Virtual reality system

Abstract

The invention discloses a virtual reality system, which comprises a visual lens and a positioning lens, and is characterized in that the visual lens sequentially comprises a first element group, a second element group, a third element group and a fourth element group from a first side far away from a screen to a second side close to the screen along a first optical axis, wherein the first side surface or the second side surface of the first lens is a plane; the second element group comprises a second lens with positive focal power; the third element group comprises a third lens with positive focal power; the positioning lens sequentially comprises a first lens with negative focal power, a second lens with negative focal power, a third lens with positive focal power, a fourth lens with focal power, a fifth lens with positive focal power and a sixth lens with negative focal power from the object side to the image side along a second optical axis; the seventh lens has positive focal power; and the eighth lens has positive focal power.

Description

Technical Field

[0001] The present application relates to the field of optical elements, and in particular, to a virtual reality system. Background Art

[0002] In recent years, the metaverse industry has been continuously upgraded, and the way humans interact will change from 2D interaction to more efficient 3D interaction. People pay more attention to the interactive experience with virtual digital space. XR (Extended Reality) technology refers to a real and virtual combination of human-computer interactive environment generated by computer technology and wearable devices. It uses VR (Virtual Reality), AR (Augmented Reality) and MR (Mixed Reality) and other visual interaction technologies to integrate virtual content with real scenes, which can change the interaction mode between people and the real world and bring users a new immersive experience. XR technology has a wide range of applications in many fields, such as entertainment, education, medical care, industry and architecture.

[0003] Perception and interaction are crucial to the establishment and application of the XR ecosystem, and tracking and positioning are its foundation and premise. Tracking and positioning technology relies on the coordination of the visual lens and positioning lens of the virtual reality system, but its recognition capabilities under different ambient light conditions and the ability to integrate and embed body recognition with virtual images still need to be strengthened.

[0004] Therefore, how to optimize the optical design of the virtual reality system so that its positioning lens can be suitable for the positioning of different ambient light sources and enhance the overall effect of integration with visual perception is one of the technical problems that need to be solved at present. Summary of the invention

[0005] According to an embodiment of the present application, a virtual reality system is provided, including a visual lens and a positioning lens. Among them, the visual lens sequentially includes, along a first optical axis, from a first side far from the screen to a second side close to the screen: a first element group, including a reflective polarizing element, a quarter-wave plate, and a first lens with a positive optical power, where the first side or the second side of the first lens is a plane; a second element group, including a second lens with a positive optical power; and a third element group, including a third lens with a positive optical power; the positioning lens sequentially includes, along a second optical axis, from the object side to the image side, a first lens with a negative optical power, a second lens with a negative optical power, a third lens with a positive optical power, a fourth lens with an optical power, a fifth lens with a positive optical power, a sixth lens with a negative optical power, a seventh lens with a positive optical power, and an eighth lens with a positive optical power; the virtual reality system satisfies: -11.0 < (f2a + f3a) / (R3a + R5a) < 0.3; 11.2 < (CT5 + CT7) / CT6 < 13.3; 1.5 < ImgH / f < 2.2; and 2.2 < TTLa / TTL < 4.7; where f2a is the effective focal length of the second lens, f3a is the effective focal length of the third lens, R3a is the curvature radius of the first side of the second lens, R5a is the curvature radius of the first side of the third lens, CT5 is the central thickness of the fifth lens, CT7 is the central thickness of the seventh lens, CT6 is the central thickness of the sixth lens, ImgH is half of the image height corresponding to the maximum field of view angle of the positioning lens, f is the total effective focal length of the positioning lens, TTLa is the distance from the first side of the first element group to the screen of the visual lens on the first optical axis, and TTL is the distance from the object side of the first lens to the imaging surface of the positioning lens on the second optical axis.

[0006] In one or more embodiments, the visual lens satisfies: -1.2 < Rna / (R3a + R4a) < 1.0, where R3a is the curvature radius of the first side of the second lens, R4a is the curvature radius of the second side of the second lens, Rna is the minimum value of the curvature radii of the first side and the second side of the first lens, and n = 1 or 2.

[0007] In one or more embodiments, the visual lens satisfies: 0.2 < f1a / V1a / CT1a < 8.0, where f1a is the effective focal length of the first lens, V1a is the Abbe number of the first lens, and CT1a is the central thickness of the first lens.

[0008] In one or more embodiments, the visual lens satisfies: -4.0 < (R4a + R5a) / (CT2a + CT3a) < -1.9, where R4a is the curvature radius of the second side of the second lens, R5a is the curvature radius of the first side of the third lens, CT2a is the central thickness of the second lens, and CT3a is the central thickness of the third lens.

[0009] In one or more embodiments, the visual lens satisfies: 2.0 < (f2a / N2a) / (f3a / N3a) < 11.0, where f2a is the effective focal length of the second lens, N2a is the refractive index of the second lens, f3a is the effective focal length of the third lens, and N3a is the refractive index of the third lens.

[0010] In one or more embodiments, the visual lens satisfies: -7.5 < R6a / R5a + R4a / R3a < 7.6, where R6a is the radius of curvature of the second side surface of the third lens, R5a is the radius of curvature of the first side surface of the third lens, R4a is the radius of curvature of the second side surface of the second lens, and R3a is the radius of curvature of the first side surface of the second lens.

[0011] In one or more embodiments, the visual lens satisfies: 29 mm < TDa < 40.0 mm, where TDa is the distance from the second side surface of the third element group to the screen of the visual lens on the first optical axis.

[0012] In one or more embodiments, the visual lens satisfies: 0.5 < CT3a / (CT1a + CT2a) < 2.5, where CT3a is the central thickness of the third lens, CT1a is the central thickness of the first lens, and CT2a is the central thickness of the second lens.

[0013] In one or more embodiments, the positioning lens satisfies: -0.2 < f / f1 < -0.15, where f is the total effective focal length of the positioning lens and f1 is the effective focal length of the first lens.

[0014] In one or more embodiments, the positioning lens satisfies: -13.5 < (R11 + R12) / f6 < -4.3, where R11 is the radius of curvature of the object side surface of the sixth lens, R12 is the radius of curvature of the image side surface of the sixth lens, and f6 is the effective focal length of the sixth lens.

[0015] In one or more embodiments, the positioning lens satisfies: 3.7 < TTL / (CT5 + CT7) < 4.3, where TTL is the distance from the object side surface of the first lens to the imaging surface of the positioning lens on the second optical axis, CT5 is the central thickness of the fifth lens, and CT7 is the central thickness of the seventh lens.

[0016] In one or more embodiments, the positioning lens satisfies: 5.8 < DT11 / CT1 / N1 < 12.5, where DT11 is the effective semi-aperture of the object side surface of the first lens, CT1 is the central thickness of the first lens, and N1 is the refractive index of the first lens.

[0017] In one or more embodiments, the positioning lens satisfies: -2.5 < f1 / N1 / (f3 / N3) < -1.5, where f1 is the effective focal length of the first lens, N1 is the refractive index of the first lens, f3 is the effective focal length of the third lens, and N3 is the refractive index of the third lens.

[0018] In one or more embodiments, the positioning lens satisfies: 2.0 < (SAG11 + SAG12) / (SAG81 + SAG82) < 6.0, where SAG11 is the distance between the intersection of the object side of the first lens on the second optical axis and the vertex of the maximum effective semi-aperture of the object side of the first lens on the second optical axis, SAG12 is the distance between the intersection of the image side of the first lens on the second optical axis and the vertex of the maximum effective semi-aperture of the image side of the first lens on the second optical axis, SAG81 is the distance between the intersection of the object side of the eighth lens on the second optical axis and the vertex of the maximum effective semi-aperture of the object side of the eighth lens on the second optical axis, and SAG82 is the distance between the intersection of the image side of the eighth lens on the second optical axis and the vertex of the maximum effective semi-aperture of the image side of the eighth lens on the second optical axis.

[0019] In one or more embodiments, the positioning lens satisfies: -0.8 < (f5 + f6) / f < 1.4, where f5 is the effective focal length of the fifth lens, f6 is the effective focal length of the sixth lens, and f is the total effective focal length of the positioning lens.

[0020] In one or more embodiments, the positioning lens satisfies: -0.8 < f6 / f3*(N6 / N3) < -0.2; N3 > 1.6 and N6 > 1.6; where f3 is the effective focal length of the third lens, f6 is the effective focal length of the sixth lens, N3 is the refractive index of the third lens, and N6 is the refractive index of the sixth lens.

[0021] The virtual reality system provided according to the embodiments of the present application may include a three-mirror catadioptric visual lens and an eight-element ultra-wide-angle positioning lens. The visual lens can achieve light path folding and reflection by using a polarization element, which is beneficial to the thin and light design of the device. The first lens and the second lens of the positioning lens have negative optical powers, which is beneficial to increasing the field of view angle of the system and expanding the range of perspective to capture real-world images. While enhancing the user's wearing experience, by restricting the ratio of the sum of the effective focal lengths of the second lens and the third lens in the visual lens to the sum of the surface curvatures of the corresponding lenses away from the screen side, the overall length of the lenses can be effectively shortened. By controlling the ratio of the center thickness of the fifth lens and the seventh lens to the center thickness of the sixth lens in the positioning lens, it is beneficial to control the shape and center thickness of the rear lenses in the visual lens and the positioning lens. And by restricting the ratio of the maximum semi-image height to the focal length of the positioning lens to expand the positioning field of view and incident light as much as possible, it is more suitable for positioning under different environmental light sources and enhances the overall effect of visual integration. In addition, by controlling the ratio of the overall lengths of the visual lens and the positioning lens, it is beneficial to the internal space layout of the whole machine and avoids interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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:

[0023] Figure 1 A schematic diagram showing the composition of a virtual reality system provided according to an embodiment of the present application is shown;

[0024] Figure 2 A schematic structural diagram of a visual lens according to Embodiment 1 of the present application is shown;

[0025] FIG. 3A to FIG. 3C The axial chromatic aberration curve, the astigmatism curve, and the distortion curve of the visual lens according to the first embodiment of the present application are respectively shown;

[0026] Figure 4 A schematic diagram of the structure of a visual lens according to Embodiment 2 of the present application is shown;

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

[0028] Figure 6 A schematic diagram of the structure of a visual lens according to Embodiment 3 of the present application is shown;

[0029] FIG. 7A to FIG. 7C The axial chromatic aberration curve, the astigmatism curve, and the distortion curve of the visual lens according to the third embodiment of the present application are respectively shown;

[0030] Figure 8 A schematic structural diagram of a positioning lens according to a fourth embodiment of the present application is shown;

[0031] 9A to 9C The axial chromatic aberration curve, the astigmatism curve, and the magnification chromatic aberration curve of the positioning lens according to the fourth embodiment of the present application are respectively shown;

[0032] Fig.10 A schematic structural diagram of a positioning lens according to Embodiment 5 of the present application is shown;

[0033] FIG. 11A to FIG. 11C The axial chromatic aberration curve, the astigmatism curve, and the magnification chromatic aberration curve of the positioning lens according to the fifth embodiment of the present application are respectively shown;

[0034] Fig.12 A structural schematic diagram of a positioning lens according to Embodiment 6 of the present application is shown;

[0035] FIG. 13A to FIG. 13CThe axial chromatic aberration curve, the astigmatism curve, and the magnification chromatic aberration curve of the positioning lens according to the sixth embodiment of the present application are respectively shown;

[0036] Fig.14 A schematic diagram of the structure of a positioning lens according to Embodiment 7 of the present application is shown; and

[0037] FIG. 15A to FIG. 15C The axial chromatic aberration curve, the astigmatism curve, and the magnification chromatic aberration curve of the positioning lens according to the seventh embodiment of the present application are respectively shown. DETAILED DESCRIPTION

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] The features, principles and other aspects of the present application are described in detail below.

[0046] refer to Figure 1 As shown, the virtual reality system 100 according to the exemplary embodiment of the present application may include a visual lens 110 and a positioning lens 120. By combining the visual lens 110 and the positioning lens 120, the integration of virtual content and real real scenes can be achieved. The visual lens 110 provides a virtual experience, and the positioning lens 120 provides a real environment, which increases boundaries and interactions while providing immersion. Specifically, the positioning lens 120 can be used to image real scenes, and the resulting real image is transmitted to the display screen in the form of an electrical signal; the imaging surface of the visual lens 110 can be located on the display screen, and the visual lens 110 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 user's eyes, so that the user can see a picture that combines virtual and real, thereby improving the user's immersion.

[0047] The visual lens 110 may be configured as a catadioptric visual optical system, for example, and the number of the visual lens 110 may be one or more. The positioning lens 120 may be configured as a video perspective optical system, for example, and the number of the positioning lens 120 may be one or more. In one example, the virtual reality system 100 may include two visual lenses 110 that are symmetrically arranged. In one example, the virtual reality system 100 also includes a body, the visual lens 110 may be arranged on the inner side of the body, and the positioning lens 120 may be arranged on the outer side of the body.

[0048] In an exemplary embodiment, the eyepiece lens 110 may include a first element group, a second element group, and a third element group 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. There may be an air gap between the first element group and the second element group, and between the second element group and the third element group.

[0049] In an exemplary embodiment, the first side may be a side away from the screen, and the second side may be a side close to the screen. Accordingly, the first side of each element (first lens, second lens, reflective polarizing element, quarter wave plate, third lens, etc.) in the eyepiece lens 110 may be a surface away from the screen, and the second side may be a surface close to the screen.

[0050] In an exemplary embodiment, the first lens, the second lens, and the third lens all have positive refractive power. Using lenses with positive refractive power can balance aberrations and diverge or converge through the lenses, thereby meeting the performance requirements of a large field of view angle with only three lenses.

[0051] In an exemplary embodiment, a reflective polarizing element and a quarter wave plate are attached to the first side or the second side of the first lens of the eyepiece lens 110. The first side or the second side of the first lens can be a plane. When light passes through the reflective polarizing element, the reflective polarizing element can reflect light in a certain direction and transmit light orthogonal to the reflected light. The quarter wave plate can be used to convert between circularly polarized light and linearly polarized light to achieve the refraction of the light path, which is conducive to shortening the length of the eyepiece lens 110.

[0052] 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 visual lens 110 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, the aberration occurring during imaging can be eliminated as much as possible, thereby improving the imaging quality.

[0053] In an exemplary embodiment, the eyepiece lens 110 may also include a partial reflective element, which may be, for example, a partial reflective layer attached or plated on the first side or the second side of the second 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 first side or the second side of the second lens, and combining the reflective polarizing element and the quarter-wave plate, the light can be refracted multiple times, thereby effectively reducing the body length of the eyepiece lens.

[0054] In an exemplary embodiment, the positioning lens 120 may include a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens arranged in sequence from the object side to the image side along the second optical axis. An air gap may be provided between adjacent two lenses of the first lens to the eighth lens.

[0055] The virtual reality system 100 according to the exemplary embodiment of the present application can be used in a variety of virtual reality display devices, such as a VR head-mounted device, an MR head-mounted device, or an AR electronic device.

[0056] In an exemplary embodiment of the present application, the virtual reality system includes a visual lens and a positioning lens, the visual lens includes a first element group, a second element group and a third element group in sequence from the first side to the second side along the first optical axis, wherein the first element group includes a reflective polarizing element, a quarter wave plate and a first lens with positive optical power; the second element group includes a second lens with positive optical power; the third element group includes a third lens with positive optical power; the positioning lens includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens in sequence from the object side to the image side along the second optical axis, the first lens and the second lens have negative optical power, the third lens has positive optical power, the fourth lens may have positive optical power or negative optical power, the fifth lens has positive optical power, the sixth lens has negative optical power, and the seventh lens and the eighth lens have positive optical power. Wherein, the real image formed by the positioning lens is transmitted to the display screen in the form of an electrical signal, and the visual lens is used to project the virtual image on the display screen and the real image transmitted to the display screen.

[0057] The virtual reality system according to an exemplary embodiment of the present application can satisfy: -11.0 < (f2a + f3a) / (R3a + R5a) < 0.3; 11.2 < (CT5 + CT7) / CT6 < 13.3; 1.5 < ImgH / f < 2.2; and 2.2 < TTLa / TTL < 4.7; where f2a is the effective focal length of the second lens, f3a is the effective focal length of the third lens, R3a is the radius of curvature of the first side surface of the second lens, R5a is the radius of curvature of the first side surface of the third lens, CT5 is the central thickness of the fifth lens, CT7 is the central thickness of the seventh lens, CT6 is the central thickness of the sixth lens, ImgH is half of the image height corresponding to the maximum field of view angle of the positioning lens, f is the total effective focal length of the positioning lens, TTLa is the distance from the first side surface of the first element group to the screen of the visual lens on the first optical axis, and TTL is the distance from the object side surface of the first lens to the imaging surface of the positioning lens on the second optical axis.

[0058] The virtual reality system according to the above embodiment of the present application includes a three-mirror catadioptric visual lens, which can achieve optical path folding and reflection by using a polarizing element, facilitating the thin and light design of the device; it is paired with an eight-element ultra-wide-angle positioning lens, where the first lens and the second lens of the positioning lens have negative optical powers, which is beneficial to increasing the field of view angle of the system and expanding the range of capturing real-world images in perspective; while enhancing the wearing comfort of the user, by restricting the ratio of the sum of the effective focal lengths of the second lens and the third lens in the visual lens to the sum of the radii of curvature of the corresponding lens surfaces away from the screen side, the overall length of the lens can be effectively shortened, and by controlling the ratio of the sum of the central thicknesses of the fifth lens and the seventh lens to the central thickness of the sixth lens in the positioning lens, it is beneficial to control the shapes and central thicknesses of the rear-section lenses in the visual lens and the positioning lens; and by restricting the ratio of the maximum half-image height to the focal length of the positioning lens to expand the positioning field of view and incident light as much as possible, making it more suitable for positioning under different ambient light sources and strengthening the overall effect of visual integration; in addition, by controlling the ratio of the overall lengths of the visual lens and the positioning lens, it is beneficial to the internal space layout of the whole machine and avoids interference.

[0059] In an exemplary embodiment, the visual lens of the virtual reality system can satisfy: -1.2 < Rna / (R3a + R4a) < 1.0, where R3a is the radius of curvature of the first side surface of the second lens, R4a is the radius of curvature of the second side surface of the second lens, Rna is the minimum value of the radii of curvature of the first side surface and the second side surface of the first lens, and n = 1 or 2. By controlling the ratio of the radii of curvature of the two side surfaces of the first lens in the visual lens to the sum of the radii of curvature of the two side surfaces of the second lens, it is beneficial to restricting the shapes of the first lens and the second lens, facilitating the convergence of marginal rays of the positive lens, and avoiding assembly interference.

[0060] In an exemplary embodiment, the visual lens of the virtual reality system may satisfy: 0.2 < f1a / V1a / CT1a < 8.0, where f1a is the effective focal length of the first lens, V1a is the Abbe number of the first lens, and CT1a is the central thickness of the first lens. By controlling the ratio of the effective focal length, Abbe number, and central thickness of the first lens of the visual lens, it is beneficial to indirectly control the diameter of the first lens and the selection of low-dispersion coefficient materials, and standardize the size of the lens on the human eye side.

[0061] In an exemplary embodiment, the visual lens of the virtual reality system may satisfy: -4.0 < (R4a + R5a) / (CT2a + CT3a) < -1.9, where R4a is the radius of curvature of the second side of the second lens, R5a is the radius of curvature of the first side of the third lens, CT2a is the central thickness of the second lens, and CT3a is the central thickness of the third lens. By controlling the ratio of the sum of the radii of curvature of the second lens close to the screen side and the third lens far from the screen side to the sum of the central thicknesses of the second lens and the third lens, on the one hand, it is beneficial to ensure the basic forming and assembly strength, and on the other hand, it can indirectly control the focal lengths of the second lens and the third lens to achieve screen light convergence.

[0062] In an exemplary embodiment, the visual lens of the virtual reality system may satisfy: 2.0 < (f2a / N2a) / (f3a / N3a) < 11.0, where f2a is the effective focal length of the second lens, N2a is the refractive index of the second lens, f3a is the effective focal length of the third lens, and N3a is the refractive index of the third lens. By controlling the ratio of the ratio of the effective focal length to the refractive index of the second lens of the visual lens to the ratio of the effective focal length to the refractive index of the third lens and limiting the two within a reasonable range, it is beneficial to narrow the material selection range and facilitate the application of low-stress and birefringent materials.

[0063] In an exemplary embodiment, the visual lens of the virtual reality system may satisfy: -7.5 < R6a / R5a + R4a / R3a < 7.6, where R6a is the radius of curvature of the second side of the third lens, R5a is the radius of curvature of the first side of the third lens, R4a is the radius of curvature of the second side of the second lens, and R3a is the radius of curvature of the first side of the second lens. By controlling the ratio of the radius of curvature of the third lens close to the screen side to the radius of curvature far from the screen side and the ratio of the radius of curvature of the second lens close to the screen side to the radius of curvature far from the screen side, and limiting the sum of the two within a certain range, it is beneficial to constrain the shapes of the two, facilitate marginal light convergence, and improve the imaging marginal brightness.

[0064] In an exemplary embodiment, the visual lens of the virtual reality system may satisfy: 29 mm < TDa < 40.0 mm, where TDa is the distance from the second side surface of the third lens group to the screen of the visual lens on the first optical axis. By restricting the distance from the side surface of the third lens of the visual lens close to the screen to the screen, it is beneficial to control the object distance within a reasonable range so as to generate a virtual image with an appropriate distance, enhancing the visual experience.

[0065] In an exemplary embodiment, the visual lens of the virtual reality system may satisfy: 0.5 < CT3a / (CT1a + CT2a) < 2.5, where CT3a is the central thickness of the third lens, CT1a is the central thickness of the first lens, and CT2a is the central thickness of the second lens. By controlling the ratio of the central thickness of the third lens in the visual lens to the sum of the central thicknesses of the first lens and the second lens, on the one hand, it is beneficial to ensure the assembly strength of the lens group and guarantee actual processing; on the other hand, it is beneficial to indirectly control the total length of the lens group and avoid large space occupation within the whole device.

[0066] In an exemplary embodiment, the positioning lens of the virtual reality system may satisfy: -0.2 < f / f1 < -0.15, where f is the total effective focal length of the positioning lens and f1 is the effective focal length of the first lens. By controlling the ratio of the total effective focal length of the positioning lens to the effective focal length of the first lens, it is beneficial to the focal length distribution of the first lens in the positioning lens, indirectly controlling the object-side field of view size to achieve as much real-scene light convergence as possible, thereby achieving precise positioning.

[0067] In an exemplary embodiment, the positioning lens of the virtual reality system may satisfy: -13.5 < (R11 + R12) / f6 < -4.3, where R11 is the curvature radius of the object side of the sixth lens, R12 is the curvature radius of the image side of the sixth lens, and f6 is the effective focal length of the sixth lens. By controlling the ratio of the sum of the curvature radii of the object side and the image side of the sixth lens in the positioning lens to its focal length, on the one hand, it indirectly restricts the lens diameter and central thickness of the sixth lens, facilitating processing and forming; on the other hand, the negative curvature design can make the light diverge, facilitating cooperation with the front and rear positive lenses to weaken aberration.

[0068] In an exemplary embodiment, the positioning lens of the virtual reality system may satisfy: 3.7 < TTL / (CT5 + CT7) < 4.3, where TTL is the distance from the object side surface of the first lens to the imaging surface of the positioning lens on the second optical axis, CT5 is the central thickness of the fifth lens, and CT7 is the central thickness of the seventh lens. By controlling the ratio of the distance from the object side surface of the first lens of the positioning lens to the imaging surface to the sum of the central thicknesses of the fifth lens and the seventh lens, on the one hand, it is beneficial to ensure the assembly and processing strength of the fifth lens and the seventh lens; on the other hand, it is beneficial to further restrict the total length of the positioning lens and compress the volume of the head-mounted device.

[0069] In an exemplary embodiment, the positioning lens of the virtual reality system may satisfy: 5.8 < DT11 / CT1 / N1 < 12.5, where DT11 is the effective semi-aperture of the object side of the first lens, CT1 is the central thickness of the first lens, and N1 is the refractive index of the first lens. By controlling the ratio of the effective semi-aperture of the object side of the first lens of the positioning lens to the central thickness and the refractive index, it is beneficial to indirectly control the focal length and material selection of the first lens, narrow the design range, and increase the processing feasibility.

[0070] In an exemplary embodiment, the positioning lens of the virtual reality system may satisfy: -2.5 < f1 / N1 / (f3 / N3) < -1.5, where f1 is the effective focal length of the first lens, N1 is the refractive index of the first lens, f3 is the effective focal length of the third lens, and N3 is the refractive index of the third lens. By controlling the ratio of the effective focal length of the first lens of the positioning lens to the refractive index and the ratio of the effective focal length of the third lens to the refractive index, it is convenient to regulate the field of view size of the incident light and the incident light angle, which is beneficial to the recognition of different light environments.

[0071] In an exemplary embodiment, the positioning lens of the virtual reality system may satisfy: 2.0 < (SAG11 + SAG12) / (SAG81 + SAG82) < 6.0, where SAG11 is the distance between the intersection point of the object side of the first lens on the second optical axis and the vertex of the maximum effective semi-aperture of the object side of the first lens on the second optical axis, SAG12 is the distance between the intersection point of the image side of the first lens on the second optical axis and the vertex of the maximum effective semi-aperture of the image side of the first lens on the second optical axis, SAG81 is the distance between the intersection point of the object side of the eighth lens on the second optical axis and the vertex of the maximum effective semi-aperture of the object side of the eighth lens on the second optical axis, and SAG82 is the distance between the intersection point of the image side of the eighth lens on the second optical axis and the vertex of the maximum effective semi-aperture of the image side of the eighth lens on the second optical axis. By restricting the distances between the intersection points of the object and image sides of the first lens and the eighth lens of the positioning lens on the second optical axis and the vertices of the maximum effective semi-apertures on the second optical axis, on the one hand, the focal lengths and volume sizes of the first lens and the eighth lens can be indirectly controlled, and on the other hand, it is beneficial to the regulation of the light aperture, avoiding the reduction of RI (refractive index) caused by insufficient brightness of the marginal beam, which affects optical positioning.

[0072] In an exemplary embodiment, the positioning lens of the virtual reality system may satisfy: -0.8 < (f5 + f6) / f < 1.4, where f5 is the effective focal length of the fifth lens, f6 is the effective focal length of the sixth lens, and f is the total effective focal length of the positioning lens. By controlling the ratio of the sum of the focal lengths of the fifth lens and the sixth lens of the positioning lens to the total effective focal length of the positioning lens, it is convenient for the focal length distribution of the fifth lens and the sixth lens and the aberration regulation between the positive and negative lenses.

[0073] In an exemplary embodiment, the positioning lens of the virtual reality system may satisfy: -0.8 < f6 / f3 * (N6 / N3) < -0.2; N3 > 1.6 and N6 > 1.6; where f3 is the effective focal length of the third lens, f6 is the effective focal length of the sixth lens, N3 is the refractive index of the third lens, and N6 is the refractive index of the sixth lens. The third lens and the sixth lens of the positioning lens adopt high refractive index materials. By restricting the ratio of the focal lengths of the sixth lens to the third lens and the corresponding refractive index ratio, and controlling the product of the two within a certain range, it is beneficial to indirectly control the center thickness and semi-aperture of the lens, achieve a small radius of curvature design, ensure processing, forming, and assembly, facilitate further compression of the volume of the positioning lens, and meet the actual requirements of light weight.

[0074] 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 light path and control the light intensity. The aperture stop can be set at an appropriate position of the visual lens or the positioning lens. In one example, a first aperture stop may be included, and the first aperture stop may be located on the first side (the human eye side) of the visual lens. In one example, a second aperture stop may also be included, and the second aperture stop may be located between the third lens and the fourth lens of the positioning lens.

[0075] 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.

[0076] In an exemplary embodiment, the total effective focal length fa of the visual lens may be, for example, in the range of 31.08 mm to 32.31 mm, and the total effective focal length f of the positioning lens may be, for example, in the range of 1.20 mm to 1.56 mm.

[0077] For the virtual reality system according to some embodiments of the present application, by reasonably setting parameters such as the radius of curvature, center thickness, surface shape, refractive index, and Abbe number of the lens, as well as the effective focal length and entrance pupil diameter of the optical system, it is beneficial to improve the imaging effect and ensure the optical performance of the system; and by reasonably setting parameters such as the aperture stop, air gap between the lenses, and the distance to the display or imaging surface, it is beneficial to ensure the forming and strength of the lens, beneficial to reducing the sensitivity of the lens; at the same time, it is beneficial to constrain the total length of the optical system, improve the portability of the device; and can also increase the field of view angle and enhance the wearing experience of consumers.

[0078] The following further describes specific embodiments of the optical system applicable to the above embodiments with reference to the drawings.

[0079] Embodiment 1

[0080] The following refers to Figures 2 to 3C Describe the visual lens according to Embodiment 1 of the present application. Figure 2A schematic structural diagram of a visual lens according to Embodiment 1 of the present application is shown.

[0081] like Figure 2 As shown, the eyepiece lens includes a first element group, a second element group and a third element group arranged in sequence from the human eye side to the screen 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'.

[0082] In this embodiment, the reflective polarizing element RP and the quarter wave plate QWP are disposed on the first side surface S3 of the first lens E1 ′ away from the screen.

[0083] In this embodiment, the eyepiece lens may further include an aperture STO, and the aperture STO is disposed on the human eye side of the eyepiece lens.

[0084] In this embodiment, the eyepiece lens may further include a partial reflective element BS, and the partial reflective element BS is disposed on the second side surface S6 of the second lens E2 ′ close to the screen side.

[0085] As an exemplary embodiment, the image light from the screen can sequentially pass through the third lens E3', the second lens E2', the first lens E1' and the quarter wave plate QWP to reach the reflective polarizing element RP, then reflect at the reflective polarizing element RP, and pass through the quarter wave plate QWP, the first lens E1', the second lens E2' 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 second lens E2', the first lens E1', the quarter wave plate QWP and the reflective polarizing element RP to be emitted toward the side of the human eye. According to the eyepiece lens 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, effectively shortening the main body length of the eyepiece lens.

[0086] Table 1 shows the basic parameters of the visual lens 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 component in turn and is finally projected into the human eye.

[0087] Face number element Surface type Radius of curvature thickness Refractive Index Abbe number Refraction / Reflection Spherical unlimited unlimited STO Aperture Spherical unlimited 15.0000 refraction S1 Reflective polarizer (RP) Spherical unlimited 0.2000 1.500 57.0 refraction S2 Quarter Wave Plate (QWR) Spherical unlimited 0.2000 1.500 57.0 refraction S3 First lens (E1') Spherical unlimited 8.5505 1.545 56.0 refraction S4 Aspheric -173.0363 3.1757 refraction S5 Second lens (E2') Aspheric -170.2484 3.9305 1.545 56.0 refraction S6 Partially reflective layer (BS) Aspheric -116.6014 -3.9305 1.545 56.0 reflection S5 Aspheric -170.2484 -3.1757 refraction S4 Aspheric -173.0363 -8.5505 1.545 56.0 refraction S3 Quarter Wave Plate (QWR) Spherical unlimited -0.2000 1.500 57.0 refraction S2 Reflective polarizer (RP) Spherical unlimited 0.2000 1.500 57.0 reflection S3 Spherical unlimited 8.5505 1.545 56.0 refraction S4 Aspheric -173.0363 3.1757 refraction S5 Second lens (E2') Aspheric -170.2484 3.9305 1.545 56.0 refraction S6 Aspheric -116.6014 0.9677 refraction S7 Third lens (E3') Aspheric 51.8909 12.7588 1.545 56.0 refraction S8 Aspheric -400.6471 2.9900 refraction S9 Screen Spherical unlimited

[0088] Table 1

[0089] In this embodiment, the second side surface S4 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:

[0090]

[0091] Wherein, x is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at a height of h along the optical axis; c is the paraxial curvature of the aspheric surface, c=1 / R (i.e., the paraxial curvature c is the reciprocal of the curvature radius R in Table 1 above); k is the cone coefficient; Ai is the correction coefficient of the i-th order of the aspheric surface. Table 2 shows the cone coefficients and high-order coefficients A4, A6, A8 and A9 that can be used for each aspheric mirror surface S4, S5, S6, S7 and S8 in Example 1. 10 .

[0092] Face number / coefficient Cone coefficient A4 A6 A8 A10 S4 0.0000 -1.23E-02 6.04E-02 -4.45E-03 6.85E-03 S5 0.0000 1.82E-01 -1.91E-01 5.11E-02 1.59E-02 S6 0.0000 2.00E-01 -9.61E-02 1.83E-02 3.99E-03 S7 0.0000 -1.24E+00 1.11E-01 2.55E-02 1.11E-02 S8 0.0000 5.36E-02 -6.96E-02 -4.64E-02 3.70E-02

[0093] Table 2

[0094] Figure 3A The axial chromatic aberration curve of the eyepiece lens of the first embodiment is shown, which indicates the deviation of the focusing point of light rays of different wavelengths passing through the eyepiece lens. Figure 3B The astigmatism curve of the visual lens of Example 1 is shown, which represents the meridional image plane curvature and sagittal image plane curvature corresponding to different field angles. Figure 3C The distortion curve of the visual lens of the first embodiment is shown, which indicates the distortion value corresponding to different field angles. FIG. 3A to FIG. 3C It can be seen that the visual lens provided in the first embodiment can achieve good imaging quality.

[0095] Embodiment 2

[0096] The following reference Figures 4 to 5C The visual lens according to the second embodiment of the present application is described. Figure 4 The structure diagram of the visual lens 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 the first embodiment will be omitted.

[0097] like Figure 4 As shown, the eyepiece lens includes, in sequence from the first side to the second side along the first optical axis: an 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 partially reflecting element BS; and a third element group, including a third lens E3'.

[0098] In this embodiment, the reflective polarizing element RP and the quarter wave plate QWP are disposed on the second side surface of the first lens E1' close to the screen side. As an exemplary embodiment, the second side surface of the first lens E1' close to the screen side is a plane.

[0099] In this embodiment, the partial reflective element BS is disposed on the first side surface S5 of the second lens E2 ′ away from the screen.

[0100] Table 3 shows the basic parameters of the visual lens 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 turn and is finally projected into the human eye.

[0101]

[0102]

[0103] Table 3

[0104] In this embodiment, the first side surface S1 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.

[0105] Table 4 shows the cone coefficients and high-order coefficients A4, A6, A8 and A2 of the aspheric mirror surfaces S1, S5, S6, S7 and S8 that can be used in the second embodiment. 10 Wherein, each aspheric surface shape can be defined by the formula (1) given in the above embodiment 1.

[0106] Face number / coefficient Cone coefficient A4 A6 A8 A10 S1 0.0000 -1.50E+00 6.21E-02 4.19E-02 -5.96E-03 S5 0.0000 6.69E-03 -7.08E-02 -1.43E-02 1.11E-02 S6 0.0000 -2.46E+00 1.03E+00 -1.61E-01 -1.46E-02 S7 0.0000 -1.30E+00 5.18E-01 3.29E-02 -1.78E-04 S8 0.0000 -5.27E+00 1.45E+00 -2.39E-01 1.75E-02

[0107] Table 4

[0108] Figure 5A The axial chromatic aberration curve of the eyepiece lens of the second embodiment is shown, which indicates the deviation of the focusing point of light rays of different wavelengths passing through the eyepiece lens. Figure 5B The astigmatism curve of the visual lens of Example 2 is shown, which represents the meridional image plane curvature and sagittal image plane curvature corresponding to different field angles. Figure 5C The distortion curve of the visual lens of the second embodiment is shown, which indicates the distortion value corresponding to different field angles. FIG. 5A to FIG. 5C It can be seen that the visual lens provided in the second embodiment can achieve good imaging quality.

[0109] Embodiment 3

[0110] The following reference Figures 6 to 7C Describe the visual lens according to the third embodiment of the present application. Figure 6 A schematic structural diagram of a visual lens according to Embodiment 3 of the present application is shown.

[0111] like Figure 6As shown, the eyepiece lens includes, in sequence from the first side to the second side along the first optical axis: an aperture STO; a first element group, including a reflective polarizing element RP, a quarter-wave plate QWP and a first lens E1'; a second element group, including a second lens E2' and a partially reflecting element BS; and a third element group, including a third lens E3'.

[0112] In this embodiment, the reflective polarizing element RP and the quarter wave plate QWP are disposed on a first side surface S3 of the first lens E1' away from the screen. The first side surface S3 of the first lens E1' is a plane.

[0113] In this embodiment, the partial reflective element BS is disposed on the second side surface S6 of the second lens E2 ′ close to the screen side.

[0114] Table 5 shows the basic parameters of the visual lens 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 component in turn and is finally projected into the human eye.

[0115]

[0116] Table 5

[0117] In this embodiment, the second side surface S4 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.

[0118] Table 6 shows the cone coefficients and 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, A 10 and A 12 Wherein, each aspheric surface shape can be defined by the formula (1) given in the above embodiment 1.

[0119] Face number / coefficient Cone coefficient A4 A6 A8 A10 S4 0.0000 -3.55E-01 1.60E-01 -3.04E-02 4.45E-03 S5 0.0000 -4.47E-01 -7.69E-02 4.31E-02 8.85E-05 S6 0.0000 1.44E-01 -7.18E-02 1.50E-02 2.13E-03 S7 0.0000 -5.72E-01 1.92E-01 1.70E-02 4.14E-03 S8 0.0000 -5.09E-01 6.03E-01 -1.05E-01 -1.50E-02

[0120] Table 6

[0121] Fig. 7A The axial chromatic aberration curve of the eyepiece lens of Example 3 is shown, which indicates the deviation of the focusing point of light rays of different wavelengths passing through the eyepiece lens. Figure 7B The astigmatism curve of the visual lens of Example 3 is shown, which represents the meridional image plane curvature and sagittal image plane curvature corresponding to different field angles. Figure 7C The distortion curve of the visual lens of the third embodiment is shown, which indicates the distortion value corresponding to different field angles. FIG. 7A to FIG. 7C It can be seen that the visual lens provided in the third embodiment can achieve good imaging quality.

[0122] Table 7 shows some parameters of the visual lens according to the above-mentioned embodiments 1 to 3 of the present application, including the total effective focal length fa of the visual lens, the effective focal length f1a of the first lens, the effective focal length f2a of the second lens and the effective focal length f3a of the third lens, all in millimeters (mm).

[0123] Parameters / Examples one two three fa(mm) 31.08 31.19 32.31 f1a(mm) 316.64 203.19 4420.03 f2a(mm) 660.04 814.03 229.97 f3a(mm) 84.91 75.40 93.76

[0124] Table 7

[0125] Specific embodiments of the positioning lens applicable to the above-mentioned embodiments are further described below with reference to the accompanying drawings.

[0126] Embodiment 4

[0127] The following reference Figures 8 to 9C Describe the positioning lens according to the fourth embodiment of the present application.

[0128] like Figure 8 As shown, the positioning lens may include a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7 and an eighth lens E8 arranged in sequence from the object side to the image side along the second optical axis.

[0129] As an exemplary embodiment, the positioning lens may further include an aperture STO and a filter E9. The aperture STO may be disposed, for example, between the third lens E3 and the fourth lens E4. The filter E9 may be disposed, for example, between the image side surface of the eighth lens E8 and the imaging surface S19 of the positioning lens.

[0130] In this embodiment, the first lens E1 and the second lens E2 have negative power, the third lens E3 has positive power, the fourth lens E4 has negative power, the fifth lens E5 has positive power, the sixth lens E6 has negative power, and the seventh lens E7 and the eighth lens E8 both have positive power. The filter E9 has an object side surface S17 and an image side surface S18. Light from the object passes through each surface S1 to S18 in sequence and is finally imaged on the imaging surface S19.

[0131] Table 8 shows a basic parameter table of the positioning lens of Example 4, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm).

[0132]

[0133]

[0134] Table 8

[0135] In this embodiment, the object side surface and the image side surface of any lens from the second lens E2 to the eighth lens E8 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 .

[0136] Face number A4 A6 A8 A10 A12 A14 A16 S3 6.34E-03 -7.38E-04 1.11E-03 -4.53E-04 9.03E-05 -9.04E-06 3.62E-07 S4 5.13E-03 -1.63E-01 3.54E-01 -4.76E-01 3.73E-01 -1.55E-01 2.60E-02 S5 2.28E-02 1.45E-02 -1.83E-02 3.91E-02 -3.20E-02 1.41E-02 -3.51E-03 S6 5.08E-02 -4.26E-03 1.15E-01 -2.47E-01 2.81E-01 -1.56E-01 3.14E-02 S7 -2.27E-02 2.62E-02 -1.10E-01 1.74E-01 -1.81E-01 1.00E-01 -2.49E-02 S8 1.17E-02 1.11E-02 -6.52E-02 1.09E-01 -9.05E-02 3.60E-02 -5.57E-03 S9 -1.49E-02 1.02E-02 -1.36E-02 1.33E-02 -6.51E-03 1.43E-03 -1.07E-04 S10 -1.30E-01 1.38E-01 -6.57E-02 1.31E-03 1.05E-02 -3.72E-03 4.15E-04 S11 2.12E-01 -2.03E-01 1.63E-01 -9.82E-02 3.61E-02 -6.96E-03 5.40E-04 S12 1.28E-01 -1.14E-01 6.43E-02 -2.34E-02 5.07E-03 -5.55E-04 1.89E-05 S13 -1.16E-01 1.16E-01 -9.21E-02 4.81E-02 -1.53E-02 2.65E-03 -1.94E-04 S14 -5.10E-02 7.18E-03 1.49E-02 -1.14E-02 3.90E-03 -6.62E-04 4.58E-05 S15 -5.07E-02 7.02E-03 -4.29E-03 1.68E-03 -2.73E-04 1.89E-05 -3.88E-07 S16 6.53E-02 -9.25E-02 4.24E-02 -1.20E-02 2.19E-03 -2.31E-04 1.03E-05

[0137] Table 9

[0138] Fig. 9A The axial chromatic aberration curve of the positioning lens of the fourth embodiment is shown, which indicates the deviation of the focusing point of light rays of different wavelengths after passing through the positioning lens. Fig. 9B The astigmatism curve of the positioning lens of the fourth embodiment is shown, which represents the meridional image plane curvature and sagittal image plane curvature corresponding to different field angles. Fig. 9C The magnification chromatic aberration curve of the positioning lens of Example 4 is shown, which represents the deviation of different image heights on the imaging surface after the light passes through the positioning lens. 9A to 9C It can be seen that the positioning lens provided in the fourth embodiment can achieve good imaging quality.

[0139] Embodiment 5

[0140] The following reference Figures 10 to 11C The positioning lens according to the fifth embodiment of the present application is described. In this embodiment and the following embodiments, for the sake of brevity, some descriptions similar to those of the fourth embodiment will be omitted.

[0141] like Fig.10 As shown, the positioning lens may include a first lens E1, a second lens E2, a third lens E3, an aperture STO, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7 and an eighth lens E8 arranged in sequence from the object side to the image side along the second optical axis.

[0142] In this embodiment, the first lens E1 and the second lens E2 have negative power, the third lens E3 has positive power, the fourth lens E4 has positive power, the fifth lens E5 has positive power, the sixth lens E6 has negative power, and the seventh lens E7 and the eighth lens E8 have positive power.

[0143] Table 10 shows a basic parameter table of the positioning lens of Example 5, wherein the units of the curvature radius and thickness / distance are all millimeters (mm).

[0144]

[0145]

[0146] Table 10

[0147] In this embodiment, the object side surface and the image side surface of any lens from the second lens E2 to the eighth lens E8 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. Tables 11-1 and 11-2 show 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, 10 , A 12 , A 14 , A 16 and A 18 , A 20 , A 22 , A 24 , A 26 , A 28 and A 30 .

[0148] Face number A4 A6 A8 A10 A12 A14 A16 S3 1.09E-02 -2.77E-02 3.23E-02 -2.14E-02 9.47E-03 -2.95E-03 6.59E-04 S4 -1.59E-02 6.41E-02 -2.60E-01 3.98E-01 -3.42E-01 1.83E-01 -6.13E-02 S5 1.25E-02 5.63E-02 -1.43E-01 1.78E-01 -1.23E-01 5.08E-02 -1.20E-02 S6 3.02E-02 5.69E-02 -1.23E-01 1.78E-01 -1.17E-01 -3.81E-03 5.58E-02 S7 1.72E-02 -1.62E-01 5.85E-01 -1.24E+00 1.63E+00 -1.33E+00 6.57E-01 S8 1.27E-03 7.93E-03 -1.70E-02 2.80E-02 -2.99E-02 1.95E-02 -7.59E-03 S9 -1.04E-02 9.13E-03 -1.16E-02 1.10E-02 -7.02E-03 2.84E-03 -6.94E-04 S10 -8.11E-02 8.46E-02 -6.97E-02 5.10E-02 -2.86E-02 1.05E-02 -2.36E-03 S11 8.69E-02 -2.67E-02 -1.77E-02 3.38E-02 -2.48E-02 1.01E-02 -2.39E-03 S12 6.33E-02 -2.70E-02 -1.55E-02 4.28E-02 -4.54E-02 3.12E-02 -1.51E-02 S13 -5.97E-02 4.84E-02 -3.81E-02 2.39E-02 -9.13E-03 2.27E-04 1.99E-03 S14 -2.01E-02 -4.89E-02 1.33E-01 -1.88E-01 1.75E-01 -1.14E-01 5.30E-02 S15 -2.98E-02 -9.16E-03 3.20E-02 -4.02E-02 3.05E-02 -1.55E-02 5.55E-03 S16 6.40E-02 -8.11E-02 8.57E-02 -7.71E-02 5.07E-02 -2.38E-02 8.01E-03

[0149] Table 11-1

[0150]

[0151]

[0152] Table 11-2

[0153] Fig.11A The axial chromatic aberration curve of the positioning lens of Example 5 is shown, which indicates that the light of different wavelengths deviates from the focal point after passing through the positioning lens. Fig. 11B The astigmatism curve of the positioning lens of Example 5 is shown, which represents the meridional image plane curvature and sagittal image plane curvature corresponding to different field angles. Fig. 11C The magnification chromatic aberration curve of the positioning lens of Example 5 is shown, which represents the deviation of different image heights on the imaging surface after the light passes through the positioning lens. FIG. 11A to FIG. 11C It can be seen that the positioning lens provided in the fifth embodiment can achieve good imaging quality.

[0154] Embodiment 6

[0155] The following reference Figures 12 to 13C Describe the positioning lens according to the sixth embodiment of the present application.

[0156] like Fig.12As shown, the positioning lens may include a first lens E1, a second lens E2, a third lens E3, an aperture STO, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7 and an eighth lens E8 arranged in sequence from the object side to the image side along the second optical axis.

[0157] In this embodiment, the first lens E1 and the second lens E2 have negative power, the third lens E3 has positive power, the fourth lens E4 has positive power, the fifth lens E5 has positive power, the sixth lens E6 has negative power, and the seventh lens E7 and the eighth lens E8 have positive power.

[0158] Table 12 shows the basic parameter table of the positioning lens of Example 6, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm).

[0159]

[0160]

[0161] Table 12

[0162] In this embodiment, the object side surface and the image side surface of any lens from the second lens E2 to the eighth lens E8 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. Tables 13-1 and 13-2 show 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, 10 , A 12 , A 14 , A 16 and A 18 , A 20 , A 22 , A 24 , A 26 , A 28 and A 30 .

[0163] Face number A4 A6 A8 A10 A12 A14 A16 S3 1.27E-02 -3.23E-02 3.76E-02 -2.50E-02 1.10E-02 -3.44E-03 7.68E-04 S4 -1.85E-02 7.47E-02 -3.03E-01 4.63E-01 -3.99E-01 2.14E-01 -7.15E-02 S5 1.45E-02 6.56E-02 -1.67E-01 2.07E-01 -1.43E-01 5.92E-02 -1.39E-02 S6 3.52E-02 6.64E-02 -1.44E-01 2.07E-01 -1.36E-01 -4.44E-03 6.50E-02 S7 2.00E-02 -1.89E-01 6.82E-01 -1.45E+00 1.90E+00 -1.55E+00 7.65E-01 S8 1.48E-03 9.25E-03 -1.98E-02 3.26E-02 -3.48E-02 2.28E-02 -8.85E-03 S9 -1.21E-02 1.06E-02 -1.35E-02 1.29E-02 -8.18E-03 3.31E-03 -8.09E-04 S10 -9.45E-02 9.86E-02 -8.13E-02 5.95E-02 -3.33E-02 1.23E-02 -2.75E-03 S11 1.01E-01 -3.12E-02 -2.06E-02 3.94E-02 -2.89E-02 1.18E-02 -2.78E-03 S12 7.38E-02 -3.15E-02 -1.81E-02 4.98E-02 -5.30E-02 3.64E-02 -1.76E-02 S13 -6.96E-02 5.64E-02 -4.44E-02 2.78E-02 -1.06E-02 2.65E-04 2.32E-03 S14 -2.35E-02 -5.70E-02 1.55E-01 -2.19E-01 2.04E-01 -1.33E-01 6.18E-02 S15 -3.48E-02 -1.07E-02 3.73E-02 -4.69E-02 3.56E-02 -1.81E-02 6.47E-03 S16 7.46E-02 -9.46E-02 9.99E-02 -8.99E-02 5.91E-02 -2.77E-02 9.33E-03

[0164] Table 13-1

[0165] Face number A18 A20 A22 A24 A26 A28 A30 S3 -1.23E-04 1.37E-05 -1.01E-06 4.45E-08 -8.85E-10 0.00E+00 0.00E+00 S4 1.35E-02 -1.09E-03 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S5 1.53E-03 -3.59E-05 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S6 -3.71E-02 6.74E-03 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S7 -2.10E-01 2.45E-02 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S8 1.87E-03 -1.65E-04 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S9 1.08E-04 -5.97E-06 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S10 3.37E-04 -1.73E-05 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S11 3.56E-04 -1.92E-05 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S12 6.16E-03 -1.57E-03 2.88E-04 -3.70E-05 3.16E-06 -1.61E-07 3.70E-09 S13 -1.47E-03 5.03E-04 -1.09E-04 1.55E-05 -1.39E-06 7.11E-08 -1.58E-09 S14 -2.09E-02 5.14E-03 -9.07E-04 1.12E-04 -9.19E-06 4.49E-07 -9.86E-09 S15 -1.66E-03 3.09E-04 -4.14E-05 3.87E-06 -2.41E-07 8.94E-09 -1.50E-10 S16 -2.29E-03 4.08E-04 -5.24E-05 4.71E-06 -2.82E-07 1.00E-08 -1.61E-10

[0166] Table 13-2

[0167] Fig.13A The axial chromatic aberration curve of the positioning lens of Example 6 is shown, which indicates that the light of different wavelengths deviates from the focal point after passing through the positioning lens. Fig. 13B The astigmatism curve of the positioning lens of Example 6 is shown, which represents the meridional image plane curvature and sagittal image plane curvature corresponding to different field angles. Fig. 13C The magnification chromatic aberration curve of the positioning lens of Example 6 is shown, which represents the deviation of different image heights on the imaging surface after the light passes through the positioning lens. FIG. 13A to FIG. 13C It can be seen that the positioning lens provided in Example 6 can achieve good imaging quality.

[0168] Embodiment 7

[0169] The following reference Figures 14 to 15C Describe the positioning lens according to the seventh embodiment of the present application.

[0170] like Fig.14 As shown, the positioning lens may include a first lens E1, a second lens E2, a third lens E3, an aperture STO, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7 and an eighth lens E8 arranged in sequence from the object side to the image side along the second optical axis.

[0171] In this embodiment, the first lens E1 and the second lens E2 have negative power, the third lens E3 has positive power, the fourth lens E4 has positive power, the fifth lens E5 has positive power, the sixth lens E6 has negative power, and the seventh lens E7 and the eighth lens E8 have positive power.

[0172] Table 14 shows a basic parameter table of the positioning lens of Example 7, wherein the units of the radius of curvature and thickness / distance are all millimeters (mm).

[0173]

[0174] Table 14

[0175] In this embodiment, the object side surface and the image side surface of any lens from the second lens E2 to the eighth lens E8 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. Tables 15-1 and 15-2 show 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, 10 , A 12 , A 14 , A 16 and A 18 , A 20 , A 22 , A 24 , A 26 , A 28 and A 30 .

[0176]

[0177]

[0178] Table 15-1

[0179] Face number A18 A20 A22 A24 A26 A28 A30 S3 -3.40E-05 3.85E-06 -2.87E-07 1.27E-08 -2.50E-10 0.00E+00 0.00E+00 S4 9.64E-02 -6.31E-03 -1.98E-03 3.26E-04 0.00E+00 0.00E+00 0.00E+00 S5 2.42E-01 -5.85E-02 8.21E-03 -5.17E-04 0.00E+00 0.00E+00 0.00E+00 S6 -1.82E-01 2.32E-02 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S7 -2.89E-01 3.32E-02 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 S8 -4.52E-02 1.32E-02 -2.15E-03 1.49E-04 0.00E+00 0.00E+00 0.00E+00 S9 3.35E-03 -5.81E-04 5.82E-05 -2.56E-06 0.00E+00 0.00E+00 0.00E+00 S10 1.40E-01 -5.45E-02 1.51E-02 -2.89E-03 3.64E-04 -2.71E-05 9.07E-07 S11 9.15E-02 -3.66E-02 1.04E-02 -2.03E-03 2.59E-04 -1.96E-05 6.68E-07 S12 -3.93E-02 1.02E-02 -1.93E-03 2.61E-04 -2.36E-05 1.29E-06 -3.21E-08 S13 -8.57E-02 2.28E-02 -4.41E-03 6.02E-04 -5.49E-05 3.00E-06 -7.45E-08 S14 -4.41E-02 1.25E-02 -2.50E-03 3.50E-04 -3.23E-05 1.77E-06 -4.36E-08 S15 3.61E-03 -6.70E-04 8.93E-05 -8.32E-06 5.15E-07 -1.90E-08 3.17E-10 S16 8.07E-04 -1.44E-04 1.82E-05 -1.58E-06 9.10E-08 -3.10E-09 4.77E-11

[0180] Table 15-2

[0181] Fig.15A The axial chromatic aberration curve of the positioning lens in Embodiment 7 is shown, which represents the deviation of the focusing points of light rays with different wavelengths after passing through the positioning lens. Fig. 15B The astigmatism curve of the positioning lens in Embodiment 7 is shown, which represents the meridional image plane curvature and sagittal image plane curvature corresponding to different field angles. Fig. 15C The longitudinal chromatic aberration curve of the positioning lens in Embodiment 7 is shown, which represents the deviation of different image heights on the imaging plane after the light rays pass through the positioning lens. According to FIG. 15A to FIG. 15C it can be known that the positioning lens given in Embodiment 7 can achieve good imaging quality.

[0182] The following Table 16 shows the basic parameter data of the positioning lens according to the above Embodiments 4 to 7 of the present application. Among them, the units of focal length, height, and distance are all millimeters (mm).

[0183]

[0184]

[0185] Table 16

[0186] In summary, according to the virtual reality system provided in the above Embodiments 1 to 7 of the present application, the visual lens satisfies

[0187] the conditional formula in Table 17, and the positioning lens satisfies the conditional formula in Table 18.

[0188] Conditional / Example one two three <h2 style=";text-align:left;direction:ltr">-11.0<(f2a+f3a) / (R3a+R5a)<0.3<h2 style=";text-align:left;direction:ltr"> -6.29 -10.89 0.15 -1.2<Rna / (R3a+R4a)<1.0(n=2) 0.60 -0.48 -1.05 0.2<f1a / V1a / CT1a<8.0 0.66 0.50 7.88 <h2 style=";text-align:left;direction:ltr">-4.0<(R4a+R5a) / (CT2a+CT3a)<-1.9<h2 style=";text-align:left;direction:ltr"> -3.88 -2.13 -3.23 <h2 style=";text-align:left;direction:ltr">2.0<(f2a / N2a) / (f3a / N3a)<11.0<h2 style=";text-align:left;direction:ltr"> 7.77 10.80 2.45 -7.5<R6a / R5a+R4a / R3a<7.6 -7.04 7.49 -4.44 29mm<TDa<40mm 29.78 39.75 30.05 0.5<CT3a / (CT1a+CT2a)<2.5 1.02 2.18 0.97

[0189] Table 17

[0190] Conditional / Example Four five six seven 11.2<(CT5+CT7) / CT6<13.3 13.15 11.65 11.65 11.52 1.5<ImgH / f<2.2 1.89 1.91 1.91 1.92 -0.2<f / f1<-0.15 -0.17 -0.18 -0.18 -0.17 -13.5<(R11+R12) / f6<-4.3 -4.55 -10.09 -10.09 -13.43 5.8<DT11 / CT1 / N1<12.5 9.24 11.21 11.21 6.10 -2.5<f1 / N1 / (f3 / N3)<-1.5 -1.65 -2.18 -2.18 -1.78 2.0<(SAG11+SAG12) / (SAG81+SAG82)<6.0 2.09 2.38 2.38 5.89 -0.8<(f5+f6) / f<1.4 -0.69 1.20 1.20 1.16 -0.8<f6 / f3*(N6 / N3)<-0.2 -0.63 -0.46 -0.46 -0.48 3.7<TTL / (CT5+CT7)<4.3 3.94 4.10 4.10 4.12

[0191] Table 18

[0192] For the virtual reality system according to the embodiment of the present application, the total system length of the visual lens and the positioning lens satisfies the conditional formula 2.2 < TTLa / TTL < 4.7, as shown in Table 19. In the table, TTLa1 - TTLa3 are the axial distances from the surface of the first lens of the visual lens far from the screen side to the screen in Embodiments 1 to 3, respectively, and TTL4 - TTL7 are the axial distances from the object side surface of the first lens of the positioning lens to the imaging surface in Embodiments 4 to 7, respectively.

[0193] TTLa / TTL TTLa1 TTLa2 TTLa3 TTL4 3.35 4.55 3.23 TTL5 2.98 4.06 2.88 TTL6 2.56 3.48 2.47 TTL7 2.40 3.26 2.32

[0194] Table 19

[0195] 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 invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with the technical features with similar functions disclosed in this application (but not limited to) by each other.

Claims

1. A virtual reality system, characterized in that: It includes a visual lens and a positioning lens, where the visual lens sequentially includes, along a first optical axis, from a first side away from the screen to a second side close to the screen: a first element group including a reflective polarizing element, a quarter-wave plate, and a first lens with a positive optical power, where a first side or a second side of the first lens is a plane; a second element group including a second lens with a positive optical power; and a third element group including a third lens with a positive optical power; the positioning lens sequentially includes, along a second optical axis, from the object side to the image side, a first lens with a negative optical power, a second lens with a negative optical power, a third lens with a positive optical power, a fourth lens with an optical power, a fifth lens with a positive optical power, a sixth lens with a negative optical power, a seventh lens with a positive optical power, and an eighth lens with a positive optical power; the virtual reality system satisfies: -11.0 < (f2a + f3a) / (R3a + R5a) < 0.3; 11.2 < (CT5 + CT7) / CT6 < 13.3; 1.5 < ImgH / f < 2.2; and 2.2 < TTLa / TTL < 4.7; where f2a is the effective focal length of the second lens, f3a is the effective focal length of the third lens, R3a is the curvature radius of the first side of the second lens, R5a is the curvature radius of the first side of the third lens, CT5 is the central thickness of the fifth lens, CT7 is the central thickness of the seventh lens, CT6 is the central thickness of the sixth lens, ImgH is half of the image height corresponding to the maximum field of view angle of the positioning lens, f is the total effective focal length of the positioning lens, TTLa is the distance from the first side of the first element group to the screen of the visual lens on the first optical axis, and TTL is the distance from the object side of the first lens to the imaging surface of the positioning lens on the second optical axis.

2. The virtual reality system according to claim 1, wherein: The visual lens satisfies: -1.2 < Rna / (R3a + R4a) < 1.0, where R3a is the curvature radius of the first side of the second lens, R4a is the curvature radius of the second side of the second lens, Rna is the minimum value of the curvature radii of the first side and the second side of the first lens, and n = 1 or 2.

3. The virtual reality system according to claim 1, wherein: The visual lens satisfies: 0.2 < f1a / V1a / CT1a < 8.0, where f1a is the effective focal length of the first lens, V1a is the Abbe number of the first lens, and CT1a is the central thickness of the first lens.

4. The virtual reality system according to claim 1, wherein: The visual lens satisfies: -4.0 < (R4a + R5a) / (CT2a + CT3a) < -1.9, where R4a is the curvature radius of the second side of the second lens, R5a is the curvature radius of the first side of the third lens, CT2a is the central thickness of the second lens, and CT3a is the central thickness of the third lens.

5. The virtual reality system according to claim 1, wherein: The visual lens satisfies: 2.0 < (f2a / N2a) / (f3a / N3a) < 11.0, Among them, f2a is the effective focal length of the second lens, N2a is the refractive index of the second lens, f3a is the effective focal length of the third lens, and N3a is the refractive index of the third lens.

6. The virtual reality system according to claim 1, wherein: The visual lens meets the following requirements: -7.5 <R6a / R5a+R4a / R3a<7.6, Among them, R6a is the curvature radius of the second side surface of the third lens, R5a is the curvature radius of the first side surface of the third lens, R4a is the curvature radius of the second side surface of the second lens, and R3a is the curvature radius of the first side surface of the second lens.

7. The virtual reality system according to claim 1, wherein: The visual lens meets the following requirements: 29mm <TDa<40.0mm, Wherein, TDa is the distance from the second side surface of the third element group to the screen of the eyepiece lens on the first optical axis.

8. The virtual reality system according to claim 1, wherein: The visual lens meets the following requirements: 0.5 <CT3a / (CT1a+CT2a)<2.5, Among them, CT3a is the center thickness of the third lens, CT1a is the center thickness of the first lens, and CT2a is the center thickness of the second lens.

9. The virtual reality system according to claim 1, wherein: The positioning lens satisfies: -0.2 <f / f1<-0.15, Wherein, f is the total effective focal length of the positioning lens, and f1 is the effective focal length of the first lens.

10. The virtual reality system according to claim 1, wherein: The positioning lens satisfies: -13.5<(R11+R12) / f6<-4.3, Wherein, R11 is the curvature radius of the object side surface of the sixth lens, R12 is the curvature radius of the image side surface of the sixth lens, and f6 is the effective focal length of the sixth lens.

Images