Virtual reality devices

Abstract

A virtual reality device includes a first optical system and a second optical system. The first optical system includes a first element group and a second element group. The first element group has positive optical power and includes a reflective polarizing element, a quarter-wave plate, and a first lens. The second element group has positive or negative optical power and includes a second lens. The second optical system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens sequentially from the object side to the image side along a second optical axis. The real image formed by the second optical system is transmitted to a display screen in the form of an electrical signal. The first optical system is used to project a virtual image on the display screen and the real image transmitted to the display screen. The radius of curvature R1A of the first surface of the first lens, the effective focal length fA of the first optical system, the effective focal length fB of the second optical system, the radius of curvature R1B of the object side of the first lens, and the radius of curvature R2B of the image side of the first lens satisfy: -5 < (R1B + R2B) / f1B < -1; 0.2 < (R1A / fA) / ((R1B + R2B) / fB) < 2.7.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical elements, in particular to a virtual reality device. BACKGROUND

[0002] The perspective technology of an augmented reality (AR) device is optical perspective, which can directly superimpose a virtual image on the visual effect of the real world, so that the real world can directly interact with the virtual world.

[0003] The perspective technology of a virtual reality (VR) device is video perspective, which combines a digital three-dimensional view of the real world with a computer-generated reality simulation, and then displays it on an opaque display; by combining video perspective with appropriate rendering technology and algorithms, interaction between virtual and actual objects is achieved.

[0004] AR technology can realize the interaction between virtual and real through AR glasses, even mobile phones, computers and other display devices with cameras. Considering the mobility of the device, AR is the ultimate choice to replace smartphones. However, the traditional AR technology uses prism optical principles to refract real images, and the viewing angle is not as large as that of VR, and the clarity is also affected. Limited by the development of AR, mixed reality (MR) using video perspective technology becomes a transitional choice from VR to AR. SUMMARY

[0005] According to one aspect of the present application, a virtual reality device is provided, which includes a first optical system and a second optical system. The first optical system sequentially includes a first element group and a second element group from a first side to a second side along a first optical axis, wherein the first element group has a positive focal power and includes a reflective polarizing element, a quarter-wave plate and a first lens; the second element group has a positive focal power or a negative focal power and includes a second lens; the second optical system sequentially includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens from an object side to an image side along a second optical axis; wherein a real image formed by the second optical system is transmitted to a display screen in the form of an electrical signal, the first optical system is used to project a virtual image on the display screen and a real image transmitted to the display screen, and the curvature radius R1A of the first surface of the first lens, the effective focal length fA of the first optical system, the effective focal length fB of the second optical system, the curvature radius R1B of the object side surface of the first lens and the curvature radius R2B of the image side surface of the first lens satisfy: -5<(R1B+R2B) / f1B<-1; 0.2<(R1A / fA) / ((R1B+R2B) / fB)<2.7.

[0006] According to another aspect of this application, a virtual reality device is provided, including a first optical system and a second optical system. The first optical system includes a first element group and a second element group sequentially from a first side to a second side along a first optical axis. The first element group has positive optical power and includes a reflective polarizing element, a quarter-wave plate, and a first lens. The second element group has positive or negative optical power and includes a second lens. The second optical system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens sequentially from the object side to the image side along the second optical axis. The real image formed by the second optical system is transmitted to the first optical system in the form of an electrical signal. The first optical system is used to project a virtual image and a real image disposed on an image surface on the second side. The effective focal length f1B of the first lens, the effective focal length fB of the second optical system, the center thickness CT1A of the first lens on the first optical axis, the center thickness CTRA of the reflective polarizing element on the first optical axis, the center thickness CTQA of the quarter-wave plate on the first optical axis, and the sum of the center thicknesses of the first to sixth lenses on the second optical axis, ∑CTB, satisfy: -3 <f1B / fB<-1;4.2<(CT1A+CTRA+CTQA) / ∑CTB<5.2。

[0007] In one or more embodiments, the effective focal length FG1A of the first element group, the effective focal length f1B of the first lens, and the effective focal length f2B of the second lens satisfy: 38 <FG1A / |f1B+f2B|<49。

[0008] In one or more embodiments, the effective focal length FG2A of the second element group, the radius of curvature R11B of the object side of the sixth lens, and the radius of curvature R12B of the image side of the sixth lens satisfy: 16<|FG2A| / (R12B-R11B)<37.

[0009] In one or more embodiments, the air gap T12A between the second surface of the first lens and the first surface of the second lens on the first optical axis, the center thickness CT2A of the second lens on the first optical axis, the axial thickness CT5B of the fifth lens on the second optical axis, the air gap T56B between the fifth lens and the sixth lens on the second optical axis, and the center thickness CT6B of the sixth lens on the second optical axis satisfy: 7<(T12A+CT2A) / (CT5B+T56B+CT6B)<15.

[0010] In one or more embodiments, the effective focal length fA of the first optical system, the effective focal length f4B of the fourth lens, the effective focal length f5B of the fifth lens, and the effective focal length f6B of the sixth lens satisfy: 0.8 <fA / |f4B+f5B+f6B|<9。

[0011] In one or more embodiments, the distance TDA between the first surface of the first lens and the second surface of the second lens on the first optical axis, the distance TDB between the object surface of the first lens and the image surface of the sixth lens on the second optical axis, the maximum field of view FOVA of the first optical system, and the maximum field of view FOVB of the second optical system satisfy: 3<(TDA*tan(FOVA / 2)) / (TDB*tan(FOVB / 2))<4.5.

[0012] In one or more embodiments, the effective focal length FG1A of the first element group, the entrance pupil diameter EPDA of the first optical system, the effective focal length f1B of the first lens, and the entrance pupil diameter EPDB of the second optical system satisfy: -34<(FG1A*EPDA)) / (f1B*EPDB)<-31.

[0013] In one or more embodiments, the distance TDA between the first surface of the first lens and the second surface of the second lens on the first optical axis, the distance TDB between the object surface of the first lens and the image surface of the sixth lens on the second optical axis, the effective focal length fA of the first optical system, and the effective focal length fB of the second optical system satisfy: 2 < (TDA / fA) * (TDB / fB) < 2.7.

[0014] In one or more embodiments, the combined focal length f234B of the second lens, the third lens, and the fourth lens, the center thickness CT2B of the second lens on the second optical axis, the center thickness CT3B of the third lens on the second optical axis, and the center thickness CT4B of the fourth lens on the second optical axis satisfy: 0.8 <f234B / (CT2B+CT3B+CT4B)<2.3。

[0015] In one or more embodiments, the air gap T56B between the fifth and sixth lenses on the second optical axis, the air gap T45B between the fourth and fifth lenses on the second optical axis, the combined focal length f34B of the third and fourth lenses, and the combined focal length f56B of the fifth and sixth lenses satisfy: 2.5 < (T56B / T45B) / |f34B / f56B| < 17.5.

[0016] In one or more embodiments, the radius of curvature R3B of the object side of the second lens, the radius of curvature R4B of the image side of the second lens, the radius of curvature R5B of the object side of the third lens, and the radius of curvature R6B of the image side of the third lens satisfy: -0.6 < (R4B / R3B)*(R6B / R5B) < -0.1.

[0017] In one or more embodiments, the optical power signs of the first lens and the second lens are opposite; the optical power signs of the third lens and the fourth lens are opposite; and the optical power signs of the fifth lens and the sixth lens are opposite.

[0018] The virtual reality device provided according to the embodiments of this application may include a first optical system and a second optical system, which are optimized for video perspective lens and visual lens. The visual lens combined with the video perspective lens can transmit more real-world content to the consumer's eyes, thereby enhancing the sense of boundary between the virtual and real worlds on the one hand, and enhancing the sense of interaction between the virtual and real worlds on the other hand.

[0019] According to the virtual reality device provided in the embodiments of this application, by controlling the curvature radius and effective focal length of each lens in the second optical system, it is beneficial to increase the field of view of the video perspective lens, and constrain the curvature radius of the first lens in the first optical system, thereby increasing the feasibility of forming within a certain range while converging light.

[0020] According to the virtual reality device provided in the embodiments of this application, in addition to constraining the ratio of the effective focal length of the first lens of the second optical system to the effective focal length of the second optical system, the ratio of the sum of the thickness of the first lens and the film thickness in the first optical system to the sum of the thicknesses of the lenses in the second system is further constrained, thereby indirectly constraining the aperture and size of the lenses in the first and second optical systems, thereby controlling the size of the screen and the chip in the first and second optical systems. Attached Figure Description

[0021] 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:

[0022] Figure 1 A plan view of a virtual reality device provided according to an embodiment of this application is shown;

[0023] Figure 2A A schematic diagram (front view) of a virtual reality device according to an embodiment of this application is shown;

[0024] Figure 2B A schematic diagram (rear view) of a virtual reality device according to an embodiment of this application is shown;

[0025] Figure 3 A schematic diagram of the structure of the first optical system according to Embodiment 1 of this application is shown;

[0026] Figures 4A to 4C The on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the first optical system according to Embodiment 1 of this application are shown respectively.

[0027] Figure 5 A schematic diagram of the structure of the first optical system according to Embodiment 2 of this application is shown;

[0028] Figures 6A to 6CThe on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the first optical system according to Embodiment 2 of this application are shown respectively.

[0029] Figure 7 A schematic diagram of the structure of the first optical system according to Embodiment 3 of this application is shown;

[0030] Figures 8A to 8C The on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the first optical system according to Embodiment 3 of this application are shown respectively.

[0031] Figure 9 A schematic diagram of the structure of the second optical system according to Embodiment 4 of this application is shown;

[0032] Figures 10A to 10C The on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the second optical system according to Embodiment 4 of this application are shown respectively.

[0033] Figure 11 A schematic diagram of the structure of the second optical system according to Embodiment 5 of this application is shown;

[0034] Figures 12A to 12C The on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the second optical system according to Embodiment 5 of this application are shown respectively.

[0035] Figure 13 A schematic diagram of the structure of the second optical system according to Embodiment Six of this application is shown;

[0036] Figures 14A to 14C The on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the second optical system according to Embodiment Six of this application are shown respectively.

[0037] Figure 15 A schematic diagram of the structure of the second optical system according to Embodiment 7 of this application is shown; and

[0038] Figures 16A to 16C The on-axis chromatic aberration curve, astigmatism curve, and distortion curve of the second optical system according to Embodiment 7 of this application are shown respectively. Detailed Implementation

[0039] 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. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0040] 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 first lens.

[0041] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0042] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject 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.

[0043] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0044] 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.

[0045] It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other. The following embodiments only illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be pointed out that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of this application, and these all fall within the protection scope of this application.

[0046] The features, principles and other aspects of this application are described in detail below.

[0047] refer to Figure 1 , Figure 2A and Figure 2B As shown, the virtual reality device 10 according to an exemplary embodiment of this application may include a first optical system 100 and a second optical system 200. By combining the first optical system 100 and the second optical system 200, virtual reality fusion of the virtual reality device can be achieved. Specifically, the second optical system 200 can be used to image real-world objects, and the resulting real image is transmitted to a display screen in the form of an electrical signal; the image surface of the first optical system 100 may be located on the display screen, and the first optical system 100 can be used to project a virtual image on the display screen and the aforementioned real image transmitted to the display screen. If projected into the user's eyes, the user can see a combined virtual and real image, enhancing the user's immersion. The first optical system 100 may be configured, for example, as a folding optical system, and its number may be one or more; the second optical system 200 may be configured, for example, as a video perspective optical system, and its number may be one or more. In one example, the virtual reality device 10 may include two symmetrically arranged first optical systems 100. In one example, the virtual reality device 10 also includes a body, the first optical system 100 may be disposed on the inner side of the body, and the second optical system 200 may be disposed on the outer side of the body. The virtual reality device 10 may also include other optical systems, such as a third optical system 300 for interacting with reality, and the number of third optical systems may be one or more.

[0048] In an exemplary embodiment, the first optical system 100 may include a first element group and a second element group arranged sequentially from the first side to the second side along the first optical axis, wherein the first element group may include a reflective polarizing element RP, a quarter-wave plate QWP and a first lens E1'; and the second element group may include a second lens E2'.

[0049] In an exemplary embodiment, the first element group may have positive optical power, and the second element group may have positive or negative optical power. An air gap exists between the first element group and the second element group.

[0050] In an exemplary embodiment, the first side of the first optical system 100 can be, for example, the human eye side, and the second side can be, for example, the display screen side. Correspondingly, the first surface of each element (first lens, second lens, reflective polarizing element, quarter-wave plate) can be a surface near the human eye side, and the second surface can be a surface near the display screen side. In this application, when light passes through the reflective polarizing element, the reflective polarizing element can reflect light in a certain direction and transmit light orthogonal to the reflected light. The quarter-wave plate can be used to convert between circularly polarized light and linearly polarized light to achieve optical path reversal, which is beneficial for shortening the length of the first optical system.

[0051] In an exemplary embodiment, the second surface of the first lens E1' of the first optical system 100 can be a convex surface or a flat surface.

[0052] In an exemplary embodiment, the second surface of the second lens E2' of the first optical system 100 can be aspherical. Aspherical lenses have better radius of curvature characteristics, which has the advantages of improving distortion aberration and astigmatism. By using aspherical lenses, aberrations that occur during imaging can be eliminated as much as possible, thereby improving image quality.

[0053] In an exemplary embodiment, the first optical system 100 may further include a partial reflective element BS, which may be, for example, a partial reflective layer attached to or deposited on the second surface of the first lens E1'. The partial reflective layer has a semi-transmissive and semi-reflective effect on light. By providing a partial reflective layer on the second surface of the first lens and combining it with a reflective polarizing element and a quarter-wave plate, light can be reflected multiple times, thereby effectively reducing the overall length of the first optical system.

[0054] In an exemplary embodiment, the first optical system 100 may further include a first aperture stop STO1, which may be disposed, for example, between the first side and the first lens E1'.

[0055] In an exemplary embodiment, a display screen is provided on the image surface IMG. Image light from the display screen sequentially passes through the second lens E2' and the first lens E1', reaches the reflective polarizing element RP, is reflected at the reflective polarizing element RP, and then passes again through the quarter-wave plate QWP and the first lens E1' to reach the partial reflective element BS. Afterward, the light beam is reflected again at the partial reflective element BS and sequentially passes through the first lens E1', the quarter-wave plate QWP, and the reflective polarizing element RP to exit towards the human 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.

[0056] In an exemplary embodiment, the second optical system 200 may include a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens arranged sequentially along a second optical axis from the object side to the image side. Air gaps may exist between adjacent lenses in the first to sixth lenses. In one example, the first and sixth lenses both have negative optical power, the second and fifth lenses both have positive optical power, and the third and fourth lenses have opposite signs of optical power.

[0057] The virtual display device 10 according to an exemplary embodiment of this application may include at least a first optical system 100 and a second optical system 200, wherein the first optical system 100 may be, for example, a folding eyepiece, and the second optical system 200 may be, for example, a video perspective lens, wherein the eyepiece provides a virtual experience, and the video perspective lens provides a real environment, thereby providing immersion while increasing boundaries and interactivity.

[0058] According to the exemplary embodiment of the virtual reality device 10 of this application, the first optical system 100 is used to transmit the virtual image of the display screen to the user's eyes, the second optical system 200 is used to image the real scene, and transmit the formed real image to the display screen of the first optical system 100 through the chip of the second optical system 200. The first optical system 100 then transmits the real image on the display screen to the user, so that the user can see the image after the virtual scene and the real scene are merged, thereby improving the visual immersion of the virtual reality device.

[0059] The virtual reality device 10 according to an exemplary embodiment of this application may include a VR device or a MR device.

[0060] In an exemplary embodiment of this application, the virtual reality device includes a first optical system and a second optical system. The first optical system includes a first element group and a second element group sequentially from a first side to a second side along a first optical axis. The first element group has positive optical power and includes a reflective polarizing element, a quarter-wave plate, and a first lens. The second element group has positive or negative optical power and includes a second lens. The second optical system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens sequentially from the object side to the image side along a second optical axis. The real image formed by the second optical system is transmitted in the form of an electrical signal. The virtual image is transmitted to the display screen in a certain way. The first optical system is used to project the virtual image on the display screen and transmit the real image to the display screen. The virtual reality device can satisfy the following conditions: -5<(R1B+R2B) / f1B<-1; 0.2<(R1A / fA) / ((R1B+R2B) / fB)<2.7, where R1A is the radius of curvature of the first surface of the first lens, fA is the effective focal length of the first optical system, fB is the effective focal length of the second optical system, 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. By controlling the radius of curvature and effective focal length of each lens in the second optical system, it is beneficial to increase the field of view of the video perspective lens. On this basis, the radius of curvature of the first lens of the eyepiece is further constrained, so that within a certain range, under the premise of converging light, the feasibility of forming is increased.

[0061] In an exemplary embodiment of the present application, a virtual reality device includes a first optical system and a second optical system. The first optical system sequentially includes a first element group and a second element group along a first optical axis from a first side to a second side. Among them, the first element group has a positive optical power and includes a reflective polarizing element, a quarter-wave plate, and a first lens; the second element group has a positive or negative optical power and includes a second lens. The second optical system sequentially includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens along a second optical axis from an object side to an image side. Among them, the real image formed by the second optical system is transmitted to a display screen in the form of an electrical signal, and the first optical system is used to project a virtual image on the display screen and transmit the real image to the display screen. The virtual reality device can satisfy the following conditional expressions: -3 < f1B / fB < -1; 4.2 < (CT1A + CTR A + CTQ A) / ∑CTB < 5.2, where f1B is the effective focal length of the first lens, fB is the effective focal length of the second optical system, CT1A is the central thickness of the first lens on the first optical axis, CTR A is the central thickness of the reflective polarizing element on the first optical axis, CTQ A is the central thickness of the quarter-wave plate on the first optical axis, and ∑CTB is the sum of the central thicknesses of the first lens to the sixth lens in the second optical system on the second optical axis. On the basis of restricting the ratio of the effective focal length of the first lens of the second optical system to the effective focal length of the second optical system, the ratio of the sum of the central thickness and film thickness of the first lens in the first optical system to the sum of the central thicknesses of the lenses in the second system is further restricted, indirectly restricting the apertures and sizes of the lenses in the first optical system and the second optical system, thereby controlling the sizes of the screen and the chip in the two systems.

[0062] In an exemplary embodiment, the virtual reality device can satisfy the conditional expression: 38 < FG1A / |f1B + f2B| < 49, where FG1A is the effective focal length of the first element group, f1B is the effective focal length of the first lens, and f2B is the effective focal length of the second lens. By controlling the ratio of the effective focal lengths of the first group of lenses in the first optical system to the first two groups of lenses in the second optical system, the effective focal length of the first group of lenses in the first optical system is made larger, restricting the curvature radius of the lenses, and ensuring the manufacturability of the first group of lenses with a large aperture.

[0063] In an exemplary embodiment, the virtual reality device can satisfy the following conditional expression: 16 < |FG2A| / (R12B - R11B) < 37, where FG2A is the effective focal length of the second element group, R11B is the curvature radius of the object side of the sixth lens, and R12B is the curvature radius of the image side of the sixth lens. By controlling the ratio of the effective focal length of the second element group in the first optical system to the curvature radius of the last sixth lens in the second optical system, the difference in the curvature radii of the two sides of the last lens in the second optical system is made smaller, which is beneficial to improving the related ghost images of the last lens.

[0064] In an exemplary embodiment, the virtual reality device may satisfy the following conditional formula: 7 < (T12A + CT2A) / (CT5B + T56B + CT6B) < 15, where T12A is the air gap between the second surface of the first lens and the first surface of the second lens on the first optical axis, CT2A is the central thickness of the second lens on the first optical axis, CT5B is the axial thickness of the fifth lens on the second optical axis, T56B is the air gap between the fifth lens and the sixth lens on the second optical axis, and CT6B is the central thickness of the sixth lens on the second optical axis. By controlling the ratio of the sum of the relevant air gaps and lens thicknesses in the latter half of the first optical system and the second optical system, while reducing the thickness of the second optical system, it is beneficial to the miniaturization design of the first optical system.

[0065] In an exemplary embodiment, the virtual reality device may satisfy the following conditional formula: 0.8 < fA / |f4B + f5B + f6B| < 9, where fA is the effective focal length of the first optical system, f4B is the effective focal length of the fourth lens, f5B is the effective focal length of the fifth lens, and f6B is the effective focal length of the sixth lens. By controlling the ratio of the effective focal length of the first optical system to the sum of the effective focal lengths of the last three lenses in the second optical system, making the sum of the effective focal lengths of the last three lenses in the second optical system within a certain range, it is beneficial to the distribution of the optical power of the last three lenses, thereby correcting the system aberration.

[0066] In an exemplary embodiment, the virtual reality device may satisfy the following conditional formula: 3 < (TDA * tan(FOVA / 2)) / (TDB * tan(FOVB / 2)) < 4.5, where TDA is the distance between the first surface of the first lens and the second surface of the second lens on the first optical axis, TDB is the distance between the object side surface of the first lens and the image side surface of the sixth lens on the second optical axis, FOVA is the maximum field angle of the first optical system, and FOVB is the maximum field angle of the second optical system. By controlling the ratio of the product of the mechanical lengths and field angles of the first optical system and the second optical system, on the premise of wide angles of the two systems, the mechanical lengths of the first optical system and the second optical system are constrained and their ratio is within a certain range, while meeting the miniaturization design, the optical performance is guaranteed.

[0067] In an exemplary embodiment, the virtual reality device may satisfy the following conditional formula: -34 < (FG1A * EPDA) / (f1B * EPDB) < -31, where FG1A is the effective focal length of the first element group, EPDA is the entrance pupil diameter of the first optical system, f1B is the effective focal length of the first lens, and EPDB is the entrance pupil diameter of the second optical system. Considering the matching of the human eye pupil, by reasonably controlling this conditional formula, the focal length of the first lens of the first optical system is positive, and the focal length of the first lens of the second optical system is negative. On the one hand, it is beneficial to the light convergence of the first optical system, and on the other hand, it is beneficial to increasing the field angle of the second optical system.

[0068] In an exemplary embodiment, the virtual reality device may satisfy the following conditional formula: 2 < (TDA / fA) * (TDB / fB) < 2.7, where TDA is the distance on the first optical axis from the first surface of the first lens to the second surface of the second lens, TDB is the distance on the second optical axis from the object side surface of the first lens to the image side surface of the sixth lens, fA is the effective focal length of the first optical system, and fB is the effective focal length of the second optical system. By controlling the product of the ratio of the mechanical length to the focal length of the first optical system and the second optical system to be greater than 2, considering the requirement of miniaturization of the folding eyepiece, TDA / fA is less than 1, and it is required that TDB / fB is greater than 1, which is beneficial to restricting the focal length of the second optical system and increasing the field range of the second optical system.

[0069] In an exemplary embodiment, the virtual reality device may satisfy the following conditional formula: 0.8 < f234B / (CT2B + CT3B + CT4B) < 2.3, where f234B is the combined focal length of the second lens, the third lens, and the fourth lens, CT2B is the central thickness of the second lens on the second optical axis, CT3B is the central thickness of the third lens on the second optical axis, and CT4B is the central thickness of the fourth lens on the second optical axis. By controlling the ratio of the combined focal length of the second lens, the third lens, and the fourth lens of the second optical system to the combined central thickness, it is beneficial to the distribution of the optical powers of the three lenses. Combining the material distribution of the three lenses is beneficial to correcting the chromatic aberration of the system, thereby improving the system performance.

[0070] In an exemplary embodiment, the virtual reality device may satisfy the following conditional formula: 2.5 < (T56B / T45B) / |f34B / f56B| < 17.5, where T56B is the air gap between the fifth lens and the sixth lens on the second optical axis, T45B is the air gap between the fourth lens and the fifth lens on the second optical axis, f34B is the combined focal length of the third lens and the third lens, and f56B is the combined focal length of the fifth lens and the sixth lens. By controlling the relationship between the lens thickness, air gap, and combined focal length of the second optical system, it is beneficial to restricting the bearing of the lens against the lens, thereby improving the assembly stability.

[0071] In an exemplary embodiment, the virtual reality device can satisfy the following condition: -0.6 < (R4B / R3B)*(R6B / R5B) < -0.1, where R3B is the radius of curvature of the object-side surface of the second lens, R4B is the radius of curvature of the image-side surface of the second lens, R5B is the radius of curvature of the object-side surface of the third lens, and R6B is the radius of curvature of the image-side surface of the third lens. By controlling the radii of curvature of the second and third lenses, the shape of the lenses is constrained, which is beneficial for lens forming and for constraining the direction of light, thus helping to control the chief ray angle (CRA) of the system and match it with the chip.

[0072] In an exemplary embodiment, the optical powers of the first lens and the second lens in the second optical system have opposite signs; the optical powers of the third lens and the fourth lens have opposite signs; and the optical powers of the fifth lens and the sixth lens have opposite signs. By controlling the optical powers of different lenses in the second optical system, on the one hand, the wide-angle and small focal length characteristics of the second optical system are achieved through the combination of optical powers; on the other hand, the combination of positive and negative optical powers is beneficial for correcting system aberrations and improving image quality.

[0073] In an exemplary embodiment, the virtual reality device of this application may include at least one aperture stop. The aperture stop can constrain the optical path and control the light intensity. The aperture stop may be positioned appropriately in a first optical system or a second optical system. In one example, a first aperture stop may be included, which may be located between a first side (eye side) of the first optical system and a first element group. In another example, a second aperture stop may also be included, which may be located between a first lens and a second lens of the second optical system.

[0074] In an exemplary embodiment, the virtual reality device of this application may optionally include protective glass for protecting the photosensitive element located on the imaging surface.

[0075] In an exemplary embodiment, the effective focal length fA of the first optical system may be, for example, in the range of 25.20 mm to 25.22 mm, the effective focal length FG1A of the first element group may be, for example, in the range of 25.65 mm to 26.46 mm, and the effective focal length FG2A of the second element group may be, for example, in the range of -148.47 mm to 161.02 mm.

[0076] Specific embodiments of the optical system applicable to the above-described embodiments are further described below with reference to the accompanying drawings.

[0077] Example One

[0078] The following is for reference Figures 3 to 4C A first optical system according to Embodiment 1 of this application is described. Figure 3A schematic diagram of the structure of a first optical system according to Embodiment 1 of this application is shown.

[0079] like Figure 3 As shown, the first optical system comprises a first element group and a second element group arranged sequentially along the first optical axis from the human eye side to the display side. The first element group includes a reflective polarizing element RP, a quarter-wave plate QWP, and a first lens E1', and the second element group includes a second lens E2'.

[0080] In some embodiments, the first optical system may further include a first aperture stop STO1, which may be disposed between a first side of the first optical system and a first lens E1'. The first optical system may also include a partial reflective element BS, which may be disposed on a second surface of the first lens E1'. An image plane IMG may be disposed on the second side of the first optical system. In an exemplary embodiment, a display screen may be disposed on the image plane IMG. Image light from the display screen is finally projected to the user's eye after multiple refractions and reflections through the second lens E2', the first lens E1', the reflective polarizing element RP, the quarter-wave plate QWP, and the partial reflective element BS.

[0081] In this embodiment, the first element group has positive optical power, wherein the first surface of the first lens E1' is convex and the second surface is convex. By controlling the surface shape of the first lens E1' near the human eye and near the display, it is beneficial to control the light emission angle and to improve the field of view.

[0082] The second element group has negative optical power, wherein the first surface of the second lens E2' is convex, and the second surface is convex. By reasonably controlling the surface shape of the second lens E2', the light direction can be further optimized, which is beneficial to improving the image quality of the system, and constraining the incident angle of edge light rays, which is beneficial to chip matching.

[0083] 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 each element sequentially in the order of S14' to S1' and is finally projected into the human eye.

[0084]

[0085] Table 1

[0086] In this embodiment, the effective focal length FG1A of the first element group is 26.44 mm, the effective focal length FG2A of the second element group is -104.18 mm, the total effective focal length fA of the first optical system is 25.21 mm, the maximum field of view FOVA of the first optical system is 100.0°, and the entrance pupil diameter EPDA of the first optical system is 4.50 mm. The distance TDA between the first surface of the first lens E1' and the second surface of the second lens E2' on the first optical axis is 25.65 mm, the center thickness CTRA of the reflective polarizing element RP on the first optical axis is 0.18 mm, and the center thickness CTQA of the quarter-wave plate QWP on the first optical axis is 0.18 mm.

[0087] In this embodiment, the first surface S4' and the second surface S5' of the first lens E1', and the first surface S10' and the second surface S11' of the second lens E2' are all aspherical surfaces. The surface shape x of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0088]

[0089] 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 shows the higher-order coefficients A4, A6, A8, A10, and A11' that can be used for the aspherical mirrors S4', S5', S10', and S11' in Example 1. 10 A 12 A 14 A 16 A 18 and A 20 .

[0090] Coefficient / Face Number S4' S5' S10' S11' A4 -6.3679E-07 0.0000E+00 0.0000E+00 5.0132E+00 A6 3.3068E-10 0.0000E+00 0.0000E+00 -4.2251E+00 A8 -1.0175E-13 0.0000E+00 0.0000E+00 3.9157E+00 A10 -1.1279E-16 0.0000E+00 0.0000E+00 -1.6258E+00 A12 5.2040E-20 0.0000E+00 0.0000E+00 1.9246E+00 A14 0.0000E+00 0.0000E+00 0.0000E+00 -5.9853E-01 A16 0.0000E+00 0.0000E+00 0.0000E+00 7.0015E-01 A18 0.0000E+00 0.0000E+00 0.0000E+00 -1.4372E-01 A20 0.0000E+00 0.0000E+00 0.0000E+00 1.3883E-01

[0091] Table 2

[0092] Figure 4A The on-axis chromatic aberration curve of the first optical system 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 4B The astigmatism curves of the first optical system of Embodiment 1 are shown, which represent the meridional image plane curvature and sagittal image plane curvature corresponding to different field of view angles. Figure 4C The distortion curves of the first optical system in Embodiment 1 are shown, representing the distortion magnitudes corresponding to different field of view angles. According to... Figures 4A to 4C As can be seen, the first optical system given in Example 1 can achieve good imaging quality.

[0093] Example Two

[0094] The following is for reference Figures 5 to 6C A first optical system according to Embodiment 2 of this application is described. Figure 5 A schematic diagram of the structure of the first optical system according to Embodiment 2 of this application is shown.

[0095] like Figure 5 As shown, the first optical system comprises a first element group and a second element group arranged sequentially along the first optical axis from the human eye side to the display side. The first element group includes a reflective polarizing element RP, a quarter-wave plate QWP, and a first lens E1', and the second element group includes a second lens E2'.

[0096] In this embodiment, the first optical system may further include a first aperture stop STO1, which may be disposed between a first side of the first optical system and a first lens E1'. The first optical system may also include a partial reflective element BS, which may be disposed, for example, on a second surface of the first lens E1'. An image plane IMG may be disposed on the second side of the first optical system. In an exemplary embodiment, a display screen may be disposed on the image plane IMG. Image light from the display screen is finally projected to the user's eye after multiple refractions and reflections through the second lens E2', the first lens E1', the reflective polarizing element RP, the quarter-wave plate QWP, and the partial reflective element BS.

[0097] In this embodiment, the first element group has positive optical power, wherein the first surface of the first lens E1' is convex and the second surface is planar. By controlling the surface shape of the first lens E1' near the human eye and near the display, it is beneficial to control the light emission angle and to improve the field of view.

[0098] The second element group has negative optical power, wherein the first surface of the second lens E2' is convex and the second surface is concave. By reasonably controlling the surface shape of the second lens E2', the light direction can be further optimized, which is beneficial to improving the image quality of the system, and constraining the incident angle of edge light rays, which is beneficial to chip matching.

[0099] 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 sequentially in the order of S14' to S1' and is finally projected into the human eye.

[0100]

[0101] Table 3

[0102] In this embodiment, the effective focal length FG1A of the first element group is 26.46 mm, the effective focal length FG2A of the second element group is -148.47 mm, the total effective focal length fA of the first optical system is 25.22 mm, the maximum field of view FOVA of the first optical system is 106.0°, and the entrance pupil diameter EPDA of the first optical system is 4.50 mm. The distance TDA between the first surface of the first lens E1' and the second surface of the second lens E2' on the first optical axis is 27.23 mm, the center thickness CTRA of the reflective polarizing element RP on the first optical axis is 0.18 mm, and the center thickness CTQA of the quarter-wave plate QWP on the first optical axis is 0.18 mm.

[0103] In this embodiment, the first surface S4' of the first lens E1' and the first surface S10' and the second surface S11' of the second lens E2' are both aspherical surfaces. Table 4 shows the higher-order coefficients A4, A6, A8, and A6 that can be used for each aspherical surface S4', S10', and S11' in Embodiment 2. 10 A 12 A 14 A 16 A 18 and A 20 Each aspherical surface shape can be defined by formula (1) given in the above embodiment 1.

[0104] Coefficient / Face Number S4' S10' S11' A4 -4.6903E-07 0.0000E+00 -9.4090E-01 A6 3.5937E-10 0.0000E+00 -1.6934E+00 A8 -3.4457E-13 0.0000E+00 2.3965E+00 A10 5.6028E-17 0.0000E+00 -1.2226E+00 A12 3.3287E-20 0.0000E+00 1.9456E+00 A14 0.0000E+00 0.0000E+00 -8.5748E-01 A16 0.0000E+00 0.0000E+00 8.5916E-01 A18 0.0000E+00 0.0000E+00 -2.4919E-01 A20 0.0000E+00 0.0000E+00 1.5513E-01

[0105] Table 4

[0106] Figure 6A The on-axis chromatic aberration curve of the first optical system 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 of Embodiment 2 are shown, which represent the meridional image plane curvature and sagittal image plane curvature corresponding to different field of view angles. Figure 6C The distortion curves of the first optical system in Embodiment 2 are shown, representing the distortion magnitudes corresponding to different field of view angles. According to... Figures 6A to 6C It can be seen that the first optical system given in Embodiment 2 can achieve good imaging quality.

[0107] Example Three

[0108] The following is for reference Figures 7 to 8C The first optical system according to Embodiment 3 of this application is described. Figure 7 A schematic diagram of the structure of the first optical system according to Embodiment 3 of this application is shown.

[0109] like Figure 7As shown, the first optical system comprises a first element group and a second element group arranged sequentially along the first optical axis from the human eye side to the display side. The first element group includes a reflective polarizing element RP, a quarter-wave plate QWP, and a first lens E1', and the second element group includes a second lens E2'.

[0110] In this embodiment, the first optical system may further include a first aperture stop STO1, which may be disposed between a first side of the first optical system and a first lens E1'. The first optical system may further include a partial reflective element BS, which may be disposed on a second surface of the first lens E1'. An image surface IMG may be disposed on the second side of the first optical system. In an exemplary embodiment, a display screen may be disposed on the image surface IMG. Image light from the display screen is finally projected to the user's eye after multiple refractions and reflections through the second lens E2', the first lens E1', the reflective polarizing element RP, the quarter-wave plate QWP, and the partial reflective element BS.

[0111] In this embodiment, the first element group has positive optical power, wherein the first surface of the first lens E1' is convex and the second surface is planar. By controlling the surface shape of the first lens E1' near the human eye and near the display, it is beneficial to control the light emission angle and improve the field of view.

[0112] The second element group has positive optical power, wherein the first surface of the second lens E2' is planar and the second surface is convex. By reasonably controlling the surface shape of the second lens E2', the light direction can be further optimized, which is beneficial to improving the image quality of the system, and constraining the incident angle of edge light rays, which is beneficial to chip matching.

[0113] 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 sequentially in the order of S14' to S1' and is finally projected into the human eye.

[0114]

[0115]

[0116] Table 5

[0117] In this embodiment, the effective focal length FG1A of the first element group is 25.65 mm, the effective focal length FG2A of the second element group is 161.02 mm, the total effective focal length fA of the first optical system is 25.20 mm, the maximum field of view FOVA of the first optical system is 100.0°, and the entrance pupil diameter EPDA of the first optical system is 4.50 mm. The distance TDA between the first surface of the first lens E1' and the second surface of the second lens E2' on the first optical axis is 27.40 mm, the center thickness CTRA of the reflective polarizing element RP on the first optical axis is 0.18 mm, and the center thickness CTQA of the quarter-wave plate QWP on the first optical axis is 0.18 mm.

[0118] In this embodiment, the first surface S4' of the first lens E1' and the second surface S11' of the second lens E2' are both aspherical. Table 6 shows the higher-order coefficients A4, A6, A8, and A6 that can be used for each aspherical mirror surface S4' and S11' in Embodiment 3. 10 A 12 A 14 A 16 A 18 and A 20 Each aspherical surface shape can be defined by formula (1) given in the above embodiment 1.

[0119] Coefficient / Face Number S4' S11' A4 -7.4714E-07 -4.5540E-01 A6 3.2633E-10 -2.3284E+00 A8 -2.9996E-13 1.3028E+00 A10 7.5670E-18 -9.3232E-01 A12 4.7642E-20 9.7296E-01 A14 0.0000E+00 -3.5557E-01 A16 0.0000E+00 4.6267E-01 A18 0.0000E+00 -4.7469E-02 A20 0.0000E+00 1.3965E-01

[0120] Table 6

[0121] Figure 8A The on-axis chromatic aberration curve of the first optical system 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 of Embodiment 3 are shown, which represent the meridional image plane curvature and sagittal image plane curvature corresponding to different field of view angles. Figure 8C The distortion curves of the first optical system in Embodiment 3 are shown, representing the distortion magnitudes corresponding to different field of view angles. According to... Figures 8A to 8C It can be seen that the first optical system given in Embodiment 3 can achieve good imaging quality.

[0122] The following describes a specific embodiment of the second optical system applicable to the above embodiments with reference to the accompanying drawings.

[0123] Example Four

[0124] The following is for reference Figures 9 to 16C A second optical system according to Embodiment 4 of this application is described.

[0125] like Figure 9As shown, the second optical system may include a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, and a sixth lens E6 arranged sequentially from the object side to the image side along the second optical axis. The second aperture STO2 may be disposed between the first lens E1 and the second lens E2.

[0126] The first lens E1 has negative optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being convex. The third lens E3 has positive optical power, with its object-side surface S5 being concave and its image-side surface S6 being convex. The fourth lens E4 has negative optical power, with its object-side surface S7 being concave and its image-side surface S8 being concave. The fifth lens E5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being convex. The sixth lens E6 has negative optical power, with its object-side surface S11 being concave and its image-side surface S12 being concave. The filter E7 has an object-side surface S13 and an image-side surface S14. Light from the object passes sequentially through surfaces S1 to S14 and is finally imaged onto the imaging surface S15.

[0127] 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).

[0128]

[0129] Table 7

[0130] In this embodiment, the total effective focal length fB of the second optical system is 2.08 mm, the entrance pupil diameter EPDB of the second optical system is 1.16 mm, the maximum field of view FOVB of the second optical system is 130.08°, the sum of the center thicknesses ∑CTB of the first to sixth lenses on the second optical axis is 2.85 mm, the distance TDB between the object side of the first lens and the image side of the sixth lens on the second optical axis is 4.52 mm, the combined focal length f234B of the second, third, and fourth lenses is 3.17 mm, the combined focal length f34B of the third and fourth lenses is -6.80 mm, and the combined focal length f56B of the fifth and sixth lenses is 2.76 mm.

[0131] In this embodiment, the object-side surface and image-side surface of any one of the first lens E1 to the sixth lens E6 are aspherical. The surface shape x of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0132]

[0133] 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 8 shows the higher-order coefficients A4, A6, A8, A12 that can be used for each aspherical mirror S1-S12 in Example 4. 10 A 12 A 14 and A 16 .

[0134] Face Number A4 A6 A8 A10 A12 A14 A16 S1 5.3530E-03 5.5944E-03 -5.1516E-02 8.5538E-02 -6.6786E-02 2.5677E-02 -3.9256E-03 S2 6.7215E-02 -9.6751E-02 9.3328E-01 -3.6338E+00 7.6131E+00 -7.8087E+00 3.2575E+00 S3 -3.2741E-02 5.2083E-02 -4.0829E-01 1.3047E+00 -2.3728E+00 2.1906E+00 -8.5286E-01 S4 -2.0206E-01 6.5647E-04 4.3282E-01 -8.2242E-01 8.5986E-01 -5.1282E-01 1.2783E-01 S5 -2.6645E-01 -5.4066E-02 -2.1073E-01 1.4248E+00 -2.3947E+00 1.7886E+00 -5.0080E-01 S6 -9.1744E-02 1.0603E+00 -3.1389E+00 4.5815E+00 -3.6242E+00 1.5133E+00 -2.6515E-01 S7 -1.7928E-01 1.6012E+00 -4.2264E+00 5.5655E+00 -3.9303E+00 1.4426E+00 -2.1762E-01 S8 -1.8054E-01 -7.8645E-02 1.1473E-02 1.8240E-01 -2.1140E-01 1.2065E-01 -2.5802E-02 S9 1.3650E-01 -2.7011E-01 2.7449E-01 -2.3475E-01 1.5100E-01 -5.4015E-02 7.8118E-03 S10 -1.3580E-01 4.9439E-01 -7.3243E-01 5.7346E-01 -2.6691E-01 7.4026E-02 -9.1947E-03 S11 -3.8551E-02 -1.9620E-01 2.7493E-01 -1.7859E-01 7.3786E-02 -1.8022E-02 1.9325E-03 S12 -1.6484E-01 3.0050E-02 3.1251E-02 -2.8981E-02 1.0768E-02 -1.9716E-03 1.2498E-04

[0135] Table 8

[0136] Figure 10A The on-axis chromatic aberration curve of the second optical system 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 in Embodiment 4 are shown, which represent the meridional and sagittal image plane curvatures corresponding to different image heights. Figure 10C The distortion curves of the second optical system in Embodiment 4 are shown, representing the distortion magnitude values ​​corresponding to different image heights. According to... Figures 10A to 10C It can be seen that the second optical system given in Example 4 can achieve good imaging quality.

[0137] Example Five

[0138] The following is for reference Figures 11 to 12C A second optical system according to Embodiment 5 of this application is described.

[0139] like Figure 11 As shown, the second optical system may include a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, and a sixth lens E6 arranged sequentially from the object side to the image side along the second optical axis. The second aperture STO2 may be disposed between the first lens E1 and the second lens E2.

[0140] The first lens E1 has negative optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being convex. The third lens E3 has negative optical power, with its object-side surface S5 being convex and its image-side surface S6 being concave. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being convex. The fifth lens E5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being concave. The sixth lens E6 has negative optical power, with its object-side surface S11 being concave and its image-side surface S12 being concave. The filter E7 has an object-side surface S13 and an image-side surface S14. Light from the object passes sequentially through surfaces S1 to S14 and is finally imaged onto the imaging surface S15.

[0141] 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).

[0142]

[0143]

[0144] Table 9

[0145] In this embodiment, the total effective focal length fB of the second optical system is 2.08 mm, the entrance pupil diameter EPDB of the second optical system is 1.16 mm, the maximum field of view FOVB of the second optical system is 122.01°, the sum of the center thicknesses of the first to sixth lenses on the second optical axis ∑CTB is 2.74 mm, the distance TDB between the object side of the first lens and the image side of the sixth lens on the second optical axis is 4.60 mm, the combined focal length f234B of the second, third, and fourth lenses is 1.72 mm, the combined focal length f34B of the third and fourth lenses is 3.00 mm, and the combined focal length f56B of the fifth and sixth lenses is -2.82 mm.

[0146] In this embodiment, the object-side surface and image-side surface of any one of the first lens E1 to the sixth lens E6 are aspherical. Table 10 shows the higher-order coefficients A4, A6, A8, and A6 that can be used for each aspherical mirror S1-S12 in Embodiment 5. 10 A 12 A 14 and A 16 .

[0147] Face Number A4 A6 A8 A10 A12 A14 A16 S1 -9.4401E-03 -1.1714E-02 2.8593E-02 -2.6859E-02 1.4257E-02 -4.1656E-03 5.1562E-04 S2 5.2423E-02 -7.4557E-02 5.4234E-01 -1.5668E+00 2.7684E+00 -2.4975E+00 9.4308E-01 S3 -2.0063E-02 1.5018E-02 -3.9738E-01 1.2477E+00 -2.2752E+00 2.1174E+00 -8.4466E-01 S4 2.0526E-02 -4.1591E-01 5.6219E-01 -2.0492E-01 -1.5727E-01 1.2907E-01 -2.2173E-02 S5 -2.7556E-01 6.1618E-01 -2.3932E+00 4.7582E+00 -4.9759E+00 2.6849E+00 -5.9335E-01 S6 -1.8519E-01 9.5441E-01 -2.5579E+00 3.7997E+00 -3.1493E+00 1.3929E+00 -2.5893E-01 S7 -1.2688E-01 3.6470E-01 -5.1218E-01 2.2839E-01 1.5525E-01 -1.6398E-01 3.8626E-02 S8 -3.4397E-01 4.4004E-01 -4.5823E-01 3.8037E-01 -2.3225E-01 8.2812E-02 -7.4678E-03 S9 2.2219E-01 -1.0279E+00 1.8866E+00 -1.8995E+00 1.0506E+00 -2.8985E-01 2.9368E-02 S10 1.7798E-01 -7.7343E-01 1.1151E+00 -7.8660E-01 2.2557E-01 9.8779E-03 -1.2204E-02 S11 -2.6452E-01 -5.7844E-02 3.0256E-01 -1.8298E-02 -2.2241E-01 1.4213E-01 -2.6791E-02 S12 -3.5629E-01 1.8767E-01 3.2874E-03 -5.0537E-02 2.5183E-02 -5.6701E-03 4.9869E-04

[0148] Table 10

[0149] Figure 12AThe on-axis chromatic aberration curve of the second optical system 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 in Embodiment 5 are shown, which represent the meridional and sagittal image plane curvatures corresponding to different image heights. Figure 12C The distortion curves of the second optical system in Embodiment 5 are shown, representing the distortion magnitude values ​​corresponding to different image heights. According to... Figures 12A to 12C As can be seen, the second optical system given in Example 5 can achieve good imaging quality.

[0150] Example Six

[0151] The following is for reference Figures 13 to 14C A second optical system according to Embodiment Six of this application is described.

[0152] like Figure 13 As shown, the second optical system may include a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, and a sixth lens E6 arranged sequentially from the object side to the image side along the second optical axis. The second aperture STO2 may be disposed between the first lens E1 and the second lens E2.

[0153] The first lens E1 has negative optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being convex. The third lens E3 has negative optical power, with its object-side surface S5 being convex and its image-side surface S6 being concave. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave. The fifth lens E5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being convex. The sixth lens E6 has negative optical power, with its object-side surface S11 being concave and its image-side surface S12 being concave. The filter E7 has an object-side surface S13 and an image-side surface S14. Light from the object passes sequentially through surfaces S1 to S14 and is finally imaged onto the imaging surface S15.

[0154] 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).

[0155]

[0156] Table 11

[0157] In this embodiment, the total effective focal length fB of the second optical system is 2.08 mm, the entrance pupil diameter EPDB of the second optical system is 1.16 mm, the maximum field of view FOVB of the second optical system is 122.04°, the sum of the center thicknesses of the first to sixth lenses on the second optical axis ∑CTB is 2.84 mm, the distance TDB between the object side of the first lens and the image side of the sixth lens on the second optical axis is 4.58 mm, the combined focal length f234B of the second, third, and fourth lenses is 2.15 mm, the combined focal length f34B of the third and fourth lenses is 13.10 mm, and the combined focal length f56B of the fifth and sixth lenses is 13.91 mm.

[0158] In this embodiment, the object-side surface and image-side surface of any one of the first lens E1 to the sixth lens E6 are aspherical. Table 12 shows the higher-order coefficients A4, A6, A8, and A6 that can be used for each aspherical mirror S1-S12 in Embodiment 5. 10 A 12 A 14 and A 16 .

[0159] Face Number A4 A6 A8 A10 A12 A14 A16 S1 3.5258E-02 -7.4437E-02 6.2196E-02 -2.9202E-02 7.7591E-03 -1.0417E-03 5.1269E-05 S2 -3.9109E-02 2.4254E-01 -5.6360E-01 5.1938E-01 8.9814E-01 -2.0271E+00 1.1933E+00 S3 -2.4740E-02 5.7415E-02 -6.0086E-01 1.9089E+00 -3.3620E+00 3.0000E+00 -1.1153E+00 S4 -1.0416E-01 -7.4064E-02 -1.6498E-01 1.1300E+00 -1.7557E+00 1.1533E+00 -2.8467E-01 S5 -2.9177E-01 7.9142E-01 -3.1417E+00 6.5931E+00 -7.4649E+00 4.3826E+00 -1.0496E+00 S6 -2.7139E-01 1.5701E+00 -4.3663E+00 6.8713E+00 -6.2278E+00 3.0603E+00 -6.3087E-01 S7 -1.6134E-01 4.8812E-01 -7.3209E-01 4.3901E-01 -3.0129E-02 -2.0669E-02 -7.8021E-03 S8 -9.0941E-02 -3.4152E-01 6.2125E-01 -3.6946E-01 -1.2646E-01 2.4610E-01 -7.3715E-02 S9 1.3064E-01 -5.1378E-01 7.0942E-01 -4.8505E-01 1.5673E-01 -7.5675E-03 -5.9642E-03 S10 -1.7475E-02 7.9186E-03 -1.5756E-01 3.4862E-01 -2.9490E-01 1.1230E-01 -1.6133E-02 S11 -1.6983E-01 -6.1748E-02 2.9700E-01 -2.4291E-01 7.7272E-02 -3.1978E-03 -1.8396E-03 S12 -2.5001E-01 1.2718E-01 -2.7560E-02 -8.4084E-03 4.6545E-03 -1.7606E-04 -1.4694E-04

[0160] Table 12

[0161] Figure 14A The on-axis chromatic aberration curve of the second optical system 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 of Embodiment Six are shown, which represent the meridional and sagittal image plane curvatures corresponding to different image heights. Figure 14C The distortion curves of the second optical system in Embodiment Six are shown, representing the distortion magnitude values ​​corresponding to different image heights. According to... Figures 14A to 14C As can be seen, the second optical system given in Example 6 can achieve good imaging quality.

[0162] Example Seven

[0163] The following is for reference Figures 15 to 16C A second optical system according to Embodiment Seven of this application is described.

[0164] like Figure 15 As shown, the second optical system may include a first lens E1, a second lens E2, a third lens E3, a fourth lens E4, a fifth lens E5, and a sixth lens E6 arranged sequentially from the object side to the image side along the second optical axis. The second aperture STO2 may be disposed between the first lens E1 and the second lens E2.

[0165] The first lens E1 has negative optical power, with its object-side surface S1 being convex and its image-side surface S2 being concave. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being convex. The third lens E3 has negative optical power, with its object-side surface S5 being convex and its image-side surface S6 being concave. The fourth lens E4 has positive optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave. The fifth lens E5 has positive optical power, with its object-side surface S9 being convex and its image-side surface S10 being convex. The sixth lens E6 has negative optical power, with its object-side surface S11 being concave and its image-side surface S12 being concave. The filter E7 has an object-side surface S13 and an image-side surface S14. Light from the object passes sequentially through surfaces S1 to S14 and is finally imaged onto the imaging surface S15.

[0166] Table 13 shows the basic parameters of the second optical system in Embodiment 7, where the units for radius of curvature and thickness / distance are millimeters (mm).

[0167]

[0168] Table 13

[0169] In this embodiment, the total effective focal length fB of the second optical system is 2.08 mm, the entrance pupil diameter EPDB of the second optical system is 1.16 mm, the maximum field of view FOVB of the second optical system is 126.05°, the sum of the center thicknesses ∑CTB of the first to sixth lenses on the second optical axis is 2.96 mm, the distance TDB between the object side of the first lens and the image side of the sixth lens on the second optical axis is 4.62 mm, the combined focal length f234B of the second, third, and fourth lenses is 2.23 mm, the combined focal length f34B of the third and fourth lenses is 15.71 mm, and the combined focal length f56B of the fifth and sixth lenses is 7.73 mm.

[0170] In this embodiment, the object-side surface and image-side surface of any one of the first lens E1 to the sixth lens E6 are aspherical. Table 14 shows the higher-order coefficients A4, A6, A8, and A6 that can be used for each aspherical mirror S1-S12 in Embodiment 7. 10 A 12 A 14 and A 16 .

[0171] Face Number A4 A6 A8 A10 A12 A14 A16 S1 2.7119E-02 -3.3251E-02 1.6844E-02 -5.5227E-03 1.7201E-03 -4.7279E-04 6.2985E-05 S2 8.1245E-03 -9.8360E-02 1.1253E+00 -4.5067E+00 9.7847E+00 -1.0640E+01 4.7975E+00 S3 -1.5168E-02 -4.3750E-02 -6.1801E-02 2.3386E-01 -4.0791E-01 2.4475E-01 -5.6704E-02 S4 2.2783E-02 -4.8317E-01 5.0919E-01 4.9484E-01 -1.3595E+00 9.2008E-01 -1.8728E-01 S5 -2.2674E-01 6.1969E-01 -2.9570E+00 6.6570E+00 -7.7875E+00 4.6445E+00 -1.1186E+00 S6 -2.1249E-01 1.2315E+00 -3.5071E+00 5.5420E+00 -4.9680E+00 2.4007E+00 -4.8835E-01 S7 -1.1668E-01 2.6081E-01 -2.2652E-01 -2.9557E-01 6.6629E-01 -3.9546E-01 7.6823E-02 S8 -3.6007E-02 -6.5589E-01 1.4256E+00 -1.6122E+00 1.0690E+00 -3.9806E-01 7.1747E-02 S9 1.6610E-01 -6.4128E-01 9.5041E-01 -8.0199E-01 4.4916E-01 -1.6134E-01 2.6543E-02 S10 -8.1258E-03 2.8875E-03 -1.3731E-01 2.4221E-01 -1.3235E-01 1.3720E-02 4.8684E-03 S11 -2.5777E-01 1.4770E-01 5.1641E-02 -6.7443E-02 5.6075E-03 1.1267E-02 -2.8523E-03 S12 -3.2880E-01 2.8121E-01 -1.8747E-01 9.7342E-02 -3.8632E-02 9.8365E-03 -1.1532E-03

[0172] Table 14

[0173] Figure 16A The on-axis chromatic aberration curve of the second optical system of Embodiment 7 is shown, which represents the deflection of the focal point of light of different wavelengths after passing through the second optical system.Figure 16B The astigmatism curves of the second optical system of Embodiment 7 are shown, which represent the meridional image plane curvature and sagittal image plane curvature corresponding to different image heights. Figure 16C The distortion curves of the second optical system in Embodiment 7 are shown, representing the distortion magnitude values ​​corresponding to different image heights. According to... Figures 16A to 16C It can be seen that the second optical system given in Example 7 can achieve good imaging quality.

[0174] refer to Figure 1 The virtual reality device 10 provided in this application can be composed of a first optical system in any of the above embodiments and a second optical system in any of the above embodiments. The first optical system and the second optical system can be combined in pairs to form 12 virtual reality devices, that is, there are 12 examples of virtual reality devices. In this example, the virtual reality device corresponding to Example 1 is composed of the first optical system of Embodiment 1 and the second optical system of Embodiment 4; the virtual reality device corresponding to Example 2 is composed of the first optical system of Embodiment 1 and the second optical system of Embodiment 5; the virtual reality device corresponding to Example 3 is composed of the first optical system of Embodiment 1 and the second optical system of Embodiment 6; the virtual reality device corresponding to Example 4 is composed of the first optical system of Embodiment 1 and the second optical system of Embodiment 7; the virtual reality device corresponding to Example 5 is composed of the first optical system of Embodiment 2 and the second optical system of Embodiment 4; the virtual reality device corresponding to Example 6 is composed of the first optical system of Embodiment 2 and the second optical system of Embodiment 5; the virtual reality device corresponding to Example 7 is composed of the first optical system of Embodiment 2 and the second optical system of Embodiment 6; the virtual reality device corresponding to Example 8 is composed of the first optical system of Embodiment 2 and the second optical system of Embodiment 7; the virtual reality device corresponding to Example 9 is composed of the first optical system of Embodiment 3 and the second optical system of Embodiment 4; the virtual reality device corresponding to Example 10 is composed of the first optical system of Embodiment 3 and the second optical system of Embodiment 5; the virtual reality device corresponding to Example 11 is composed of the first optical system of Embodiment 3 and the second optical system of Embodiment 6; and the virtual reality device corresponding to Example 12 is composed of the first optical system of Embodiment 3 and the second optical system of Embodiment 7.

[0175] In summary, Examples 1 to 12 above satisfy the conditions shown in Table 15 below.

[0176]

[0177]

[0178] Table 15

[0179] 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 apparatus, characterized by, The first optical system comprises a first element group and a second element group in order from a first side to a second side along a first optical axis, wherein the first element group has positive refractive power, comprises a reflective polarizing element, a quarter-wave plate, a first lens, and a partially reflective element; the second element group has positive refractive power or negative refractive power, comprises a second lens; the first lens has positive refractive power, and a first side surface thereof is convex; the reflective polarizing element is disposed on a first side surface of the quarter-wave plate, and the quarter-wave plate is disposed on a first side surface of the first lens; the partially reflective element is disposed on a second side surface of the first lens; a number of lenses with refractive power in the first optical system is two; the first side is an eye side, and the second side is a display side; the second optical system comprises, in order from an object side to an image side along a second optical axis, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a sixth lens; the first lens has negative refractive power, and an object side surface thereof is convex and an image side surface thereof is concave; the second lens has positive refractive power, and an object side surface thereof is convex and an image side surface thereof is convex; the third lens and the fourth lens have opposite positive or negative refractive power; the fifth lens has positive refractive power, and an object side surface thereof is convex; the sixth lens has negative refractive power, and an object side surface thereof is concave and an image side surface thereof is concave; a number of lenses with refractive power in the second optical system is six; wherein a real image formed by the second optical system is transmitted to a display screen in the form of an electrical signal, the first optical system is used for projecting a virtual image on the display screen and transmitting the real image on the display screen, and a radius of curvature R1A of a first surface of the first lens, an effective focal length fA of the first optical system, an effective focal length fB of the second optical system, an effective focal length f1B of the first lens, a radius of curvature R1B of an object side surface of the first lens, a radius of curvature R2B of an image side surface of the first lens, an effective focal length FG1A of the first element group, and an effective focal length f2B of the second lens satisfy: -4.59≤(R1B+R2B) / f1B≤-1.33; 0.48≤(R1A / fA) / ((R1B+R2B) / fB)≤2.57; 38.71≤FG1A / |f1B+f2B|≤48.

65.

2. The virtual reality device of claim 1, wherein, an effective focal length FG2A of the second element group, a radius of curvature R11B of an object side surface of the sixth lens, and a radius of curvature R12B of an image side surface of the sixth lens satisfy: 16.37≤|FG2A| / (R12B-R11B)≤36.

16.

3. The virtual reality apparatus of claim 1, wherein, The air separation T12A of the second surface of the first lens and the first surface of the second lens on the first optical axis, the central thickness CT2A of the second lens on the first optical axis, the axial thickness CT5B of the fifth lens on the second optical axis, the air separation T56B of the fifth lens and the sixth lens on the second optical axis, and the central thickness CT6B of the sixth lens on the second optical axis satisfy: 7.34 ≤ (T12A + CT2A) / (CT5B + T56B + CT6B) ≤ 14.

45.

4. The virtual reality device of claim 1, wherein, The effective focal length fA of the first optical system, the effective focal length f4B of the fourth lens, the effective focal length f5B of the fifth lens, and the effective focal length f6B of the sixth lens satisfy: 0.89 ≤ fA / |f4B + f5B + f6B| ≤ 8.

91.

5. The virtual reality device of claim 1, wherein, A distance TDA on the first optical axis from the first surface of the first lens to the second surface of the second lens, a distance TDB on the second optical axis from the object side surface of the first lens to the image side surface of the sixth lens, a maximum field angle FOVA of the first optical system, and a maximum field angle FOVB of the second optical system satisfy: 3.14 ≤ (TDA tan(FOVA / 2)) / (TDB tan(FOVB / 2)) ≤ 4.

37.

6. The virtual reality device of claim 1, wherein, The effective focal length FG1A of the first element group, the entrance pupil diameter EPDA of the first optical system, the effective focal length f1B of the first lens, and the entrance pupil diameter EPDB of the second optical system satisfy: -33.56 ≤ (FG1A EPDA)) / (f1B EPDB) ≤ -31.

06.

7. The virtual reality device of claim 1, wherein, A distance TDA on the first optical axis of the first surface of the first lens to the second surface of the second lens, a distance TDB on the second optical axis of the object side surface of the first lens to the image side surface of the sixth lens, an effective focal length fA of the first optical system, and an effective focal length fB of the second optical system satisfy: 2.22 ≤ (TDA / fA) (TDB / fB) ≤ 2.

41.

8. The virtual reality device of claim 1, wherein, The combined focal length f234B of the second lens, the third lens, and the fourth lens, the central thickness CT2B of the second lens on the second optical axis, the central thickness CT3B of the third lens on the second optical axis, and the central thickness CT4B of the fourth lens on the second optical axis satisfy: 0.88 ≤ f234B / (CT2B + CT3B + CT4B) ≤ 2.

14.

9. The virtual reality device of claim 1, wherein, The air separation T56B of the fifth lens and the sixth lens on the second optical axis, the air separation T45B of the fourth lens and the fifth lens on the second optical axis, the combined focal length f34B of the third lens and the fourth lens, and the combined focal length f56B of the fifth lens and the sixth lens satisfy: 2.79 ≤ (T56B / T45B) / |f34B / f56B| ≤ 17.

28.

10. The virtual reality apparatus of any one of claims 1-9, wherein, The curvature radius R3B of the object side surface of the second lens, the curvature radius R4B of the image side surface of the second lens, the curvature radius R5B of the object side surface of the third lens, and the curvature radius R6B of the image side surface of the third lens satisfy: -0.54 ≤ (R4B / R3B) (R6B / R5B) ≤ -0.

23.

11. The virtual reality device of claim 1, wherein, The effective focal length f1B of the first lens and the effective focal length fB of the second optical system satisfy: -1.54 ≤ f1B / fB ≤ -1.

47.

12. The virtual reality device of claim 1, wherein, The central thickness CT1A of the first lens on the first optical axis, the central thickness CTRA of the reflective polarizing element on the first optical axis, the central thickness CTQA of the quarter-wave plate on the first optical axis, and the sum ∑CTB of the central thicknesses of the first lens to the sixth lens on the second optical axis satisfy: 4.28 ≤ (CT1A + CTRA + CTQA) / ∑CTB ≤ 5.15.

Images