Virtual reality device

Abstract

The application discloses a virtual reality device, which comprises a first optical system and a second optical system; the first optical system comprises a first element group, a second element group and a third element group in sequence from a first side to a second side along a first optical axis, 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 arranged in sequence from the first side to the second side along the first optical axis, the reflective polarizing element and the quarter-wave plate are attached to each other and attached to a second side surface of the second lens, and the third element group comprises a third lens; the second optical system comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens in sequence from an object side to an image side along a second optical axis; wherein a maximum field of view FOV of the second optical system satisfies 95°≤FOV / 2≤110°; and a total effective focal length f' of the first optical system, an effective focal length f2' of the second element group, a total effective focal length f of the second optical system and an effective focal length f2 of the second lens satisfy -0.60<f' / f2'+f / f2< -0.28.

Description

Technical Field

[0001] This application relates to the field of optical devices, and more specifically to a virtual reality device. Background Technology

[0002] With the development of virtual reality technology, virtual reality devices have gradually transitioned from simple magnifying projection tools to interactive devices. To meet the needs of interactive interaction, virtual reality devices typically include two types of lenses, such as viewing lenses and positioning lenses. Positioning lenses acquire environmental information, and when paired with viewing lenses, they can connect the real world and the virtual world, enabling interaction between them.

[0003] However, the positioning lenses of virtual reality devices need to meet the requirement of a wide field of view. In order to meet the requirement of a wide field of view, positioning lenses usually adopt a fisheye design. This leads to unreasonable design of the curvature radius and thickness ratio of some lenses, which in turn introduces a lot of astigmatism into the positioning lens, accompanied by severe distortion and chromatic aberration, causing the edge image quality to be distorted, thus affecting the final imaging effect of the virtual reality device. Summary of the Invention

[0004] This application provides a virtual reality device that can at least solve or partially solve at least one problem or other problems existing in the prior art.

[0005] One aspect of this application provides a virtual reality device comprising a first optical system and a second optical system. The first optical system, along a first optical axis from a first side to a second side, sequentially includes a first element group, a second element group, and a third element group. 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, arranged sequentially along the first optical axis from the first side to the second side. The reflective polarizing element and the quarter-wave plate are bonded and attached to a second side surface of the second lens. The third element group includes a third lens. The second optical system, along the second optical axis from the object side to the image side, sequentially includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens. The maximum field of view (FOV) of the second optical system satisfies: 95° ≤ FOV / 2 ≤ 110°. Furthermore, the total effective focal length f' of the first optical system, the effective focal length f2' of the second element group, and the total effective focal length f of the second optical system combined with the effective focal length f2 of the second lens satisfy: -0.60. <f' / f2'+f / f2<-0.28。

[0006] According to an exemplary embodiment of this application, the maximum field of view (FOV)' of the first optical system and the maximum field of view (FOV) of the second optical system satisfy: 1.80 <FOV / FOV'<2.10。

[0007] According to an exemplary embodiment of this application, the axial distance TTL' from the first side surface of the first lens to the image plane of the first optical system and the axial distance TTL from the object side surface of the first lens to the image plane of the second optical system satisfy: 1.80 <TTL' / TTL<2.50。

[0008] According to an exemplary embodiment of this application, the axial distance TD' from the first side surface of the first lens to the second side surface of the third lens, the total effective focal length f' of the first optical system, the axial distance TD from the object side surface of the first lens to the image side surface of the eighth lens, and the total effective focal length f of the second optical system satisfy: 8.60 <TD' / f'+TD / f<11.00。

[0009] According to an exemplary embodiment of this application, the axial distance TTL' from the first side surface of the first lens to the image plane of the first optical system, the effective focal length f1' of the first element group, the axial distance TTL from the object side surface of the first lens to the image plane of the second optical system, and the effective focal length f8 of the eighth lens satisfy: 2.80 <TTL' / f1'+TTL / f8<4.30。

[0010] According to an exemplary embodiment of this application, the second optical system further includes a second aperture stop, wherein the center thickness CT1' of the first lens on the first optical axis, the center thickness CT2' of the second lens on the first optical axis, the center thickness CT3' of the third lens on the first optical axis and the on-axis distance SD from the second aperture stop to the image side of the eighth lens satisfy: 2.30 < (CT1' + CT2' + CT3') / SD < 3.30.

[0011] According to an exemplary embodiment of this application, the total effective focal length f' of the first optical system and the effective focal length f1 of the first lens satisfy: -5.30 <f' / f1<-3.60。

[0012] According to an exemplary embodiment of this application, the effective focal length f1' of the first element group and the radius of curvature R2' of the second side surface of the first lens satisfy: -2.00 <f1' / R2'<-1.60。

[0013] According to an exemplary embodiment of this application, the center thickness CT4 of the fourth lens on the second optical axis, the center thickness CT5 of the fifth lens on the second optical axis, the radius of curvature R8 of the image side of the fourth lens and the radius of curvature R10 of the image side of the fifth lens satisfy: -0.50<(CT4+CT5) / (R8+R10)<-0.35.

[0014] According to an exemplary embodiment of this application, the effective focal length f1 of the first lens, the effective focal length f2 of the second lens, the effective focal length f7 of the seventh lens, and the effective focal length f8 of the eighth lens satisfy: 2.50 < (f1 / f2) × (f7 / f8) < 3.60.

[0015] According to an exemplary embodiment of this application, the radius of curvature R2 of the image side of the first lens, the radius of curvature R3 of the object side of the second lens, and the radius of curvature R4 of the image side of the second lens satisfy: -9.00<(R2+R3) / R4<-3.10.

[0016] According to an exemplary embodiment of this application, the radius of curvature R1 of the object side of the first lens, the Abbe number V1 of the first lens, the radius of curvature R16 of the image side of the eighth lens, and the Abbe number V8 of the eighth lens satisfy: 0.80 < (R1 × V1) / (R16 × V8) < 2.60.

[0017] According to an exemplary embodiment of this application, the effective focal length f7 of the seventh lens and the refractive index N7 of the seventh lens satisfy: 2.70mm <f7 / N7<4.60mm。

[0018] According to an exemplary embodiment of this application, the effective focal length f8 of the eighth lens, the radius of curvature R15 of the object side of the eighth lens, and the radius of curvature R16 of the image side of the eighth lens satisfy: 1.60 <f8 / (R16-R15)<2.60。

[0019] According to an exemplary embodiment of this application, the effective focal length f3 of the third lens, the effective focal length f4 of the fourth lens, and the effective focal length f5 of the fifth lens satisfy: 2.20 < (f3 + f4) / f5 < 2.50.

[0020] According to an exemplary embodiment of this application, the center thickness CT4 of the fourth lens on the second optical axis, the center thickness CT5 of the fifth lens on the second optical axis, and the center thickness CT6 of the sixth lens on the second optical axis satisfy: 7.80 < (CT4 + CT5) / CT6 ≤ 11.00.

[0021] According to an exemplary embodiment of this application, the radius of curvature R1 of the object side of the first lens, the radius of curvature R2 of the image side of the first lens, and the combined focal length f12 of the first lens and the second lens satisfy: -9.00<(R1+R2) / f12<-6.40.

[0022] The virtual reality device provided in this application is configured as a combination of a first optical system and a second optical system. The first optical system is a folding optical system, which effectively shortens the length of the first optical system. At the same time, the maximum field of view of the second optical system is reasonably configured, enabling the second optical system to achieve a large field of view, meeting the basic requirements of a virtual reality device. However, the curvature radius and thickness ratio of some lenses in the large field of view second optical system are easily designed improperly. This can lead to the introduction of a large amount of astigmatism into the second optical system, accompanied by severe distortion and chromatic aberration, and edge image quality distortion, thus affecting the final imaging effect of the virtual reality device. This application constrains the ratio of the total effective focal length of the first optical system to the effective focal length of the second element group, and the ratio of the total effective focal length of the second optical system to the second lens, and limits the sum of these two ratios to a small range. On the one hand, this helps to control the foreground and background depth of focus of each optical system and to rationally allocate the principal values ​​at the foreground and background. On the other hand, it also helps to control the radius of curvature, thickness, and material selection range of the second lens and the second element group, reduce astigmatism of each optical system, optimize distortion and chromatic aberration of each optical system, and improve the imaging quality of each optical system. At the same time, it also facilitates the design integration of the two optical systems, making it easier to balance and compensate between the two optical systems, so as to achieve the final clear and accurate imaging function. Attached Figure Description

[0023] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings.

[0024] Figure 1 A schematic diagram of the structure of a virtual reality device according to this application is shown;

[0025] Figure 2 A schematic diagram of the optical path of the first optical system according to this application is shown;

[0026] Figure 3 A schematic diagram of the structure of the first optical system according to Embodiment 1 of this application is shown;

[0027] Figures 4A to 4C The on-axis chromatic aberration curve, astigmatism curve, and magnification chromatic aberration curve of the first optical system according to Embodiment 1 of this application are shown respectively.

[0028] Figure 5 A schematic diagram of the structure of the first optical system according to Embodiment 2 of this application is shown;

[0029] Figures 6A to 6C The on-axis chromatic aberration curve, astigmatism curve, and magnification chromatic aberration curve of the first optical system according to Embodiment 2 of this application are shown respectively.

[0030] Figure 7A schematic diagram of the structure of the first optical system according to Embodiment 3 of this application is shown;

[0031] Figures 8A to 8C The on-axis chromatic aberration curve, astigmatism curve, and magnification chromatic aberration curve of the first optical system according to Embodiment 3 of this application are shown respectively.

[0032] Figure 9 A schematic diagram of the structure of the second optical system according to Embodiment 4 of this application is shown;

[0033] Figure 10A and Figure 10B The on-axis chromatic aberration curve and astigmatism curve of the second optical system according to Embodiment 4 of this application are shown respectively;

[0034] Figure 11 A schematic diagram of the structure of the second optical system according to Embodiment 5 of this application is shown;

[0035] Figure 12A and Figure 12B The on-axis chromatic aberration curve and astigmatism curve of the second optical system according to Embodiment 5 of this application are shown respectively;

[0036] Figure 13 A schematic diagram of the structure of a second optical system according to Embodiment Six of this application is shown; and

[0037] Figure 14A and Figure 14B The on-axis chromatic aberration curve and astigmatism curve of the second optical system according to Embodiment Six of this application are shown respectively. Detailed Implementation

[0038] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements.

[0039] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of this application, the first lens discussed below may also be referred to as the second lens or the third lens.

[0040] In the accompanying drawings, for ease of illustration, the thickness, size, and shape of the lenses and / or mirrors have been slightly exaggerated. 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 drawn strictly to scale.

[0041] In this text, the paraxial region refers to the region near the optical axis. If the lens and / or lens surface is convex and the location of the convexity is not defined, it means that the lens and / or lens surface is convex at least in the paraxial region; if the lens and / or lens surface is concave and the location of the concaveness is not defined, it means that the lens and / or lens surface is concave at least in the paraxial region. The surface of each lens closest to the first side (e.g., the human eye side) is called the first side surface of the lens, and the surface of each lens closest to the second side (e.g., the display screen side) is called the second side surface of the lens. The surface of each lens closest to the object being photographed is called the object side surface of the lens, and the surface of each lens closest to the imaging plane is called the image side surface of the lens.

[0042] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising" as 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 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.

[0043] 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 sense, unless expressly so specified herein.

[0044] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

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

[0046] refer to Figure 1The first aspect of this application provides a virtual reality device that may include a first optical system and a second optical system. The second optical system images a real scene, and the resulting real image is transmitted to a display screen on a second side of the first optical system via an electrical signal. The first optical system projects a virtual image onto the display screen and the aforementioned real image transmitted to the display screen; here, the virtual image refers to a virtual image on the display screen. By combining the first and second optical systems, virtual reality fusion of the virtual reality device can be achieved. The first optical system may be configured as a catadioptric optical system, and the number of such systems may be one or more. The second optical system is configured as a positioning optical system, and the number of such systems may be one or more. In one example, the virtual reality device may include two symmetrically arranged first optical systems. In one example, the virtual reality device may also include a third optical system.

[0047] In an exemplary embodiment, the first optical system may include a first element group, a second element group, and a third element group arranged sequentially along a first optical axis from a first side to a second side. The first element group may include a first lens. The second element group may include a second lens, a reflective polarizing element, and a quarter-wave plate arranged sequentially along the first optical axis from the first side to the second side, wherein the reflective polarizing element and the quarter-wave plate are bonded and attached to a second side surface of the second lens. The third element group may include a third lens. An air gap may exist between adjacent element groups in the first to third element groups.

[0048] In an exemplary embodiment, the first side may be the human eye side, and the second side may be the display screen side. Accordingly, the first side of each element (first lens, second lens, third lens, reflective polarizing element, quarter-wave plate) may be referred to as the side near the human eye, and the second side may be referred to as the side near the screen.

[0049] In an exemplary embodiment, a reflective polarizing element and a quarter-wave plate are bonded together to form a single film layer, which is then attached to the second side of the second lens. By combining the reflective polarizing element and the quarter-wave plate to form a single film layer, the number of attachment surfaces of the film layer can be reduced, thereby improving the adhesion yield of the film layer.

[0050] As an example, the second side of the second lens is configured as a plane, and a film layer formed by bonding a reflective polarizing element and a quarter-wave plate is attached to the second side of the second lens. Using a planar film-attaching method to attach the composite film layer to a plane helps improve the stability of the film layer after attachment, thereby enhancing the external field-of-view performance of the first optical system.

[0051] In an exemplary embodiment, the first optical system may further include a partially reflective layer, which may, for example, be attached to a first side surface of the third lens. The partially reflective layer has a semi-transmissive and semi-reflective effect on light. By providing a partially reflective layer on the first side surface of the third lens, and combining it with a reflective polarizing element and a quarter-wave plate, light can be refracted multiple times, effectively reducing the overall length of the first optical system.

[0052] In an exemplary embodiment, the first optical system may further include a first aperture stop, which may be disposed, for example, between the first side and the first lens. The image light on the display screen is finally projected to the user's eyes after multiple refractions and reflections through the third lens, quarter-wave plate, reflective polarizing element, second lens, and first lens.

[0053] In an exemplary embodiment, a second side of the first optical system may be provided with an image surface. This image surface may, for example, be provided with a display screen. Figure 2 As shown, image light from the display screen sequentially passes through the third lens and the quarter-wave plate, reaching the reflective polarizing element located on the second side of the second lens, where it is reflected to form the first reflected image light. The first reflected image light passes through the quarter-wave plate and reaches the partial reflective layer located on the first side of the third lens, where it is reflected to form the second reflected image light. The second reflected image light sequentially passes through the quarter-wave plate, the reflective polarizing element, the second lens, the first lens, and finally the first aperture stop, ultimately projecting onto the user's eye. The first optical system provided in this application folds the required optical path without affecting the projection quality by combining light reflection and refraction, effectively shortening the overall length of the first optical system.

[0054] In an exemplary embodiment, the second optical system may include a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens arranged sequentially along a second optical axis from the object side to the image side. An air gap may exist between adjacent lenses from the first to the eighth lens.

[0055] In an exemplary embodiment, the first lens may have negative optical power, its object-side surface may be convex, and its image-side surface may be concave. The second lens may have negative optical power, its object-side surface may be concave, and its image-side surface may be concave. The third lens may have positive optical power, its object-side surface may be convex, and its image-side surface may be concave. The fourth lens may have positive optical power, and its image-side surface may be convex. The fifth lens may have positive optical power, its object-side surface may be convex, and its image-side surface may be convex. The sixth lens may have negative optical power, and its object-side surface may be concave. The seventh lens may have positive optical power, and its object-side surface may be convex. The eighth lens may have positive optical power, its object-side surface may be convex, and its image-side surface may be concave.

[0056] In an exemplary embodiment, the second optical system may further include a second aperture stop, which may be disposed, for example, between the third lens and the fourth lens.

[0057] In an exemplary embodiment, the maximum field of view FOV of the second optical system may satisfy: 95° ≤ FOV / 2 ≤ 110°; the total effective focal length f' of the first optical system, the effective focal length f2' of the second element group, the total effective focal length f of the second optical system, and the effective focal length f2 of the second lens may satisfy: -0.60 < f' / f2' + f / f2 < -0.28. In an example, 100° ≤ FOV / 2 ≤ 110°. The first optical system is a catadioptric optical system, which effectively shortens the body length of the first optical system. At the same time, by reasonably configuring the maximum field of view of the second optical system, the second optical system can achieve the characteristic of a large field of view, meeting the basic requirements of the virtual reality device. However, for some lenses of the second optical system with a large field of view, the curvature radius and the thickness-to-thickness ratio are likely to be designed unreasonably, which will cause a large amount of astigmatism in the second optical system, accompanied by serious distortion and chromatic aberration, and edge image quality distortion, thus affecting the final imaging effect of the virtual reality device. In this application, by restricting the ratio of the total effective focal length of the first optical system to the effective focal length of the second element group and the ratio of the total effective focal length of the second optical system to the second lens, and limiting the sum of these two ratios within a small range, on the one hand, it is beneficial to control the front depth of field and the back focal depth of each optical system, and reasonably distribute the front and rear main values; on the other hand, it is also beneficial to control the range of the curvature radius, thickness, and material selection of the second lens and the second lens, reduce the astigmatism of each optical system, optimize the distortion and chromatic aberration of each optical system, improve the imaging quality of each optical system. At the same time, it is also beneficial to the design connection between the two optical systems, facilitating the balance and compensation between the two optical systems to achieve the final clear and accurate imaging function.

[0058] In an exemplary embodiment, the maximum field of view FOV' of the first optical system and the maximum field of view FOV of the second optical system may satisfy: 1.80 < FOV / FOV' < 2.10. By restricting the ratio of the maximum field of view of the second optical system to that of the first optical system within a reasonable range, it is beneficial to the field of view connection between the second optical system and the first optical system. At the same time, it can also indirectly control the magnification of the real scene and the virtual scene, avoiding the abrupt disconnection of the final imaging of the virtual reality device and affecting the immersion of the virtual reality device.

[0059] In an exemplary embodiment, the on-axis distance TTL' from the first side surface of the first lens to the image plane of the first optical system and the on-axis distance TTL from the object side surface of the first lens to the imaging plane of the second optical system may satisfy: 1.80 < TTL' / TTL < 2.50. By constraining the ratio of the body lengths of the first optical system and the second optical system within a reasonable range, the first optical system can have a relatively large body length, ensuring the optical path length required for the light path folding and reflection of the first optical system, and guaranteeing that the first optical system achieves a magnified projection effect. At the same time, the second optical system can have a relatively small body length, avoiding problems such as the overall device being too large or the appearance being prominent due to the excessive occupied space of the second optical system, and meeting the practicality requirements of the virtual reality device.

[0060] In an exemplary embodiment, the on-axis distance TD' from the first side surface of the first lens to the second side surface of the third lens, the total effective focal length f' of the first optical system, the on-axis distance TD from the object side surface of the first lens to the image side surface of the eighth lens, and the total effective focal length f of the second optical system may satisfy: 8.60 < TD' / f' + TD / f < 11.00. By constraining the ratio of the on-axis distance from the first side surface of the first lens to the second side surface of the third lens to the total effective focal length of the first optical system and the ratio of the on-axis distance from the object side surface of the first lens to the image side surface of the eighth lens to the total effective focal length of the second optical system, and limiting the sum of these two ratios within a reasonable range, it is beneficial to take into account the lens group lengths of these two optical systems while ensuring the design main values of these two optical systems, avoiding extreme thicknesses or gaps caused by performance optimization, improving the processing and assembly feasibility of the virtual reality device, and ensuring the practicality of the virtual reality device.

[0061] In an exemplary embodiment, the on-axis distance TTL' from the first side surface of the first lens to the image plane of the first optical system, the effective focal length f1' of the first element group, the on-axis distance TTL from the object side surface of the first lens to the imaging plane of the second optical system, and the effective focal length f8 of the eighth lens may satisfy: 2.80 < TTL' / f1' + TTL / f8 < 4.30. By constraining the ratio of the on-axis distance from the first side surface of the first lens to the image plane of the first optical system to the effective focal length of the first element group and the ratio of the on-axis distance from the object side surface of the first lens to the imaging plane of the second optical system to the effective focal length of the eighth lens, and limiting the sum of these two ratios within a reasonable range, it is beneficial to control the body lengths of each optical system, avoiding the problem of the overall virtual reality device being too large, meeting the practicality requirements of the virtual reality device. At the same time, it is also beneficial to control the exit field of view of the second optical system and the entrance field of view of the first optical system to meet the design requirements of the virtual reality device.

[0062] In an exemplary embodiment, the central thickness CT1' of the first lens on the first optical axis, the central thickness CT2' of the second lens on the first optical axis, the central thickness CT3' of the third lens on the first optical axis, and the axial distance SD from the second aperture stop to the image side surface of the eighth lens may satisfy: 2.30 < (CT1' + CT2' + CT3') / SD < 3.30. By restricting the sum of the central thicknesses of the first lens, the second lens, and the third lens, it is beneficial to ensure the molding and assembly strength of each lens of the first optical system, and indirectly restrict the body length of the first optical system. At the same time, restricting the ratio of it to the axial distance from the second aperture stop to the image side surface of the eighth lens optimizes the spatial arrangement of the two optical systems and meets the basic usage requirements of the lightweight of the virtual reality device.

[0063] In an exemplary embodiment, the total effective focal length f' of the first optical system and the effective focal length f1 of the first lens may satisfy: -5.30 < f' / f1 < -3.60. By restricting the ratio of the total effective focal length of the first optical system to the effective focal length of the first lens, it is beneficial to indirectly control the body length of the first optical system and the shape and thickness of the first lens of the second optical system, facilitating size presetting, and further beneficial to optimizing the arrangement of the radius of curvature and thickness.

[0064] In an exemplary embodiment, the effective focal length f1' of the first element group and the radius of curvature R2' of the second side surface of the first lens may satisfy: -2.00 < f1' / R2' < -1.60. By restricting the ratio of the effective focal length of the first element group to the radius of curvature of the second side surface of the first lens, it is beneficial to control the shape and light of the lens on the entrance pupil side to conform to the ergonomic field of view design, and avoid the problem of poor wearing and usage experience caused by extreme shapes and eye interference.

[0065] In an exemplary embodiment, the central thickness CT4 of the fourth lens on the second optical axis, the central thickness CT5 of the fifth lens on the second optical axis, the radius of curvature R8 of the image side surface of the fourth lens, and the radius of curvature R10 of the image side surface of the fifth lens may satisfy: -0.50 < (CT4 + CT5) / (R8 + R10) < -0.35. By restricting the ratio of the sum of the central thicknesses of the fourth lens and the fifth lens to the sum of the radii of curvature of the image side surfaces of the fourth lens and the fifth lens, it is beneficial to ensure the processing and assembly strength of the fourth lens and the fifth lens of the second optical system, and make the radius of curvature of the image side surface of the fourth lens and / or the fifth lens negative, diverging the converging large aperture, enhancing the light control space of the rear lens, further optimizing the astigmatism and distortion of the second optical system, and improving the imaging quality of the second optical system.

[0066] In an exemplary embodiment, the effective focal length f1 of the first lens, the effective focal length f2 of the second lens, the effective focal length f7 of the seventh lens, and the effective focal length f8 of the eighth lens may satisfy: 2.50 < (f1 / f2) × (f7 / f8) < 3.60. By constraining the ratio of the effective focal lengths of the first lens and the second lens and the ratio of the effective focal lengths of the seventh lens and the eighth lens, and limiting the product of these two ratios within a relatively small range, it is beneficial to control the incident light and the outgoing light of the second optical system, and further control the entrance pupil field of view and the chief ray angle (CRA) of the second optical system, and control the object-side field angle and the image-side image height of the second optical system, so that the principal value parameters of the second optical system meet the actual functional requirements, facilitating the selection of the backend chip and the evaluation of its form factor.

[0067] In an exemplary embodiment, the radius of curvature R2 of the image side of the first lens, the radius of curvature R3 of the object side of the second lens, and the radius of curvature R4 of the image side of the second lens may satisfy: -9.00 < (R2 + R3) / R4 < -3.10. By constraining the sum of the radii of curvature of the image side of the first lens and the object side of the second lens, it is beneficial to constrain the shape of the first lens, providing a prerequisite for the design of a large field angle of the second optical system, and to a certain extent ensuring the processing feasibility of the first lens. At the same time, by restricting the ratio of its radius of curvature to that of the image side of the second lens, it is beneficial for the second lens to receive incident light at a large angle, avoiding introducing a large amount of astigmatism and the distortion caused by a large amount of astigmatism, providing room for further image quality optimization of the backend lens.

[0068] In an exemplary embodiment, the radius of curvature R1 of the object side of the first lens, the Abbe number V1 of the first lens, the radius of curvature R16 of the image side of the eighth lens, and the Abbe number V8 of the eighth lens satisfy: 0.80 < (R1 × V1) / (R16 × V8) < 2.60. By constraining the product of the radius of curvature of the object side of the first lens and the Abbe number of the first lens and the product of the radius of curvature of the image side of the eighth lens and the Abbe number of the eighth lens, and limiting the ratio of these two products within a certain range, it is beneficial to control the chromatic aberration of the incident light and the outgoing light of the second optical system, improve the problem of color distortion in the edge field of view caused by a large field of view, and improve the imaging quality of the virtual reality device.

[0069] In an exemplary embodiment, the effective focal length f7 of the seventh lens and the refractive index N7 of the seventh lens may satisfy: 2.70 mm < f7 / N7 < 4.60 mm. By constraining the ratio of the effective focal length of the seventh lens to the refractive index of the seventh lens, it is beneficial to narrow the material selection range of the seventh lens, facilitating the selection of a suitable refractive index material to regulate the optical path of the second optical system and constraining the astigmatism of the second optical system.

[0070] In an exemplary embodiment, the effective focal length f8 of the eighth lens, the radius of curvature R15 of the object side surface of the eighth lens, and the radius of curvature R16 of the image side surface of the eighth lens may satisfy: 1.60 < f8 / (R16 - R15) < 2.60. By restricting the ratio of the effective focal length of the eighth lens to the difference between the radius of curvature of the image side surface and the radius of curvature of the object side surface of the eighth lens, it is beneficial to control the shape and thickness of the eighth lens, ensure the forming processability and assembly arrangement of the eighth lens; at the same time, it can also control the exit light angle of the second optical system, limit the selection of the rear-end chip by the interval, and improve the feasibility of the physical process.

[0071] In an exemplary embodiment, the effective focal length f3 of the third lens, the effective focal length f4 of the fourth lens, and the effective focal length f5 of the fifth lens may satisfy: 2.20 < (f3 + f4) / f5 < 2.50. By restricting the ratio of the sum of the effective focal lengths of the third lens and the fourth lens to the effective focal length of the fifth lens within a relatively small range, it is beneficial to reasonably distribute the focal lengths of the intermediate lenses of the second optical system, limit the radius of curvature and thickness of the intermediate lenses, and at the same time, it is also beneficial to perform ray tracing analysis on this part of the light and restrict the astigmatism of the second optical system.

[0072] In an exemplary embodiment, the central thickness CT4 of the fourth lens on the second optical axis, the central thickness CT5 of the fifth lens on the second optical axis, and the central thickness CT6 of the sixth lens on the second optical axis satisfy: 7.80 < (CT4 + CT5) / CT6 ≤ 11.00. By restricting the ratio of the sum of the central thicknesses of the fourth lens and the fifth lens to the central thickness of the sixth lens, it is beneficial to reasonably distribute the central thicknesses of the fourth lens, the fifth lens, and the sixth lens, ensure the forming and assembly strength of the fourth lens, the fifth lens, and the sixth lens; and it is also beneficial to limit the optical path of the light in these three lenses and facilitate the adjustment of the overall aberration of the second optical system.

[0073] In an exemplary embodiment, the radius of curvature R1 of the object side surface of the first lens, the radius of curvature R2 of the image side surface of the first lens, and the combined focal length f12 of the first lens and the second lens may satisfy: -9.00 < (R1 + R2) / f12 < -6.40. By restricting the ratio of the sum of the radius of curvature of the object side surface and the radius of curvature of the image side surface of the first lens to the combined focal length of the first lens and the second lens, it is beneficial to control the shape of the first lens and the air gap between the first lens and the second lens, and facilitate the control of the incident light angle and the exit distribution.

[0074] The virtual reality device according to the above embodiments of this application may include a first optical system and a second optical system. The first optical system may employ multiple lenses, such as the three lenses described above, and the second optical system may employ multiple lenses, such as the eight lenses described above. By rationally configuring the parameters of the first and second optical systems, the imaging quality and visual immersion of the virtual reality device can be improved. Furthermore, the virtual reality device configured as described above features miniaturization and good imaging quality, effectively meeting the usage needs of various portable electronic products in projection scenarios.

[0075] In embodiments of this application, at least one surface of each of the first to third lenses is an aspherical surface. An aspherical lens is characterized by a continuously changing curvature from its center to its periphery. Unlike a spherical lens, which has a constant curvature from its center to its periphery, an aspherical lens has superior curvature radius characteristics, offering advantages in improving distortion and astigmatism. By using an aspherical lens, aberrations occurring during imaging can be eliminated as much as possible, thereby improving image quality. Similarly, at least one surface of each of the first to eighth lenses is an aspherical surface.

[0076] However, those skilled in the art should understand that, without departing from the technical solutions claimed in this application, the number of lenses and / or mirrors can be changed to obtain the various results and advantages described in this specification.

[0077] refer to Figure 1 The second aspect of this application provides a virtual reality device that may include a first optical system and a second optical system; the first optical system includes, sequentially from a first side to a second side along a first optical axis, a first element group, a second element group, and a third element group, wherein 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 arranged sequentially from the first side to the second side along the first optical axis, the reflective polarizing element and the quarter-wave plate being attached to and attached to a second side surface of the second lens, and the third element group includes a third lens; the second optical system includes, sequentially from the object side to the image side along the second optical axis, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens.

[0078] Among them, the on-axis distance TTL' from the first side surface of the first lens to the image surface of the first optical system, the effective focal length f1' of the first element group, the on-axis distance TTL from the object side surface of the first lens to the imaging surface of the second optical system, and the effective focal length f8 of the eighth lens can satisfy: 2.80 < TTL' / f1' + TTL / f8 < 4.30. By restricting the ratio of the on-axis distance from the first side surface of the first lens to the image surface of the first optical system to the effective focal length of the first element group and the ratio of the on-axis distance from the object side surface of the first lens to the imaging surface of the second optical system to the effective focal length of the eighth lens, and limiting the sum of these two ratios within a reasonable range, it is beneficial to control the body length of each optical system, avoid the problem of the overall size of the virtual reality device being too large, and meet the practical requirements of the virtual reality device; at the same time, it is also beneficial to control the exit field of view of the second optical system and the entrance field of view of the first optical system to meet the design requirements of the virtual reality device.

[0079] Reference Figure 1 , the third aspect of the present application provides such a virtual reality device, which may include a first optical system and a second optical system; the first optical system sequentially includes a first element group, a second element group, and a third element group along the first optical axis from the first side to the second side. Among them, 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 sequentially arranged along the first optical axis from the first side to the second side. The reflective polarizing element and the quarter-wave plate are bonded and attached to the second side surface of the second lens. The third element group includes a third lens; the second optical system sequentially includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens along the second optical axis from the object side to the image side.

[0080] Among them, the on-axis distance TD' from the first side surface of the first lens to the second side surface of the third lens, the total effective focal length f' of the first optical system, the on-axis distance TD from the object side surface of the first lens to the image side surface of the eighth lens, and the total effective focal length f of the second optical system can satisfy: 8.60 < TD' / f' + TD / f < 11.00. By restricting the ratio of the on-axis distance from the first side surface of the first lens to the second side surface of the third lens to the total effective focal length of the first optical system and the ratio of the on-axis distance from the object side surface of the first lens to the image side surface of the eighth lens to the total effective focal length of the second optical system, and limiting the sum of these two ratios within a reasonable range, it is beneficial to consider the lens group lengths of these two optical systems while ensuring the design main values of these two optical systems, avoid extreme thickness or gaps caused by performance optimization, improve the processing and assembly feasibility of the virtual reality device, and ensure the practicality of the virtual reality device.

[0081] The following further describes specific embodiments of the first optical system applicable to the above embodiments with reference to the accompanying drawings.

[0082] Example 1

[0083] The following is for reference Figures 3 to 4C A first optical system according to Embodiment 1 of this application is described.

[0084] like Figure 3 As shown, the first optical system 100 includes a first element group, a second element group, and a third element group arranged sequentially along a first optical axis from a first side to a second side. The first element group includes a first lens E1'. The second element group includes a second lens E2', a reflective polarizing element RP, and a quarter-wave plate QWP. The third element group includes a third lens E3'. A first aperture stop STO1 may be disposed between the first side and the first lens E1'. A partial reflective layer BS (not shown) may also be disposed on the first side of the third lens E3'. In this embodiment, the first side refers to the human eye side, and the second side refers to the display screen side. The first side of each element (first lens E1', second lens E2', third lens E3', reflective polarizing element RP, quarter-wave plate QWP) is referred to as the near-human eye side, and the second side is referred to as the near-screen side.

[0085] The first lens E1' has a convex surface on its near-eye side S1 and a convex surface on its near-screen side S2. The second lens E2' has a concave surface on its near-eye side S3 and a flat surface on its near-screen side S4. The reflective polarizing element RP has a near-eye side and a near-screen side, and the near-eye side of the reflective polarizing element RP is attached to the near-screen side S4 of the second lens E2'. The quarter-wave plate QWP has a near-eye side and a near-screen side, and its near-eye side is attached to the near-screen side of the reflective polarizing element RP. The third lens E3' has a concave surface on its near-eye side S5 and a convex surface on its near-screen side S6. A partial reflective layer BS can be attached to the near-eye side S5 of the third lens E3'.

[0086] In this example, the second side of the first optical system 100 may be provided with an image surface S7, which may, for example, be a display screen. Image light from the display screen sequentially passes through the third lens E3', the quarter-wave plate QWP, and reaches the reflective polarizing element RP located on the near-screen side S4 of the second lens E2', where it undergoes a first reflection. The light after the first reflection passes through the quarter-wave plate QWP and reaches the partial reflective layer BS located on the near-eye side S5 of the third lens E3', where it undergoes a second reflection. The light after the second reflection sequentially passes through the quarter-wave plate QWP, the reflective polarizing element RP, the second lens E2', the first lens E1', and reaches the first aperture STO1, finally being projected into the user's eye. For example, the light from the first optical system 100 after two reflections is finally projected into the user's eye.

[0087] Table 1 shows the basic parameters of the first optical system of Embodiment 1, where the units for radius of curvature and thickness / distance are millimeters (mm). Image light from the display screen passes through the elements in the order of number 13 to number 1 and is finally projected into the human eye.

[0088]

[0089]

[0090] Table 1

[0091] In this embodiment, the total effective focal length f' of the first optical system is 30.98 mm, the effective focal length f1' of the first element group is 43.58 mm, the effective focal length f2' of the second element group is -1203.01 mm, the effective focal length f3' of the third element group is -219.02 mm, the maximum field of view FOV' of the first optical system is 106.00°, and the on-axis distance TTL' from the first side of the first lens to the image plane of the first optical system is 30.92 mm.

[0092] In this embodiment, the near-eye side S1 and near-screen side S2 of the first lens E1', the near-eye side S3 of the second lens E2', and the near-eye side S5 and near-screen side S6 of the third lens E3' are all aspherical. The surface shape x of each aspherical lens can be limited by, but is not limited to, the following aspherical formula:

[0093]

[0094] Where x is the distance vector from the vertex of the aspherical surface at a height of h along the optical axis; c is the paraxial curvature of the aspherical surface, c = 1 / R (i.e., the paraxial curvature c is the reciprocal of the radius of curvature R in Table 1 above); k is the conic coefficient; Ai is the i-th order correction coefficient of the aspherical surface. Table 2 gives the higher-order coefficients A4, A6, A8, A9, and A1 that can be used for the aspherical surfaces S1, S2, S3, S5, and S6 in Example 1. 10 A 12 and A 14 .

[0095] Face number <![CDATA[A4]]> <![CDATA[A6]]> <![CDATA[A8]]> <![CDATA[A 10 ]]> <![CDATA[A 12 ]]> <![CDATA[A 14 ]]> S1 -3.1865E+00 -7.5453E-02 -1.2837E-02 -1.2187E-03 1.9018E-03 -5.6743E-04 S2 -2.0625E+00 -8.0111E-02 -1.7584E-01 -5.6291E-02 -1.8020E-02 0.0000E+00 S3 1.3324E+00 9.0231E-01 -2.0304E-01 2.4737E-02 0.0000E+00 0.0000E+00 S5 -2.3349E-01 -1.2488E-01 3.8891E-02 6.1584E-03 0.0000E+00 0.0000E+00 S6 -4.6536E+00 -6.1114E-01 -2.6109E-01 1.8175E-02 -3.0916E-01 0.0000E+00

[0096] Table 2

[0097] Figure 4A The on-axis chromatic aberration curve of the first optical system 100 of Embodiment 1 is shown, which represents the deflection of the focal point of light of different wavelengths after passing through the first optical system. Figure 4BThe astigmatism curves of the first optical system 100 of Embodiment 1 are shown, which represent the meridional image plane curvature and sagittal image plane curvature corresponding to different half-field angles. Figure 4C The magnification chromatic aberration curve of the first optical system 100 of Embodiment 1 is shown, which represents the deviation of different image heights after light passes through the first optical system. According to Figures 4A to 4C As can be seen, the first optical system 100 given in Example 1 can achieve good imaging quality.

[0098] Example 2

[0099] The following is for reference Figures 5 to 6C A first optical system according to Embodiment 2 of this application is described.

[0100] like Figure 5 As shown, the first optical system 100 includes a first element group, a second element group, and a third element group arranged sequentially along a first optical axis from a first side to a second side. The first element group includes a first lens E1'. The second element group includes a second lens E2', a reflective polarizing element RP, and a quarter-wave plate QWP. The third element group includes a third lens E3'. A first aperture stop STO1 may be disposed between the first side and the first lens E1'. A partial reflective layer BS (not shown) may also be disposed on the first side of the third lens E3'. In this embodiment, the first side refers to the human eye side, and the second side refers to the display screen side. The first side of each element (first lens E1', second lens E2', third lens E3', reflective polarizing element RP, quarter-wave plate QWP) is referred to as the near-human eye side, and the second side is referred to as the near-screen side.

[0101] The first lens E1' has a concave side (S1) near the human eye and a convex side (S2) near the screen. The second lens E2' has a convex side (S3) near the human eye and a flat side (S4) near the screen. The reflective polarizing element RP has a near-eye side and a near-screen side, and the near-eye side of the reflective polarizing element RP is attached to the near-screen side (S4) of the second lens E2'. The quarter-wave plate QWP has a near-eye side and a near-screen side, and its near-eye side is attached to the near-screen side of the reflective polarizing element RP. The third lens E3' has a concave side (S5) near the human eye and a convex side (S6) near the screen. A partial reflective layer BS can be attached to the near-eye side (S5) of the third lens E3'.

[0102] In this example, the second side of the first optical system 100 may be provided with an image surface S7, which may, for example, be a display screen. Image light from the display screen sequentially passes through the third lens E3', the quarter-wave plate QWP, and reaches the reflective polarizing element RP located on the near-screen side S4 of the second lens E2', where it undergoes a first reflection. The light after the first reflection passes through the quarter-wave plate QWP and reaches the partial reflective layer BS located on the near-eye side S5 of the third lens E3', where it undergoes a second reflection. The light after the second reflection sequentially passes through the quarter-wave plate QWP, the reflective polarizing element RP, the second lens E2', the first lens E1', and reaches the first aperture STO1, finally being projected into the user's eye. For example, the light from the first optical system 100 after two reflections is finally projected into the user's eye.

[0103] Table 3 shows the basic parameters of the first optical system in Embodiment 2, where the units for radius of curvature and thickness / distance are millimeters (mm). Image light from the display screen passes through each element in the order of number 13 to number 1 and is finally projected into the human eye.

[0104]

[0105]

[0106] Table 3

[0107] In this embodiment, the total effective focal length f' of the first optical system is 31.00 mm, the effective focal length f1' of the first element group is 55.66 mm, the effective focal length f2' of the second element group is 205.64 mm, the effective focal length f3' of the third element group is -618.26 mm, the maximum field of view FOV' of the first optical system is 106.00°, and the on-axis distance TTL' from the first side of the first lens to the image plane of the first optical system is 29.06 mm.

[0108] In this embodiment, the near-eye side S1 and near-screen side S2 of the first lens E1', the near-eye side S3 of the second lens E2', and the near-eye side S5 and near-screen side S6 of the third lens E3' are all aspherical surfaces. Table 4 shows the higher-order coefficients A4, A6, A8, and A6 that can be used for each aspherical surface S1, S2, S3, S5, and S6 in Embodiment 2. 10 A 12 and A 14 .

[0109] Face number <![CDATA[A4]]> <![CDATA[A6]]> <![CDATA[A8]]> <![CDATA[A 10 ]]> <![CDATA[A 12 ]]> <![CDATA[A 14 ]]> S1 -3.6521E-01 4.3423E-02 -1.5389E-02 1.3846E-03 0.0000E+00 0.0000E+00 S2 1.4534E+00 5.2532E-01 8.1074E-02 1.9381E-02 0.0000E+00 0.0000E+00 S3 5.6144E-01 -1.5226E-01 -1.8480E-04 7.6626E-04 0.0000E+00 0.0000E+00 S5 -1.7819E-01 -3.8356E-02 8.8601E-05 3.2125E-05 0.0000E+00 0.0000E+00 S6 -8.2470E-01 -3.0878E-01 4.8785E-02 7.8163E-03 4.8422E-05 4.5211E-07

[0110] Table 4

[0111] Figure 6A The on-axis chromatic aberration curve of the first optical system 100 of Embodiment 2 is shown, which represents the deflection of the focal point of light of different wavelengths after passing through the first optical system. Figure 6B The astigmatism curves of the first optical system 100 of Embodiment 2 are shown, which represent the meridional image plane curvature and sagittal image plane curvature corresponding to different half-field angles. Figure 6C The magnification chromatic aberration curve of the first optical system 100 in Embodiment 2 is shown, representing the deviation of different image heights after light passes through the first optical system. According to... Figures 6A to 6C It can be seen that the first optical system 100 given in Embodiment 2 can achieve good imaging quality.

[0112] Example 3

[0113] The following is for reference Figures 7 to 8C The first optical system according to Embodiment 3 of this application is described.

[0114] like Figure 7 As shown, the first optical system 100 includes a first element group, a second element group, and a third element group arranged sequentially along a first optical axis from a first side to a second side. The first element group includes a first lens E1'. The second element group includes a second lens E2', a reflective polarizing element RP, and a quarter-wave plate QWP. The third element group includes a third lens E3'. A first aperture stop STO1 may be disposed between the first side and the first lens E1'. A partial reflective layer BS (not shown) may also be disposed on the first side of the third lens E3'. In this embodiment, the first side refers to the human eye side, and the second side refers to the display screen side. The first side of each element (first lens E1', second lens E2', third lens E3', reflective polarizing element RP, quarter-wave plate QWP) is referred to as the near-human eye side, and the second side is referred to as the near-screen side.

[0115] The first lens E1' has a concave side (S1) near the human eye and a convex side (S2) near the screen. The second lens E2' has a convex side (S3) near the human eye and a flat side (S4) near the screen. The reflective polarizing element RP has a near-eye side and a near-screen side, and the near-eye side of the reflective polarizing element RP is attached to the near-screen side (S4) of the second lens E2'. The quarter-wave plate QWP has a near-eye side and a near-screen side, and its near-eye side is attached to the near-screen side of the reflective polarizing element RP. The third lens E3' has a concave side (S5) near the human eye and a convex side (S6) near the screen. A partial reflective layer BS can be attached to the near-eye side (S5) of the third lens E3'.

[0116] In this example, the second side of the first optical system 100 may be provided with an image surface S7, which may, for example, be a display screen. Image light from the display screen sequentially passes through the third lens E3', the quarter-wave plate QWP, and reaches the reflective polarizing element RP located on the near-screen side S4 of the second lens E2', where it undergoes a first reflection. The light after the first reflection passes through the quarter-wave plate QWP and reaches the partial reflective layer BS located on the near-eye side S5 of the third lens E3', where it undergoes a second reflection. The light after the second reflection sequentially passes through the quarter-wave plate QWP, the reflective polarizing element RP, the second lens E2', the first lens E1', and reaches the first aperture STO1, finally being projected into the user's eye. For example, the light from the first optical system 100 after two reflections is finally projected into the user's eye.

[0117] Table 5 shows the basic parameters of the first optical system in Embodiment 3, where the units for radius of curvature and thickness / distance are millimeters (mm). Image light from the display screen passes through each element in the order of number 13 to number 1 and is finally projected into the human eye.

[0118]

[0119] Table 5

[0120] In this embodiment, the total effective focal length f' of the first optical system is 31.00 mm, the effective focal length f1' of the first element group is 57.05 mm, the effective focal length f2' of the second element group is 192.56 mm, the effective focal length f3' of the third element group is -334.07 mm, the maximum field of view FOV' of the first optical system is 106.00°, and the on-axis distance TTL' from the first side of the first lens to the image plane of the first optical system is 27.76 mm.

[0121] In this embodiment, the near-eye side S1 and near-screen side S2 of the first lens E1', the near-eye side S3 of the second lens E2', and the near-eye side S5 and near-screen side S6 of the third lens E3' are all aspherical surfaces. Table 6 shows the higher-order coefficients A4, A6, A8, and A6 of the aspherical surfaces S1, S2, S3, S5, and S6 that can be used in Embodiment 3. 10 .

[0122]

[0123]

[0124] Table 6

[0125] Figure 8AThe on-axis chromatic aberration curve of the first optical system 100 of Embodiment 3 is shown, which represents the deflection of the focal point of light of different wavelengths after passing through the first optical system. Figure 8B The astigmatism curves of the first optical system 100 of Embodiment 3 are shown, which represent the meridional image plane curvature and sagittal image plane curvature corresponding to different half-field angles. Figure 8C The magnification chromatic aberration curve of the first optical system 100 in Embodiment 3 is shown, representing the deviation of different image heights after light passes through the first optical system. According to... Figures 8A to 8C It can be seen that the first optical system 100 given in Embodiment 3 can achieve good imaging quality.

[0126] The following describes a specific embodiment of the second optical system applicable to the above embodiments with reference to the accompanying drawings.

[0127] Example 4

[0128] The following is for reference Figures 9 to 10B A second optical system according to Embodiment 4 of this application is described.

[0129] like Figure 9 As shown, the second optical system 200 includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, and an eighth lens E8 arranged sequentially along the second optical axis from the object side to the image side. The second aperture STO2 may be disposed between the third lens E3 and the fourth lens E4.

[0130] The first lens, E1, has negative power; its object-side surface, S1, is convex, and its image-side surface, S2, is concave. The second lens, E2, has negative power; its object-side surface, S3, is concave, and its image-side surface, S4, is concave. The third lens, E3, has positive power; its object-side surface, S5, is convex, and its image-side surface, S6, is concave. The fourth lens, E4, has positive power; its object-side surface, S7, is concave, and its image-side surface, S8, is convex. The fifth lens, E5, has positive power; its object-side surface, S9, is convex, and its image-side surface, S10, is convex. The sixth lens, E6, has negative power; its object-side surface, S11, is concave, and its image-side surface, S12, is concave. The seventh lens, E7, has positive power; its object-side surface, S13, is convex, and its image-side surface, S14, is convex. The eighth lens, E8, has positive power; its object-side surface, S15, is convex, and its image-side surface, S16, is concave. The filter E9 has an object-side surface S17 and an image-side surface S18. Light from the object passes sequentially through each surface S1 to S18 and is finally imaged onto the imaging surface S19.

[0131] Table 7 shows the basic parameters of the second optical system in Embodiment 4, where the units for radius of curvature and thickness / distance are millimeters (mm).

[0132]

[0133]

[0134] Table 7

[0135] In this embodiment, the total effective focal length f of the second optical system is 1.42 mm, the maximum field of view (FOV) of the second optical system is 214.00°, and the on-axis distance TTL from the object side of the first lens to the imaging surface of the second optical system is 12.42 mm.

[0136] In this embodiment, the object-side surface and image-side surface of any one of the second lens E2 to the eighth lens E8 are aspherical, and the surface shape x of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0137]

[0138] Where x is the distance vector from the vertex of the aspherical surface at a height of h along the optical axis; c is the paraxial curvature of the aspherical surface, c = 1 / R (i.e., the paraxial curvature c is the reciprocal of the radius of curvature R in Table 7 above); k is the conic coefficient; Ai is the i-th order correction coefficient of the aspherical surface. Table 8 shows the higher-order coefficients A4, A6, A8, and A16 that can be used for the aspherical surfaces S3-S16 in Example 4. 10 A 12 A 14 A 16 A 18 A 20 A 22 A 24 A 26 A 28 and A 30 .

[0139]

[0140]

[0141] Table 8

[0142] Figure 10A The on-axis chromatic aberration curve of the second optical system 200 of Embodiment 4 is shown, which represents the deflection of the focal point of light of different wavelengths after passing through the second optical system. Figure 10B The astigmatism curves of the second optical system 200 of Embodiment 4 are shown, representing the meridional and sagittal image plane curvatures corresponding to different image heights. According to... Figure 10A and Figure 10B It can be seen that the second optical system 200 given in Embodiment 4 can achieve good imaging quality.

[0143] Example 5

[0144] The following is for reference Figures 11 to 12B A second optical system according to Embodiment 5 of this application is described.

[0145] like Figure 11 As shown, the second optical system 200 includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, and an eighth lens E8 arranged sequentially along the second optical axis from the object side to the image side. The second aperture STO2 may be disposed between the third lens E3 and the fourth lens E4.

[0146] The first lens, E1, has negative power; its object-side surface, S1, is convex, and its image-side surface, S2, is concave. The second lens, E2, has negative power; its object-side surface, S3, is concave, and its image-side surface, S4, is concave. The third lens, E3, has positive power; its object-side surface, S5, is convex, and its image-side surface, S6, is concave. The fourth lens, E4, has positive power; its object-side surface, S7, is convex, and its image-side surface, S8, is convex. The fifth lens, E5, has positive power; its object-side surface, S9, is convex, and its image-side surface, S10, is convex. The sixth lens, E6, has negative power; its object-side surface, S11, is concave, and its image-side surface, S12, is convex. The seventh lens, E7, has positive power; its object-side surface, S13, is convex, and its image-side surface, S14, is concave. The eighth lens, E8, has positive power; its object-side surface, S15, is convex, and its image-side surface, S16, is concave. The filter E9 has an object-side surface S17 and an image-side surface S18. Light from the object passes sequentially through each surface S1 to S18 and is finally imaged onto the imaging surface S19.

[0147] Table 9 shows the basic parameters of the second optical system in Embodiment 5, where the units for radius of curvature and thickness / distance are millimeters (mm).

[0148]

[0149]

[0150] Table 9

[0151] In this embodiment, the total effective focal length f of the second optical system is 1.36 mm, the maximum field of view (FOV) of the second optical system is 200.00°, and the on-axis distance TTL from the object side of the first lens to the imaging surface of the second optical system is 15.15 mm.

[0152] In this embodiment, the object-side surface and image-side surface of any one of the second lens E2 to the eighth lens E8 are aspherical. Table 10 lists the higher-order coefficients A4, A6, A8, and A6 that can be used for the aspherical surfaces S3-S16 in Embodiment 5. 10 A12 A 14 A 16 A 18 A 20 A 22 A 24 A 26 A 28 and A 30 .

[0153] Face number A4 A6 A8 A10 A12 A14 A16 S3 2.2196E-02 -1.2711E-02 -1.5369E-03 1.2754E-02 -1.3145E-02 7.6974E-03 -3.0045E-03 S4 -3.3621E-02 3.8880E-01 -2.0092E+00 6.3183E+00 -1.3683E+01 2.1246E+01 -2.4000E+01 S5 1.2336E-02 1.4851E-01 -7.8425E-01 2.6854E+00 -6.3968E+00 1.0917E+01 -1.3444E+01 S6 8.1987E-02 -5.1279E-01 4.5787E+00 -2.5382E+01 9.4956E+01 -2.4910E+02 4.6905E+02 S7 1.6066E-02 -9.6070E-02 4.2782E-01 -1.1947E+00 2.2315E+00 -2.8733E+00 2.5811E+00 S8 -1.0992E-02 4.0919E-02 -8.3467E-02 1.1880E-01 -1.1351E-01 7.3506E-02 -3.2292E-02 S9 -1.7834E-02 3.1534E-02 -5.7491E-02 7.4269E-02 -6.6299E-02 4.1924E-02 -1.9125E-02 S10 -3.4260E-02 -9.8509E-02 4.2388E-01 -7.5933E-01 7.9363E-01 -5.3465E-01 2.4385E-01 S11 3.9480E-02 9.3632E-03 2.3121E-01 -6.3541E-01 7.9918E-01 -6.1049E-01 3.1252E-01 S12 -9.5686E-03 5.0448E-02 7.4080E-02 -2.5290E-01 3.1279E-01 -2.3488E-01 1.2057E-01 S13 -2.9798E-03 -1.0037E-01 1.8789E-01 -2.0547E-01 1.5089E-01 -7.8969E-02 3.0532E-02 S14 1.7206E-01 -5.4159E-01 7.1772E-01 -6.0501E-01 3.5399E-01 -1.4713E-01 4.3261E-02 S15 1.1649E-01 -3.7581E-01 4.8694E-01 -4.2647E-01 2.6776E-01 -1.2278E-01 4.1614E-02 S16 7.0545E-02 -1.8506E-02 -8.9250E-02 1.2400E-01 -9.0735E-02 4.4336E-02 -1.5406E-02 Face number A18 A20 A22 A24 A26 A28 A30 S3 8.2342E-04 -1.6120E-04 2.2470E-05 -2.1806E-06 1.4009E-07 -5.3564E-09 9.2303E-11 S4 1.9833E+01 -1.1960E+01 5.1957E+00 -1.5813E+00 3.1963E-01 -3.8505E-02 2.0908E-03 S5 1.1986E+01 -7.7210E+00 3.5514E+00 -1.1358E+00 2.3973E-01 -2.9999E-02 1.6851E-03 S6 -6.4118E+02 6.3675E+02 -4.5438E+02 2.2687E+02 -7.5196E+01 1.4857E+01 -1.3237E+00 S7 -1.6122E+00 6.8554E-01 -1.8910E-01 3.0487E-02 -2.1794E-03 0.0000E+00 0.0000E+00 S8 9.4660E-03 -1.7703E-03 1.9085E-04 -9.0179E-06 0.0000E+00 0.0000E+00 0.0000E+00 S9 6.3498E-03 -1.5330E-03 2.6583E-04 -3.2203E-05 2.5823E-06 -1.2292E-07 2.6240E-09 S10 -7.7032E-02 1.6881E-02 -2.5100E-03 2.3849E-04 -1.2450E-05 1.8831E-07 7.1180E-09 S11 -1.1217E-01 2.8758E-02 -5.2616E-03 6.7270E-04 -5.7180E-05 2.9048E-06 -6.6720E-08 S12 -4.4242E-02 1.1777E-02 -2.2632E-03 3.0653E-04 -2.7788E-05 1.5143E-06 -3.7528E-08 S13 -8.8754E-03 1.9443E-03 -3.1720E-04 3.7446E-05 -3.0266E-06 1.4994E-07 -3.4342E-09 S14 -8.6873E-03 1.0692E-03 -4.6111E-05 -8.1021E-06 1.5755E-06 -1.1384E-07 3.1984E-09 S15 -1.0478E-02 1.9530E-03 -2.6567E-04 2.5616E-05 -1.6575E-06 6.4520E-08 -1.1414E-09 S16 3.8869E-03 -7.1364E-04 9.4276E-05 -8.7175E-06 5.3470E-07 -1.9513E-08 3.2023E-10

[0154] Table 10

[0155] Figure 12A The on-axis chromatic aberration curve of the second optical system 200 of Embodiment 5 is shown, which represents the deflection of the focal point of light of different wavelengths after passing through the second optical system. Figure 12B The astigmatism curves of the second optical system 200 of Embodiment 5 are shown, representing the meridional and sagittal image plane curvatures corresponding to different image heights. According to... Figure 12A and Figure 12B It can be seen that the second optical system 200 given in Embodiment 5 can achieve good imaging quality.

[0156] Example 6

[0157] The following is for reference Figures 13 to 14B A second optical system according to Embodiment Six of this application is described.

[0158] like Figure 13 As shown, the second optical system 200 includes a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a sixth lens E6, a seventh lens E7, and an eighth lens E8 arranged sequentially along the second optical axis from the object side to the image side. The second aperture STO2 may be disposed between the third lens E3 and the fourth lens E4.

[0159] The first lens, E1, has negative power; its object-side surface, S1, is convex, and its image-side surface, S2, is concave. The second lens, E2, has negative power; its object-side surface, S3, is concave, and its image-side surface, S4, is concave. The third lens, E3, has positive power; its object-side surface, S5, is convex, and its image-side surface, S6, is concave. The fourth lens, E4, has positive power; its object-side surface, S7, is concave, and its image-side surface, S8, is convex. The fifth lens, E5, has positive power; its object-side surface, S9, is convex, and its image-side surface, S10, is convex. The sixth lens, E6, has negative power; its object-side surface, S11, is concave, and its image-side surface, S12, is convex. The seventh lens, E7, has positive power; its object-side surface, S13, is convex, and its image-side surface, S14, is concave. The eighth lens, E8, has positive power; its object-side surface, S15, is convex, and its image-side surface, S16, is concave. The filter E9 has an object-side surface S17 and an image-side surface S18. Light from the object passes sequentially through each surface S1 to S18 and is finally imaged onto the imaging surface S19.

[0160] Table 11 shows the basic parameters of the second optical system in Embodiment 6, where the units for radius of curvature and thickness / distance are millimeters (mm).

[0161]

[0162] Table 11

[0163] In this embodiment, the total effective focal length f of the second optical system is 1.37 mm, the maximum field of view (FOV) of the second optical system is 203.00°, and the on-axis distance (TTL) from the object side of the first lens to the imaging surface of the second optical system is 14.16 mm.

[0164] In this embodiment, the object-side surface and image-side surface of any one of the second lens E2 to the eighth lens E8 are aspherical. Table 12 lists the higher-order coefficients A4, A6, A8, and A6 that can be used for the aspherical surfaces S3-S16 in Embodiment Six. 10 A 12 A 14 A 16 A 18 A 20 A 22 A 24 A 26 A 28 and A 30 .

[0165] Face number A4 A6 A8 A10 A12 A14 A16 S3 2.2120E-02 -1.8192E-02 1.3443E-02 -5.9300E-03 1.0660E-03 4.1322E-04 -3.7057E-04 S4 -2.3594E-02 2.8283E-01 -1.4836E+00 4.6534E+00 -9.9118E+00 1.5076E+01 -1.6714E+01 S5 2.4778E-02 1.5673E-02 -8.0549E-02 2.5755E-01 -5.8279E-01 1.0906E+00 -1.6023E+00 S6 9.7850E-02 -7.3132E-01 6.4682E+00 -3.5882E+01 1.3444E+02 -3.5271E+02 6.6291E+02 S7 7.0552E-03 -4.9493E-02 1.0697E-01 1.9192E-01 -1.5894E+00 4.0925E+00 -6.0120E+00 S8 -7.2162E-03 2.8472E-02 -6.0155E-02 9.1743E-02 -9.4213E-02 6.5619E-02 -3.1020E-02 S9 -1.7322E-02 3.1466E-02 -5.9273E-02 7.8009E-02 -7.0247E-02 4.4588E-02 -2.0377E-02 S10 -3.6216E-02 -9.5237E-02 4.2743E-01 -7.7257E-01 8.1052E-01 -5.4848E-01 2.5220E-01 S11 4.0178E-02 5.6136E-03 2.2283E-01 -5.9901E-01 7.4367E-01 -5.6128E-01 2.8377E-01 S12 -9.1608E-03 4.9101E-02 7.6110E-02 -2.5862E-01 3.2169E-01 -2.4254E-01 1.2452E-01 S13 -1.1616E-02 -8.7714E-02 1.9814E-01 -2.5309E-01 2.1352E-01 -1.2632E-01 5.4162E-02 S14 1.7400E-01 -5.5771E-01 7.6326E-01 -6.7287E-01 4.1591E-01 -1.8486E-01 5.9423E-02 S15 1.2741E-01 -3.9553E-01 5.1879E-01 -4.5925E-01 2.8931E-01 -1.3218E-01 4.4366E-02 S16 7.3430E-02 -3.7037E-02 -4.7688E-02 7.2670E-02 -5.0257E-02 2.2515E-02 -7.0792E-03 Face number A18 A20 A22 A24 A26 A28 A30 S3 1.3735E-04 -3.1783E-05 4.9442E-06 -5.1933E-07 3.5448E-08 -1.4225E-09 2.5502E-11 S4 1.3609E+01 -8.1193E+00 3.5025E+00 -1.0618E+00 2.1430E-01 -2.5827E-02 1.4048E-03 S5 1.7441E+00 -1.3671E+00 7.5703E-01 -2.8823E-01 7.1701E-02 -1.0485E-02 6.8278E-04 S6 -9.0291E+02 8.9218E+02 -6.3283E+02 3.1386E+02 -1.0329E+02 2.0259E+01 -1.7917E+00 S7 5.5998E+00 -3.3722E+00 1.2754E+00 -2.7588E-01 2.6060E-02 0.0000E+00 0.0000E+00 S8 9.7853E-03 -1.9690E-03 2.2834E-04 -1.1602E-05 0.0000E+00 0.0000E+00 0.0000E+00 S9 6.7772E-03 -1.6408E-03 2.8591E-04 -3.4905E-05 2.8316E-06 -1.3701E-07 2.9904E-09 S10 -8.0852E-02 1.8183E-02 -2.8312E-03 2.9364E-04 -1.8676E-05 6.0275E-07 -5.1966E-09 S11 -1.0050E-01 2.5393E-02 -4.5732E-03 5.7476E-04 -4.7961E-05 2.3886E-06 -5.3712E-08 S12 -4.5472E-02 1.1980E-02 -2.2659E-03 3.0051E-04 -2.6550E-05 1.4040E-06 -3.3634E-08 S13 -1.7075E-02 3.9619E-03 -6.6860E-04 7.9840E-05 -6.3952E-06 3.0835E-07 -6.7665E-09 S14 -1.3693E-02 2.2038E-03 -2.3383E-04 1.4098E-05 -2.1128E-07 -2.5876E-08 1.1978E-09 S15 -1.1004E-02 2.0111E-03 -2.6718E-04 2.5075E-05 -1.5747E-06 5.9343E-08 -1.0143E-09 S16 1.5997E-03 -2.5992E-04 2.9856E-05 -2.3345E-06 1.1559E-07 -3.1303E-09 3.1707E-11

[0166] Table 12

[0167] Figure 14AThe on-axis chromatic aberration curve of the second optical system 200 of Embodiment Six is ​​shown, which represents the deflection of the focal point of light of different wavelengths after passing through the second optical system. Figure 14B The astigmatism curves of the second optical system 200 of Embodiment Six are shown, representing the meridional and sagittal image plane curvatures corresponding to different image heights. According to... Figure 14A and Figure 14B It can be seen that the second optical system 200 given in Embodiment Six can achieve good imaging quality.

[0168] refer to Figure 1 The virtual reality device 10 provided in this application may include a first optical system 100 and a second optical system 200 from any of the above embodiments. The first and second optical systems are combined in pairs to form nine virtual reality devices, meaning there are nine examples of virtual reality devices.

[0169] Example 1: The virtual reality device includes a first optical system of Embodiment 1 and a second optical system of Embodiment 4;

[0170] Example 2: The virtual reality device includes the first optical system of Embodiment 2 and the second optical system of Embodiment 4;

[0171] Example 3: The virtual reality device includes the first optical system of Embodiment 3 and the second optical system of Embodiment 4;

[0172] Example 4: The virtual reality device includes the first optical system of Embodiment 1 and the second optical system of Embodiment 5;

[0173] Example 5: The virtual reality device includes the first optical system of Embodiment 2 and the second optical system of Embodiment 5;

[0174] Example 6: The virtual reality device includes the first optical system of Embodiment 3 and the second optical system of Embodiment 5;

[0175] Example 7: The virtual reality device includes a first optical system of Embodiment 1 and a second optical system of Embodiment 6;

[0176] Example 8: The virtual reality device includes the first optical system of Embodiment 2 and the second optical system of Embodiment 6;

[0177] Example 9: The virtual reality device includes a first optical system of Embodiment 3 and a second optical system of Embodiment 6.

[0178] It should be understood that, such as Figure 1 As shown, the virtual reality device 10 provided in this application may further include a third optical system 300, the structure of which may be different from the structure of the first optical system 100 and the second optical system 200.

[0179] In summary, Table 13 shows the values ​​of the conditional expressions for each of the examples in Examples 1 through 9.

[0180] Conditional / Example 1 2 3 4 5 6 7 8 9 f' / f1 -3.72 -3.72 -3.72 -5.28 -5.29 -5.29 -4.85 -4.85 -4.85 FOV / FOV' 2.02 2.02 2.02 1.89 1.89 1.89 1.92 1.92 1.92 (CT1'+CT2'+CT3') / SD 3.25 2.86 2.56 3.10 2.73 2.43 2.98 2.62 2.34 f1' / R2' -1.61 -1.87 -1.80 -1.61 -1.87 -1.80 -1.61 -1.87 -1.80 f' / f2'+f / f2 -0.59 -0.42 -0.41 -0.48 -0.31 -0.29 -0.50 -0.32 -0.31 (CT4+CT5) / (R8+R10) -0.45 -0.45 -0.45 -0.39 -0.39 -0.39 -0.41 -0.41 -0.41 TTL' / TTL 2.49 2.34 2.24 2.04 1.92 1.83 2.18 2.05 1.96 TD' / f'+TD / f 8.84 8.75 8.70 10.99 10.90 10.85 10.11 10.02 9.96 (f1 / f2)×(f7 / f8) 2.70 2.70 2.70 3.22 3.22 3.22 3.57 3.57 3.57 (R2+R3) / R4 -8.95 -8.95 -8.95 -3.16 -3.16 -3.16 -3.16 -3.16 -3.16 (R1×V1) / (R16×V8) 0.90 0.90 0.90 2.55 2.55 2.55 1.92 1.92 1.92 f7 / N7 2.76 2.76 2.76 4.51 4.51 4.51 4.46 4.46 4.46 f8 / (R16-R15) 2.03 2.03 2.03 1.76 1.76 1.76 1.66 1.66 1.66 TTL' / f1'+TTL / f8 3.08 2.89 2.86 4.27 4.08 4.04 4.05 3.87 3.83 (f3+f4) / f5 2.22 2.22 2.22 2.49 2.49 2.49 2.44 2.44 2.44 (CT4+CT5) / CT6 11.00 11.00 11.00 9.01 9.01 9.01 7.90 7.90 7.90 (R1+R2) / f12 -6.44 -6.44 -6.44 -8.90 -8.90 -8.90 -7.38 -7.38 -7.38

[0181] Table 13

[0182] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A virtual reality device, comprising a first optical system and a second optical system, characterized in that, The first optical system comprises, sequentially from the first side to the second side along the first optical axis: The first element group includes a first lens with positive optical power; the second side surface of the first lens is a convex surface. The second element group includes a second lens, a reflective polarizing element, and a quarter-wave plate arranged sequentially along the first optical axis from the first side to the second side. The reflective polarizing element and the quarter-wave plate are bonded together and attached to the second side surface of the second lens; the second side surface of the second lens is a plane. The third element group includes a partially reflective layer arranged sequentially along the first optical axis from the first side to the second side and a third lens with negative optical power; the first side of the third lens is concave and the second side is convex. The second optical system comprises, in sequence from the object side to the image side along the second optical axis: The first lens with negative optical power has a convex object side and a concave image side. The second lens has negative optical power, with both its object side and image side being concave. The third lens with positive power has a convex object side and a concave image side. The fourth lens has positive optical power and its image side is convex. The fifth lens has positive optical power, with both its object side and image side being convex. The sixth lens has negative optical power and its object side is concave. The seventh lens, which has positive optical power, has a convex object side. The eighth lens, which has positive optical power, has a convex object side and a concave image side. The first optical system has three lenses with optical power, the first side is the human eye side, and the second side is the display screen side; The second optical system has eight lenses with optical power. The maximum field of view (FOV) of the second optical system satisfies 100°≤FOV / 2≤107.00°; The total effective focal length f' of the first optical system, the effective focal length f2' of the second element group, the total effective focal length f of the second optical system, and the effective focal length f2 of the second lens satisfy: -0.60 < f' / f2' + f / f2 < -0.28; and The effective focal length f1' of the first element group and the radius of curvature R2' of the second side surface of the first lens satisfy: -1.87≤f1' / R2'<-1.

60.

2. The virtual reality device according to claim 1, characterized in that, The maximum field of view (FOV)' of the first optical system and the maximum field of view (FOV) of the second optical system satisfy: 1.89≤FOV / FOV'≤2.

02.

3. The virtual reality device according to claim 1, characterized in that, The on-axis distance TTL' from the first side surface of the first lens to the image plane of the first optical system and the on-axis distance TTL from the object side surface of the first lens to the image plane of the second optical system satisfy: 1.80 < TTL' / TTL < 2.

50.

4. The virtual reality device according to claim 1, characterized in that, The axial distance TD' from the first side surface of the first lens to the second side surface of the third lens, the total effective focal length f' of the first optical system, the axial distance TD from the object side surface of the first lens to the image side surface of the eighth lens, and the total effective focal length f of the second optical system satisfy: 8.70≤TD' / f'+TD / f<11.

00.

5. The virtual reality device according to claim 1, characterized in that, The on-axis distance TTL' from the first side surface of the first lens to the image plane of the first optical system, the effective focal length f1' of the first element group, the on-axis distance TTL from the object side surface of the first lens to the image plane of the second optical system, and the effective focal length f8 of the eighth lens satisfy: 2.86≤TTL' / f1'+TTL / f8<4.

30.

6. The virtual reality device according to claim 1, characterized in that, The second optical system further includes a second aperture stop, wherein the center thickness CT1' of the first lens on the first optical axis, the center thickness CT2' of the second lens on the first optical axis, the center thickness CT3' of the third lens on the first optical axis and the on-axis distance SD from the second aperture stop to the image side of the eighth lens satisfy: 2.30 < (CT1' + CT2' + CT3') / SD ≤ 3.

25.

7. The virtual reality device according to claim 1, characterized in that, The total effective focal length f' of the first optical system and the effective focal length f1 of the first lens satisfy the condition: -5.30 < f' / f1 ≤ -3.

72.

8. The virtual reality device according to any one of claims 1-7, characterized in that, The center thickness CT4 of the fourth lens on the second optical axis, the center thickness CT5 of the fifth lens on the second optical axis, the radius of curvature R8 of the image side of the fourth lens and the radius of curvature R10 of the image side of the fifth lens satisfy: -0.45≤(CT4+CT5) / (R8+R10)<-0.

35.

9. The virtual reality device according to any one of claims 1-7, characterized in that, The effective focal length f1 of the first lens, the effective focal length f2 of the second lens, the effective focal length f7 of the seventh lens, and the effective focal length f8 of the eighth lens satisfy the following condition: 2.70 ≤ (f1 / f2) × (f7 / f8) < 3.

60.

10. The virtual reality device according to any one of claims 1-7, characterized in that, The radius of curvature R2 of the image side of the first lens, the radius of curvature R3 of the object side of the second lens, and the radius of curvature R4 of the image side of the second lens satisfy: -8.95≤(R2+R3) / R4≤-3.

16.

11. The virtual reality device according to any one of claims 1-7, characterized in that, The radius of curvature R1 of the object side of the first lens, the Abbe number V1 of the first lens, the radius of curvature R16 of the image side of the eighth lens, and the Abbe number V8 of the eighth lens satisfy: 0.90≤(R1×V1) / (R16×V8)≤2.

55.

12. The virtual reality device according to any one of claims 1-7, characterized in that, The effective focal length f7 of the seventh lens and the refractive index N7 of the seventh lens satisfy the following condition: 2.76mm≤f7 / N7≤4.51mm.

13. The virtual reality device according to any one of claims 1-7, characterized in that, The effective focal length f8 of the eighth lens, the radius of curvature R15 of the object side of the eighth lens, and the radius of curvature R16 of the image side of the eighth lens satisfy: 1.66≤f8 / (R16-R15)≤2.

03.

14. The virtual reality device according to any one of claims 1-7, characterized in that, The effective focal length f3 of the third lens, the effective focal length f4 of the fourth lens, and the effective focal length f5 of the fifth lens satisfy the following condition: 2.20 < (f3 + f4) / f5 < 2.

50.

15. The virtual reality device according to any one of claims 1-7, characterized in that, The center thickness CT4 of the fourth lens on the second optical axis, the center thickness CT5 of the fifth lens on the second optical axis, and the center thickness CT6 of the sixth lens on the second optical axis satisfy: 7.90≤(CT4+CT5) / CT6≤11.

00.

16. The virtual reality device according to any one of claims 1-7, characterized in that, The radius of curvature R1 of the object side of the first lens, the radius of curvature R2 of the image side of the first lens, and the combined focal length f12 of the first lens and the second lens satisfy: -8.90≤(R1+R2) / f12<-6.40.

Images