded without affecting the projection quality by combining light reflection and refraction, thereby effectively shortening the main body length of the first optical system.

[0080] In this embodiment, the first lens E1' has positive power, wherein the first side surface of the first lens E1' is convex, and the second side surface is convex. By controlling the surface shape of the first lens E1' close to the human eye side and the display side, it is helpful to control the light emission angle and help improve the field of view.

[0081] In this embodiment, the second lens E2' has positive power, wherein the first side surface of the second lens E2' is concave, and the second side surface is convex. The third lens E3' has positive power, wherein the first side surface of the third lens E3' is convex, and the second side surface is convex. By reasonably controlling the surface shapes of the second lens E2' and the third lens E3', the direction of light can be further optimized, which is beneficial to improving the image quality of the system, and the incident angle of the edge light is constrained, which is beneficial to chip matching.

[0082] Table 1 shows the basic parameters of the first optical system of Example 1, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm). The image light from the display screen passes through the optical surfaces of each element in turn and is finally projected into the human eye.

[0083]

[0084]

[0085] Table 1

[0086] In this embodiment, the first side surface S1' and the second side surface S2' of the first lens E1', the first side surface S5' and the second side surface S6' of the second lens E2', and the first side surface S7' and the second side surface S8' of the third lens E3' are all aspherical surfaces, and the surface shape x of each aspherical lens can be defined by but not limited to the following aspherical surface formula:

[0087]

[0088] Wherein, x is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at a height of h along the optical axis; c is the paraxial curvature of the aspheric surface, c=1 / R (i.e., the paraxial curvature c is the inverse of the curvature radius R in Table 1 above); k is the cone coefficient; Ai is the correction coefficient of the i-th order of the aspheric surface. Table 2 shows the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A36, A37, A38, A39, A40, A41, A42, A43, A44, A45, A46, A47, A48, A49, A50, A51, A52, A53, A54, A55, A56, A57, A58, A59, A60, A61, A71, A72, A73, A74, A75, A76, A77, A78, A79, A80, A81, A81, A82, A83, A84, A85, A90, A91, A10, A111, A122, A133, A134, A135, A136, A137, A143, A159, A164, A175, A180, A190, A201, A212, A223, A233, A244, A259, 10 and A 12 .

[0089] Face number / coefficient A4 A6 A8 A10 A12 S1' -2.6430E-05 1.7279E-08 -3.7429E-10 2.2033E-12 -3.1153E-15 S2' -1.0849E-05 -1.4784E-08 7.5311E-11 -1.2008E-14 0.0000E+00 S5' -4.4124E-07 1.8693E-08 1.5940E-11 4.4891E-15 -4.5548E-17 S6' -1.8006E-05 -3.2396E-09 -1.1316E-11 2.7411E-14 2.9307E-16 S7' -1.0663E-05 1.4288E-08 1.0527E-11 3.8084E-14 1.2810E-16 S8' -4.3315E-06 -4.9026E-09 6.4551E-12 -1.9815E-14 7.0059E-17

[0090] Table 2

[0091] Figure 3A The axial chromatic aberration curve of the first optical system of the first embodiment is shown, which indicates the deviation of the convergence point of light of different wavelengths after passing through the first optical system. Figure 3B The astigmatism curve of the first optical system of the first embodiment is shown, which represents the meridional image curvature and sagittal image curvature corresponding to different field angles. Figure 3C The distortion curve of the first optical system of the first embodiment is shown, which indicates the distortion magnitude values ​​corresponding to different field angles. FIG. 3A to FIG. 3C It can be seen that the first optical system provided in the first embodiment can achieve good imaging quality.

[0092] Embodiment 2

[0093] The following reference Figures 4 to 5C The first optical system according to the second embodiment of the present application is described. Figure 4 The schematic diagram of the structure of the first optical system according to the second embodiment of the present application is shown. In this embodiment and the following third embodiment, for the sake of brevity, some descriptions similar to those in the first embodiment will be omitted.

[0094] like Figure 4 As shown, the first optical system includes, in sequence from the first side to the second side along the first optical axis: a first aperture STO'; a first element group, including a first lens E1', a reflective polarizing element RP and a quarter-wave plate QWP; a second element group, including a second lens E2'; and a third element group, including a third lens E3' and a partially reflective element BS.

[0095] In this embodiment, the first lens E1' has positive power, wherein the first side surface of the first lens E1' is convex, and the second side surface is convex. By controlling the surface shape of the first lens E1' close to the human eye side and the display side, it is helpful to control the light emission angle and help improve the field of view.

[0096] In this embodiment, the second lens E2' has positive focal power, wherein the first side surface of the second lens E2' is concave and the second side surface is convex. The third lens E3' has negative focal power, wherein the first side surface of the third lens E3' is concave and the second side surface is convex. By reasonably controlling the surface shapes of the second lens E2' and the third lens E3', the direction of light can be further optimized, which is beneficial to improving the image quality of the system, and the incident angle of the edge light is constrained, which is beneficial to chip matching.

[0097] Table 3 shows the basic parameters of the first optical system of Example 2, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm). The image light from the display screen passes through the optical surfaces of each component in sequence and is finally projected into the human eye.

[0098] Face number element Surface type Radius of curvature thickness Refractive Index Abbe number Cone coefficient Spherical endless endless STO First aperture (STO') Spherical endless 12.7500 S1' First lens (E1') Aspheric 1254.0868 3.7450 1.5460 55.9235 0.0000 S2' Reflective polarizer (RP) Aspheric -58.0193 0.0992 1.5000 57.0000 0.0000 S3' Quarter Wave Plate (QWP) Aspheric -58.0193 0.0992 1.5000 57.0000 S4' Aspheric -58.0193 0.5435 S5' Second lens (E2') Aspheric -45.4985 4.3124 1.5460 55.9235 0.0000 S6' Aspheric -27.5610 0.4250 0.0000 S7' Third lens (E3') Aspheric -31.4394 3.0605 1.5460 55.9235 0.0000 S8' Partially reflective element (BS) Aspheric -37.7778 -3.0605 1.5460 55.9235 0.0000 S7' Aspheric -31.4394 -0.4250 S6' Second lens (E2') Aspheric -27.5610 -4.3124 1.5460 55.9235 S5' Aspheric -45.4985 -0.5435 S4' Reflective polarizer (RP) Aspheric -58.0193 -0.0992 1.5000 57.0000 S3' Quarter Wave Plate (QWP) Aspheric -58.0193 0.0992 1.5000 57.0000 S4' Aspheric -58.0193 0.5435 S5' Second lens (E2') Aspheric -45.4985 4.3124 1.5460 55.9235 S6' Aspheric -27.5610 0.4250 S7' Third lens (E3') Aspheric -31.4394 3.0605 1.5460 55.9235 S8' Aspheric -37.7778 3.3997

[0099] Table 3

[0100] In this embodiment, the first side surface S1 ′ and the second side surface S2 ′ of the first lens E1 ′, the first side surface S5 ′ and the second side surface S6 ′ of the second lens E2 ′, and the first side surface S7 ′ and the second side surface S8 ′ of the third lens E3 ′ are all aspherical surfaces.

[0101] Table 4 shows the high-order coefficients A4, A6, A8, A9 and A10 of the aspherical mirror surfaces S1', S2', S5', S6', S7' and S8' that can be used in the second embodiment. 10 and A 12 Wherein, each aspheric surface shape can be defined by the formula (1) given in the above embodiment 1.

[0102] Face number / coefficient A4 A6 A8 A10 A12 S1' -5.2757E-05 9.3110E-08 -1.2306E-09 4.9156E-12 -7.6151E-15 S2' -3.4081E-05 5.8436E-08 -6.7131E-10 2.1240E-12 0.0000E+00 S5' -1.0628E-05 -1.3745E-08 5.1135E-11 -4.1079E-13 3.8432E-18 S6' -1.9571E-05 -2.9713E-08 -4.0891E-10 4.0226E-12 -9.6980E-15 S7' -2.7705E-05 -8.9272E-08 1.5793E-10 -3.5020E-13 2.3168E-15 S8' -8.4159E-06 -5.8918E-09 -1.3562E-11 9.9713E-15 4.8754E-17

[0103] Table 4

[0104] Figure 5A The axial chromatic aberration curve of the first optical system of the second embodiment is shown, which indicates that the convergence point of light of different wavelengths deviates after passing through the first optical system. Figure 5B The astigmatism curve of the first optical system of the second embodiment is shown, which represents the meridional image curvature and sagittal image curvature corresponding to different field angles. Figure 5C The distortion curve of the first optical system of the second embodiment is shown, which indicates the distortion magnitude values ​​corresponding to different field angles. FIG. 5A to FIG. 5C It can be seen that the first optical system provided in the second embodiment can achieve good imaging quality.

[0105] Embodiment 3

[0106] The following reference Figures 6 to 7C The first optical system according to the third embodiment of the present application is described. Figure 6 A schematic structural diagram of a first optical system according to Embodiment 3 of the present application is shown.

[0107] like Figure 6 As shown, the first optical system includes, in sequence from the first side to the second side along the first optical axis: a first aperture STO'; a first element group, including a first lens E1', a reflective polarizing element RP and a quarter-wave plate QWP; a second element group, including a second lens E2'; and a third element group, including a third lens E3' and a partially reflective element BS.

[0108] In this embodiment, the first lens E1' has a negative optical power, wherein the first side surface of the first lens E1' is a convex surface and the second side surface is a concave surface. By controlling the surface shape of the first lens E1' close to the human eye side and the display side, it is helpful to control the light emission angle and help improve the field of view.

[0109] In this embodiment, the second lens E2' has positive power, wherein the first side surface of the second lens E2' is concave and the second side surface is convex. The third lens E3' has positive power, wherein the first side surface of the third lens E3' is concave and the second side surface is convex. By properly controlling the surface shapes of the second lens E2' and the third lens E3', the direction of light can be further optimized, which is beneficial to improving the image quality of the system, and the incident angle of the edge light is constrained, which is beneficial to chip matching.

[0110] Table 5 shows the basic parameters of the first optical system of Example 3, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm). The image light from the display screen passes through the optical surfaces of each element in turn and is finally projected into the human eye.

[0111]

[0112]

[0113] Table 5

[0114] In this embodiment, the first side surface S1 ′ and the second side surface S2 ′ of the first lens E1 ′, the first side surface S5 ′ and the second side surface S6 ′ of the second lens E2 ′, and the first side surface S7 ′ and the second side surface S8 ′ of the third lens E3 ′ are all aspherical surfaces.

[0115] Table 6 shows the high-order coefficients A4, A6, A8, A9 and A10 that can be used for the aspherical mirror surfaces S1', S2', S5', S6', S7' and S8' in the third embodiment. 10 and A 12 Wherein, each aspheric surface shape can be defined by the formula (1) given in the above embodiment 1.

[0116] Face number / coefficient A4 A6 A8 A10 A12 S1' -3.7817E-05 9.1299E-09 -3.7637E-10 1.7155E-12 -3.4337E-16 S2' -1.0513E-05 -4.9432E-09 7.4603E-11 -5.9401E-14 0.0000E+00 S5' 2.5711E-06 1.1626E-08 7.3457E-12 2.3016E-14 2.2143E-17 S6' -3.2378E-06 1.5693E-08 1.0196E-11 7.6973E-14 1.0448E-16 S7' -9.7535E-06 2.9919E-09 -9.6016E-12 2.5725E-14 1.7504E-16 S8' -5.2725E-06 -1.8407E-09 6.9290E-12 -8.5217E-15 4.3428E-17

[0117] Table 6

[0118] Fig. 7A The axial chromatic aberration curve of the first optical system of the third embodiment is shown, which indicates the deviation of the convergence point of light of different wavelengths after passing through the first optical system. Figure 7B The astigmatism curve of the first optical system of the third embodiment is shown, which represents the meridional image curvature and sagittal image curvature corresponding to different field angles. Figure 7C The distortion curve of the first optical system of the third embodiment is shown, which indicates the distortion magnitude values ​​corresponding to different field angles. FIG. 7A to FIG. 7C It can be seen that the first optical system provided in the third embodiment can achieve good imaging quality.

[0119] Table 7 below shows basic parameter data of the first optical system according to the above-mentioned embodiments 1 to 3 of the present application, wherein the units of focal length, thickness and distance are all millimeters (mm).

[0120]

[0121]

[0122] Table 7

[0123] Specific embodiments of the second optical system applicable to the above-mentioned embodiment will be further described below with reference to the accompanying drawings.

[0124] Embodiment 4

[0125] The following reference Figures 8 to 9C The second optical system according to the fourth embodiment of the present application is described.

[0126] like Figure 8 As shown, the second optical system may include a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5 and a sixth lens E6 arranged in sequence from the object side to the image side along the second optical axis.

[0127] In an exemplary embodiment, the second optical system may further include a second stop STO, which may be disposed, for example, between the first lens E1 and the second lens E2.

[0128] In this embodiment, the first lens E1 has negative optical power, its object side surface S1 is convex, and its image side surface S2 is concave. The second lens E2 has positive optical power, its object side surface S3 is convex, and its image side surface S4 is convex. The third lens E3 has negative optical power, its object side surface S5 is concave, and its image side surface S6 is convex. The fourth lens E4 has positive optical power, its object side surface S7 is convex, and its image side surface S8 is convex. The fifth lens E5 has negative optical power, its object side surface S9 is concave, and its image side surface S10 is convex. The sixth lens E6 has positive optical power, its object side surface S11 is convex, and its image side surface S12 is concave. The filter E7 has an object side surface S13 and an image side surface S14. The light from the object passes through each surface S1 to S14 in sequence and is finally imaged on the imaging surface S15.

[0129] Table 8 shows a basic parameter table of the second optical system of Example 4, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm).

[0130]

[0131] Table 8

[0132] In this embodiment, the object side surface and the image side surface of any lens from the first lens E1 to the sixth lens E6 are both aspherical surfaces, and the surface shape x of each aspherical lens can be defined by, but not limited to, the formula (1) given in the first embodiment. Table 9 shows the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A36, A37, A38, A39, A40, A41, A42, A43, A44, A45, A46, A47, A48, A49, A50, A5 10 , A 12 , A 14 and A 16 .

[0133] Face number A4 A6 A8 A10 A12 A14 A16 S1 4.8454E-01 -9.9458E-01 1.8952E+00 -3.1215E+00 3.1278E+00 -1.4465E+00 1.4494E-01 S2 1.2811E+00 -1.2070E+00 7.8169E+00 -2.7861E+01 7.5130E+01 -7.2789E+01 7.2164E+01 S3 7.4196E-02 -2.7097E-01 6.0163E-01 -6.3735E+00 2.0161E+01 -7.8184E+01 1.4748E+02 S4 -8.1252E-01 2.9673E+00 -1.6520E+01 5.7397E+01 -1.5034E+02 2.1542E+02 -1.1346E+02 S5 -3.1492E-02 -2.6626E-02 -2.3127E+00 6.1418E+00 -1.6609E+01 1.6202E+01 -1.6094E+01 S6 -3.3944E-01 1.2577E+00 -4.5582E+00 1.1410E+01 -1.8239E+01 1.5327E+01 -6.0878E+00 S7 -8.9841E-02 -1.9480E-02 5.5650E-01 -2.2598E+00 4.9000E+00 -6.3998E+00 5.0293E+00 S8 -6.8179E-02 2.5662E-01 -8.9680E-01 2.1424E+00 -3.1447E+00 3.1708E+00 -2.2194E+00 S9 -6.0717E-03 1.4127E-02 -3.6736E+00 1.5476E+01 -2.5084E+01 1.8427E+01 -5.1973E+00 S10 4.8075E-01 -1.0397E+00 3.0577E-01 2.6076E+00 -3.8932E+00 2.1448E+00 -4.2840E-01 S11 -5.3735E-01 2.8790E-01 -1.1487E+00 2.1094E+00 -1.7716E+00 7.9228E-01 -1.5788E-01 S12 -3.6703E-01 2.1984E-01 -6.5962E-02 -3.5071E-03 6.5395E-03 -1.1303E-03 -1.4438E-06

[0134] Table 9

[0135] Fig. 9A The axial chromatic aberration curve of the second optical system of the fourth embodiment is shown, which indicates that the convergence point of light of different wavelengths after passing through the second optical system deviates. Fig. 9B The astigmatism curve of the second optical system of the fourth embodiment is shown, which represents the meridional image curvature and sagittal image curvature corresponding to different image heights. Fig. 9C The distortion curve of the second optical system of the fourth embodiment is shown, which indicates the distortion magnitude values ​​corresponding to different image heights. 9A to 9C It can be seen that the second optical system provided in the fourth embodiment can achieve good imaging quality.

[0136] Embodiment 5

[0137] The following reference Figures 10 to 11CThe second optical system according to the fifth embodiment of the present application is described.

[0138] like Fig.10 As shown, the second optical system may include a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5 and a sixth lens E6 arranged in sequence from the object side to the image side along the second optical axis. The second stop STO may be disposed between the first lens E1 and the second lens E2.

[0139] The first lens E1 has negative optical power, and its object side surface S1 is concave, and its image side surface S2 is concave. The second lens E2 has positive optical power, and its object side surface S3 is convex, and its image side surface S4 is convex. The third lens E3 has negative optical power, and its object side surface S5 is concave, and its image side surface S6 is concave. The fourth lens E4 has negative optical power, and its object side surface S7 is concave, and its image side surface S8 is convex. The fifth lens E5 has positive optical power, and its object side surface S9 is convex, and its image side surface S10 is concave. The sixth lens E6 has positive optical power, and its object side surface S11 is convex, and its image side surface S12 is concave. The filter E7 has an object side surface S13 and an image side surface S14. The light from the object passes through each surface S1 to S14 in sequence and is finally imaged on the imaging surface S15.

[0140] Table 10 shows a basic parameter table of the second optical system of Example 5, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm).

[0141]

[0142]

[0143] Table 10

[0144] In this embodiment, the object side surface and the image side surface of any lens from the first lens E1 to the sixth lens E6 are both aspherical surfaces, and the surface shape x of each aspherical lens can be defined by, but not limited to, the formula (1) given in the first embodiment. Table 11 shows the high-order coefficients A4, A6, A8, A9, A10, A111, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A36, A37, A38, A39, A40, A41, A42, A43, A44, A45, A46, A47, A48, A49, A50, 10 , A 12 , A 14 and A 16 .

[0145] Face number A4 A6 A8 A10 A12 A14 A16 S1 3.0679E-01 -5.7122E-01 9.1480E-01 -1.1500E+00 9.8242E-01 -4.8575E-01 1.0294E-01 S2 4.1642E-01 -4.1763E-01 5.0317E-01 -1.0474E+00 3.8729E+00 -6.3476E+00 3.6468E+00 S3 1.3405E-02 1.2299E-02 -1.9130E+00 1.1053E+01 -3.4750E+01 5.2245E+01 -3.3542E+01 S4 -4.0927E-01 2.7524E-01 -1.9862E-01 -7.7567E-01 1.4408E+00 -1.0471E+00 -1.2639E-01 S5 -8.8175E-02 -5.0365E-01 5.8568E-01 -3.3053E-04 -1.4381E+00 2.2983E+00 -7.9297E-01 S6 -1.5246E-01 3.0653E-01 -1.1157E+00 2.6968E+00 -3.6961E+00 2.8821E+00 -8.3937E-01 S7 -2.1666E-02 7.1515E-02 4.1666E-01 -2.0996E+00 4.9057E+00 -6.7406E+00 5.4472E+00 S8 -2.7023E-01 8.1076E-01 -1.8384E+00 3.1584E+00 -4.1077E+00 4.0501E+00 -2.7573E+00 S9 -3.4526E-01 8.5137E-01 -1.9637E+00 2.3907E+00 -1.6469E+00 6.3172E-01 -1.2696E-01 S10 -1.3136E-01 2.9697E-01 -6.4101E-01 7.1208E-01 -4.2496E-01 1.3198E-01 -1.6681E-02 S11 -2.5246E-01 -3.8212E-01 1.0962E+00 -1.2188E+00 6.8493E-01 -1.8826E-01 2.0139E-02 S12 -3.9802E-01 3.5061E-01 -1.9183E-01 4.9671E-02 -8.7981E-04 -2.4357E-03 3.8649E-04

[0146] Table 11

[0147] Fig.11A The axial chromatic aberration curve of the second optical system of the fifth embodiment is shown, which indicates that the convergence point of light of different wavelengths deviates after passing through the second optical system. Fig. 11BThe astigmatism curve of the second optical system of the fifth embodiment is shown, which represents the meridional image curvature and sagittal image curvature corresponding to different image heights. Fig. 11C The distortion curve of the second optical system of the fifth embodiment is shown, which indicates the distortion magnitude values ​​corresponding to different image heights. FIG. 11A to FIG. 11C It can be seen that the second optical system provided in the fifth embodiment can achieve good imaging quality.

[0148] Embodiment 6

[0149] The following reference Figures 12 to 13C The second optical system according to the sixth embodiment of the present application is described.

[0150] like Fig.12 As shown, the second optical system may include a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5 and a sixth lens E6 arranged in sequence from the object side to the image side along the second optical axis. The second stop STO may be disposed between the first lens E1 and the second lens E2.

[0151] The first lens E1 has negative optical power, and its object side surface S1 is convex, and its image side surface S2 is concave. The second lens E2 has positive optical power, and its object side surface S3 is convex, and its image side surface S4 is convex. The third lens E3 has negative optical power, and its object side surface S5 is concave, and its image side surface S6 is convex. The fourth lens E4 has positive optical power, and its object side surface S7 is convex, and its image side surface S8 is convex. The fifth lens E5 has negative optical power, and its object side surface S9 is concave, and its image side surface S10 is convex. The sixth lens E6 has positive optical power, and its object side surface S11 is convex, and its image side surface S12 is concave. The filter E7 has an object side surface S13 and an image side surface S14. The light from the object passes through each surface S1 to S14 in sequence and is finally imaged on the imaging surface S15.

[0152] Table 12 shows a basic parameter table of the second optical system of Example 6, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm).

[0153]

[0154] Table 12

[0155] In this embodiment, the object side surface and the image side surface of any lens from the first lens E1 to the sixth lens E6 are both aspherical surfaces, and the surface shape x of each aspherical lens can be defined by, but not limited to, the formula (1) given in the first embodiment. Table 13 shows the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A36, A37, A38, A39, A40, A41, A42, A43, A44, A45, A46, A47, A48, A49, A50, A 10 , A 12 , A 14 and A 16.

[0156]

[0157]

[0158] Table 13

[0159] Fig.13A The axial chromatic aberration curve of the second optical system of Example 6 is shown, which indicates that the convergence point of light of different wavelengths deviates after passing through the second optical system. Fig. 13B The astigmatism curve of the second optical system of Example 6 is shown, which represents the meridional image curvature and sagittal image curvature corresponding to different image heights. Fig. 13C The distortion curve of the second optical system of Example 6 is shown, which indicates the distortion magnitude values ​​corresponding to different image heights. FIG. 13A to FIG. 13C It can be seen that the second optical system provided in Example 6 can achieve good imaging quality.

[0160] Embodiment 7

[0161] The following reference Figures 14 to 15C The second optical system according to the seventh embodiment of the present application is described.

[0162] like Fig.14 As shown, the second optical system may include a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5 and a sixth lens E6 arranged in sequence from the object side to the image side along the second optical axis. The second stop STO may be disposed between the first lens E1 and the second lens E2.

[0163] The first lens E1 has negative optical power, and its object side surface S1 is concave, and its image side surface S2 is convex. The second lens E2 has positive optical power, and its object side surface S3 is convex, and its image side surface S4 is convex. The third lens E3 has negative optical power, and its object side surface S5 is concave, and its image side surface S6 is concave. The fourth lens E4 has negative optical power, and its object side surface S7 is concave, and its image side surface S8 is convex. The fifth lens E5 has positive optical power, and its object side surface S9 is convex, and its image side surface S10 is concave. The sixth lens E6 has positive optical power, and its object side surface S11 is convex, and its image side surface S12 is concave. The filter E7 has an object side surface S13 and an image side surface S14. The light from the object passes through each surface S1 to S14 in sequence and is finally imaged on the imaging surface S15.

[0164] Table 14 shows a basic parameter table of the second optical system of Example 7, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm).

[0165]

[0166]

[0167] Table 14

[0168] In this embodiment, the object side surface and the image side surface of any lens from the first lens E1 to the sixth lens E6 are both aspherical surfaces, and the surface shape x of each aspherical lens can be defined by, but not limited to, the formula (1) given in the first embodiment. Table 15 shows the high-order coefficients A4, A6, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A36, A37, A38, A39, A40, A41, A42, A43, A44, A45, A46, A47, A48, A49, A50, A 10 , A 12 , A 14 and A 16 .

[0169] Face number A4 A6 A8 A10 A12 A14 A16 S1 1.9762E-01 -2.7445E-01 3.2783E-01 -3.0738E-01 1.9586E-01 -7.2229E-02 1.1417E-02 S2 2.6824E-01 -2.0065E-01 1.8031E-01 -2.7995E-01 7.7210E-01 -9.4387E-01 4.0446E-01 S3 8.6347E-03 5.9094E-03 -6.8553E-01 2.9542E+00 -6.9278E+00 7.7686E+00 -3.7201E+00 S4 -2.6364E-01 1.3224E-01 -7.1176E-02 -2.0733E-01 2.8723E-01 -1.5570E-01 -1.4018E-02 S5 -5.6799E-02 -2.4198E-01 2.0988E-01 -8.8347E-05 -2.8670E-01 3.4175E-01 -8.7947E-02 S6 -9.8211E-02 1.4727E-01 -3.9982E-01 7.2083E-01 -7.3685E-01 4.2856E-01 -9.3093E-02 S7 -2.5087E-02 8.2807E-02 4.8245E-01 -2.4311E+00 5.6803E+00 -7.8049E+00 6.3073E+00 S8 -3.1290E-01 9.3877E-01 -2.1286E+00 3.6571E+00 -4.7563E+00 4.6896E+00 -3.1927E+00 S9 -2.2240E-01 4.0905E-01 -7.0372E-01 6.3901E-01 -3.2833E-01 9.3934E-02 -1.4081E-02 S10 -8.4616E-02 1.4268E-01 -2.2971E-01 1.9033E-01 -8.4720E-02 1.9624E-02 -1.8500E-03 S11 -1.6262E-01 -1.8359E-01 3.9283E-01 -3.2577E-01 1.3655E-01 -2.7993E-02 2.2336E-03 S12 -2.5639E-01 1.6845E-01 -6.8743E-02 1.3277E-02 -1.7540E-04 -3.6219E-04 4.2865E-05

[0170] Table 15

[0171] Fig.15A The axial chromatic aberration curve of the second optical system of Example 7 is shown, which indicates that the convergence point of light of different wavelengths after passing through the second optical system deviates. Fig. 15B The astigmatism curve of the second optical system of Example 7 is shown, which represents the meridional image curvature and sagittal image curvature corresponding to different image heights. Fig. 15C The distortion curve of the second optical system of the seventh embodiment is shown, which indicates the distortion magnitude values ​​corresponding to different image heights. FIG. 15A to FIG. 15C It can be seen that the second optical system provided in the seventh embodiment can achieve good imaging quality.

[0172] Table 16 below shows basic parameter data of the second optical system according to the above-mentioned embodiments 4 to 7 of the present application, wherein the units of focal length, thickness and distance are all millimeters (mm).

[0173] Parameters / Examples Four five six seven f(mm) 1.85 2.06 2.26 2.38 f1(mm) -2.69 -2.78 -3.29 -3.21 f2(mm) 1.80 1.38 2.20 1.60 f3(mm) -7.31 -4.45 -8.93 -5.15 f4(mm) 1.50 -104.47 1.83 -120.97 f5(mm) -2.62 34.96 -3.21 40.48 f6(mm) 35.37 11.80 43.23 13.66 TTL(mm) 4.18 4.72 5.11 5.47 ImgH(mm) 1.99 2.22 2.43 2.57 FOV(°) 91.37 100.78 91.37 100.78 EPD(mm) 0.84 0.93 1.02 1.07

[0174] Table 16

[0175] refer to Figure 1According to the implementation manner of the present application, the virtual reality system 10 provided can be composed of the first optical system in any one of the above embodiments and the second optical system in any one of the above embodiments. The first optical system and the second optical system can be combined in pairs to form 12 virtual reality systems, that is, the virtual reality system has 12 examples. Among them, the virtual reality system corresponding to Example 1 is composed of the first optical system of Example 1 and the second optical system of Example 4, the virtual reality system corresponding to Example 2 is composed of the first optical system of Example 1 and the second optical system of Example 5, the virtual reality system corresponding to Example 3 is composed of the first optical system of Example 1 and the second optical system of Example 6, the virtual reality system corresponding to Example 4 is composed of the first optical system of Example 1 and the second optical system of Example 7, the virtual reality system corresponding to Example 7 is composed of the first optical system of Example 2 and the second optical system of Example 6, the virtual reality system corresponding to Example 8 is composed of the first optical system of Example 2 and the second optical system of Example 7, the virtual reality system corresponding to Example 9 is composed of the first optical system of Example 3 and the second optical system of Example 4, the virtual reality system corresponding to Example 10 is composed of the first optical system of Example 3 and the second optical system of Example 5, the virtual reality system corresponding to Example 11 is composed of the first optical system of Example 3 and the second optical system of Example 6, and the virtual reality system corresponding to Example 12 is composed of the first optical system of Example 3 and the second optical system of Example 7.

[0176] In summary, the above Examples 1 to 12 satisfy the conditions shown in Table 17 and Table 18 below, respectively.

[0177] Conditional / Example 1 2 3 4 5 6 2<TD' / TTL<3.5 3.08 2.94 2.75 2.73 2.60 2.43 -2.5mm<f / (R4 / R12)<0mm -0.78 -0.78 -0.78 -1.46 -1.46 -1.46 0mm<f' / (R3' / R6')<16.5mm 6.24 14.65 0.18 6.24 14.65 0.18 5<[f'×tan(FOV' / 2)] / [f×tan(FOV / 2)]<10.5 9.48 9.33 9.03 7.22 7.10 6.87 6<f' / f<11 9.71 9.55 9.24 8.72 8.58 8.30 1<TTL' / ∑CT'<1.6 1.38 1.41 1.44 1.38 1.41 1.44 1.6<TTL / ∑CT<2.1 1.82 1.82 1.82 1.88 1.88 1.88 -3.0<f1 / f2<-0.5 -1.50 -1.50 -1.50 -2.00 -2.00 -2.00 -0.7<R6' / R1'<0 -0.44 -0.03 -0.03 -0.44 -0.03 -0.03 5.5<f' / (NR+NP)<6.1 5.98 5.88 5.69 5.98 5.88 5.69 2.8<SD / CTmax<3.7 3.15 3.15 3.15 3.40 3.40 3.40 1<T12' / T23'<2 1.57 1.75 1.24 1.57 1.75 1.24 -4.5<f3 / f<-1.5 -3.96 -3.96 -3.96 -2.16 -2.16 -2.16 <h2 style=";text-align:left;direction:ltr">6<(R5+R6)) / f3<11.5<h2 style=";text-align:left;direction:ltr"> 6.58 6.58 6.58 9.96 9.96 9.96 0<f6 / V6<1.5 0.63 0.63 0.63 0.21 0.21 0.21 0<|f / f4+f / f5|<1 0.53 0.53 0.53 0.04 0.04 0.04 15<TD' / ATmax'<21 19.30 16.56 18.38 19.30 16.56 18.38 2<EPD' / EPD<6.5 4.07 5.65 5.65 3.67 5.10 5.10

[0178] Table 17

[0179]

[0180]

[0181] Table 18

[0182] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the utility model involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the concept of the utility model. For example, the above features are replaced with the technical features with similar functions disclosed in the present application (but not limited to) by each other to form a technical solution.

Claims

1. A virtual reality system, characterized in that: It includes a first optical system and a second optical system, where the first optical system sequentially includes, along a first optical axis, from a first side to a second side: a first element group including a first lens with a focal power, a reflective polarizing element, and a quarter-wave plate; a second element group including a second lens with a positive focal power; a third element group including a third lens with a focal power; and a display; the second optical system sequentially includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens along a second optical axis from an object side to an image side, where the third lens has a negative focal power, and the second lens and the sixth lens have positive focal powers; wherein, the distance TD' on the first optical axis from the first side surface of the first lens in the first optical system to the second side surface of the third lens, the distance TTL on the second optical axis from the object side surface of the first lens in the second optical system to the imaging surface of the second optical system, the effective focal length f' of the first optical system, the effective focal length f of the second optical system, the curvature radius R4 of the image side surface of the second lens, the curvature radius R12 of the image side surface of the sixth lens, the curvature radius R3' of the first side surface of the second lens, and the curvature radius R6' of the second side surface of the third lens satisfy: 2 < TD' / TTL < 3.5; -2.5 mm < f / (R4 / R12) < 0 mm; and 0 mm < f' / (R3' / R6') < 16.5 mm.

2. The virtual reality system according to claim 1, wherein: The effective focal length f' of the first optical system, the effective focal length f of the second optical system, the maximum field of view FOV' of the first optical system, and the maximum field of view FOV of the second optical system satisfy: 5 < [f'×tan(FOV' / 2)] / [f×tan(FOV / 2)] < 10.

5.

3. The virtual reality system according to claim 1, wherein: The entrance pupil diameter EPD' of the first optical system and the entrance pupil diameter EPD of the second optical system satisfy: 2 < EPD' / EPD < 6.

5.

4. The virtual reality system according to claim 1, wherein: The effective focal length f' of the first optical system and the effective focal length f of the second optical system satisfy: 6 < f' / f < 11.

5. The virtual reality system according to claim 1, wherein: The distance TTL' on the first optical axis from the first side surface of the first lens in the first optical system to the first side surface of the display of the first optical system, the total thickness sum ∑CT on the first optical axis from the first lens to the third lens in the first optical system, the total thickness sum ∑CT on the second optical axis from the first lens to the sixth lens in the second optical system, and the distance TTL on the second optical axis from the object side surface of the first lens in the second optical system to the imaging surface satisfy: 1 < TTL' / ∑CT' < 1.6; 1.6 < TTL / ∑CT < 2.

1.

6. The virtual reality system according to claim 1, wherein: The focal length f1 of the first lens and the focal length f2 of the second lens satisfy: -3.0 < f1 / f2 < -0.

5.

7. The virtual reality system according to claim 1, wherein: The effective focal length f' of the first optical system, the refractive index NR of the reflective polarizing element, and the refractive index NP of the quarter-wave plate satisfy: 5.5 <f' / (NR+NP)<6.1。 8. The virtual reality system according to claim 1, wherein: The curvature radius R1' of the first side surface of the first lens and the curvature radius R6' of the second side surface of the third lens satisfy: -0.7 <R6' / R1'<0。 9. The virtual reality system according to claim 1, wherein: The second optical system further comprises a stop, The distance SD from the aperture to the image side surface of the sixth lens and the maximum value CTmax of the center thickness of each lens in the second optical system on the second optical axis satisfy: 2.8 <SD / CTmax<3.7。 10. The virtual reality system according to claim 1, wherein: The air interval T12′ between the first element group and the second element group on the first optical axis and the air interval T23′ between the second element group and the third element group on the first optical axis satisfy: 1 <T12' / T23'<2。 11. The virtual reality system according to any one of claims 1 to 10, wherein: The effective focal length f of the second optical system, the focal length f3 of the third lens, the curvature radius R5 of the object side surface of the third lens, and the curvature radius R6 of the image side surface of the third lens satisfy: -4.5 <f3 / f<-1.5;6<(R5+R6)) / f3<11.5。 12. The virtual reality system according to any one of claims 1 to 10, wherein: The focal length f6 of the sixth lens and the dispersion coefficient V6 of the sixth lens satisfy: 0 <f6 / V6<1.5。 13. The virtual reality system according to any one of claims 1 to 10, wherein: The effective focal length f of the second optical system, the focal length f4 of the fourth lens and the focal length f5 of the fifth lens satisfy: 0<|f / f4+f / f5|<1.

14. The virtual reality system according to any one of claims 1 to 10, wherein: The distance TD' from the first side surface of the first lens to the second side surface of the third lens on the first optical axis in the first optical system and the maximum value ATmax' of the air interval between adjacent lenses in the first optical system on the first optical axis satisfy: 15 <TD' / ATmax'<21。

Images