Visual system for vr

Abstract

The application discloses a visual system for VR, which comprises a first element group, a second element group, a third element group and a light source; the first element group comprises a first lens; the second element group comprises a second lens, a reflective polarizing element and a quarter-wave plate; the third element group comprises a third lens; each lens in the first to third element groups has at least one viewing side far away from the light source and one display side close to the light source; the viewing side or the display side of at least one lens has a partial reflection layer; wherein the focal length F2 of the second element group, the central thickness CT2 of the second lens and the refractive index N2 of the second lens satisfy the condition: 4 < F2 / CT2 x N2 < 10. The visual system comprises the light source, the lens, the reflective polarizing element and the quarter-wave plate attached to the lens, and the partial reflection layer plated on the lens; after the light passes through the plating layer and the attached film layer, the polarization state changes, the light path is folded and reflected, and the length of the visual system is compressed.

Description

Technical Field

[0001] This invention belongs to the field of optical imaging, and particularly relates to a visual system for VR. Background Technology

[0002] In recent years, as mobile phone development has reached a bottleneck, other visual display technologies have become an important alternative, with concepts such as Virtual Reality (VR), Augmented Reality (AR), Mixed Reality (MR), and Extended Reality (XR) gradually emerging. Among these, Virtual Reality (VR) technology has developed rapidly, progressing through aspherical lenses, Fresnel lenses, and folding lens structures, with its development direction gradually converging. Compared to aspherical and Fresnel solutions, the folding optical path structure using folding lenses significantly reduces the thickness and weight of the visual system, increasing user comfort and gaining consumer favor.

[0003] However, due to limitations in coating technology, the lenses used in folded optical path solutions have fewer degrees of freedom, and therefore the performance of existing folded optical path structures using 1P and 2P still needs improvement. This patent proposes a 3P architecture, combined with curved coating technology, to further shorten the thickness of the visual system, while improving the system performance and enhancing the consumer's visual experience. Summary of the Invention

[0004] This application aims to provide a visual system for VR that, by adjusting the folded optical path structure, effectively improves the ghosting problem while compressing the system length, and further increases the field of view.

[0005] This application provides a visual system for VR, including: a first element group, a second element group, a third element group, and a light source;

[0006] The first element group includes a first lens;

[0007] The second element group includes a second lens and a reflective polarizing element and a quarter-wave plate in contact with the second lens;

[0008] The third element group includes a third lens;

[0009] The first to third element groups are arranged sequentially along the optical axis from the position away from the light source to the position close to the light source. Each lens in the first to third element groups has at least one eye side away from the light source and one display side far from and close to the light source.

[0010] The eye side or display side of the at least one lens has a partial reflective layer;

[0011] Wherein, the focal length F2 of the second element group, the center thickness CT2 of the second lens, and the refractive index N2 of the second lens satisfy: 4 <F2 / CT2×N2<10。

[0012] According to one embodiment provided in this application, the reflective polarizing element includes at least one eye-side away from the light source and at least one display-side close to the light source, the quarter-wave plate includes at least one eye-side away from the light source and at least one display-side close to the light source, and the display-side of the reflective polarizing element is at least partially in contact with the eye-side of the quarter-wave plate.

[0013] According to one embodiment provided in this application, the partial reflective layer is deposited on the display side of the second lens or the eye side of the third element group.

[0014] According to one embodiment provided in this application, the second lens and the third element group of the visual system are both meniscus lenses with a concave eye side.

[0015] According to one embodiment provided in this application, the radius of curvature R3 of the eye side of the second lens and the radius of curvature R4 of the display side of the second lens satisfy: -1<(R3-R4) / (R3+R4)<2.

[0016] According to one embodiment provided in this application, the effective focal length f of the visual system, the semi-field-of-view angle semi-fov of the visual system, and the on-axis distance TD from the eye side of the first element group to the display side of the third element group satisfy: 1 <f×tan(semi-fov) / TD<2。

[0017] According to one embodiment provided in this application, the dispersion coefficient V1 of the first element group, the dispersion coefficient V2 of the second lens, and the dispersion coefficient V3 of the third element group satisfy: 0.5 < (V1 + V3) / V2 < 2.

[0018] According to one embodiment provided in this application, the radius of curvature R5 of the side surface of the third element group, the radius of curvature R6 of the side surface of the third element group, and the refractive index N3 of the third element group satisfy: 0 <R5 / R6×N3<2。

[0019] According to one embodiment provided in this application, the center thickness CT1 of the first element group on the optical axis, the center thickness CT2 of the second lens on the optical axis, the center thickness CT3 of the third element group on the optical axis, and the axial distance TD from the eye side of the first element group to the display side of the third element group satisfy: 1 <TD / (CT1+CT2+CT3)<2.5。

[0020] According to one embodiment provided in this application, the refractive index N1 of the first element group, the refractive index N2 of the second lens, and the refractive index N3 of the third element group satisfy: 1.5 < (N1 + N2) / N3 < 2.

[0021] According to one embodiment provided in this application, the focal length F2 of the second element group and the effective focal length f of the visual system satisfy: 0.5 <F2 / f<1.5。

[0022] According to one embodiment provided in this application, both the reflective polarizing element and the quarter-wave plate have a certain thickness.

[0023] According to one embodiment provided in this application, the focal length F2 of the second element group, the center thickness CT2 of the second lens on the optical axis, the center thickness CTRP of the reflective polarizing element, and the center thickness CTQWP of the quarter-wave plate satisfy: 2 <F2 / (CT2+CTRP+CTQWP)<8。

[0024] According to one embodiment provided in this application, the center thickness CT1 of the first element group on the optical axis, the center thickness CT3 of the third element group on the optical axis, the focal length f1 of the first element group, and the focal length f3 of the third element group satisfy: -0.5<(CT1+CT3) / (f1+f3)<0.5.

[0025] According to one embodiment provided in this application, the distance T12 between the display side of the first element group and the eye side of the second lens on the optical axis, the distance T23 between the display side of the second lens and the eye side of the third element group on the optical axis, and the center thickness CT2 of the second lens on the optical axis satisfy: 0<(T12+T23) / CT2<5.

[0026] According to one embodiment provided in this application, the refractive index NRP of the reflective polarizing element, the refractive index NQWP of the quarter-wave plate, and the refractive index N2 of the second lens satisfy: 1.9 < (NRP + NQWP) / N2 < 2.1.

[0027] The beneficial effects of this invention are:

[0028] The visual system for VR provided by this invention includes a light source, lenses, reflective polarizing elements and quarter-wave plates attached to the lenses, and a partially reflective layer coated on the lenses. After light passes through the coating and adhesive layers, the polarization state changes, causing the light path to be reflected, thus compressing the length of the visual system. The second lens is mainly used for light path reflection; by controlling the focal length, thickness, and refractive index of the second lens, the reflection length can be increased, which is beneficial for compressing the thickness of the visual system. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the lens group structure of Embodiment 1 of the visual system for VR of the present invention;

[0031] Figure 2a , Figure 2b and Figure 2c These are the on-axis chromatic aberration curve, astigmatism curve, and distortion curve of Embodiment 1 of the visual system for VR of the present invention;

[0032] Figure 3 This is a schematic diagram of the lens group structure of Embodiment 2 of the visual system for VR of the present invention;

[0033] Figure 4a , Figure 4b and Figure 4c These are the on-axis chromatic aberration curve, astigmatism curve, and distortion curve of Embodiment 2 of the visual system for VR of the present invention, respectively;

[0034] Figure 5 This is a schematic diagram of the lens group structure of Embodiment 3 of the visual system for VR of the present invention;

[0035] Figure 6a , Figure 6b and Figure 6c These are the on-axis chromatic aberration curve, astigmatism curve, and distortion curve of Embodiment 3 of the visual system for VR of the present invention;

[0036] Figure 7 This is a schematic diagram of the lens group structure of Embodiment 4 of the visual system for VR of the present invention;

[0037] Figure 8a , Figure 8b and Figure 8c These are the on-axis chromatic aberration curve, astigmatism curve, and distortion curve of Embodiment 4 of the VR visual system of the present invention;

[0038] Figure 9 This is a schematic diagram of the lens group structure of Embodiment 5 of the visual system for VR of the present invention;

[0039] Figure 10a , Figure 10b and Figure 10c These are the on-axis chromatic aberration curve, astigmatism curve, and distortion curve of Embodiment 5 of the visual system for VR of the present invention;

[0040] Figure 11 This is a schematic diagram of the lens group structure of Embodiment 5 of the visual system for VR of the present invention;

[0041] Figure 12a , Figure 12b and Figure 12c These are the on-axis chromatic aberration curve, astigmatism curve, and distortion curve of Embodiment 6 of the VR visual system of the present invention;

[0042] Figure 13 This is a schematic diagram of the lens group structure of Embodiment 7 of the visual system for VR of the present invention;

[0043] Figure 14a , Figure 14b and Figure 14c These are the on-axis chromatic aberration curve, astigmatism curve, and distortion curve of Embodiment 7 of the VR visual system of the present invention;

[0044] Figure 15 This is a schematic diagram of the lens group structure of Embodiment 8 of the visual system for VR of the present invention;

[0045] Figure 16a , Figure 16b and Figure 16c These are the on-axis chromatic aberration curve, astigmatism curve, and distortion curve of Embodiment 8 of the visual system for VR of the present invention;

[0046] Figure 17 This is a schematic diagram of the lens group structure of Embodiment 9 of the visual system for VR of the present invention;

[0047] Figure 18a , Figure 18b and Figure 18c These are the on-axis chromatic aberration curve, astigmatism curve, and distortion curve of Embodiment 9 of the visual system for VR of the present invention. Detailed Implementation

[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of the invention, the first group of elements discussed below may also be referred to as the second lens or the third group of elements.

[0050] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0051] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0052] In the description of this invention, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region. If the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the display screen is called the display side of the lens, and the surface of each lens closest to the human eye is called the eye side of the lens.

[0053] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formalized manner unless expressly so specified herein.

[0054] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The features, principles, and other aspects of the present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0055] Exemplary Implementation

[0056] This exemplary embodiment provides a visual system for VR, including: a first element group, a second element group, a third element group, and a light source; the first element group includes a first lens; the second element group includes a second lens, a reflective polarizing element and a quarter-wave plate in contact with the second lens; the third element group includes a third lens; the first to third element groups are arranged in sequence along the optical axis from a position far from the light source to a position close to the light source, and each lens of the first to third element groups has at least one eye side facing away from the light source and one display side close to the light source; at least one of the eye sides or display sides of the at least one lens has a partial reflection layer; wherein, the focal length F2 of the second element group, the central thickness CT2 of the second lens, and the refractive index N2 of the second lens satisfy: 4 < F2 / CT2 × N2 < 10. The visual system for VR includes a light source, lenses, a reflective polarizing element and a quarter-wave plate attached to the lenses, and a partial reflection layer plated on the lenses. After the light passes through the coating layer and the film layer, the polarization state changes, and the optical path is refracted and reflected, reducing the length of the visual system for VR. Among them, the second lens is mainly used for refracting and reflecting the optical path. By controlling the focal length, central thickness, and refractive index of the second lens, the length of the refraction and reflection can be increased, which is beneficial to reducing the thickness of the visual system. More specifically, the focal length F2 of the second element group, the central thickness CT2 of the second lens, and the refractive index N2 of the second lens satisfy: 3.6 < F2 / CT2 × N2 < 7.

[0057] In this exemplary embodiment, the reflective polarizing element includes at least one eye side facing away from the light source and at least one display side close to the light source, the quarter-wave plate includes at least one eye side facing away from the light source and at least one display side close to the light source, and at least part of the display side of the reflective polarizing element is in contact with the eye side of the quarter-wave plate. The reflective polarizing element and the quarter-wave plate are attached together to form a single film, reducing the number of attachment surfaces of the film and improving the attachment efficiency of the film.

[0058] In this exemplary embodiment, the partial reflection layer is plated on the display side of the second lens or the eye side of the third element group. Plating the partial reflection layer on the display side of the second lens or the eye side of the third element group away from the reflective polarizing element is beneficial to increasing the length of the refraction and reflection.

[0059] In this exemplary embodiment, both the second lens and the third element group of the visual system are meniscus lenses with concave eye sides. Both the second lens and the third element group are meniscus lenses with concave eye sides, which is beneficial to reducing the incident angle of light on the lens surface and increasing the efficiency of light passing through the polarizing element; at the same time, the meniscus lens increases the viewing angle of the visual system for VR, which is beneficial to reducing the boundary effect of the visual system.

[0060] In the present exemplary embodiment, the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R4 of the display side surface of the second lens satisfy: -1 < (R3 - R4) / (R3 + R4) < 2. By controlling the radii of curvature of the two surfaces of the second lens, it is beneficial to constrain the shape of the second lens, which is conducive to applying a film to the curved surface of the second lens. More specifically, the radius of curvature R3 of the object side surface of the second lens and the radius of curvature R4 of the display side surface of the second lens satisfy: -0.05 < (R3 - R4) / (R3 + R4) < 0.09.

[0061] In the present exemplary embodiment, the effective focal length f of the visual system, the semi-field angle semi-fov of the visual system, and the on-axis distance TD from the object side surface of the first element group to the display side surface of the third element group satisfy: 1 < f×tan(semi-fov) / TD < 2. By controlling the focal length, field angle, and on-axis distance from the object side surface of the first element group to the display side surface of the third element group of the system, the focal length of the visual system for VR is small, the field angle is large, and the on-axis distance from the object side surface of the first element group to the display side surface of the third element group is small, so that the system meets the important indicators of the visual system. More specifically, the effective focal length f of the visual system, the semi-field angle semi-fov of the visual system, and the on-axis distance TD from the object side surface of the first element group to the display side surface of the third element group satisfy: 1.4 < f×tan(semi-fov) / TD < 1.80.

[0062] In the present exemplary embodiment, the dispersion coefficient V1 of the first element group, the dispersion coefficient V2 of the second lens, and the dispersion coefficient V3 of the third element group satisfy: 0.5 < (V1 + V3) / V2 < 2. By controlling the dispersion coefficients of the first element group, the second lens, and the third element group, it is beneficial to constrain the chromatic aberration of the system, thereby reducing the influence of the visual system on the screen chromaticity. More specifically, the dispersion coefficient V1 of the first element group, the dispersion coefficient V2 of the second lens, and the dispersion coefficient V3 of the third element group satisfy: 1.18 < (V1 + V3) / V2 < 1.80.

[0063] In the present exemplary embodiment, the radius of curvature R5 of the object side surface of the third element group, the radius of curvature R6 of the display side surface of the third element group, and the refractive index N3 of the third element group satisfy: 0 < R5 / R6×N3 < 2. By controlling the radii of curvature of the two surfaces and the refractive index of the third element group, the focal length of the third element group is effectively controlled, thereby controlling the angle of the light passing through the third element group and reducing the incident angle of the light on the screen. More specifically, the radius of curvature R5 of the object side surface of the third element group, the radius of curvature R6 of the display side surface of the third element group, and the refractive index N3 of the third element group satisfy: 0.40 < R5 / R6×N3 < 1.99.

[0064] In the present exemplary embodiment, the central thickness CT1 of the first element group on the optical axis, the central thickness CT2 of the second lens on the optical axis, the central thickness CT3 of the third element group on the optical axis, and the on-axis distance TD from the object side of the first element group to the image side of the third element group satisfy: 1 < TD / (CT1 + CT2 + CT3) < 2.5. By controlling the ratio of the sum of the thicknesses of the first element group, the second lens, and the third element group to the on-axis distance from the first element group to the third element group, the air gap between the lenses is restricted, which is beneficial to the thinning and lightening of the visual system. More specifically, the central thickness CT1 of the first element group on the optical axis, the central thickness CT2 of the second lens on the optical axis, the central thickness CT3 of the third element group on the optical axis, and the on-axis distance TD from the object side of the first element group to the image side of the third element group satisfy: 1.15 < TD / (CT1 + CT2 + CT3) < 2.1.

[0065] In the present exemplary embodiment, the refractive index N1 of the first element group, the refractive index N2 of the second lens, and the refractive index N3 of the third element group satisfy: 1.5 < (N1 + N2) / N3 < 2. By controlling the ratio of the sum of the refractive indices of the first element group and the second lens to the refractive index of the third element group, the material selection of the third element group is restricted, which is beneficial to reducing the stress of the lens material, thereby improving the polarization efficiency of the visual system for VR. More specifically, the refractive index N1 of the first element group, the refractive index N2 of the second lens, and the refractive index N3 of the third element group satisfy: 1.60 < (N1 + N2) / N3 < 1.98.

[0066] In the present exemplary embodiment, the focal length F2 of the second element group and the effective focal length f of the visual system satisfy: 0.5 < F2 / f < 1.5. By controlling the ratio of the focal length of the second lens to the focal length of the visual system for VR, the optical power of the system is reasonably distributed, which is beneficial to ensuring the optical performance of the system. More specifically, the focal length F2 of the second element group and the effective focal length f of the visual system satisfy: 1.0 < F2 / f < 1.3.

[0067] In the present exemplary embodiment, both the reflective polarizing element and the quarter-wave plate have a certain thickness. The reflective polarizing element and the quarter-wave plate having a certain thickness are, on the one hand, required for polarization characteristics, and on the other hand, are beneficial to the support of the polarizing element and facilitate the film attachment.

[0068] In the present exemplary embodiment, the focal length F2 of the second element group, the central thickness CT2 of the second lens on the optical axis, the central thickness CTRP of the reflective polarizing element, and the central thickness CTQWP of the quarter-wave plate satisfy: 2 < F2 / (CT2 + CTRP + CTQWP) < 8. By controlling the focal length of the second lens, the central thickness, and the thickness of the polarizing element attached to the surface of the second lens, on the one hand, it is beneficial to control the focal length of the second lens, and on the other hand, it is beneficial to control the shape of the second lens. Combining with the thickness of the polarizing element is beneficial to the attachment of the polarizing element. More specifically, the focal length F2 of the second element group, the central thickness CT2 of the second lens on the optical axis, the central thickness CTRP of the reflective polarizing element, and the central thickness CTQWP of the quarter-wave plate satisfy: 2.3 < F2 / (CT2 + CTRP + CTQWP) < 5.

[0069] In the present exemplary embodiment, the central thickness CT1 of the first element group on the optical axis, the central thickness CT3 of the third element group on the optical axis, the focal length f1 of the first element group, and the focal length f3 of the third element group satisfy: -0.5 < (CT1 + CT3) / (f1 + f3) < 0.5. By controlling the central thicknesses of the first element group and the third element group and the focal lengths of the first element group and the third element group, the first element group is flatter and the third element group is more curved, which is beneficial to reducing the influence of the structural part of the first element group on the total length of the visual system and is also beneficial to the control of the light exit angle by the third element group. More specifically, the central thickness CT1 of the first element group on the optical axis, the central thickness CT3 of the third element group on the optical axis, the focal length f1 of the first element group, and the focal length f3 of the third element group satisfy: -0.45 < (CT1 + CT3) / (f1 + f3) < 0.3.

[0070] In the present exemplary embodiment, the spacing distance T12 between the display side of the first element group and the eye side of the second lens on the optical axis, the spacing distance T23 between the display side of the second lens and the eye side of the third element group on the optical axis, and the central thickness CT2 of the second lens on the optical axis satisfy: 0 < (T12 + T23) / CT2 < 5. Through the above formula, the central thickness of the lens and the gap between the lenses are effectively controlled. On the one hand, it is beneficial to the shaping of each lens, and on the other hand, it is beneficial to the assembly between the lenses. More specifically, the spacing distance T12 between the display side of the first element group and the eye side of the second lens on the optical axis, the spacing distance T23 between the display side of the second lens and the eye side of the third element group on the optical axis, and the central thickness CT2 of the second lens on the optical axis satisfy: 0.2 < (T12 + T23) / CT2 < 1.

[0071] In this exemplary embodiment, the refractive index NRP of the reflective polarizing element, the refractive index NQWP of the quarter-wave plate, and the refractive index N2 of the second lens satisfy the following condition: 1.9 < (NRP + NQWP) / N2 < 2.1. By controlling the ratio of the refractive indices of the reflective polarizing element, the quarter-wave plate, and the second lens, the refractive indices of the three are made close, which helps to reduce the impact of changes in the thickness of the reflective polarizing element and the quarter-wave plate on the visual system used in VR, and increases the selectivity of the polarizing element. More specifically, the refractive index NRP of the reflective polarizing element, the refractive index NQWP of the quarter-wave plate, and the refractive index N2 of the second lens satisfy the following condition: 2.0 < (NRP + NQWP) / N2 < 2.05.

[0072] In this exemplary embodiment, the eye-side and display-side surfaces of any lens in the first element group E1 to the third element group E3 are aspherical, and the surface shape x of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0073]

[0074] Where x is the distance vector from the vertex of the aspherical surface along the optical axis at a height of h; c is the paraxial curvature of the aspherical surface, c = 1 / R (that is, the paraxial curvature c is the reciprocal of the radius of curvature R in Table 1); k is the conic coefficient; Ai is the correction coefficient of the i-th order of the aspherical surface.

[0075] In this exemplary embodiment, the visual system for VR described above may further include an aperture stop. The aperture stop may be positioned as needed, for example, the aperture stop may be positioned before the first element group. Optionally, the visual system for VR described above may further include a filter for correcting color deviation and / or a protective glass for protecting the photosensitive element located on the imaging surface.

[0076] The VR visual system according to the above embodiments of the present invention can employ multiple lenses, such as the three lenses described above. By rationally allocating the optical power, surface shape, center thickness of each lens, and on-axis spacing between each lens, the VR visual system has a large imaging surface, a wide imaging range, and high imaging quality, while ensuring the ultra-thinness of the mobile phone.

[0077] In an exemplary embodiment, at least one of the mirror surfaces of each lens is an aspherical mirror surface; that is, at least one mirror surface from the eye-side of the first element group to the display-side of the third element group is an aspherical mirror surface. The characteristic of an aspherical lens is that its curvature changes continuously from the lens center to the lens periphery. Unlike a spherical lens, which has a constant curvature from the lens center to the lens periphery, an aspherical lens has better curvature radius characteristics, offering advantages in improving distortion aberrations and astigmatism. By using an aspherical lens, aberrations occurring during imaging can be eliminated as much as possible, thereby improving image quality. Optionally, at least one of the eye-side and display-side surfaces of each lens in the first element group, the second lens, and the third element group is an aspherical mirror surface.

[0078] However, those skilled in the art will understand that the number of lenses constituting the visual system for VR can be changed without departing from the technical solutions claimed in this application to obtain the various results and advantages described in this specification. For example, although three lenses are described as an example in the embodiments, the visual system for VR is not limited to including three lenses, and may include other numbers of lenses if desired.

[0079] The following describes in further detail, with reference to the accompanying drawings, a specific embodiment of the visual system for VR applicable to the above embodiments. Specific Implementation Example 1

[0081] Figure 1 This is a schematic diagram of the lens group structure of Embodiment 1 of the visual system of the present invention. The visual system includes: a first element group, a second element group, a third element group, and a light source; the first to third element groups are arranged sequentially along the optical axis from the position away from the light source to the position close to the light source; the first element group includes a first lens; the second element group includes a second lens and a reflective polarizing element and a quarter-wave plate in contact with the second lens; the third element group includes a third lens; each lens in the first to third element groups has at least one eye side away from the light source and one display side far from the light source; the eye side or display side of the at least one lens has a partial reflective layer.

[0082] The first optical lens E1 has positive refractive power, its surface away from the light source is concave, and its surface near the light source is convex; and both of its surfaces are aspherical.

[0083] The second optical lens E2 has positive refractive power, its surface away from the light source is concave, and its surface near the light source is convex; and both of its surfaces are aspherical.

[0084] The third optical lens E3 has negative refractive power. Its surface away from the light source is concave, and its surface near the light source is convex. Both of its surfaces are aspherical.

[0085] A portion of the reflective layer is deposited on the surface of the second lens E2 near the light source.

[0086] Table 1 shows the basic parameters of the visual system in Example 1, where the units for radius of curvature, thickness, and focal length are all millimeters (mm).

[0087] Face number Surface type radius of curvature thickness Refractive index Dispersion coefficient Refraction / Reflection spherical endless endless refraction STO Stabilizer (STO) spherical endless 15.0000 refraction S1 First lens (E1) aspherical -1982.41 8.4016 1.48 52.6 refraction S2 aspherical -60.9137 3.2680 refraction S3 Reflective polarizing element (RP) aspherical -40.2343 0.2000 1.50 57.0 refraction S4 Quarter-wave plate (QWP) aspherical -40.2343 0.2000 1.50 57.0 refraction S5 Second lens (E2) aspherical -40.2343 11.3442 1.48 60.0 refraction S6 Partial reflective layer (BS) aspherical -42.7991 -11.3442 1.48 60.0 reflection S5 Quarter-wave plate (QWP) aspherical -40.2343 -0.2000 1.50 57.0 refraction S4 aspherical -40.2343 0.2000 1.50 57.0 reflection S5 aspherical -40.2343 11.3442 refraction S6 aspherical -42.7991 0.1540 refraction S7 Third lens (E3) aspherical -42.7082 0.8376 1.67 19.0 refraction S8 aspherical -162.731 1.9308 refraction S9 light source spherical endless

[0088] Table 1

[0089] As shown in Table 2, in Example 1, the total effective focal length of the visual system is f = 28.33 mm, the effective focal length of the first element group is f1 = 145.67 mm, the effective focal length of the second element group is f2 = 34.41 mm, and the effective focal length of the third element group is f3 = -111.17 mm. Half of the maximum field of view of the visual system (Semi-FOV) is 53.0°.

[0090]

[0091] Table 2

[0092] The visual system in Example 1 satisfies:

[0093] F2 / CT2×N2=4.49; where F2 is the focal length of the second element group, CT2 is the center thickness of the second lens, and N2 is the refractive index of the second lens;

[0094] (R3-R4) / (R3+R4)=-0.03; where R3 is the radius of curvature of the eye side of the second lens and R4 is the radius of curvature of the display side of the second lens.

[0095] f×tan(semi-fov) / TD=1.54; where f is the effective focal length of the visual system, semi-fov is the half field of view of the visual system, and TD is the on-axis distance from the eye side of the first element group to the display side of the third element group.

[0096] (V1+V3) / V2=1.19; where V1 is the dispersion coefficient of the first element group, V2 is the dispersion coefficient of the second lens, and V3 is the dispersion coefficient of the third element group.

[0097] R5 / R6×N3=0.44; where R5 is the radius of curvature of the side of the third element group, R6 is the radius of curvature of the side of the third element group, and N3 is the refractive index of the third element group.

[0098] TD / (CT1+CT2+CT3)=1.19; where CT1 is the center thickness of the first element group on the optical axis, CT2 is the center thickness of the second lens on the optical axis, CT3 is the center thickness of the third element group on the optical axis, and TD is the on-axis distance from the eye side of the first element group to the display side of the third element group.

[0099] (N1+N2) / N3=1.77; where N1 is the refractive index of the first element group, N2 is the refractive index of the second lens, and N3 is the refractive index of the third element group.

[0100] F2 / f = 1.21; where F2 is the focal length of the second element group and f is the effective focal length of the visual system.

[0101] F2 / (CT2+CTRP+CTQWP)=2.93; where F2 is the focal length of the second element group, CT2 is the center thickness of the second lens on the optical axis, CTRP is the center thickness of the reflective polarizing element, and CTQWP is the center thickness of the quarter-wave plate.

[0102] (CT1+CT3) / (f1+f3)=0.27; where CT1 is the center thickness of the first element group on the optical axis, CT3 is the center thickness of the third element group on the optical axis, f1 is the focal length of the first element group, and f3 is the focal length of the third element group.

[0103] (T12+T23) / CT2=0.34; where T12 is the distance between the display side of the first element group and the eye side of the second lens on the optical axis, T23 is the distance between the display side of the second lens and the eye side of the third element group on the optical axis, and CT2 is the center thickness of the second lens on the optical axis.

[0104] (NRP+NQWP) / N2=2.03; where NRP is the refractive index of the reflective polarizing element, NQWP is the refractive index of the quarter-wave plate, and N2 is the refractive index of the second lens.

[0105] In Example 1, Table 3 shows the higher-order coefficients A4, A6, A8, and A5 that can be used for each aspherical mirror S1, S2, S5-8 in Example 1. 10 .

[0106]

[0107]

[0108] Table 3

[0109] Figure 2aThe on-axis chromatic aberration curve of the visual system of Embodiment 1 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 2b The astigmatic curves of the visual system of Embodiment 1 are shown, representing the meridional image plane curvature and the sagittal image plane curvature. Figure 2c The distortion curves of the visual system of Embodiment 1 are shown, representing the magnitude of distortion under different viewing angles. According to... Figures 2a to 2c As shown, the visual system given in Example 1 can achieve good imaging quality. Specific Implementation Example 2

[0111] Figure 3 This is a schematic diagram of the lens group structure of Embodiment 2 of the visual system of the present invention. The visual system includes: a first element group, a second element group, a third element group, and a light source; the first to third element groups are arranged sequentially along the optical axis from the position away from the light source to the position close to the light source. The first element group includes a first lens; the second element group includes a second lens and a reflective polarizing element and a quarter-wave plate in contact with the second lens; the third element group includes a third lens; each lens in the first to third element groups has at least one eye side away from the light source and one display side far from and close to the light source; the eye side or display side of the at least one lens has a partial reflective layer.

[0112] The first optical lens E1 has positive refractive power, its surface away from the light source is concave, and its surface near the light source is convex; and both of its surfaces are aspherical.

[0113] The second optical lens E2 has positive refractive power, its surface away from the light source is concave, and its surface near the light source is convex; and both of its surfaces are aspherical.

[0114] The third optical lens E3 has negative refractive power. Its surface away from the light source is concave, and its surface near the light source is convex. Both of its surfaces are aspherical.

[0115] A portion of the reflective layer is deposited on the surface of the second lens E2 near the light source.

[0116] Table 4 shows the basic parameters of the visual system in Example 2, where the units for radius of curvature, thickness, and focal length are all millimeters (mm).

[0117] Face number Surface type radius of curvature thickness Refractive index Dispersion coefficient Refraction / Reflection spherical endless endless refraction STO Stabilizer (STO) spherical endless 15.0000 refraction S1 First lens (E1) aspherical -110.368 2.5868 1.48 52.6 refraction S2 aspherical -98.43213 4.6622 refraction S3 Reflective polarizing element (RP) aspherical -39.8246 0.2000 1.50 57.0 refraction S4 Quarter-wave plate (QWP) aspherical -39.8246 0.2000 1.50 57.0 refraction S5 Second lens (E2) aspherical -39.8246 12.7154 1.48 60.0 refraction S6 Partial reflective layer (BS) aspherical -42.0052 -12.7154 1.48 60.0 reflection S5 Quarter-wave plate (QWP) aspherical -39.8246 -0.2000 1.50 57.0 refraction S4 aspherical -39.8246 0.2000 1.50 57.0 reflection S5 aspherical -39.8246 12.7154 refraction S6 aspherical -42.0052 0.1000 refraction S7 Third lens (E3) aspherical -365.3409 1.4858 1.50 47.4 refraction S8 aspherical -276.2928 1.8094 refraction S9 light source spherical endless

[0118] Table 4

[0119] As shown in Table 5, in Example 2, the total effective focal length of the visual system is f = 29.60 mm, the effective focal length of the first element group is f1 = 1088.07 mm, the effective focal length of the second element group is f2 = 30.53 mm, and the effective focal length of the third element group is f3 = -1131.62 mm. Half of the maximum field of view of the visual system (Semi-FOV) is 53.0°.

[0120]

[0121] Table 5

[0122] The visual system in Example 2 satisfies:

[0123] F2 / CT2×N2=3.55; where F2 is the focal length of the second element group, CT2 is the center thickness of the second lens, and N2 is the refractive index of the second lens;

[0124] (R3-R4) / (R3+R4)=-0.03; where R3 is the radius of curvature of the eye side of the second lens and R4 is the radius of curvature of the display side of the second lens.

[0125] f×tan(semi-fov) / TD=1.79; where f is the effective focal length of the visual system, semi-fov is the half field of view of the visual system, and TD is the on-axis distance from the eye side of the first element group to the display side of the third element group.

[0126] (V1+V3) / V2=1.79; where V1 is the dispersion coefficient of the first element group, V2 is the dispersion coefficient of the second lens, and V3 is the dispersion coefficient of the third element group.

[0127] R5 / R6×N3=1.98; where R5 is the radius of curvature of the side of the third element group, R6 is the radius of curvature of the side of the third element group, and N3 is the refractive index of the third element group.

[0128] TD / (CT1+CT2+CT3)=1.31; where CT1 is the center thickness of the first element group on the optical axis, CT2 is the center thickness of the second lens on the optical axis, CT3 is the center thickness of the third element group on the optical axis, and TD is the on-axis distance from the eye side of the first element group to the display side of the third element group.

[0129] (N1+N2) / N3=1.97; where N1 is the refractive index of the first element group, N2 is the refractive index of the second lens, and N3 is the refractive index of the third element group.

[0130] F2 / f = 1.03; where F2 is the focal length of the second element group and f is the effective focal length of the visual system.

[0131] F2 / (CT2+CTRP+CTQWP)=2.33; where F2 is the focal length of the second element group, CT2 is the center thickness of the second lens on the optical axis, CTRP is the center thickness of the reflective polarizing element, and CTQWP is the center thickness of the quarter-wave plate.

[0132] (CT1+CT3) / (f1+f3)=-0.09; where CT1 is the center thickness of the first element group on the optical axis, CT3 is the center thickness of the third element group on the optical axis, f1 is the focal length of the first element group, and f3 is the focal length of the third element group.

[0133] (T12+T23) / CT2=0.30; where T12 is the distance between the display side of the first element group and the eye side of the second lens on the optical axis, T23 is the distance between the display side of the second lens and the eye side of the third element group on the optical axis, and CT2 is the center thickness of the second lens on the optical axis.

[0134] (NRP+NQWP) / N2=2.03; where NRP is the refractive index of the reflective polarizing element, NQWP is the refractive index of the quarter-wave plate, and N2 is the refractive index of the second lens.

[0135] In Example 2, Table 6 shows the higher-order coefficients A4, A6, A8, and A5 that can be used for each aspherical mirror S1, S2, S5-8 in Example 2. 10 .

[0136]

[0137]

[0138] Table 6

[0139] Figure 4a The on-axis chromatic aberration curve of the visual system of Embodiment 2 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 4b The astigmatic curves of the visual system of Embodiment 2 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 4c The distortion curves of the visual system of Embodiment 2 are shown, representing the magnitude of distortion under different viewing angles. According to... Figures 4a to 4c As shown, the visual system given in Example 2 can achieve good imaging quality. Specific Implementation Example 3

[0141] Figure 5This is a schematic diagram of the lens group structure of Embodiment 3 of the visual system of the present invention. The visual system includes: a first element group, a second element group, a third element group, and a light source; the first to third element groups are arranged sequentially along the optical axis from the position away from the light source to the position close to the light source; the first element group includes a first lens; the second element group includes a second lens and a reflective polarizing element and a quarter-wave plate in contact with the second lens; the third element group includes a third lens; each lens in the first to third element groups has at least one eye side away from the light source and one display side far from the light source; the eye side or display side of the at least one lens has a partial reflective layer.

[0142] The first optical lens E1 has positive refractive power, and its surface away from the light source is convex, as is its surface near the light source; and both of its surfaces are aspherical.

[0143] The second optical lens E2 has positive refractive power, its surface away from the light source is concave, and its surface near the light source is convex; and both of its surfaces are aspherical.

[0144] The third optical lens E3 has negative refractive power. Its surface away from the light source is concave, and its surface near the light source is convex. Both of its surfaces are aspherical.

[0145] A portion of the reflective layer is deposited on the surface of the second lens E2 near the light source.

[0146] Table 7 shows the basic parameters of the visual system in Example 3, where the units for radius of curvature, thickness, and focal length are all millimeters (mm).

[0147]

[0148]

[0149] Table 7

[0150] As shown in Table 8, in Example 3, the total effective focal length of the visual system is f = 29.64 mm, the effective focal length of the first element group is f1 = 286.11 mm, the effective focal length of the second element group is f2 = 29.90 mm, and the effective focal length of the third element group is f3 = -120.02 mm. Half of the maximum field of view of the visual system (Semi-FOV) is 53.0°.

[0151]

[0152] Table 8

[0153] The visual system in Example 3 satisfies:

[0154] F2 / CT2×N2=6.22; where F2 is the focal length of the second element group, CT2 is the center thickness of the second lens, and N2 is the refractive index of the second lens;

[0155] (R3-R4) / (R3+R4)=-0.03; where R3 is the radius of curvature of the eye side of the second lens and R4 is the radius of curvature of the display side of the second lens.

[0156] f×tan(semi-fov) / TD=1.48; where f is the effective focal length of the visual system, semi-fov is the half field of view of the visual system, and TD is the on-axis distance from the eye side of the first element group to the display side of the third element group.

[0157] (V1+V3) / V2=1.33; where V1 is the dispersion coefficient of the first element group, V2 is the dispersion coefficient of the second lens, and V3 is the dispersion coefficient of the third element group.

[0158] R5 / R6×N3=1.01; where R5 is the radius of curvature of the side of the third element group, R6 is the radius of curvature of the side of the third element group, and N3 is the refractive index of the third element group.

[0159] TD / (CT1+CT2+CT3)=2.03; where CT1 is the center thickness of the first element group on the optical axis, CT2 is the center thickness of the second lens on the optical axis, CT3 is the center thickness of the third element group on the optical axis, and TD is the on-axis distance from the eye side of the first element group to the display side of the third element group.

[0160] (N1+N2) / N3=1.78; where N1 is the refractive index of the first element group, N2 is the refractive index of the second lens, and N3 is the refractive index of the third element group.

[0161] F2 / f = 1.01; where F2 is the focal length of the second element group and f is the effective focal length of the visual system.

[0162] F2 / (CT2+CTRP+CTQWP)=3.98; where F2 is the focal length of the second element group, CT2 is the center thickness of the second lens on the optical axis, CTRP is the center thickness of the reflective polarizing element, and CTQWP is the center thickness of the quarter-wave plate.

[0163] (CT1+CT3) / (f1+f3)=0.04; where CT1 is the center thickness of the first element group on the optical axis, CT3 is the center thickness of the third element group on the optical axis, f1 is the focal length of the first element group, and f3 is the focal length of the third element group.

[0164] (T12+T23) / CT2=0.75; where T12 is the distance between the display side of the first element group and the eye side of the second lens on the optical axis, T23 is the distance between the display side of the second lens and the eye side of the third element group on the optical axis, and CT2 is the center thickness of the second lens on the optical axis.

[0165] (NRP+NQWP) / N2=2.03; where NRP is the refractive index of the reflective polarizing element, NQWP is the refractive index of the quarter-wave plate, and N2 is the refractive index of the second lens.

[0166] In Example 3, Table 9 shows the higher-order coefficients A4, A6, A8, and A5 that can be used for each aspherical mirror S1, S2, S5-8 in Example 3. 10 .

[0167] Face number A4 A6 A8 A10 S1 1.6709E-01 -1.2098E-01 1.2906E-01 2.0462E-03 S2 -2.9479E-02 -2.8129E-01 1.8536E-01 -1.5443E-02 S5 -1.3492E-01 2.2885E-01 3.7190E-02 -4.0488E-02 S6 4.7858E-02 2.2429E-01 -9.7967E-02 6.2033E-02 S7 7.4028E-02 7.1332E-02 -2.8110E-02 -1.8243E-02 S8 3.4701E+00 -4.6935E-01 -4.0010E-01 2.8946E-02

[0168] Table 9

[0169] Figure 6a The on-axis chromatic aberration curve of the visual system of Embodiment 3 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 6b The astigmatic curves of the visual system of Embodiment 3 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 6c The distortion curves of the visual system in Embodiment 3 are shown, representing the magnitude of distortion under different viewing angles. According to... Figures 6a to 6c As shown, the visual system given in Example 3 can achieve good imaging quality. Specific Implementation Example 4

[0171] Figure 7 This is a schematic diagram of the lens group structure of Embodiment 4 of the visual system of the present invention. The visual system includes: a first element group, a second element group, a third element group, and a light source; the first to third element groups are arranged sequentially along the optical axis from the position away from the light source to the position close to the light source; the first element group includes a first lens; the second element group includes a second lens and a reflective polarizing element and a quarter-wave plate in contact with the second lens; the third element group includes a third lens; each lens in the first to third element groups has at least one eye side away from the light source and one display side far from the light source; the eye side or display side of the at least one lens has a partial reflective layer.

[0172] The first optical lens E1 has positive refractive power, and its surface away from the light source is convex, as is its surface near the light source; and both of its surfaces are aspherical.

[0173] The second optical lens E2 has positive refractive power, its surface away from the light source is concave, and its surface near the light source is convex; and both of its surfaces are aspherical.

[0174] The third optical lens E3 has negative refractive power. Its surface away from the light source is concave, and its surface near the light source is convex. Both of its surfaces are aspherical.

[0175] A portion of the reflective layer is deposited on the surface of the second lens E2 near the light source.

[0176] Table 10 shows the basic parameters of the visual system in Example 4, where the units for radius of curvature, thickness, and focal length are all millimeters (mm).

[0177]

[0178]

[0179] Table 10

[0180] As shown in Table 11, in Example 4, the total effective focal length of the visual system is f = 28.19 mm, the effective focal length of the first element group is f1 = 183.05 mm, the effective focal length of the second element group is f2 = 30.40 mm, and the effective focal length of the third element group is f3 = -199.93 mm. Half of the maximum field of view of the visual system (Semi-FOV) is 53.0°.

[0181]

[0182] Table 11

[0183] The visual system in Example 4 satisfies:

[0184] F2 / CT2×N2=5.27; where F2 is the focal length of the second element group, CT2 is the center thickness of the second lens, and N2 is the refractive index of the second lens;

[0185] (R3-R4) / (R3+R4)=0.08; where R3 is the radius of curvature of the eye side of the second lens and R4 is the radius of curvature of the display side of the second lens.

[0186] f×tan(semi-fov) / TD=1.66; where f is the effective focal length of the visual system, semi-fov is the half field of view of the visual system, and TD is the on-axis distance from the eye side of the first element group to the display side of the third element group.

[0187] (V1+V3) / V2=1.32; where V1 is the dispersion coefficient of the first element group, V2 is the dispersion coefficient of the second lens, and V3 is the dispersion coefficient of the third element group.

[0188] R5 / R6×N3=0.94; where R5 is the radius of curvature of the side of the third element group, R6 is the radius of curvature of the side of the third element group, and N3 is the refractive index of the third element group.

[0189] TD / (CT1+CT2+CT3)=1.41; where CT1 is the center thickness of the first element group on the optical axis, CT2 is the center thickness of the second lens on the optical axis, CT3 is the center thickness of the third element group on the optical axis, and TD is the on-axis distance from the eye side of the first element group to the display side of the third element group.

[0190] (N1+N2) / N3=1.77; where N1 is the refractive index of the first element group, N2 is the refractive index of the second lens, and N3 is the refractive index of the third element group.

[0191] F2 / f = 1.08; where F2 is the focal length of the second element group and f is the effective focal length of the visual system.

[0192] F2 / (CT2+CTRP+CTQWP)=3.40; where F2 is the focal length of the second element group, CT2 is the center thickness of the second lens on the optical axis, CTRP is the center thickness of the reflective polarizing element, and CTQWP is the center thickness of the quarter-wave plate.

[0193] (CT1+CT3) / (f1+f3)=-0.44; where CT1 is the center thickness of the first element group on the optical axis, CT3 is the center thickness of the third element group on the optical axis, f1 is the focal length of the first element group, and f3 is the focal length of the third element group.

[0194] (T12+T23) / CT2=0.45; where T12 is the distance between the display side of the first element group and the eye side of the second lens on the optical axis, T23 is the distance between the display side of the second lens and the eye side of the third element group on the optical axis, and CT2 is the center thickness of the second lens on the optical axis.

[0195] (NRP+NQWP) / N2=2.03; where NRP is the refractive index of the reflective polarizing element, NQWP is the refractive index of the quarter-wave plate, and N2 is the refractive index of the second lens.

[0196] In Example 4, Table 12 shows the higher-order coefficients A4, A6, A8, and A5 that can be used for each aspherical mirror S1, S2, S5-8 in Example 4. 10 .

[0197] Face number A4 A6 A8 A10 S1 3.6325E-01 -5.2713E-02 4.0628E-02 -1.3604E-02 S2 -3.3387E-01 -1.0481E-01 5.2097E-02 -3.0148E-02 S5 -1.4815E-01 2.8961E-01 -2.9316E-02 -1.7431E-02 S6 1.7186E-02 2.9568E-01 -5.0959E-02 -8.7128E-03 S7 2.8006E-01 1.1234E-02 -2.1659E-02 3.5001E-03 S8 8.0228E-01 -2.8530E-01 -1.3174E-01 -1.9945E-02

[0198] Table 12

[0199] Figure 8a The on-axis chromatic aberration curve of the visual system of Embodiment 4 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 8b The astigmatic curves of the visual system of Embodiment 4 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 8c The distortion curves of the visual system in Example 4 are shown, representing the magnitude of distortion under different viewing angles. According to... Figures 8a to 8c As shown, the visual system given in Example 4 can achieve good imaging quality. Specific Implementation Example 5

[0201] Figure 9 This is a schematic diagram of the lens group structure of Embodiment 5 of the visual system of the present invention. The visual system includes: a first element group, a second element group, a third element group, and a light source; the first to third element groups are arranged sequentially along the optical axis from the position away from the light source to the position close to the light source; the first element group includes a first lens; the second element group includes a second lens and a reflective polarizing element and a quarter-wave plate in contact with the second lens; the third element group includes a third lens; each lens in the first to third element groups has at least one eye side away from the light source and one display side far from the light source; the eye side or display side of the at least one lens has a partial reflective layer.

[0202] The first optical lens E1 has positive refractive power, and its surface away from the light source is convex, as is its surface near the light source; and both of its surfaces are aspherical.

[0203] The second optical lens E2 has positive refractive power, its surface away from the light source is concave, and its surface near the light source is convex; and both of its surfaces are aspherical.

[0204] The third optical lens E3 has negative refractive power. Its surface away from the light source is concave, and its surface near the light source is convex. Both of its surfaces are aspherical.

[0205] A portion of the reflective layer is deposited on the surface of the second lens E2 near the light source.

[0206] Table 13 shows the basic parameters of the visual system in Example 5, where the units for radius of curvature, thickness, and focal length are all millimeters (mm).

[0207]

[0208]

[0209] Table 13

[0210] As shown in Table 14, in Example 5, the total effective focal length of the visual system is f = 29.07 mm, the effective focal length of the first element group is f1 = 279.67 mm, the effective focal length of the second element group is f2 = 29.93 mm, and the effective focal length of the third element group is f3 = -132.87 mm. Half of the maximum field of view of the visual system (Semi-FOV) is 53.0°.

[0211]

[0212] Table 14

[0213] The visual system in Example 5 satisfies:

[0214] F2 / CT2×N2=6.25; where F2 is the focal length of the second element group, CT2 is the center thickness of the second lens, and N2 is the refractive index of the second lens;

[0215] (R3-R4) / (R3+R4)=-0.03; where R3 is the radius of curvature of the eye side of the second lens and R4 is the radius of curvature of the display side of the second lens.

[0216] f×tan(semi-fov) / TD=1.62; where f is the effective focal length of the visual system, semi-fov is the half field of view of the visual system, and TD is the on-axis distance from the eye side of the first element group to the display side of the third element group.

[0217] (V1+V3) / V2=1.32; where V1 is the dispersion coefficient of the first element group, V2 is the dispersion coefficient of the second lens, and V3 is the dispersion coefficient of the third element group.

[0218] R5 / R6×N3=1.11; where R5 is the radius of curvature of the side of the third element group, R6 is the radius of curvature of the side of the third element group, and N3 is the refractive index of the third element group.

[0219] TD / (CT1+CT2+CT3)=2.06; where CT1 is the center thickness of the first element group on the optical axis, CT2 is the center thickness of the second lens on the optical axis, CT3 is the center thickness of the third element group on the optical axis, and TD is the on-axis distance from the eye side of the first element group to the display side of the third element group.

[0220] (N1+N2) / N3=1.77; where N1 is the refractive index of the first element group, N2 is the refractive index of the second lens, and N3 is the refractive index of the third element group.

[0221] F2 / f = 1.03; where F2 is the focal length of the second element group and f is the effective focal length of the visual system.

[0222] F2 / (CT2+CTRP+CTQWP)=4.00; where F2 is the focal length of the second element group, CT2 is the center thickness of the second lens on the optical axis, CTRP is the center thickness of the reflective polarizing element, and CTQWP is the center thickness of the quarter-wave plate.

[0223] (CT1+CT3) / (f1+f3)=0.03; where CT1 is the center thickness of the first element group on the optical axis, CT3 is the center thickness of the third element group on the optical axis, f1 is the focal length of the first element group, and f3 is the focal length of the third element group.

[0224] (T12+T23) / CT2=0.74; where T12 is the distance between the display side of the first element group and the eye side of the second lens on the optical axis, T23 is the distance between the display side of the second lens and the eye side of the third element group on the optical axis, and CT2 is the center thickness of the second lens on the optical axis.

[0225] (NRP+NQWP) / N2=2.03; where NRP is the refractive index of the reflective polarizing element, NQWP is the refractive index of the quarter-wave plate, and N2 is the refractive index of the second lens.

[0226] In Example 5, Table 15 shows the higher-order coefficients A4, A6, A8, and A6 that can be used for each aspherical mirror S1, S2, S5-8 in Example 5. 10 .

[0227] Face number A4 A6 A8 A10 S1 3.6325E-01 -5.2713E-02 4.0628E-02 -1.3604E-02 S2 -3.3387E-01 -1.0481E-01 5.2097E-02 -3.0148E-02 S5 -1.4815E-01 2.8961E-01 -2.9316E-02 -1.7431E-02 S6 1.7186E-02 2.9568E-01 -5.0959E-02 -8.7128E-03 S7 2.8006E-01 1.1234E-02 -2.1659E-02 3.5001E-03 S8 8.0228E-01 -2.8530E-01 -1.3174E-01 -1.9945E-02

[0228] Table 15

[0229] Figure 10a The on-axis chromatic aberration curve of the visual system of Embodiment 5 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 10b The astigmatic curves of the visual system of Embodiment 5 are shown, which represent the meridional image plane curvature and the sagittal image plane curvature. Figure 10c The distortion curves of the visual system of Embodiment 5 are shown, representing the magnitude of distortion under different viewing angles. According to... Figures 10a to 10c As shown, the visual system given in Example 5 can achieve good imaging quality. Specific Implementation Example 6

[0231] Figure 11This is a schematic diagram of the lens group structure of Embodiment 6 of the visual system of the present invention. The visual system includes: a first element group, a second element group, a third element group, and a light source; the first to third element groups are arranged sequentially along the optical axis from the position away from the light source to the position close to the light source; the first element group includes a first lens; the second element group includes a second lens and a reflective polarizing element and a quarter-wave plate in contact with the second lens; the third element group includes a third lens; each lens in the first to third element groups has at least one eye side away from the light source and one display side far from the light source; the eye side or display side of the at least one lens has a partial reflective layer.

[0232] The first optical lens E1 has negative refractive power, its surface away from the light source is convex, and its surface near the light source is concave; and both of its surfaces are aspherical.

[0233] The second optical lens E2 has positive refractive power, its surface away from the light source is concave, and its surface near the light source is convex; and both of its surfaces are aspherical.

[0234] The third optical lens E3 has positive refractive power, its surface away from the light source is concave, and its surface near the light source is convex; and both of its surfaces are aspherical.

[0235] A portion of the reflective layer is deposited on the surface of the second lens E2 near the light source.

[0236] Table 16 shows the basic parameters of the visual system in Example 6, where the units for radius of curvature, thickness, and focal length are millimeters (mm).

[0237] Face number Surface type radius of curvature thickness Refractive index Dispersion coefficient Refraction / Reflection spherical endless endless refraction STO Stabilizer (STO) spherical endless 15.0000 refraction S1 First lens (E1) aspherical 44387.4648 3.9518 1.67 19.0 refraction S2 aspherical 166.6287 0.1120 refraction S3 Second lens (E2) aspherical 175.6364 12.0772 1.54 56.0 refraction S4 Reflective polarizing element (RP) aspherical -47.1930 0.2000 1.50 57.0 refraction S5 Quarter-wave plate (QWP) aspherical -47.1930 0.2000 1.50 57.0 refraction S6 aspherical -47.1930 8.5407 refraction S7 Partial reflective layer (BS) aspherical -41.2917 -8.5407 reflection S6 Quarter-wave plate (QWP) aspherical -47.1930 -0.2000 1.50 57.0 refraction S5 aspherical -47.1930 0.2000 1.50 57.0 reflection S6 aspherical -47.1930 8.5407 refraction S7 Third lens (E3) aspherical -41.2917 2.0086 1.67 19.0 refraction S8 aspherical -42.1166 2.6322 refraction S9 light source spherical endless

[0238] Table 16

[0239] As shown in Table 17, in Example 6, the total effective focal length of the visual system is f = 27.85 mm, the effective focal length of the first element group is f1 = -237.70 mm, the effective focal length of the second element group is f2 = 25.13 mm, and the effective focal length of the third element group is f3 = 317.60 mm. Half of the maximum field of view of the visual system (Semi-FOV) is 53.0°.

[0240]

[0241] Table 17

[0242] The visual system in Example 6 satisfies:

[0243] F2 / CT2×N2=38.7002 / 12.0772; where F2 is the focal length of the second element group, CT2 is the center thickness of the second lens, and N2 is the refractive index of the second lens;

[0244] (R3-R4) / (R3+R4)=222.8294 / 128.4434; where R3 is the radius of curvature of the eye side of the second lens and R4 is the radius of curvature of the display side of the second lens.

[0245] f×tan(semi-fov) / TD=27.85×tan(53.0°) / 27.0903; where f is the effective focal length of the visual system, semi-fov is the half field of view of the visual system, and TD is the on-axis distance from the eye side of the first element group to the display side of the third element group.

[0246] (V1+V3) / V2=19 / 28; where V1 is the dispersion coefficient of the first element group, V2 is the dispersion coefficient of the second lens, and V3 is the dispersion coefficient of the third element group.

[0247] R5 / R6×N3=41.2917 / 42.1166×1.67; where R5 is the radius of curvature of the side of the third element group, R6 is the radius of curvature of the side of the third element group, and N3 is the refractive index of the third element group.

[0248] TD / (CT1+CT2+CT3)=27.0903 / 18.0376; where CT1 is the center thickness of the first element group on the optical axis, CT2 is the center thickness of the second lens on the optical axis, CT3 is the center thickness of the third element group on the optical axis, and TD is the on-axis distance from the eye side of the first element group to the display side of the third element group.

[0249] (N1+N2) / N3=3.21 / 1.67; where N1 is the refractive index of the first element group, N2 is the refractive index of the second lens, and N3 is the refractive index of the third element group.

[0250] F2 / f = 25.13 / 27.85; where F2 is the focal length of the second element group and f is the effective focal length of the visual system.

[0251] F2 / (CT2+CTRP+CTQWP)=25.13 / 12.4772; where F2 is the focal length of the second element group, CT2 is the center thickness of the second lens on the optical axis, CTRP is the center thickness of the reflective polarizing element, and CTQWP is the center thickness of the quarter-wave plate.

[0252] (CT1+CT3) / (f1+f3)=5.9604 / 79.9; where CT1 is the center thickness of the first element group on the optical axis, CT3 is the center thickness of the third element group on the optical axis, f1 is the focal length of the first element group, and f3 is the focal length of the third element group.

[0253] (T12+T23) / CT2=9.0527 / 12.0772; where T12 is the distance between the display side of the first element group and the eye side of the second lens on the optical axis, T23 is the distance between the display side of the second lens and the eye side of the third element group on the optical axis, and CT2 is the center thickness of the second lens on the optical axis.

[0254] (NRP+NQWP) / N2=3 / 1.54; where NRP is the refractive index of the reflective polarizing element, NQWP is the refractive index of the quarter-wave plate, and N2 is the refractive index of the second lens.

[0255] In Example 6, Table 18 shows the higher-order coefficients A4, A6, A8, and A5 that can be used for each aspherical mirror S1, S2, S5-8 in Example 6. 10 .

[0256] Face number A4 A6 A8 A10 S1 -7.3256E-02 -1.4849E-02 -1.5704E-02 1.1632E-02 S2 1.5598E-01 -4.9783E-02 -4.9627E-02 2.3375E-02 S5 5.3147E-02 -5.1986E-02 -3.4298E-02 2.0519E-02 S6 -2.1413E-01 1.8271E-01 -2.2805E-03 -1.8567E-03 S7 5.1243E-02 -3.8986E-03 1.9485E-03 -1.7253E-03 S8 -2.1627E-01 2.8835E-02 -2.1930E-01 -8.7078E-02

[0257] Table 18

[0258] Figure 12a The on-axis chromatic aberration curve of the visual system of Embodiment 6 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 12b The astigmatic curves of the visual system of Embodiment 6 are shown, representing the meridional image plane curvature and the sagittal image plane curvature. Figure 12c The distortion curves of the visual system of Embodiment 6 are shown, representing the magnitude of distortion under different viewing angles. According to... Figures 12a to 12c As shown, the visual system given in Example 6 can achieve good imaging quality. Specific Implementation Example 7

[0260] Figure 13 This is a schematic diagram of the lens group structure of Embodiment 7 of the visual system of the present invention. The visual system includes: a first element group, a second element group, a third element group, and a light source; the first to third element groups are arranged sequentially along the optical axis from the position away from the light source to the position close to the light source; the first element group includes a first lens; the second element group includes a second lens and a reflective polarizing element and a quarter-wave plate in contact with the second lens; the third element group includes a third lens; each lens in the first to third element groups has at least one eye side away from the light source and one display side far from the light source; the eye side or display side of the at least one lens has a partial reflective layer.

[0261] The first optical lens E1 has positive refractive power, and its surface away from the light source is convex, as is its surface near the light source; and both of its surfaces are aspherical.

[0262] The second optical lens E2 has positive refractive power, its surface away from the light source is concave, and its surface near the light source is convex; and both of its surfaces are aspherical.

[0263] The third optical lens E3 has positive refractive power, its surface away from the light source is concave, and its surface near the light source is convex; and both of its surfaces are aspherical.

[0264] A portion of the reflective layer is deposited on the surface of the second lens E2 near the light source.

[0265] Table 19 shows the basic parameters of the visual system in Example 7, where the units for radius of curvature, thickness, and focal length are millimeters (mm).

[0266] Face number Surface type radius of curvature thickness Refractive index Dispersion coefficient Refraction / Reflection spherical endless endless refraction STO Stabilizer (STO) spherical endless 15.0000 refraction S1 First lens (E1) aspherical 682.5151 6.0138 1.67 19.0 refraction S2 aspherical -81.6779 6.5082 refraction S3 Second lens (E2) aspherical -33.6007 4.0221 1.54 56.0 refraction S4 Reflective polarizing element (RP) aspherical -32.8063 0.2000 1.50 57.0 refraction S5 Quarter-wave plate (QWP) aspherical -32.8063 0.2000 1.50 57.0 refraction S6 aspherical -32.8063 7.2736 refraction S7 Partial reflective layer (BS) aspherical -32.1866 -7.2736 reflection S6 Quarter-wave plate (QWP) aspherical -32.8063 -0.2000 1.50 57.0 refraction S5 aspherical -32.8063 0.2000 1.50 57.0 reflection S6 aspherical -32.8063 7.2736 refraction S7 Third lens (E3) aspherical -32.1866 1.9922 1.67 18.9 refraction S8 aspherical -38.1672 2.4467 refraction S9 light source spherical endless

[0267] Table 19

[0268] As shown in Table 20, in Example 7, the total effective focal length of the visual system is f = 25.95 mm, the effective focal length of the first element group is f1 = -129.80 mm, the effective focal length of the second element group is f2 = 30.15 mm, and the effective focal length of the third element group is f3 = 1452.96 mm. Half of the maximum field of view of the visual system (Semi-FOV) is 53.0°.

[0269]

[0270] Table 20

[0271] The visual system in Example 7 satisfies:

[0272] F2 / CT2×N2=46.431 / 4.0221; where F2 is the focal length of the second element group, CT2 is the center thickness of the second lens, and N2 is the refractive index of the second lens;

[0273] (R3-R4) / (R3+R4)=0.7944 / 66.4070; where R3 is the radius of curvature of the eye side of the second lens and R4 is the radius of curvature of the display side of the second lens.

[0274] f×tan(semi-fov) / TD=27.95×tan(53.0°) / 26.2099; where f is the effective focal length of the visual system, semi-fov is the half field of view of the visual system, and TD is the on-axis distance from the eye side of the first element group to the display side of the third element group.

[0275] (V1+V3) / V2=37.9 / 56; where V1 is the dispersion coefficient of the first element group, V2 is the dispersion coefficient of the second lens, and V3 is the dispersion coefficient of the third element group.

[0276] R5 / R6×N3=32.1866 / 38.1672×1.67; where R5 is the radius of curvature of the side of the third element group, R6 is the radius of curvature of the side of the third element group, and N3 is the refractive index of the third element group.

[0277] TD / (CT1+CT2+CT3)=26.2099 / 12.0281; where CT1 is the center thickness of the first element group on the optical axis, CT2 is the center thickness of the second lens on the optical axis, CT3 is the center thickness of the third element group on the optical axis, and TD is the on-axis distance from the eye side of the first element group to the display side of the third element group.

[0278] (N1+N2) / N3=3.21 / 1.67; where N1 is the refractive index of the first element group, N2 is the refractive index of the second lens, and N3 is the refractive index of the third element group.

[0279] F2 / f = 30.15 / 25.95; where F2 is the focal length of the second element group and f is the effective focal length of the visual system.

[0280] F2 / (CT2+CTRP+CTQWP)=30.15 / 4.4221; where F2 is the focal length of the second element group, CT2 is the center thickness of the second lens on the optical axis, CTRP is the center thickness of the reflective polarizing element, and CTQWP is the center thickness of the quarter-wave plate.

[0281] (CT1+CT3) / (f1+f3)=8.006 / 1323.16; where CT1 is the center thickness of the first element group on the optical axis, CT3 is the center thickness of the third element group on the optical axis, f1 is the focal length of the first element group, and f3 is the focal length of the third element group.

[0282] (T12+T23) / CT2=14.1818 / 4.0221; where T12 is the distance between the display side of the first element group and the eye side of the second lens on the optical axis, T23 is the distance between the display side of the second lens and the eye side of the third element group on the optical axis, and CT2 is the center thickness of the second lens on the optical axis.

[0283] (NRP+NQWP) / N2=3 / 1.54; where NRP is the refractive index of the reflective polarizing element, NQWP is the refractive index of the quarter-wave plate, and N2 is the refractive index of the second lens.

[0284] In Example 7, Table 21 shows the higher-order coefficients A4, A6, A8, and A5 that can be used for each aspherical mirror S1, S2, S5-8 in Example 7. 10 .

[0285] Face number A4 A6 A8 A10 S1 -4.0489E-02 -2.4942E-02 1.0098E-01 8.3840E-03 S2 -6.6110E-02 -1.6556E-01 2.4626E-01 -3.9753E-02 S5 2.2642E-01 5.9724E-02 -9.2844E-03 4.9912E-02 S6 -6.4740E-02 3.2681E-01 -9.9637E-02 3.7951E-02 S7 2.6190E-01 -8.6859E-02 4.0788E-02 -7.1538E-03 S8 2.0488E-01 -1.3814E-01 -2.6077E-01 -3.8780E-02

[0286] Table 21

[0287] Figure 14a The on-axis chromatic aberration curve of the visual system of Embodiment 7 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 14b The astigmatic curves of the visual system of Embodiment 7 are shown, representing the meridional image plane curvature and the sagittal image plane curvature. Figure 14c The distortion curves of the visual system of Embodiment 7 are shown, representing the magnitude of distortion under different viewing angles. According to... Figures 14a to 14c As shown, the visual system given in Example 7 can achieve good imaging quality. Specific Implementation Example 8

[0289] Figure 15 This is a schematic diagram of the lens group structure of Embodiment 8 of the visual system of the present invention. The visual system includes: a first element group, a second element group, a third element group, and a light source; the first to third element groups are arranged sequentially along the optical axis from the position away from the light source to the position close to the light source; the first element group includes a first lens; the second element group includes a second lens and a reflective polarizing element and a quarter-wave plate in contact with the second lens; the third element group includes a third lens; each lens in the first to third element groups has at least one eye side away from the light source and one display side far from the light source; the eye side or display side of the at least one lens has a partial reflective layer.

[0290] The first optical lens E1 has positive refractive power, and its surface away from the light source is convex, as is its surface near the light source; and both of its surfaces are aspherical.

[0291] The second optical lens E2 has positive refractive power, its surface away from the light source is concave, and its surface near the light source is convex; and both of its surfaces are aspherical.

[0292] The third optical lens E3 has positive refractive power, its surface away from the light source is concave, and its surface near the light source is convex; and both of its surfaces are aspherical.

[0293] A portion of the reflective layer is deposited on the surface of the second lens E2 near the light source.

[0294] Table 22 shows the basic parameters of the visual system in Example 8, where the units for radius of curvature, thickness, and focal length are all millimeters (mm).

[0295] Face number Surface type radius of curvature thickness Refractive index Dispersion coefficient Refraction / Reflection spherical endless endless refraction STO Stabilizer (STO) spherical endless 15.0000 refraction S1 First lens (E1) aspherical 628.6514 6.0217 1.67 19.0 refraction S2 aspherical -82.9759 7.1073 refraction S3 Second lens (E2) aspherical -33.8083 3.9135 1.54 56.0 refraction S4 Reflective polarizing element (RP) aspherical -32.7048 0.2000 1.50 57.0 refraction S5 Quarter-wave plate (QWP) aspherical -32.7048 0.2000 1.50 57.0 refraction S6 aspherical -32.7048 7.3070 refraction S7 Partial reflective layer (BS) aspherical -32.2264 -7.3070 reflection S6 Quarter-wave plate (QWP) aspherical -32.7048 -0.2000 1.50 57.0 refraction S5 aspherical -32.7048 0.2000 1.50 57.0 reflection S6 aspherical -32.7048 7.3070 refraction S7 Third lens (E3) aspherical -32.2264 2.1500 1.67 19.0 refraction S8 aspherical -38.8790 2.5158 refraction S9 light source spherical endless

[0296] Table 22

[0297] As shown in Table 23, in Example 8, the total effective focal length of the visual system is f = 26.43 mm, the effective focal length of the first element group is f1 = -135.82 mm, the effective focal length of the second element group is f2 = 30.34 mm, and the effective focal length of the third element group is f3 = 2591.65 mm. Half of the maximum field of view of the visual system (Semi-FOV) is 53.0°.

[0298]

[0299]

[0300] Table 23

[0301] The visual system in Example 8 satisfies:

[0302] F2 / CT2×N2=46.7236 / 3.9135; where F2 is the focal length of the second element group, CT2 is the center thickness of the second lens, and N2 is the refractive index of the second lens;

[0303] (R3-R4) / (R3+R4)=1.1035 / 66.5131; where R3 is the radius of curvature of the eye side of the second lens and R4 is the radius of curvature of the display side of the second lens.

[0304] f×tan(semi-fov) / TD=26.43×tan(53.0°) / 26.8995; where f is the effective focal length of the visual system, semi-fov is the half field of view of the visual system, and TD is the on-axis distance from the eye side of the first element group to the display side of the third element group.

[0305] (V1+V3) / V2=19 / 28; where V1 is the dispersion coefficient of the first element group, V2 is the dispersion coefficient of the second lens, and V3 is the dispersion coefficient of the third element group.

[0306] R5 / R6×N3=32.2264 / 38.8790×1.67; where R5 is the radius of curvature of the side of the third element group, R6 is the radius of curvature of the side of the third element group, and N3 is the refractive index of the third element group.

[0307] TD / (CT1+CT2+CT3)=26.8995 / 12.0852; where CT1 is the center thickness of the first element group on the optical axis, CT2 is the center thickness of the second lens on the optical axis, CT3 is the center thickness of the third element group on the optical axis, and TD is the on-axis distance from the eye side of the first element group to the display side of the third element group.

[0308] (N1+N2) / N3=3.21 / 1.67; where N1 is the refractive index of the first element group, N2 is the refractive index of the second lens, and N3 is the refractive index of the third element group.

[0309] F2 / f = 30.34 / 26.43; where F2 is the focal length of the second element group and f is the effective focal length of the visual system.

[0310] F2 / (CT2+CTRP+CTQWP)=30.34 / 4.3135; where F2 is the focal length of the second element group, CT2 is the center thickness of the second lens on the optical axis, CTRP is the center thickness of the reflective polarizing element, and CTQWP is the center thickness of the quarter-wave plate.

[0311] (CT1+CT3) / (f1+f3)=8.1717 / 2455.83; where CT1 is the center thickness of the first element group on the optical axis, CT3 is the center thickness of the third element group on the optical axis, f1 is the focal length of the first element group, and f3 is the focal length of the third element group.

[0312] (T12+T23) / CT2=14.8143 / 3.9135; where T12 is the distance between the display side of the first element group and the eye side of the second lens on the optical axis, T23 is the distance between the display side of the second lens and the eye side of the third element group on the optical axis, and CT2 is the center thickness of the second lens on the optical axis.

[0313] (NRP+NQWP) / N2=3 / 1.54; where NRP is the refractive index of the reflective polarizing element, NQWP is the refractive index of the quarter-wave plate, and N2 is the refractive index of the second lens.

[0314] In Example 8, Table 24 shows the higher-order coefficients A4, A6, A8, and A5 that can be used for each aspherical mirror S1, S2, S5-8 in Example 8. 10 .

[0315] Face number A4 A6 A8 A10 S1 -1.9643E-02 -1.8457E-02 1.0141E-01 1.0365E-02 S2 -7.4296E-02 -1.6740E-01 2.4528E-01 -3.7460E-02 S5 2.2280E-01 4.3728E-02 -1.3511E-02 6.0293E-02 S6 -1.1556E-01 3.3774E-01 -8.8434E-02 4.2664E-02 S7 2.6707E-01 -8.7889E-02 4.1269E-02 -7.3991E-03 S8 2.2043E-01 -1.5188E-01 -1.9533E-01 -1.0953E-01

[0316] Table 24

[0317] Figure 16a The on-axis chromatic aberration curve of the visual system of Embodiment 8 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 16b The astigmatic curves of the visual system of Embodiment 8 are shown, representing the meridional image plane curvature and the sagittal image plane curvature. Figure 16c The distortion curves of the visual system of Embodiment 8 are shown, representing the magnitude of distortion under different viewing angles. According to... Figures 16a to 16cAs shown, the visual system given in Example 8 can achieve good imaging quality. Specific Implementation Example 9

[0319] Figure 17 This is a schematic diagram of the lens group structure of Embodiment 9 of the visual system of the present invention. The visual system includes: a first element group, a second element group, a third element group, and a light source; the first to third element groups are arranged sequentially along the optical axis from the position away from the light source to the position close to the light source; the first element group includes a first lens; the second element group includes a second lens and a reflective polarizing element and a quarter-wave plate in contact with the second lens; the third element group includes a third lens; each lens in the first to third element groups has at least one eye side away from the light source and one display side far from the light source; the eye side or display side of the at least one lens has a partial reflective layer.

[0320] The first optical lens E1 has positive refractive power, and its surface away from the light source is convex, as is its surface near the light source; and both of its surfaces are aspherical.

[0321] The second optical lens E2 has positive refractive power, its surface away from the light source is concave, and its surface near the light source is convex; and both of its surfaces are aspherical.

[0322] The third optical lens E3 has positive refractive power, its surface away from the light source is concave, and its surface near the light source is convex; and both of its surfaces are aspherical.

[0323] A portion of the reflective layer is deposited on the surface of the second lens E2 near the light source.

[0324] Table 25 shows the basic parameters of the visual system in Example 9, where the units for radius of curvature, thickness, and focal length are all millimeters (mm).

[0325] Face number Surface type radius of curvature thickness Refractive index Dispersion coefficient Refraction / Reflection spherical endless endless refraction STO Stabilizer (STO) spherical endless 15.0000 refraction S1 First lens (E1) aspherical 529.1291 6.0061 1.67 19.0 refraction S2 aspherical -82.4782 6.7175 refraction S3 Second lens (E2) aspherical -33.7405 3.8265 1.54 56.0 refraction S4 Reflective polarizing element (RP) aspherical -32.5822 0.2000 1.50 57.0 refraction S5 Quarter-wave plate (QWP) aspherical -32.5822 0.2000 1.50 57.0 refraction S6 aspherical -32.5822 7.3309 refraction S7 Partial reflective layer (BS) aspherical -32.3103 -7.3309 reflection S6 Quarter-wave plate (QWP) aspherical -32.5822 -0.2000 1.50 57.0 refraction S5 aspherical -32.5822 0.2000 1.50 57.0 reflection S6 aspherical -32.5822 7.3309 refraction S7 Third lens (E3) aspherical -32.3103 2.4141 1.67 18.9 refraction S8 aspherical -39.5300 2.6756 refraction S9 light source spherical endless

[0326] Table 25

[0327] As shown in Table 26, in Example 9, the total effective focal length of the visual system is f = 26.58 mm, the effective focal length of the first element group is f1 = -139.26 mm, the effective focal length of the second element group is f2 = 30.68 mm, and the effective focal length of the third element group is f3 = 283.96 mm. Half of the maximum field of view of the visual system (Semi-FOV) is 53.0°.

[0328]

[0329] Table 26

[0330] The visual system in Example 9 satisfies:

[0331] F2 / CT2×N2=47.2472 / 3.8265; where F2 is the focal length of the second element group, CT2 is the center thickness of the second lens, and N2 is the refractive index of the second lens;

[0332] (R3-R4) / (R3+R4)=1.1583 / 66.3227; where R3 is the radius of curvature of the eye side of the second lens and R4 is the radius of curvature of the display side of the second lens.

[0333] f×tan(semi-fov) / TD=26.58×tan(53.0°) / 26.6951; where f is the effective focal length of the visual system, semi-fov is the half field of view of the visual system, and TD is the on-axis distance from the eye side of the first element group to the display side of the third element group.

[0334] (V1+V3) / V2=37.9 / 56; where V1 is the dispersion coefficient of the first element group, V2 is the dispersion coefficient of the second lens, and V3 is the dispersion coefficient of the third element group.

[0335] R5 / R6×N3=32.3103 / 39.5300×1.67; where R5 is the radius of curvature of the side of the third element group, R6 is the radius of curvature of the side of the third element group, and N3 is the refractive index of the third element group.

[0336] TD / (CT1+CT2+CT3)=26.6951 / 12.2467; where CT1 is the center thickness of the first element group on the optical axis, CT2 is the center thickness of the second lens on the optical axis, CT3 is the center thickness of the third element group on the optical axis, and TD is the on-axis distance from the eye side of the first element group to the display side of the third element group.

[0337] (N1+N2) / N3=3.21 / 1.67; where N1 is the refractive index of the first element group, N2 is the refractive index of the second lens, and N3 is the refractive index of the third element group.

[0338] F2 / f = 30.68 / 26.58; where F2 is the focal length of the second element group and f is the effective focal length of the visual system.

[0339] F2 / (CT2+CTRP+CTQWP)=30.68 / 4.2265; where F2 is the focal length of the second element group, CT2 is the center thickness of the second lens on the optical axis, CTRP is the center thickness of the reflective polarizing element, and CTQWP is the center thickness of the quarter-wave plate.

[0340] (CT1+CT3) / (f1+f3)=8.4202 / 144.70; where CT1 is the center thickness of the first element group on the optical axis, CT3 is the center thickness of the third element group on the optical axis, f1 is the focal length of the first element group, and f3 is the focal length of the third element group.

[0341] (T12+T23) / CT2=14.4484 / 3.8265; where T12 is the distance between the display side of the first element group and the eye side of the second lens on the optical axis, T23 is the distance between the display side of the second lens and the eye side of the third element group on the optical axis, and CT2 is the center thickness of the second lens on the optical axis.

[0342] (NRP+NQWP) / N2=3 / 1.54; where NRP is the refractive index of the reflective polarizing element, NQWP is the refractive index of the quarter-wave plate, and N2 is the refractive index of the second lens.

[0343] In Example 9, Table 27 shows the higher-order coefficients A4, A6, A8, and A5 that can be used for each aspherical mirror S1, S2, S5-8 in Example 9. 10 .

[0344] Face number A4 A6 A8 A10 S1 -3.8620E-02 -1.5002E-02 1.0362E-01 1.0078E-02 S2 -8.9322E-02 -1.8016E-01 2.3981E-01 -4.1920E-02 S5 2.2569E-01 2.5065E-02 -9.2860E-03 5.5021E-02 S6 -1.4032E-02 3.6949E-01 -9.6099E-02 3.6654E-02 S7 2.8224E-01 -7.8431E-02 3.4863E-02 -6.6794E-03 S8 -4.6461E-02 -3.2386E-01 -3.8097E-01 -6.9796E-02

[0345] Table 27

[0346] Figure 18a The on-axis chromatic aberration curve of the visual system of Embodiment 9 is shown, which represents the deviation of the focal point of light of different wavelengths after passing through the lens. Figure 18b The astigmatic curves of the visual system of Embodiment 9 are shown, representing the meridional image plane curvature and the sagittal image plane curvature. Figure 18c The distortion curves of the visual system of Embodiment 9 are shown, representing the magnitude of distortion under different viewing angles. According to... Figures 18a to 18c As shown, the visual system given in Example 9 can achieve good imaging quality.

[0347] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, improvements, or equivalent substitutions made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A visual system for VR, characterized in that, The visual system for VR has three lenses with optical power, and the visual system for VR includes: a first element group, a second element group, a third element group, and a light source; The first element group includes a first lens; The second element group consists of a second lens with positive optical power, a reflective polarizing element in contact with the second lens, and a quarter-wave plate; The third element group includes a third lens; The first to third element groups are arranged sequentially along the optical axis from the position away from the light source to the position close to the light source. Each lens in the first to third element groups has at least one eye side away from the light source and one display side close to the light source. The first lens has positive optical power, and the third lens has either negative or positive optical power; or the first lens has negative optical power, and the third lens has positive optical power. The second lens has a convex display side. The third lens has a concave eye side and a convex display side. The reflective polarizing element and the quarter-wave plate are arranged sequentially along the optical axis from the position away from the light source to the position close to the light source and are attached to the eye side or display side of the second lens; A portion of the reflective layer is deposited on the display side of the second lens or the eye side of the third element group; Wherein, the focal length F2 of the second element group, the center thickness CT2 of the second lens, and the refractive index N2 of the second lens satisfy: 38.7002 / 12.0772≤F2 / (CT2×N2)≤47.2472 / 3.8265; The radius of curvature R3 of the eye side of the second lens and the radius of curvature R4 of the display side of the second lens satisfy: -0.03≤(R3-R4) / (R3+R4)≤222.8294 / 128.4434.

2. The visual system for VR according to claim 1, characterized in that, The reflective polarizing element includes at least one eye side away from the light source and at least one display side close to the light source. The quarter-wave plate includes at least one eye side away from the light source and at least one display side close to the light source. The display side of the reflective polarizing element is at least partially in contact with the eye side of the quarter-wave plate.

3. The visual system for VR according to claim 1, characterized in that, The second lens and the third element group of the visual system are both meniscus lenses with a concave eye side.

4. The visual system for VR according to claim 1, characterized in that, The effective focal length f of the visual system, the semi-field-of-view angle semi-fov of the visual system, and the on-axis distance TD from the eye side of the first element group to the display side of the third element group satisfy: 26.43×tan(53.0°) / 26.8995≤f×tan(semi-fov) / TD≤1.

79.

5. The visual system for VR according to claim 1, characterized in that, The dispersion coefficients V1 of the first element group, V2 of the second lens, and V3 of the third element group satisfy: 37.9 / 56≤(V1+V3) / V2≤1.

79.

6. The visual system for VR according to claim 1, characterized in that, The radius of curvature R5 of the side of the third element group, the radius of curvature R6 of the side of the third element group, and the refractive index N3 of the third element group satisfy: 0.44≤R5 / R6×N3≤1.

98.

7. The visual system for VR according to claim 1, characterized in that, The center thickness CT1 of the first element group on the optical axis, the center thickness CT2 of the second lens on the optical axis, the center thickness CT3 of the third element group on the optical axis, and the on-axis distance TD from the eye side of the first element group to the display side of the third element group satisfy: 1.19≤TD / (CT1+CT2+CT3)≤26.8995 / 12.0852.

8. The visual system for VR according to claim 1, characterized in that, The refractive indices N1 of the first element group, N2 of the second lens, and N3 of the third element group satisfy the following condition: 1.77≤(N1+N2) / N3≤1.

97.

9. The visual system for VR according to claim 1, characterized in that, The focal length F2 of the second element group and the effective focal length f of the visual system satisfy: 25.13 / 27.85≤F2 / f≤1.

21.

10. The visual system for VR according to claim 1, characterized in that, Both the reflective polarizing element and the quarter-wave plate have a certain thickness.

11. The visual system for VR according to claim 1, characterized in that, The focal length F2 of the second element group, the center thickness CT2 of the second lens on the optical axis, the center thickness CTRP of the reflective polarizing element, and the center thickness CTQWP of the quarter-wave plate satisfy: 25.13 / 12.4772≤F2 / (CT2+CTRP+CTQWP)≤30.68 / 4.2265.

12. The visual system for VR according to claim 1, characterized in that, The center thickness CT1 of the first element group on the optical axis, the center thickness CT3 of the third element group on the optical axis, the focal length f1 of the first element group, and the focal length f3 of the third element group satisfy: -0.44≤(CT1+CT3) / (f1+f3)≤0.

27.

13. The visual system for VR according to claim 1, characterized in that, The distance T12 between the display side of the first element group and the eye side of the second lens on the optical axis, the distance T23 between the display side of the second lens and the eye side of the third element group on the optical axis, and the center thickness CT2 of the second lens on the optical axis satisfy: 0.3≤(T12+T23) / CT2≤14.8143 / 3.9135.

14. The visual system for VR according to claim 1, characterized in that, The refractive index NRP of the reflective polarizing element, the refractive index NQWP of the quarter-wave plate, and the refractive index N2 of the second lens satisfy: 3 / 1.54≤(NRP+NQWP) / N2≤2.03.

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