CN220340488U

CN220340488U - Virtual reality device

Info

Publication number: CN220340488U
Application number: CN202321180635.5U
Authority: CN
Inventors: 张晓彬; 宋立通; 丁海洋; 游金兴; 金银芳; 赵烈烽
Original assignee: Zhejiang Sunny Optics Co Ltd
Current assignee: Zhejiang Sunny Optics Co Ltd
Priority date: 2023-05-15
Filing date: 2023-05-15
Publication date: 2024-01-12
Anticipated expiration: 2033-05-15

Abstract

The application discloses a virtual reality device, including first optical system and second optical system. The first optical system sequentially comprises an optical filter, a reflective polarizing element, a quarter wave plate, a first lens and a second lens from the eye side to the image side along a first optical axis, wherein the first lens has positive optical power or negative optical power, and the second lens has positive optical power or negative optical power. The second optical system sequentially comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens with focal power from the object side to the image side along a second optical axis, wherein the first lens has negative focal power, the second lens has positive focal power, and the third lens has positive focal power. The second optical system is used for projecting a virtual image on the display screen and transmitting the real image on the display screen. The virtual reality device satisfies: 0 < |f1B+f5B|/fA < 3 and 0 < (Ct1A+Ct2A)/(|R9B+R10B|) are < 5.1.

Description

Virtual reality device

Technical Field

The present application relates to the field of optical elements, and in particular, to a virtual reality device.

Background

With the development of virtual reality technology, virtual reality devices are widely used in various fields. In general, a virtual reality apparatus includes at least one optical system of an eyepiece for providing immersion, a perspective lens for interacting with reality, a positioning lens for capturing motion, a face recognition lens for constructing an expression, and the like.

Currently, most manufacturers often configure a plurality of different kinds of optical systems on different virtual reality devices in order to enhance the immersion of the virtual reality devices and improve the user experience. However, how to improve the performance of the optical system by optimizing the architecture of a plurality of optical systems to improve the user experience of the virtual reality device has become one of the challenges to be solved by many optical system designers.

Disclosure of Invention

The present application provides such a virtual reality device. The virtual reality device includes a first optical system and a second optical system. The first optical system sequentially comprises an optical filter, a reflective polarizing element, a quarter wave plate, a first lens and a second lens from the eye side to the image side along a first optical axis, wherein the first lens has positive optical power or negative optical power, and the second lens has positive optical power or negative optical power. The second optical system sequentially comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens with focal power from the object side to the image side along a second optical axis, wherein the first lens has negative focal power, the second lens has positive focal power, and the third lens has positive focal power. The second optical system is used for projecting a virtual image on the display screen and transmitting the real image on the display screen. The virtual reality device can satisfy: 0 < |f1B+f5B|/fA < 3 and 0 < (C1A+C2A)/(|R9B+R10B|) are < 5.1, wherein fA is the effective focal length of the first optical system, f1B is the effective focal length of the first lens, f5B is the effective focal length of the fifth lens, CT1A is the center thickness of the first lens on the first optical axis, CT2A is the center thickness of the second lens on the first optical axis, R9B is the radius of curvature of the object side of the fifth lens, and R10B is the radius of curvature of the image side of the fifth lens.

In one embodiment, at least one of the object-side surface of the first lens to the image-side surface of the fifth lens is an aspherical mirror surface.

In one embodiment, the virtual reality device may satisfy: 26 < R1A/(R1B+R2B) < 134, where R1A is the radius of curvature of the near-eye side of the first lens, R1B is the radius of curvature of the object side of the first lens, and R2B is the radius of curvature of the image side of the first lens.

In one embodiment, the virtual reality device may satisfy: 3 < FG 2A/(f2B+f3B) < 4, where FG2A is the combined focal length of the quarter-wave plate and the first lens, f2B is the effective focal length of the second lens, and f3B is the effective focal length of the third lens.

In one embodiment, the virtual reality device may satisfy: 3 < R2A/(R3B+R4B) < 12, wherein R2A is the radius of curvature of the near image side of the first lens element, R3B is the radius of curvature of the object side of the second lens element, and R4B is the radius of curvature of the image side of the second lens element.

In one embodiment, the virtual reality device may satisfy: 1.2 < CT 2A/(T45B+CT5B) < 3.7, wherein CT2A is the center thickness of the second lens on the first optical axis, T45B is the air gap of the fourth lens and the fifth lens on the second optical axis, and CT5B is the center thickness of the fifth lens on the second optical axis.

In one embodiment, the virtual reality device may satisfy: 7 < |R3A|/(C1A+CTQA) < 30.5, wherein R3A is the radius of curvature of the near-eye side of the second lens, CT1A is the center thickness of the first lens on the first optical axis, and CTQA is the center thickness of the quarter wave plate on the first optical axis.

In one embodiment, the virtual reality device may satisfy: 9.3 < TDA/(CTFA+CTRA+CTQA) < 15, wherein TDA is the distance on the first optical axis between the near-eye side of the first lens and the near-image side of the second lens, CTFA is the center thickness of the optical filter on the first optical axis, CTRA is the center thickness of the reflective polarizing element on the first optical axis, and CTQA is the center thickness of the quarter-wave plate on the first optical axis.

In one embodiment, the virtual reality device may satisfy: 1.7 < (R6B-R5B)/(R7 B+R8B) < 2.7, wherein R5B is the radius of curvature of the object side of the third lens, R6B is the radius of curvature of the image side of the third lens, R7B is the radius of curvature of the object side of the fourth lens, and R8B is the radius of curvature of the image side of the fourth lens.

In one embodiment, the virtual reality device may satisfy: 6.8 < (fA/EPDA) × (fB/EPDB) < 8.8, wherein fA is the effective focal length of the first optical system, EPDA is the entrance pupil diameter of the first optical system, fB is the effective focal length of the second optical system, and EPDB is the entrance pupil diameter of the second optical system.

In one embodiment, the virtual reality device may satisfy: 3.5 < (fA×tan (FOVA/2))/(fB×tan (FOVB/2)) < 11, where fA is the effective focal length of the first optical system, FOVA is the maximum field angle of the first optical system, fB is the effective focal length of the second optical system, and FOVB is the maximum field angle of the second optical system.

In one embodiment, the virtual reality device may satisfy: 2.1mm < TDA/(tan (FOVB/2)) < 8.6mm, where TDA is the distance on the first optical axis from the near-eye side of the first lens to the near-image side of the second lens, and FOVB is the maximum field angle of the second optical system.

In one embodiment, the object side surface of the second lens element is concave, and the image side surface is convex; and the object side surface of the third lens is a convex surface, and the image side surface is a convex surface.

In one embodiment, the reflective polarizer is attached to the near-image side of the filter; and the quarter wave plate is attached to the near human eye side of the first lens.

In one embodiment, the virtual reality device further comprises a partially reflective element attached to the near image side of the first lens, the near eye side of the second lens, or the near image side of the second lens.

In the exemplary embodiment of the application, by reasonably setting the architecture of the first optical system and the second optical system and setting the optical power of each lens and the optical technical parameters 0 < |f1b+f5b|/fA < 3 and 0 < (CT 1a+ct2a)/(|r9b+r10b|) to < 5.1, the first optical system can have a shorter length, the second optical system has a larger angle of view, and aberration generated by the first lens and the fifth lens in the second optical system can be compensated, so that the performance of the second optical system and the user experience of the virtual reality device can be improved.

Drawings

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

fig. 1 is a schematic structural view of a virtual reality device according to an exemplary embodiment of the present application;

fig. 2A and 2B are schematic structural views of a virtual reality device according to first and second viewing angles, respectively, according to an exemplary embodiment of this application;

fig. 3 is a schematic structural view of the first optical system in embodiment 1;

fig. 4A to 4C show an on-axis chromatic aberration curve, an astigmatism curve, and a distortion curve of the first optical system of embodiment 1, respectively;

fig. 5 is a schematic structural diagram of the first optical system in embodiment 2;

fig. 6A to 6C show an on-axis chromatic aberration curve, an astigmatism curve, and a distortion curve of the first optical system of embodiment 2, respectively;

fig. 7 is a schematic structural diagram of a first optical system in embodiment 3;

fig. 8A to 8C show an on-axis chromatic aberration curve, an astigmatism curve, and a distortion curve of the first optical system of embodiment 3, respectively;

fig. 9 is a schematic structural diagram of a second optical system in embodiment 4;

fig. 10A to 10C show an on-axis chromatic aberration curve, an astigmatism curve, and a distortion curve of the second optical system of embodiment 4, respectively;

Fig. 11 is a schematic structural diagram of a second optical system in embodiment 5;

fig. 12A to 12C show an on-axis chromatic aberration curve, an astigmatism curve, and a distortion curve of the second optical system of embodiment 5, respectively;

fig. 13 is a schematic structural diagram of a second optical system in embodiment 6;

fig. 14A to 14C show an on-axis chromatic aberration curve, an astigmatism curve, and a distortion curve of the second optical system of embodiment 6, respectively;

fig. 15 is a schematic structural diagram of a second optical system in embodiment 7;

fig. 16A to 16C show an on-axis chromatic aberration curve, an astigmatism curve, and a distortion curve of the second optical system of embodiment 7, respectively;

fig. 17 is a schematic structural diagram of a second optical system in embodiment 8;

fig. 18A to 18C show an on-axis chromatic aberration curve, an astigmatism curve, and a distortion curve of the second optical system of embodiment 8, respectively;

fig. 19 is a schematic structural view of a second optical system in embodiment 9; and

fig. 20A to 20C show an on-axis chromatic aberration curve, an astigmatism curve, and a distortion curve of the second optical system of embodiment 9, respectively.

Detailed Description

For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed description are merely illustrative of exemplary embodiments of the application and are not intended to limit the scope of the application in any way. Like reference numerals refer to like elements throughout the specification. The expression "and/or" includes any and all combinations of one or more of the associated listed items.

It should be noted that in the present specification, the expressions of first, second, third, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the feature. Accordingly, a first lens discussed below may also be referred to as a second lens, and a first lens may also be referred to as a second lens or a third lens, without departing from the teachings of the present application.

In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for convenience of explanation. In particular, the spherical or aspherical shape shown in the drawings is shown by way of example. That is, the shape of the spherical or aspherical surface is not limited to the shape of the spherical or aspherical surface shown in the drawings. The figures are merely examples and are not drawn to scale.

Herein, the paraxial region refers to a region near the first optical axis or the second optical axis. If the lens and/or lens surface is convex and the convex location is not defined, then it is meant 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 concave position is not defined, it is meant that the lens and/or lens surface is concave to at least the paraxial region. The human eye side refers to, for example, a side close to the eyes of a user, and the image side refers to, for example, a side close to a display screen, wherein the display screen may have an image surface thereon. The surface of each lens closest to the eye side is referred to as the near eye side of the lens, and the surface of each lens closest to the image side is referred to as the near image side of the lens. The surface of each lens closest to the object is referred to as the object side of the lens, and the surface of each lens closest to the imaging plane is referred to as the image side of the lens.

It will be further understood that the terms "comprises," "comprising," "includes," "including," "having," "containing," and/or "including," when used in this specification, specify the presence of stated features, elements, and/or components, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof. Furthermore, when a statement such as "at least one of the following" appears after a list of features that are listed, the entire listed feature is modified instead of modifying a separate element in the list. Furthermore, when describing embodiments of the present application, use of "may" means "one or more embodiments of the present application. Also, the term "exemplary" is intended to refer to an example or illustration.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other. The following examples merely represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the present application. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which fall within the protection scope of the present application, for example, any combination between the first optical system and the second optical system in the embodiments of the present application can be made. Specifically, any of the first optical systems in embodiments 1 to 3 may be combined with any of the second optical systems in embodiments 4 to 9. In other words, the virtual reality device provided in the present application may include any of the first optical systems of embodiments 1 to 3 and any of the second optical systems of embodiments 4 to 9. The present application will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

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

As shown in fig. 1 to 2B, a virtual reality device 100 according to an exemplary embodiment of the present application may include a first optical system 110 and a second optical system 120. For example, the virtual reality device 100 may include two first optical systems 110 and one second optical system 120, wherein the two first optical systems 110 may correspond to the left and right eyes of the user, respectively. For example, as shown in fig. 1, the virtual reality device 100 may also include other optical systems, such as optical system 130 for recognizing facial expressions. It should be understood that the present application exemplifies only the number of optical systems in the virtual reality device 100, and does not specifically limit the number of optical systems in the virtual reality device 100.

The second optical system 120 can capture a real image to form a real image on the imaging surface, wherein the real image formed by the second optical system 120 is transmitted to the display screen in the form of an electrical signal. The image surface of the first optical system 110 may be located on the display screen. The first optical system 110 may be used to project a virtual image on a display screen and a real image transferred to the display screen. Specifically, the first optical system 110 can project the virtual image on the display screen, such as into the eyes of the user, to enhance the immersion of the user. The real image formed by the second optical system 120 can pass through the first optical system 110 through the display screen and be projected, for example, into the eyes of the user, so as to finally realize that the user sees the image combining the virtual and the real images. The virtual reality device 100 provided by the application can combine the immersion of the first optical system 110 with the perspective function of the second optical system 120 to realize the interaction between the real world and the virtual world of the virtual device, so that the virtual device is not limited by space any more.

In an exemplary embodiment, the first optical system includes, in order from the human eye side to the image side along the first optical axis, a filter, a reflective polarizing element, a quarter-wave plate, a first lens, and a second lens. The reflective polarizer may be attached to the near image side of the filter. The quarter wave plate may be attached to the near-eye side of the first lens. The filter may be planar, for example, to facilitate attachment of the reflective polarizing element to the filter. In the present application, when light passes through the reflective polarizing element, the reflective polarizing element may reflect light in a certain direction and may transmit light orthogonal to the reflected light. The quarter wave plate can be used for converting between circularly polarized light and linearly polarized light so as to realize the refraction and reflection of the light path, and the length of the first optical system is shortened.

In an exemplary embodiment, the first optical system according to the present application further comprises a diaphragm arranged at the eye side. The eyes of the user can watch the image projected by the image surface at the position of the aperture, namely, the image light on the image surface is finally projected to the eyes of the user after being refracted and reflected for many times by the second lens, the first lens, the quarter wave plate, the reflective polarizing element and the like. According to the optical system projection system, the reflection type polarizing element, the quarter wave plate, the partial reflecting element and the plurality of lenses such as the first lens and the second lens are reasonably arranged, and the length of the lens group required by the projection of the first optical system can be compressed by utilizing the light reflection and/or refraction mode on the premise of not affecting the projection quality.

In an exemplary embodiment, the second optical system includes five lenses having optical power, which are a first lens, a second lens, a third lens, a fourth lens, and a fifth lens, respectively. The five lenses are arranged in order from the object side to the image side along the second optical axis. Any two adjacent lenses in the first lens to the fifth lens can have a spacing distance.

In exemplary embodiments, the first lens may have positive or negative optical power; the second lens may have positive or negative optical power; the first lens may have a negative optical power; the second lens may have positive optical power; the third lens may have positive optical power; the fourth lens may have positive or negative optical power; the fifth lens may have positive or negative optical power. For example, the quarter wave plate and first lens combination can have positive optical power.

In an exemplary embodiment, a virtual reality device according to this application may satisfy: 0 < |f1B+f5B|/fA < 3 and 0 < (C1A+C2A)/(|R9B+R10B|) are < 5.1, wherein fA is the effective focal length of the first optical system, f1B is the effective focal length of the first lens, f5B is the effective focal length of the fifth lens, CT1A is the center thickness of the first lens on the first optical axis, CT2A is the center thickness of the second lens on the first optical axis, R9B is the radius of curvature of the object side of the fifth lens, and R10B is the radius of curvature of the image side of the fifth lens.

In the application, by reasonably setting the architecture of the first optical system and the second optical system and setting the optical power of each lens and the optical technical parameters 0 < |f1B+f5B|/fA < 3 and 0 < (CT 1 A+CT2A)/(|R9B+R10B|) less than 5.1, the first optical system can have a shorter length, the second optical system has a larger angle of view, and aberration phase compensation generated by the first lens and the fifth lens in the second optical system is facilitated, so that the performance of the second optical system and the user experience of the virtual reality device are improved.

In an exemplary embodiment, a virtual reality device according to this application may satisfy: 26 < R1A/(R1B+R2B) < 134, where R1A is the radius of curvature of the near-eye side of the first lens, R1B is the radius of curvature of the object side of the first lens, and R2B is the radius of curvature of the image side of the first lens. The curvature radius of the first lens is controlled to enable the curvature degree of the side surface close to the human eye to be smaller so as to facilitate the attachment of the quarter wave plate, and meanwhile, the curvature radius of the object side surface and the image side surface of the first lens is controlled to control the light rays of the edge view field in the second optical system so as to facilitate the reduction of vignetting of the edge view field and the increase of the light intensity of the edge view field.

In an exemplary embodiment, a virtual reality device according to this application may satisfy: 3 < FG 2A/(f2B+f3B) < 4, where FG2A is the combined focal length of the quarter-wave plate and the first lens, f2B is the effective focal length of the second lens, and f3B is the effective focal length of the third lens. Satisfying 3 < FG 2A/(f2B+f3B) < 4, the light height in the first optical system can be compressed by the quarter wave plate and the first lens by controlling the ratio of the combined focal length of the quarter wave plate and the first lens to the effective focal length of the second lens and the third lens, so as to reduce the image surface size, and simultaneously, the light passing through the first lens can be compressed by the combination of the second lens and the third lens, so that the chip size is reduced.

In an exemplary embodiment, a virtual reality device according to this application may satisfy: 3 < R2A/(R3B+R4B) < 12, wherein R2A is the radius of curvature of the near image side of the first lens element, R3B is the radius of curvature of the object side of the second lens element, and R4B is the radius of curvature of the image side of the second lens element. Satisfies 3 < R2A/(R3B+R4B) < 12, and the shapes of the first lens and the second lens can be reasonably controlled by controlling the curvature radius of the first lens and the curvature radius of the object side surface and the image side surface of the second lens, so that the uniformity of the first lens and the second lens is ensured, and the risk of the influence of the first lens and the second lens on the performance of the first optical system and the second optical system is reduced.

In an exemplary embodiment, a quasi-reality device according to the present application may satisfy: 1.2 < CT 2A/(T45B+CT5B) < 3.7, wherein CT2A is the center thickness of the second lens on the first optical axis, T45B is the air gap of the fourth lens and the fifth lens on the second optical axis, and CT5B is the center thickness of the fifth lens on the second optical axis. The method satisfies that CT 2A/(T45B+CT5B) < 3.7, can improve the molding of the second lens, the fourth lens and the fifth lens by controlling the ratio of the medium thickness of the second lens, the air gap between the fourth lens and the fifth lens and the medium thickness of the fifth lens, and simultaneously can ensure that the first optical system and the second optical system are compact in structure, and can reduce the length of the optical system while ensuring that the lenses and the lenses can be molded so as to satisfy the requirement of lightening and thinning of the virtual reality device.

In an exemplary embodiment, a virtual reality device according to this application may satisfy: 7 < |R3A|/(C1A+CTQA) < 30.5, wherein R3A is the radius of curvature of the near-eye side of the second lens, CT1A is the center thickness of the first lens on the first optical axis, and CTQA is the center thickness of the quarter wave plate on the first optical axis. Satisfies 7 < |R3A|/(C1A+CTQA) < 30.5, the trend of light in the first optical system can be controlled by controlling the curvature radius of the second lens, the middle thickness of the first lens and the middle thickness of the quarter wave plate, the height of off-axis vision field light is reduced, the reflection between the second lens and the image surface is reduced, and further the intensity of ghost images is reduced.

In an exemplary embodiment, a virtual reality device according to this application may satisfy: 9.3 < TDA/(CTFA+CTRA+CTQA) < 15, wherein TDA is the distance on the first optical axis between the near-eye side of the first lens and the near-image side of the second lens, CTFA is the center thickness of the optical filter on the first optical axis, CTRA is the center thickness of the reflective polarizing element on the first optical axis, and CTQA is the center thickness of the quarter-wave plate on the first optical axis. The refractive-back length of the first optical system can be ensured by controlling the ratio of the distance from the near human eye side surface of the first lens to the near image side surface of the second lens on the first optical axis, the middle thickness of the optical filter, the center thickness of the reflective polarizing element and the center thickness of the quarter wave plate to be less than 9.3/(CTFA+CTRA+CTQA) < 15, so that the whole height of the virtual reality device can be compressed.

In an exemplary embodiment, a virtual reality device according to this application may satisfy: 1.7 < (R6B-R5B)/(R7 B+R8B) < 2.7, wherein R5B is the radius of curvature of the object side of the third lens, R6B is the radius of curvature of the image side of the third lens, R7B is the radius of curvature of the object side of the fourth lens, and R8B is the radius of curvature of the image side of the fourth lens. Satisfying 1.7 < (R6B-R5B)/(R7 B+R8B) < 2.7, the object-side and image-side surface profiles of the third lens and fourth lens can be constrained by controlling the radius of curvature of the object-side and image-side surfaces of the third lens and fourth lens, ensuring the uniformity and workability of the third lens and fourth lens.

In an exemplary embodiment, a virtual reality device according to this application may satisfy: 6.8 < (fA/EPDA) × (fB/EPDB) < 8.8, wherein fA is the effective focal length of the first optical system, EPDA is the entrance pupil diameter of the first optical system, fB is the effective focal length of the second optical system, and EPDB is the entrance pupil diameter of the second optical system. Satisfying 6.8 < (fA/EPDA) × (fB/EPDB) < 8.8, the decrease in the distortion performance of the pupil moving image when the human eye rotates can be reduced by controlling the effective focal length and entrance pupil diameter of the first optical system, while the luminous flux of the second optical system can be controlled such as to increase the luminous flux of the second optical system by controlling the effective focal length and entrance pupil diameter of the second optical system, thereby contributing to the improvement of the brightness of the image.

In an exemplary embodiment, a virtual reality device according to this application may satisfy: 3.5 < (fA×tan (FOVA/2))/(fB×tan (FOVB/2)) < 11, where fA is the effective focal length of the first optical system, FOVA is the maximum field angle of the first optical system, fB is the effective focal length of the second optical system, and FOVB is the maximum field angle of the second optical system. Satisfying 3.5 < (fA×tan (FOVA/2))/(fB×tan (FOVB/2)) < 11, the image plane size of the first optical system and the chip size of the second optical system can be controlled by controlling the effective focal lengths and the maximum field angles of the first optical system and the second optical system. In the virtual reality device, the image information on the chip of the second optical system can be transferred to the image surface of the first optical system, so that the image information can enter human eyes, and the image conversion between the two optical systems is facilitated by controlling the ratio.

In an exemplary embodiment, a virtual reality device according to this application may satisfy: 2.1mm < TDA/(tan (FOVB/2)) < 8.6mm, where TDA is the distance on the first optical axis from the near-eye side of the first lens to the near-image side of the second lens, and FOVB is the maximum field angle of the second optical system. The method satisfies that TDA/(tan (FOVB/2)) < 8.6mm is less than 2.1mm, and the ratio of the distance from the near human eye side surface of the first lens to the near image side surface of the second lens on the first optical axis to the maximum field angle of the second optical system is controlled, so that the TDA is smaller and the FOVB is larger, thereby being beneficial to satisfying the 'thin' characteristic of the first optical system and the large field of view of the second optical system.

In an exemplary embodiment, in the second optical system, the object side surface of the second lens may be a concave surface and the image side surface may be a convex surface; and the object-side surface of the third lens element may be convex, and the image-side surface of the third lens element may be convex. The utility model discloses a through rationally setting up the optical power and the shape of thing side and image side of second lens and third lens, be favorable to second lens and third lens when converging light, still do benefit to the angle of view that increases second optical system, reduce virtual reality device's boundary effect.

In an exemplary embodiment, in the first optical system, the partially reflective element may be attached to the near-image side of the first lens, the near-eye side of the second lens, or the near-image side of the second lens. The partially reflective element BS, for example but not limited to, is a semi-transparent semi-reflective film layer, which may be configured to allow a portion of light to be transmitted and another portion to be reflected when light passes through.

In an exemplary embodiment, the second optical system according to the present application may further include a filter for correcting color deviation and/or a protective glass for protecting the photosensitive element located at the image side. The second optical system according to the above-described embodiment of the present application may employ a plurality of lenses, for example, five lenses as described above. By reasonably distributing the structure of each lens, the axial spacing between each lens and the like, the volume of the second optical system can be effectively reduced, and the workability of the second optical system can be improved, so that the second optical system is more beneficial to production and processing and can be suitable for portable electronic products.

In an embodiment of the present application, at least one of the mirrors of each lens and/or lens is an aspherical mirror, i.e. at least one of the near-eye side of the first lens to the near-image side of the second lens is an aspherical mirror, and at least one of the object side of the first lens to the image side of the fifth lens is an aspherical mirror. The aspherical mirror and/or the lens are characterized in that: the curvature is continuously variable from the center of the optic and/or lens to the periphery of the optic and/or lens. Unlike spherical lenses and/or lenses, which have a constant curvature from the center of the lens and/or lens to the periphery of the lens and/or lens, aspherical lenses and/or lenses have better radius of curvature characteristics, with the advantage of improving distortion aberration and improving astigmatic aberration. By adopting the aspherical lens and/or the lens, aberration generated during imaging or projection can be eliminated as much as possible, and imaging or projection quality can be improved. Optionally, at least one of the near-eye side to near-image side of the first lens and the second lens is an aspherical mirror, and at least one of the object side and the image side of each of the first lens, the second lens, the third lens, the fourth lens and the fifth lens is an aspherical mirror. Optionally, the object side and the image side of the first lens, the second lens, the third lens, the fourth lens and the fifth lens are aspheric mirrors.

However, those skilled in the art will appreciate that the various results and advantages described in this specification can be obtained by varying the number of lenses constituting the first optical system and the number of lenses constituting the second optical system without departing from the technical solution claimed in this application. For example, although the description has been made taking an example in which the first optical system includes two lenses and the second optical system includes five lenses in the embodiment, the first optical system is not limited to including two lenses and the second optical system is not limited to including five lenses. The first optical system and/or the second optical system may also include other numbers of lenses or lenses, if desired.

Specific examples of the first optical system or the second optical system applicable to the above-described embodiments are further described below with reference to the drawings.

Example 1

The first optical system in the virtual reality device according to embodiment 1 of this application is described below with reference to fig. 3 to 4C. It is to be understood that the second optical system in the virtual reality device may be any one of the second optical systems provided in embodiments 4 to 9 below. Fig. 3 is a schematic structural diagram of the first optical system in embodiment 1.

As shown in fig. 3, the first optical system sequentially includes, from a human eye side to an image side: stop STO, filter IR, reflective polarizer RP, quarter wave plate QWP, first lens L1, second lens L2, partial reflector BS, and image plane IMG.

The side face of the optical filter IR near the human eye is a plane, and the side face near the image is a plane. The near-eye side surface of the first lens L1 is convex, and the near-image side surface is convex. The near-eye side surface of the second lens L2 is a concave surface, and the near-image side surface is a convex surface. The reflective polarizer RP is attached to the near-image side of the filter IR. The quarter wave plate QWP is attached to the near-eye side of the first lens L1. The partial reflecting element BS is attached to the near image side of the second lens L2.

In this example, after the image light from the image plane IMG sequentially passes through the second lens L2, the first lens L1, the quarter-wave plate QWP and reaches the reflective polarizing element RP, the first reflection occurs at the reflective polarizing element RP. After the light reflected for the first time passes through the quarter wave plate QWP, the first lens L1, and reaches the partially reflecting element BS on the near image side of the second lens L2, the second reflection occurs at the partially reflecting element BS. The light reflected for the second time passes through the second lens L2, the first lens L1, the quarter wave plate QWP, the reflective polarizing element RP, and the filter IR in this order and is finally projected onto a target object (not shown) in space. For example, when the virtual reality device is mounted on an electronic device such as VR, the light reflected twice is finally projected to the eyes of the experimenter.

Table 1 shows a basic parameter table of the first optical system of embodiment 1, in which the unit of curvature radius and thickness/distance is millimeter (mm). Image light from the image plane IMG passes through the respective components in the order of sequence number 20 to sequence number 1 and is finally projected into a target object in space such as human eyes.

TABLE 1

In this example, the combined focal length FG2A of the quarter-wave plate and the first lens is 23.43mm, the effective focal length fA of the first optical system is 23.60mm, the entrance pupil diameter EPDA of the first optical system is 4.00mm, the maximum field angle FOVA of the first optical system is 106.00 °, the distance TDA from the near-human eye side of the first lens to the near-image side of the second lens on the first optical axis is 14.99mm, the center thickness CTFA of the filter on the first optical axis is 0.64mm, the center thickness CTRA of the reflective polarizing element on the first optical axis is 0.16mm, and the center thickness CTQA of the quarter-wave plate on the first optical axis is 0.40mm.

In embodiment 1, the near image side of the first lens L1 is aspheric, and the surface shape x of the aspheric lens can be defined by, but not limited to, the following aspheric formula:

wherein x is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at the position with the height h along the first optical axis direction; c is the paraxial curvature of the aspheric surface, c=1/R (i.e., paraxial curvature c is the inverse of radius of curvature R in table 1 above); k is a conic coefficient; ai is the correction coefficient of the aspherical i-th order. Table 2 below shows the higher order coefficients A that can be used for each of the aspherical mirrors in example 1 ₄ 、A ₆ 、A ₈ 、A ₁₀ 、A ₁₂ 、A ₁₄ 、A ₁₆ 、A ₁₈ And A ₂₀ 。

TABLE 2

Fig. 4A shows an on-axis chromatic aberration curve of the first optical system of embodiment 1, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the first optical system. Fig. 4B shows an astigmatism curve of the first optical system of embodiment 1, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 4C shows a distortion curve of the first optical system of embodiment 1, which represents distortion magnitude values corresponding to different angles of view. As can be seen from fig. 4A to 4C, the first optical system in embodiment 1 can achieve good projection quality.

Example 2

A first optical system in a virtual reality device according to embodiment 2 of this application is described below with reference to fig. 5 to 6C. It is to be understood that the second optical system in the virtual reality device may be any one of the second optical systems provided in embodiments 4 to 9 below. In this embodiment and the following embodiments, descriptions of portions similar to embodiment 1 will be omitted for brevity. Fig. 5 is a schematic structural diagram of the first optical system in embodiment 2.

As shown in fig. 5, the first optical system sequentially includes, from a human eye side to an image side: stop STO, filter IR, reflective polarizer RP, quarter wave plate QWP, first lens L1, partial reflector BS, second lens L2, and image plane IMG.

The side face of the optical filter IR near the human eye is a plane, and the side face near the image is a plane. The near-eye side surface of the first lens L1 is convex, and the near-image side surface is convex. The near-eye side surface of the second lens L2 is a concave surface, and the near-image side surface is a convex surface. The reflective polarizer RP is attached to the near-image side of the filter IR. The quarter wave plate QWP is attached to the near-eye side of the first lens L1. The partial reflecting element BS is attached to the near image side of the first lens L1.

In this example, after the image light from the image plane IMG sequentially passes through the second lens L2, the first lens L1, the quarter-wave plate QWP and reaches the reflective polarizing element RP, the first reflection occurs at the reflective polarizing element RP. After the light reflected for the first time passes through the quarter wave plate QWP and reaches the partially reflecting element BS on the near image side of the first mirror L1, the second reflection occurs at the partially reflecting element BS. The light reflected the second time passes through the first lens L1, the quarter wave plate QWP, the reflective polarizing element RP, and the filter IR in this order and is finally projected onto a target object (not shown) in space. For example, when the virtual reality device is mounted on an electronic device such as VR, the light reflected twice is finally projected to the eyes of the experimenter.

In this example, the combined focal length FG2A of the quarter-wave plate and the first lens is 25.36mm, the effective focal length fA of the first optical system is 25.20mm, the entrance pupil diameter EPDA of the first optical system is 4.50mm, the maximum field angle FOVA of the first optical system is 106.00 °, the distance TDA from the near-eye side of the first lens to the near-image side of the second lens on the first optical axis is 10.93mm, the center thickness CTFA of the filter on the first optical axis is 0.72mm, the center thickness CTRA of the reflective polarizing element on the first optical axis is 0.18mm, and the center thickness CTQA of the quarter-wave plate on the first optical axis is 0.27mm.

Table 3 shows a basic parameter table of the first optical system of embodiment 2, in which the unit of curvature radius and thickness/distance is millimeter (mm). Image light from the image plane IMG passes through the components in order of number 16 to number 1 and is finally projected into a target object in space, such as the human eye. Table 4 shows the higher order coefficients that can be used for each of the aspherical mirror surfaces in example 2.

TABLE 3 Table 3

Surface of the body	Near-to-eye side of the second lens L2	Near image side of the second lens L2
			A4	-2.9842E-06	-8.4684E-06
A6	-2.7804E-09	3.5811E-08
			A8	-3.8702E-12	-2.2283E-11
A10	-2.8278E-15	-3.4163E-14
			A12	3.9693E-18	2.4206E-17
A14	0.0000E+00	0.0000E+00
			A16	0.0000E+00	0.0000E+00
A18	0.0000E+00	0.0000E+00
			A20	0.0000E+00	0.0000E+00

TABLE 4 Table 4

Fig. 6A shows an on-axis chromatic aberration curve of the first optical system of embodiment 2, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the first optical system. Fig. 6B shows an astigmatism curve of the first optical system of embodiment 2, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 6C shows a distortion curve of the first optical system of embodiment 2, which represents distortion magnitude values corresponding to different angles of view. As can be seen from fig. 6A to 6C, the first optical system in embodiment 2 can achieve good projection quality.

Example 3

A first optical system in a virtual reality device according to embodiment 3 of this application is described below with reference to fig. 7 to 8C. It is to be understood that the second optical system in the virtual reality device may be any one of the second optical systems provided in embodiments 4 to 9 below. Fig. 7 is a schematic structural diagram of the first optical system in embodiment 3.

As shown in fig. 7, the first optical system sequentially includes, from a human eye side to an image side: stop STO, filter IR, reflective polarizer RP, quarter wave plate QWP, first lens L1, partial reflector BS, second lens L2, and image plane IMG.

The side face of the optical filter IR near the human eye is a plane, and the side face near the image is a plane. The near-eye side surface of the first lens L1 is convex, and the near-image side surface is convex. The near-eye side surface of the second lens L2 is a concave surface, and the near-image side surface is a plane. The reflective polarizer RP is attached to the near-image side of the filter IR. The quarter wave plate QWP is attached to the near-eye side of the first lens L1. The partially reflecting element BS is attached to the near-eye side of the second lens L2.

In this example, after the image light from the image plane IMG sequentially passes through the second lens L2, the first lens L1, the quarter-wave plate QWP and reaches the reflective polarizing element RP, the first reflection occurs at the reflective polarizing element RP. After the light reflected once passes through the quarter wave plate QWP, the first lens L1 and reaches the partially reflecting element BS on the near-eye side of the second lens L2, a second reflection occurs at the partially reflecting element BS. The light reflected the second time passes through the first lens L1, the quarter wave plate QWP, the reflective polarizing element RP, and the filter IR in this order and is finally projected onto a target object (not shown) in space. For example, when the virtual reality device is mounted on an electronic device such as VR, the light reflected twice is finally projected to the eyes of the experimenter.

In this example, the combined focal length FG2A of the quarter-wave plate and the first lens is 25.74mm, the effective focal length fA of the first optical system is 26.41mm, the entrance pupil diameter EPDA of the first optical system is 4.50mm, the maximum field angle FOVA of the first optical system is 106.00 °, the distance TDA from the near-eye side of the first lens to the near-image side of the second lens on the first optical axis is 16.15mm, the center thickness CTFA of the filter on the first optical axis is 0.72mm, the center thickness CTRA of the reflective polarizing element on the first optical axis is 0.18mm, and the center thickness CTQA of the quarter-wave plate on the first optical axis is 0.18mm.

Table 5 shows a basic parameter table of the first optical system of example 3, in which the unit of curvature radius and thickness/distance is millimeter (mm). Image light from the image plane IMG passes through the components in the order of serial number 18 to serial number 1 and is finally projected into a target object in space, such as human eyes. Table 6 shows the higher order coefficients that can be used for each of the aspherical mirror surfaces in example 3.

TABLE 5

Surface of the body	Near image side of the first lens L1
		A4	1.6112E-06
A6	-3.2482E-11
		A8	4.1111E-13
A10	-4.2810E-16
		A12	1.6348E-19
A14	0.0000E+00
		A16	0.0000E+00
A18	0.0000E+00
		A20	0.0000E+00

TABLE 6

Fig. 8A shows an on-axis chromatic aberration curve of the first optical system of embodiment 3, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the first optical system. Fig. 8B shows an astigmatism curve of the first optical system of embodiment 3, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 8C shows a distortion curve of the first optical system of embodiment 3, which represents distortion magnitude values corresponding to different angles of view. As can be seen from fig. 8A to 8C, the first optical system in embodiment 3 can achieve good projection quality.

Example 4

The second optical system in the virtual reality device according to embodiment 4 of this application is described below with reference to fig. 9 to 10C. It should be appreciated that the first optical system in the virtual reality device may be any of the first optical systems provided in embodiments 1 to 3 above. Fig. 9 shows a schematic structural diagram of a second optical system according to embodiment 4 of the present application.

As shown in fig. 9, the second optical system sequentially includes, from an object side to an image side: a first lens E1, a stop STO, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an imaging surface S13.

The first lens element E1 has negative refractive power, wherein an object-side surface S1 thereof is concave, and an image-side surface S2 thereof is concave. The second lens element E2 has positive refractive power, wherein an object-side surface S3 thereof is concave and an image-side surface S4 thereof is convex. The third lens element E3 has positive refractive power, wherein an object-side surface S5 thereof is convex, and an image-side surface S6 thereof is convex. The fourth lens element E4 has positive refractive power, wherein an object-side surface S7 thereof is concave and an image-side surface S8 thereof is convex. The fifth lens element E5 has negative refractive power, wherein an object-side surface S9 thereof is convex and an image-side surface S10 thereof is concave. The filter E6 has an object side surface S11 and an image side surface S12. Light from the object sequentially passes through the respective surfaces S1 to S12 and is finally imaged on the imaging surface S13.

Table 1 shows a basic parameter table of the second optical system of embodiment 1, in which the units of radius of curvature, thickness/distance, and focal length are all millimeters (mm).

TABLE 7

In this example, the effective focal length fB of the second optical system is 1.74mm, the entrance pupil diameter EPDB of the second optical system is 1.40mm, and the maximum field angle FOVB of the second optical system is 153.45 °.

In embodiment 4, the object side surface and the image side surface of any one of the first lens E1 to the fifth lens E5 are aspherical, and the surface profile x of each aspherical lens can be defined by, but not limited to, the following aspherical formula:

wherein x is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at the position with the height h along the second optical axis direction; c is the paraxial curvature of the aspheric surface, c=1/R (i.e., paraxial curvature c is the inverse of radius of curvature R in table 1 above); k is a conic coefficient; ai is the correction coefficient of the aspherical i-th order. The following tables 8-1 and 8-2 give the higher order coefficients A that can be used for each of the aspherical mirror faces S1-S10 in example 4 ₄ 、A ₆ 、A ₈ 、A ₁₀ 、A ₁₂ 、A ₁₄ 、A ₁₆ 、A ₁₈ 、A ₂₀ 、A ₂₂ 、A ₂₄ 、A ₂₆ 、A ₂₈ And A ₃₀ 。

TABLE 8-1

Face number

A18

A20

A22

A24

A26

A28

A30

S1

4.0751E-02

-1.2777E-02

2.8391E-03

-4.3691E-04

4.4285E-05

-2.6591E-06

7.1645E-08

S2

-1.1936E+04

2.1364E+04

-2.6469E+04

2.2342E+04

-1.2265E+04

3.9473E+03

-5.6478E+02

S3

-9.7030E+02

3.7265E+02

-3.8072E+01

0.0000E+00

S4

3.1708E-01

-6.8766E-02

5.9834E-03

0.0000E+00

S5

-9.6825E-03

2.1257E-03

-2.9245E-04

1.8263E-05

0.0000E+00

S6

-3.1720E-01

1.1241E-01

-2.4827E-02

3.1199E-03

-1.7054E-04

0.0000E+00

S7

-6.4738E-01

2.2417E-01

-4.8401E-02

5.9287E-03

-3.1435E-04

0.0000E+00

S8

-3.2740E+01

2.1050E+01

-9.8246E+00

3.2240E+00

-7.0339E-01

9.1436E-02

-5.3523E-03

S9

-4.8436E+01

3.3202E+01

-1.6276E+01

5.5440E+00

-1.2445E+00

1.6538E-01

-9.8477E-03

S10

8.1084E+00

-3.9492E+00

1.3501E+00

-3.1722E-01

4.8777E-02

-4.4173E-03

1.7852E-04

TABLE 8-2

Fig. 10A shows an on-axis chromatic aberration curve of the second optical system of embodiment 4, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the second optical system. Fig. 10B shows an astigmatism curve of the second optical system of embodiment 4, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 10C shows a distortion curve of the second optical system of embodiment 4, which represents distortion magnitude values corresponding to different image heights. As can be seen from fig. 10A to 10C, the second optical system provided in embodiment 4 can achieve good imaging quality.

Example 5

The second optical system in the virtual reality device according to embodiment 5 of this application is described below with reference to fig. 11 to 12C. It should be appreciated that the first optical system in the virtual reality device may be any of the first optical systems provided in embodiments 1 to 3 above. In this embodiment and the following embodiments, descriptions of portions similar to embodiment 4 will be omitted for brevity. Fig. 11 shows a schematic structural diagram of a second optical system according to embodiment 5 of the present application.

As shown in fig. 11, the second optical system sequentially includes, from an object side to an image side: a first lens E1, a stop STO, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an imaging surface S13.

The first lens element E1 has negative refractive power, wherein an object-side surface S1 thereof is concave, and an image-side surface S2 thereof is concave. The second lens element E2 has positive refractive power, wherein an object-side surface S3 thereof is concave and an image-side surface S4 thereof is convex. The third lens element E3 has positive refractive power, wherein an object-side surface S5 thereof is convex, and an image-side surface S6 thereof is convex. The fourth lens element E4 has negative refractive power, wherein an object-side surface S7 thereof is concave and an image-side surface S8 thereof is convex. The fifth lens element E5 has positive refractive power, wherein an object-side surface S9 thereof is convex, and an image-side surface S10 thereof is concave. The filter E6 has an object side surface S11 and an image side surface S12. Light from the object sequentially passes through the respective surfaces S1 to S12 and is finally imaged on the imaging surface S13.

In this example, the effective focal length fB of the second optical system is 1.70mm, the entrance pupil diameter EPDB of the second optical system is 1.15mm, and the maximum field angle FOVB of the second optical system is 124.21 °.

Table 9 shows a basic parameter table of the second optical system of example 5, in which the units of radius of curvature, thickness/distance, and focal length are all millimeters (mm). Tables 10-1 and 10-2 show the higher order coefficients that can be used for each of the aspherical mirror surfaces S1-S10 in example 5.

TABLE 9

Face number

A4

A6

A8

A10

A12

A14

A16

S1

1.7787E-01

-1.7428E-02

-1.6082E-01

2.9414E-01

-2.9601E-01

1.9680E-01

-9.1131E-02

S2

4.5053E-01

-6.2100E+00

1.1038E+02

-1.1322E+03

7.4782E+03

-3.3705E+04

1.0717E+05

S3

1.1877E-01

-2.3050E+00

2.2732E+01

-1.3285E+02

4.8033E+02

-1.0859E+03

1.4940E+03

S4

-1.5916E-02

4.8503E-01

-2.7700E+00

7.6040E+00

-1.2288E+01

1.2244E+01

-7.3980E+00

S5

5.6226E-02

-2.7849E-02

-1.3134E-01

-1.2477E+00

9.3626E+00

-2.9119E+01

5.4881E+01

S6

4.3883E-01

-9.1517E+00

6.0299E+01

-2.3000E+02

5.7513E+02

-9.9853E+02

1.2431E+03

S7

6.3335E-01

-8.2390E+00

6.0418E+01

-2.5244E+02

6.8055E+02

-1.2640E+03

1.6765E+03

S8

-1.9036E-01

3.2772E+00

-1.5983E+01

5.4347E+01

-1.3795E+02

2.5977E+02

-3.5922E+02

S9

-2.9958E-01

1.9635E+00

-8.3719E+00

2.2140E+01

-3.9767E+01

5.0433E+01

-4.5974E+01

S10

1.5606E-01

-1.0710E+00

4.6177E+00

-1.2314E+01

2.1240E+01

-2.5024E+01

2.0888E+01

TABLE 10-1

TABLE 10-2

Fig. 12A shows an on-axis chromatic aberration curve of the second optical system of embodiment 5, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the second optical system. Fig. 12B shows an astigmatism curve of the second optical system of embodiment 5, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 12C shows a distortion curve of the second optical system of embodiment 5, which represents distortion magnitude values corresponding to different image heights. As can be seen from fig. 12A to 12C, the second optical system provided in embodiment 5 can achieve good imaging quality.

Example 6

The second optical system in the virtual reality device according to embodiment 6 of this application is described below with reference to fig. 13 to 14C. It should be appreciated that the first optical system in the virtual reality device may be any of the first optical systems provided in embodiments 1 to 3 above. Fig. 13 shows a schematic structural diagram of a second optical system according to embodiment 6 of the present application.

As shown in fig. 13, the second optical system sequentially includes, from an object side to an image side: a first lens E1, a stop STO, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an imaging surface S13.

In this example, the effective focal length fB of the second optical system is 1.73mm, the entrance pupil diameter EPDB of the second optical system is 1.39mm, and the maximum field angle FOVB of the second optical system is 157.49 °.

Table 11 shows a basic parameter table of the second optical system of example 6, in which the units of radius of curvature, thickness/distance, and focal length are all millimeters (mm). Tables 12-1 and 12-2 show the higher order coefficients that can be used for each of the aspherical mirror surfaces S1-S10 in example 6.

TABLE 11

Face number

A4

A6

A8

A10

A12

A14

A16

S1

2.2321E-01

-1.7400E-01

1.6549E-01

-1.7499E-01

1.8568E-01

-1.7181E-01

1.2557E-01

S2

2.9880E-01

8.9848E-01

-2.0580E+01

2.4351E+02

-1.8193E+03

9.1665E+03

-3.2264E+04

S3

1.3950E-02

-2.6611E-01

1.3912E+00

-4.0157E+00

5.9918E+00

-3.2773E+00

-1.5286E+00

S4

3.3995E-02

-9.1199E-02

1.7773E-01

-2.6831E-01

2.7482E-01

-1.7571E-01

6.2389E-02

S5

3.1289E-02

-6.7758E-02

8.3689E-02

-7.1096E-02

3.8224E-02

-1.2616E-02

2.3598E-03

S6

-2.0062E-01

1.8324E-01

1.2026E-01

-4.0222E-01

3.9443E-01

-2.1641E-01

7.4041E-02

S7

2.3565E-01

-3.4258E-02

-3.7162E-02

5.8437E-02

-7.8251E-02

6.3851E-02

-2.7956E-02

S8

1.4235E-01

1.0248E-01

-1.4720E-01

-1.9132E-01

6.4904E-01

-7.4387E-01

4.6633E-01

S9

-1.6343E-01

1.1878E-01

-8.0955E-03

-3.0342E-01

5.8088E-01

-5.4386E-01

2.7324E-01

S10

1.6150E-01

-5.5349E-01

8.8429E-01

-9.5696E-02

-2.5683E+00

5.6429E+00

-6.6004E+00

TABLE 12-1

Face number

A18

A20

A22

A24

A26

A28

A30

S1

-6.8851E-02

2.7560E-02

-7.8762E-03

1.5586E-03

-2.0249E-04

1.5516E-05

-5.3111E-07

S2

8.0842E+04

-1.4502E+05

1.8488E+05

-1.6352E+05

9.5387E+04

-3.2998E+04

5.1270E+03

S3

1.8628E+00

0.0000E+00

S4

-9.3453E-03

0.0000E+00

S5

-1.9015E-04

0.0000E+00

S6

-1.5949E-02

2.0202E-03

-1.1672E-04

0.0000E+00

S7

6.1285E-03

-5.0128E-04

-9.2754E-06

0.0000E+00

S8

-1.6979E-01

3.3771E-02

-2.8430E-03

0.0000E+00

S9

-5.8312E-02

-6.8814E-03

5.7196E-03

-7.8275E-04

0.0000E+00

S10

4.9795E+00

-2.5603E+00

9.0879E-01

-2.1959E-01

3.4522E-02

-3.1860E-03

1.3101E-04

TABLE 12-2

Fig. 14A shows an on-axis chromatic aberration curve of the second optical system of embodiment 6, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the second optical system. Fig. 14B shows an astigmatism curve of the second optical system of embodiment 6, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 14C shows a distortion curve of the second optical system of embodiment 6, which represents distortion magnitude values corresponding to different image heights. As can be seen from fig. 14A to 14C, the second optical system provided in embodiment 6 can achieve good imaging quality.

Example 7

The second optical system in the virtual reality device according to embodiment 7 of this application is described below with reference to fig. 15 to 16C. It should be appreciated that the first optical system in the virtual reality device may be any of the first optical systems provided in embodiments 1 to 3 above. Fig. 15 shows a schematic structural diagram of a second optical system according to embodiment 7 of the present application.

As shown in fig. 15, the second optical system sequentially includes, from an object side to an image side: a first lens E1, a stop STO, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an imaging surface S13.

The first lens element E1 has negative refractive power, wherein an object-side surface S1 thereof is concave, and an image-side surface S2 thereof is concave. The second lens element E2 has positive refractive power, wherein an object-side surface S3 thereof is concave and an image-side surface S4 thereof is convex. The third lens element E3 has positive refractive power, wherein an object-side surface S5 thereof is convex, and an image-side surface S6 thereof is convex. The fourth lens element E4 has negative refractive power, wherein an object-side surface S7 thereof is concave and an image-side surface S8 thereof is convex. The fifth lens element E5 has positive refractive power, wherein an object-side surface S9 thereof is convex, and an image-side surface S10 thereof is convex. The filter E6 has an object side surface S11 and an image side surface S12. Light from the object sequentially passes through the respective surfaces S1 to S12 and is finally imaged on the imaging surface S13.

In this example, the effective focal length fB of the second optical system is 1.69mm, the entrance pupil diameter EPDB of the second optical system is 1.16mm, and the maximum field angle FOVB of the second optical system is 128.87 °.

Table 13 shows a basic parameter table of the second optical system of example 7, in which the units of radius of curvature, thickness/distance, and focal length are all millimeters (mm). Tables 14-1 and 14-2 show the higher order coefficients that can be used for each of the aspherical mirror surfaces S1-S10 in example 7.

TABLE 13

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TABLE 14-1

Face number

A18

A20

A22

A24

A26

A28

A30

S1

-8.1375E-01

2.2378E-01

-4.4399E-02

6.1850E-03

-5.7364E-04

3.1793E-05

-7.9631E-07

S2

5.3652E+06

-9.7182E+06

1.2647E+07

-1.1519E+07

6.9676E+06

-2.5135E+06

4.0908E+05

S3

-1.6542E+03

6.6747E+02

0.0000E+00

S4

3.3305E-01

-3.9513E-02

0.0000E+00

S5

-1.8858E+02

1.1778E+02

-5.2622E+01

1.6394E+01

-3.3813E+00

4.1474E-01

-2.2895E-02

S6

1.6498E+02

-9.9253E+01

4.2482E+01

-1.2635E+01

2.4831E+00

-2.9004E-01

1.5254E-02

S7

6.7377E+01

-4.4458E+01

2.0187E+01

-6.2306E+00

1.2505E+00

-1.4733E-01

7.7368E-03

S8

1.2482E+01

-6.0083E+00

2.0438E+00

-4.8076E-01

7.4439E-02

-6.8277E-03

2.8112E-04

S9

3.4591E-01

-1.3969E-01

3.9095E-02

-7.4457E-03

9.2090E-04

-6.6686E-05

2.1450E-06

S10

9.7917E-01

-2.9989E-01

6.5084E-02

-9.7172E-03

9.4237E-04

-5.2882E-05

1.2812E-06

TABLE 14-2

Fig. 16A shows an on-axis chromatic aberration curve of the second optical system of embodiment 7, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the second optical system. Fig. 16B shows an astigmatism curve of the second optical system of embodiment 7, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 16C shows a distortion curve of the second optical system of embodiment 7, which represents distortion magnitude values corresponding to different image heights. As can be seen from fig. 16A to 16C, the second optical system according to embodiment 7 can achieve good imaging quality.

Example 8

The second optical system in the virtual reality device according to embodiment 8 of this application is described below with reference to fig. 17 to 18C. It should be appreciated that the first optical system in the virtual reality device may be any of the first optical systems provided in embodiments 1 to 3 above. Fig. 17 shows a schematic structural diagram of a second optical system according to embodiment 8 of the present application.

As shown in fig. 17, the second optical system sequentially includes, from an object side to an image side: a first lens E1, a stop STO, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an imaging surface S13.

In this example, the effective focal length fB of the second optical system is 1.69mm, the entrance pupil diameter EPDB of the second optical system is 1.14mm, and the maximum field angle FOVB of the second optical system is 138.52 °.

Table 15 shows a basic parameter table of the second optical system of example 8, in which the units of radius of curvature, thickness/distance, and focal length are all millimeters (mm). Tables 16-1 and 16-2 show the higher order coefficients that can be used for each of the aspherical mirror surfaces S1-S10 in example 8.

TABLE 15

Face number

A4

A6

A8

A10

A12

A14

A16

S1

2.7074E-01

-1.7256E-01

-3.0000E-02

4.1882E-01

-8.4595E-01

1.0250E+00

-8.4671E-01

S2

4.8783E-01

-3.7795E+00

7.4797E+01

-9.5360E+02

8.1166E+03

-4.7856E+04

2.0011E+05

S3

4.7079E-02

-1.0302E+00

1.5961E+01

-1.4940E+02

8.5000E+02

-2.9607E+03

6.1623E+03

S4

5.8580E-02

-2.1672E-01

4.4972E-01

-7.4777E-01

1.0099E+00

-1.0107E+00

6.6077E-01

S5

8.1071E-02

-3.4031E-01

9.5486E-01

-2.0225E+00

2.9551E+00

-2.5341E+00

3.3421E-01

S6

-1.0714E-01

-1.6982E+00

1.3611E+01

-5.4155E+01

1.3496E+02

-2.2760E+02

2.7112E+02

S7

2.6525E-01

-1.6410E+00

1.2804E+01

-5.3195E+01

1.3639E+02

-2.3447E+02

2.8324E+02

S8

2.3881E-01

-1.4721E+00

1.0474E+01

-4.2046E+01

1.0845E+02

-1.9308E+02

2.4609E+02

S9

-4.2552E-02

-8.8113E-01

5.5257E+00

-1.9149E+01

4.2447E+01

-6.4333E+01

6.9052E+01

S10

2.7000E-01

-1.1579E+00

3.6629E+00

-8.5906E+00

1.4404E+01

-1.7403E+01

1.5342E+01

TABLE 16-1

Face number

A18

A20

A22

A24

A26

A28

A30

S1

4.9512E-01

-2.0717E-01

6.1654E-02

-1.2745E-02

1.7395E-03

-1.4093E-04

5.1322E-06

S2

-6.0099E+05

1.2994E+06

-2.0036E+06

2.1484E+06

-1.5216E+06

6.3975E+05

-1.2089E+05

S3

-7.0309E+03

3.3811E+03

0.0000E+00

S4

-2.4345E-01

3.7900E-02

0.0000E+00

S5

2.1613E+00

-3.0578E+00

2.2409E+00

-1.0129E+00

2.8377E-01

-4.5351E-02

3.1681E-03

S6

-2.3347E+02

1.4648E+02

-6.6481E+01

2.1291E+01

-4.5664E+00

5.8869E-01

-3.4482E-02

S7

-2.4658E+02

1.5610E+02

-7.1426E+01

2.3062E+01

-4.9924E+00

6.5102E-01

-3.8694E-02

S8

-2.2835E+02

1.5465E+02

-7.5651E+01

2.6024E+01

-5.9703E+00

8.1986E-01

-5.0960E-02

S9

-5.3379E+01

2.9813E+01

-1.1912E+01

3.3168E+00

-6.1066E-01

6.6744E-02

-3.2764E-03

S10

-9.9302E+00

4.7079E+00

-1.6137E+00

3.8881E-01

-6.2399E-02

5.9843E-03

-2.5927E-04

TABLE 16-2

Fig. 18A shows an on-axis chromatic aberration curve of the second optical system of embodiment 8, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the second optical system. Fig. 18B shows an astigmatism curve of the second optical system of embodiment 8, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 18C shows a distortion curve of the second optical system of embodiment 8, which represents distortion magnitude values corresponding to different image heights. As can be seen from fig. 18A to 18C, the second optical system provided in embodiment 8 can achieve good imaging quality.

Example 9

The second optical system in the virtual reality device according to embodiment 9 of this application is described below with reference to fig. 19 to 20C. It should be appreciated that the first optical system in the virtual reality device may be any of the first optical systems provided in embodiments 1 to 3 above. Fig. 19 shows a schematic structural view of a second optical system according to embodiment 9 of the present application.

As shown in fig. 19, the second optical system sequentially includes, from an object side to an image side: a first lens E1, a stop STO, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, a filter E6, and an imaging surface S13.

In this example, the effective focal length fB of the second optical system is 1.66mm, the entrance pupil diameter EPDB of the second optical system is 1.12mm, and the maximum field angle FOVB of the second optical system is 125.84 °.

Table 17 shows a basic parameter table of the second optical system of example 9, in which the units of radius of curvature, thickness/distance, and focal length are all millimeters (mm). Tables 18-1 and 18-2 show the higher order coefficients that can be used for each of the aspherical mirror surfaces S1-S10 in example 9.

TABLE 17

Face number

A4

A6

A8

A10

A12

A14

A16

S1

2.7355E-01

-3.0246E-01

4.1559E-01

-4.7359E-01

3.8882E-01

-2.1817E-01

7.9140E-02

S2

-1.6540E+00

5.7676E+01

-9.2013E+02

9.1241E+03

-6.0262E+04

2.7641E+05

-9.0288E+05

S3

4.8310E-02

-5.4677E-01

4.2558E+00

-2.1257E+01

6.9268E+01

-1.4478E+02

1.8599E+02

S4

-6.1927E-02

7.6799E-01

-3.7088E+00

9.5562E+00

-1.4845E+01

1.4328E+01

-8.4076E+00

S5

-6.7445E-02

9.7609E-01

-5.2384E+00

1.6732E+01

-3.6367E+01

5.6698E+01

-6.4759E+01

S6

2.4038E-01

-4.2295E+00

2.3310E+01

-8.0374E+01

1.9018E+02

-3.1967E+02

3.9015E+02

S7

3.6515E-01

-2.2595E+00

1.2238E+01

-4.2685E+01

1.0203E+02

-1.7347E+02

2.1512E+02

S8

-1.2338E-01

2.3320E+00

-1.0985E+01

3.3226E+01

-6.9534E+01

1.0416E+02

-1.1384E+02

S9

-2.4481E-01

1.2031E+00

-4.6673E+00

1.1315E+01

-1.8261E+01

2.0550E+01

-1.6565E+01

S10

-6.6123E-02

4.0155E-01

-1.7103E+00

4.5150E+00

-7.8715E+00

9.4925E+00

-8.1327E+00

TABLE 18-1

Face number

A18

A20

A22

A24

A26

A28

A30

S1

-1.5525E-02

-1.9658E-04

1.0382E-03

-3.0023E-04

4.3857E-05

-3.4095E-06

1.1232E-07

S2

2.1269E+06

-3.6186E+06

4.3987E+06

-3.7192E+06

2.0738E+06

-6.8404E+05

1.0081E+05

S3

-1.3305E+02

4.0382E+01

0.0000E+00

S4

2.7465E+00

-3.8303E-01

0.0000E+00

S5

5.4400E+01

-3.3329E+01

1.4586E+01

-4.3916E+00

8.5091E-01

-9.3206E-02

4.1833E-03

S6

-3.5013E+02

2.3150E+02

-1.1157E+02

3.8134E+01

-8.7557E+00

1.2102E+00

-7.6018E-02

S7

-1.9761E+02

1.3492E+02

-6.7733E+01

2.4286E+01

-5.8777E+00

8.5842E-01

-5.7008E-02

S8

9.1546E+01

-5.4082E+01

2.3175E+01

-7.0048E+00

1.4154E+00

-1.7154E-01

9.4268E-03

S9

9.6914E+00

-4.1227E+00

1.2623E+00

-2.7101E-01

3.8722E-02

-3.3073E-03

1.2777E-04

S10

5.0195E+00

-2.2378E+00

7.1381E-01

-1.5879E-01

2.3386E-02

-2.0487E-03

8.0795E-05

TABLE 18-2

Fig. 20A shows an on-axis chromatic aberration curve of the second optical system of embodiment 9, which indicates a convergent focus deviation of light rays of different wavelengths after passing through the second optical system. Fig. 20B shows an astigmatism curve of the second optical system of embodiment 9, which represents meridional image plane curvature and sagittal image plane curvature. Fig. 20C shows a distortion curve of the second optical system of embodiment 9, which represents distortion magnitude values corresponding to different image heights. As can be seen from fig. 20A to 20C, the second optical system as shown in embodiment 9 can achieve good imaging quality.

To sum up, in an embodiment of the present application, the virtual reality device may include the first optical system in example 1 and the second optical system in example 4. In another embodiment of the present application, the virtual reality device may include the first optical system of example 1 and the second optical system of example 5. In another embodiment of the present application, the virtual reality device may include the first optical system of example 1 and the second optical system of example 6. In another embodiment of the present application, the virtual reality device may include the first optical system of example 1 and the second optical system of example 7. In another embodiment of the present application, the virtual reality device may include the first optical system of example 1 and the second optical system of example 8. In another embodiment of the present application, the virtual reality device may include the first optical system of example 1 and the second optical system of example 9. In another embodiment of the present application, the virtual reality device may include the first optical system of example 2 and the second optical system of example 4. In another embodiment of the present application, the virtual reality device may include the first optical system of example 2 and the second optical system of example 5. In another embodiment of the present application, the virtual reality device may include the first optical system of example 2 and the second optical system of example 6. In another embodiment of the present application, the virtual reality device may include the first optical system of example 2 and the second optical system of example 7. In another embodiment of the present application, the virtual reality device may include the first optical system of example 2 and the second optical system of example 8. In another embodiment of the present application, the virtual reality device may include the first optical system of example 2 and the second optical system of example 9. In another embodiment of the present application, the virtual reality device may include the first optical system of example 3 and the second optical system of example 4. In another embodiment of the present application, the virtual reality device may include the first optical system of example 3 and the second optical system of example 5. In another embodiment of the present application, the virtual reality device may include the first optical system of example 3 and the second optical system of example 6. In another embodiment of the present application, the virtual reality device may include the first optical system of example 3 and the second optical system of example 7. In another embodiment of the present application, the virtual reality device may include the first optical system of example 3 and the second optical system of example 8. In another embodiment of the present application, the virtual reality device may include the first optical system of example 3 and the second optical system of example 9.

The above 18 virtual reality devices satisfy the relationships shown in tables 19-1, 19-2, and 19-3, respectively.

Conditional/embodiment combinations	1+4	1+5	1+6	1+7	1+8	1+9
							\|f1B+f5B\|/fA	0.67	0.05	2.54	0.06	0.36	0.05
(CT1A+CT2A)/(\|R9B+R10B\|)	5.04	2.05	4.50	0.06	4.45	0.13
							R1A/(R1B+R2B)	28.91	47.55	30.55	118.79	49.23	114.52
(fA/EPDA)×(fB/EPDB)	7.38	8.73	7.38	8.56	8.73	8.73
							FG2A/(f2B+f3B)	3.21	3.37	3.25	3.17	3.45	3.37
R2A/(R3B+R4B)	7.23	3.13	7.63	4.20	6.79	3.45
							(fA×tan(FOVA/2))/(fB×tan(FOVB/2))	4.24	9.76	3.60	8.87	7.00	9.67
CT2A/(T45B+CT5B)	2.68	2.02	2.06	1.29	1.89	1.81
							TDA/(tan(FOVB/2))(mm)	3.54	7.94	2.98	7.17	5.68	7.67
\|R3A\|/(CT1A+CTQA)	7.01	7.01	7.01	7.01	7.01	7.01
							TDA/(CTFA+CTRA+CTQA)	12.49	12.49	12.49	12.49	12.49	12.49
(R6B-R5B)/(R7B+R8B)	2.53	1.75	2.46	2.22	2.23	1.85

TABLE 19-1

TABLE 19-2

Conditional/embodiment combinations	3+4	3+5	3+6	3+7	3+8	3+9
							\|f1B+f5B\|/fA	0.60	0.05	2.27	0.06	0.33	0.04
(CT1A+CT2A)/(\|R9B+R10B\|)	3.68	1.50	3.29	0.04	3.25	0.09
							R1A/(R1B+R2B)	26.09	42.90	27.56	107.17	44.41	103.32
(fA/EPDA)×(fB/EPDB)	7.34	8.69	7.34	8.51	8.69	8.69
							FG2A/(f2B+f3B)	3.52	3.70	3.57	3.48	3.79	3.71
R2A/(R3B+R4B)	9.19	3.99	9.71	5.35	8.64	4.39
							(fA×tan(FOVA/2))/(fB×tan(FOVB/2))	4.74	10.92	4.03	9.93	7.84	10.82
CT2A/(T45B+CT5B)	3.67	2.76	2.82	1.76	2.59	2.48
							TDA/(tan(FOVB/2))(mm)	3.81	8.55	3.21	7.72	6.11	8.26
\|R3A\|/(CT1A+CTQA)	14.35	14.35	14.35	14.35	14.35	14.35
							TDA/(CTFA+CTRA+CTQA)	14.95	14.95	14.95	14.95	14.95	14.95
(R6B-R5B)/(R7B+R8B)	2.53	1.75	2.46	2.22	2.23	1.85

TABLE 19-3

The foregoing description is only of the preferred embodiments of the present application and is presented as a description of the principles of the technology being utilized. It will be appreciated by persons skilled in the art that the scope of the invention referred to in this application is not limited to the specific combinations of features described above, but it is intended to cover other embodiments in which any combination of features described above or equivalents thereof is possible without departing from the spirit of the invention. Such as the above-described features and technical features having similar functions (but not limited to) disclosed in the present application are replaced with each other.

Claims

1. Virtual reality device, its characterized in that includes:

the first optical system sequentially comprises an optical filter, a reflective polarizing element, a quarter wave plate, a first lens and a second lens from the eye side to the image side along a first optical axis, wherein the first lens has positive optical power or negative optical power, and the second lens has positive optical power or negative optical power; and

a second optical system including, in order from an object side to an image side along a second optical axis, a first lens having negative optical power, a second lens having positive optical power, a third lens having positive optical power, a fourth lens, and a fifth lens,

The first optical system is used for projecting a virtual image on the display screen and the real image transferred to the display screen, and the virtual reality device meets the following conditions: 0 < |f1B+f5B|/fA < 3 and 0 < (C1A+C2A)/(|R9B+R10B|) are < 5.1, wherein fA is the effective focal length of the first optical system, f1B is the effective focal length of the first lens, f5B is the effective focal length of the fifth lens, CT1A is the center thickness of the first lens on the first optical axis, CT2A is the center thickness of the second lens on the first optical axis, R9B is the radius of curvature of the object side of the fifth lens, and R10B is the radius of curvature of the image side of the fifth lens.

2. The virtual reality device of claim 1, wherein the virtual reality device satisfies: 26 < R1A/(R1B+R2B) < 134, where R1A is the radius of curvature of the near-eye side of the first lens, R1B is the radius of curvature of the object side of the first lens, and R2B is the radius of curvature of the image side of the first lens.

3. The virtual reality device of claim 1, wherein the virtual reality device satisfies: 3 < FG 2A/(f2B+f3B) < 4, where FG2A is the combined focal length of the quarter-wave plate and the first lens, f2B is the effective focal length of the second lens, and f3B is the effective focal length of the third lens.

4. The virtual reality device of claim 1, wherein the virtual reality device satisfies: 3 < R2A/(R3B+R4B) < 12, wherein R2A is the radius of curvature of the near image side of the first lens element, R3B is the radius of curvature of the object side of the second lens element, and R4B is the radius of curvature of the image side of the second lens element.

5. The virtual reality device of claim 1, wherein the virtual reality device satisfies: 1.2 < CT 2A/(T45B+CT5B) < 3.7, wherein CT2A is the center thickness of the second lens on the first optical axis, T45B is the air gap of the fourth lens and the fifth lens on the second optical axis, and CT5B is the center thickness of the fifth lens on the second optical axis.

6. The virtual reality device of claim 1, wherein the virtual reality device satisfies: 7 < |R3A|/(C1A+CTQA) < 30.5, wherein R3A is the radius of curvature of the near-eye side of the second lens, CT1A is the center thickness of the first lens on the first optical axis, and CTQA is the center thickness of the quarter wave plate on the first optical axis.

7. The virtual reality device of claim 1, wherein the virtual reality device satisfies: 9.3 < TDA/(CTFA+CTRA+CTQA) < 15, wherein TDA is the distance between the near-eye side of the first lens and the near-image side of the second lens on the first optical axis, CTFA is the center thickness of the optical filter on the first optical axis, CTRA is the center thickness of the reflective polarizing element on the first optical axis, and CTQA is the center thickness of the quarter-wave plate on the first optical axis.

8. The virtual reality device of claim 1, wherein the virtual reality device satisfies: 1.7 < (R6B-R5B)/(R7 B+R8B) < 2.7, wherein R5B is the radius of curvature of the object-side surface of the third lens element, R6B is the radius of curvature of the image-side surface of the third lens element, R7B is the radius of curvature of the object-side surface of the fourth lens element, and R8B is the radius of curvature of the image-side surface of the fourth lens element.

9. The virtual reality device of any one of claims 1-8, wherein the virtual reality device satisfies: 6.8 < (fA/EPDA) × (fB/EPDB) < 8.8, wherein fA is the effective focal length of the first optical system, EPDA is the entrance pupil diameter of the first optical system, fB is the effective focal length of the second optical system, EPDB is the entrance pupil diameter of the second optical system.

10. The virtual reality device of any one of claims 1-8, wherein the virtual reality device satisfies: 3.5 < (fA×tan (FOVA/2))/(fB×tan (FOVB/2)) < 11, where fA is the effective focal length of the first optical system, FOVA is the maximum field angle of the first optical system, fB is the effective focal length of the second optical system, and FOVB is the maximum field angle of the second optical system.

11. The virtual reality device of any one of claims 1-8, wherein the virtual reality device satisfies: 2.1mm < TDA/(tan (FOVB/2)) < 8.6mm, wherein TDA is the distance on the first optical axis from the near-human eye side of the first lens to the near-image side of the second lens, and FOVB is the maximum field angle of the second optical system.

12. The virtual reality device of any one of claims 1-8,

the object side surface of the second lens is a concave surface, and the image side surface is a convex surface; and

the third lens element has a convex object-side surface and a convex image-side surface.

13. The virtual reality device of any one of claims 1-8,

the reflective polarizing element is attached to the near-image side surface of the optical filter; and

the quarter wave plate is attached to the near-eye side of the first lens.

14. The virtual reality device of any one of claims 1-8, further comprising a partially reflective element affixed to a near-image side of the first lens, a near-eye side of the second lens, or a near-image side of the second lens.